Textron Bell 412, Bell 412EP Maintenance Manual

BHT-412-MM-1

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201

BELL

®

HELICOPTER TEXTRON INC.
AND BELL HELICOPTER TEXTRON
CANADA LTD.

ALL RIGHTS RESERVED

The instructions set forth in this manual, as supplemented or modified by Alert Service Bulletins (ASB) or
other directions issued by Bell Helicopter Textron Inc. and Airworthiness Directives (AD) issued by the
applicable regulatory agencies, shall be strictly followed.

Export Classification C, ECCN EAR99

MAINTENANCE MANUAL

VOLUME 1

GENERAL INFORMATION

NOTICE

REISSUE — 23 JUNE 1994

REVISION 27 — 25 SEPTEMBER 2018

BHT-412-MM-1

PROPRIETARY RIGHTS NOTICE

These data are proprietary to Bell Helicopter Textron Inc. Disclosure,
reproduction, or use of these data for any purpose other than helicopter
operation or maintenance is forbidden without prior written authorization from
Bell Helicopter Textron Inc.

DESTINATION CONTROL STATEMENT

WARNING — This document contains technical data whose export is restricted
by the Arms Export Control Act (Title 22, U.S.C., Sec 2751, et. seq.) or the Export
Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401 et. seq.
Violations of these export laws are subject to severe criminal penalties.
Disseminate in accordance with provisions of DoD Directive 5230.25.

Additional copies of this publication may be obtained by contacting:

PN Rev. 16 26 FEB 2013

Commercial Publication Distribution Center

Bell Helicopter Textron Inc.

P. O. Box 482

Fort Worth, Texas 76101-0482

Export Classification C, ECCN EAR99

WARNING

THIS MANUAL APPLIES ONLY TO HELICOPTERS AND COMPONENTS
MAINTAINED IN ACCORDANCE WITH BELL HELICOPTER TEXTRON
(BELL) APPROVED PROCEDURES USING BELL APPROVED PARTS.

ALL INSPECTION, REPAIR AND OVERHAUL PROCEDURES PUBLISHED
BY BELL, INCLUDING PART RETIREMENT LIFE, ARE BASED SOLELY ON
THE USE OF BELL PARTS THAT HAVE BEEN MAINTAINED USING BELL
APPROVED DATA. THE DATA PUBLISHED HEREIN OR OTHERWISE
SUPPLIED BY BELL IS NOT APPLICABLE TO NON-BELL PARTS OR
PARTS THAT HAVE BEEN REPAIRED USING DATA AND/OR PROCESSES
NOT APPROVED BY BELL.

BELL IS NOT RESPONSIBLE FOR ANY PART OTHER THAN THOSE THAT
IT HAS APPROVED.

BEFORE PERFORMING ANY PROCEDURE CONTAINED IN THIS MANUAL
YOU MUST INSPECT THE AFFECTED PARTS AND RECORDS FOR
EVIDENCE OF ANY MANUFACTURE, REPAIR, REWORK OR USE OF A
PROCESS NOT APPROVED BY BELL.

IF YOU IDENTIFY OR SUSPECT THE USE OF PARTS NOT AUTHORIZED
BY BELL, EITHER REMOVE THE AFFECTED ITEM FROM THE AIRCRAFT
OR OBTAIN INSTRUCTIONS FOR CONTINUED AIRWORTHINESS FROM
THE MANUFACTURER OR THE ORGANIZATION THAT APPROVED THE
REPAIR.

BHT-412-MM-1

Export Classification C, ECCN EAR99

26 FEB 2013 Rev. 16 W arning

BHT-412-MM-1

Flying smart means that no matter where you are, or what time it is, you can make a call
and get additional information, clarification, or advice on a technical or operational issue
concerning your helicopter or information contained in our Technical Publications.
Product Support Engineering (PSE) is just a phone call away and may be contacted as
follows:

CUSTOMER SUPPORT AND SERVICES

Model 206, 505, or 407

Phone: [phone] or 800-363-8023 ( U.S./Canada)
Fax: [phone]
E-mail: [e-mail]

Model 222, 230, 427, 429, or 430

Phone: [phone] or 800-463-3036 ( U.S./Canada)
Fax: [phone]
E-mail: [e-mail]

Model 204, 205, 212, or 412

Phone: [phone] or 800-363-8028 ( U.S./Canada)
Fax: [phone]
E-mail: [e-mail]

Model 210, HUEY II, and All Bell’s Active and
Military Medium Helicopter Models

Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

Model OH-58, TH-67, TH-57, Both Active and
Military

Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

Surplus

Surplus

For additional information on Customer Suppo rt a nd Ser vices as well as Pr oduct Su pp ort
Engineering (PSE) and your local Customer Service Engineering (CSE) network, please
access http://www.bellflight.com/support-and-service/support.

CSS Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

H

ELP

E

VALUATE

L

OGISTICS

P

UBLICATIONS

Have you found something wrong with this manual — an
error, an inconsistency, unclear instructions, etc.? Although
we strive for accuracy and clarity, we may make errors on
occasion. If we do and you discover it, we would appreciate
your telling us about it so that we can change whatever is
incorrect or unclear. Please be as specific as possible.

Your complaint or suggestion will be acknowledged and we
will tell you what we intend to do.

You may use the enclosed Customer Feedback form, as
applicable, to inform us where we have erred.

Your assistance is sincerely appreciated.

Export Classification C, ECCN EAR99

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Export Classification C, ECCN EAR99

SPARE PARTS WARRANTY

ONE YEAR/1,000 HOURS PRORATED

WARRANTY AND REMEDY: Seller warrants each new helicopter part or helicopter part reconditioned by seller to be free from defect
in material and workmanship under normal use and service and if installed on Bell model helicopters. Seller’s sole obligation under this
warranty is limited to replacement or repair of parts which are determined to Seller’s reasonable satisfaction to have been defective
with 1,000 hours of operation or one (1) year after installation, whichever occurs first and reimbursement of reasonable freight charges.
After 200 hours of use, there will be a prorated charge to the Purchaser for replacement parts (prorating the hours of total use against
the then applicable part life or 2,000 hours, whichever is the lesser). Defective parts must be reported in writing to the Seller’s Warranty
Administration within 90 days of being found defective. Replacement of parts may be with either new or reconditioned parts, at Seller’s
election. Warranty adjustment is contingent upon the Purchaser complying with the Warranty Remedies as described in the
Commercial Warranty Information brochure and the Seller’s Warranty Administration disposition instructions for defective parts. Failure
to comply with all of the terms of this paragraph may, at Seller’s sole option, void this warranty.

NOTE: Parts, components and assemblies of all new helicopters may have been restored or reworked due to mars, blemishes, dents
or other irregularities during the manufacturing process. Such restoration and/or rework is permitted under Seller’s approved
manufacturing and engineering processes and guidelines. The restoration and/or rework so completed does not render such items
defective in material or workmanship.

THIS WARRANTY IS GIVEN AND ACCEPTED IN PLACE OF (i) ALL OTHER WARRANTIES OR CONDITIONS, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF MERCHANT ABILITY AND
FITNESS FOR A PARTICULAR PURPOSE AND (ii) ANY OBLIGATION, LIABILITY, RIGHT, CLAIM OR REMEDY IN CONTRACTOR
IN TORT (DELICT), INCLUDING PRODUCT LIABILITIES BASED UPON STRICT LIABILITY, NEGLIGENCE, OR IMPLIED
WARRANTY IN LAW.

This warranty is the only warranty made by Seller. The Purchaser’s sole remedy for a breach of this warranty or any defect in a part is
the repair or replacement of helicopter parts and reimbursement of reasonable freight charges as provided herein. Seller excludes
liability, whether as a result of a breach of contract or warranty, negligence or strict product liability, for incidental or consequential
damages, including without limitation, damage to the helicopter or other property, costs and expenses resulting from required changes
or modifications to helicopter components and assemblies, changes in retirement lives and overhaul periods, local customs fees and
taxes, and costs or expenses for commercial losses or lost profits due to loss of use or grounding of helicopters or otherwise.

Seller makes no warranty and disclaims all liability in contract or in tort (delict), including, without limitation, negligence and strict tort
(delictual) liability, with respect to work performed by third parties at Purchaser’s request and with respect to engines, engine
accessories, batteries, radios, and avionics, except Seller assigns each manufacturer’s warranty to Purchaser to the extent such
manufacturer’s warranty exists and is assignable.

This warranty shall not apply to any helicopter part which has been repaired or altered outside Seller ’s factory in any way so as, in
Seller’s judgment, to affect its stability, safety or reliability, or which has been subject to misuse, negligence or accident, or which has
been installed in any aircraft which has been destroyed unless that helicopter has been rebuilt by Bell. A list of destroyed aircraft is
obtainable from Bell Product Support. Repairs and alterations which use or incorporate parts and components other than genuine Bell
parts or parts approved by Bell for direct acquisition from sources other than Bell itself are not warranted by Bell, and this warranty shall
be void to the extent that such repairs and alterations, in Seller’s sole judgment, affect the stability, safety or reliability of the helicopter
or any part thereof, or damage genuine Bell or Bell-approved parts. No person, corporation or organization, including Bell Customer
Service Facilities, is authorized by Seller to assume for it any other liability in connection with the sale of its helicopters and parts.

NO STATEMENT, WHETHER WRITTEN OR ORAL, MADE BY ANY PERSON, CORPORATION OR ORGANIZATION, INCLUDING
BELL CUSTOMER SERVICE FACILITIES MAY BE TAKEN AS A WARRANTY NOR WILL IT BIND SELLER.

Seller makes no warranty and disclaims all liability with respect to components or parts damaged by, or worn due to, corrosion. Seller
makes no warranty and disclaims all liability for consumables (wear items) which are defined as items required for normal and routine
maintenance or replaced at scheduled intervals shorter than the warranty period. “Consumables” include but are not limited to engine
and hydraulic oil, oil filters, packings and o-rings, anti-corrosion and/or sealing compounds, brush plating material, nuts, bolts, washers,
screws, fluids, compounds, and standard aircraft hardware that is readily available to aircraft operators from sources other than Seller.

All legal actions based upon claims or disputes pertaining to or involving this warranty including, but not limited to, Seller’s denial of any
claim or portion thereof under this warranty, must be filed in the courts of general jurisdiction of Tarrant County, Texas or in the United
States District Court for the Northern District of Texas, Ft. Worth Division located in Ft. Worth, Tarrant County, Texas. In the event that
Purchaser files such an action in either of the court systems identified above, and a final judgment in Seller’s favor is rendered by such
court, then Purchaser shall indemnify Seller for all costs, expenses and attorneys’ fees incurred by Seller in defense of such claims. In
the event Purchaser files such a legal action in a court other than those specified, and Seller successfully obtains dismissal of that
action or transfer thereof to the above described court systems, then Purchaser shall indemnify Seller for all costs, expenses and
attorneys’ fees incurred by Seller in obtaining such dismissal or transfer.

January 2007

BHT-412-MM-1

Export Classification C, ECCN EAR99

26 FEB 2013 Rev. 16 Warranty

FAA APPROVED BHT-412-MM-2

TABLE OF CONTENTS

Paragraph Chapter/Section Page
Number Title Number Number

FIGURES

Figure Page
Number Title Number

TABLES

Table Page
Number Title Number

CHAPTER 4 — AIRWORTHINESS LIMITATIONS SCHEDULE

AIRWORTHINESS LIMITATIONS SCHEDULE

4-1 Airworthiness Limitations Schedule............................................... 4-00-00 5

4-1 Longitudinal/Lateral CG Envelope for Hoist Operations ..................................... 16

4-1 Airworthiness Limitations Schedule.................................................................... 6

Export Classification C, ECCN EAR99

15 SEP 2016 Rev. 24 Page 1

4-00-00

BHT-412-MM-2 FAA APPROVED

REVISION

NO.

Original 1 January 1981

1 15 May 1981

2 15 November 1981

3 24 February 1982

4 9 November 1982

5 9 December 1982

6N/A N/A
7 31 March 1983

DATE OF SIGNATURE FAA/ODA* SIGNATURE

8N/A N/A
9N/A N/A

10 20 October 1983

11 N/A N/A
12 N/A N/A
13 N/A N/A
14 30 July 1984

15 N/A N/A
16 19 November 1984

17 N/A N/A
18 3 June 1987

4-00-00

Page 2 Rev. 24 15 SEP 2016

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

REVISION

NO.

Reissue 29 March 1990

1 20 February 1991

2N/A N/A
3N/A N/A

Reissue N/A N/A

1N/A N/A

Reissue 23 June 1994

1 12 April 1995

2N/A N/A
3N/A N/A

DATE OF SIGNATURE FAA/ODA* SIGNATURE

4N/A N/A
5N/A N/A
6 1 October 2002

7N/A N/A
8N/A N/A

9N/A N/A
10 N/A N/A
11 30 March 2007

12 27 February 2009

13 N/A
14 N/A

N/A
N/A

Export Classification C, ECCN EAR99

4-00-00

15 SEP 2016 Rev. 24 Page 3

BHT-412-MM-2 FAA APPROVED

REVISION

NO.

15 1 May 2012

16 N/A N/A
17 26 March 2013

18 N/A N/A
19 N/A N/A
20 N/A N/A
21 N/A N/A
22 N/A N/A
23 N/A N/A
24 15 September 2016

DATE OF SIGNATURE FAA/ODA* SIGNATURE

25 N/A
26 14 June 2018

27 25 SEP 2018

4-00-00
Page 4 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

WARNING

WARNING

NOTE

AIRWORTHINESS LIMITATIONS SCHEDULE

4-1. AIRWORTHINESS LIMITATIONS

SCHEDULE

The Airworthiness Limitations section is FAA approved
and specifies maintenance required under Secs. 43.16
and [91.403] of the Federal Aviation Regulations
unless an alternative program has been FAA
approved.

ALL REPAIR AND OVERHAUL
PROCEDURES LIVES PUBLISHED BY
BELL HELICOPTER TEXTRON,
INCLUDING COMPONENT RETIREMENT
LIFE, ARE BASED SOLELY ON THE USE
OF BELL APPROVED PARTS AND
PROCESSES. IF PARTS OR
PROCESSES DEVELOPED OR
APPROVED BY PARTIES OTHER THAN
BELL HELICOPTER ARE USED, THEN
THE DATA PUBLISHED OR OTHERWISE
SUPPLIED BY BELL HELICOPTER ARE
NOT APPLICABLE. THE USER IS
WARNED TO NOT RELY ON BELL
HELICOPTER DATA FOR PARTS AND
PROCESSES NOT APPROVED BY BELL
HELICOPTER. ALL APPLICABLE
INSPECTIONS AND REPAIR METHODS
MUST BE OBTAINED FROM THE
SUPPLIER OF THE PARTS OR
PROCESSES NOT APPROVED BY BELL
HELICOPTER. BELL HELICOPTER IS
NOT RESPONSIBLE FOR PARTS OR
PROCESSES OTHER THAN THOSE
WHICH IT HAS ITSELF DEVELOPED OR
APPROVED.

COMPONENT PAST ITS STATED LIMITS
IS NOT PERMITTED AS IT COULD
SERIOUSLY AFFECT THE
AIRWORTHINESS OF THE HELICOPTER.

THE COMPONENT MUST BE REMOVED
FROM THE HELICOPTER NOT LATER
THAN THE END OF THE LIFE LIMIT. IT
MUST EITHER BE MADE
UNSERVICEABLE OR MARKED IN A
CONSPICUOUS MANNER TO PREVENT
CONTINUED USE, EVEN INADVERTENT
USE.

WHEN A REPLACEMENT PART IS
INSTALLED, THE PART NAME, PART
NUMBER, SERIAL NUMBER, AND
CURRENT OPERATING HOURS, IF
APPLICABLE, MUST BE RECORDED IN
THE HISTORICAL SERVICE RECORD
FOR THE ASSEMBLY OR HELICOPTER.

The mandatory airworthiness limitations schedule
(Table 4-1) summarizes the mandatory maximum life,
in hours, years or by Retirement Index Number (RIN)
of components with a limited airworthiness life. Parts
that are not on the schedule have an unlimited
airworthiness life.

Refer to the engine manufacturer's publications for the
airworthiness limitations schedule of the engine and
components. For the PT6T-3 series engine, refer to
the Pratt and Whitney Service Bulletin No. 5002. For
the PT6T-9 Engine, refer to the Pratt and Whitney
Maintenance Manual airworthiness limitation section.

CONTINUED USE OF ANY TIME/
CALENDAR/RIN LIFE LIMITED

Export Classification C, ECCN EAR99

The airworthiness life or inspection interval
for any part number contained in this
schedule applies to all the successive dash
numbers for that component unless it is
otherwise specified.

4-00-00

25 SEP 2018 Rev. 27 Page 5

BHT-412-MM-2 FAA APPROVED

WARNING

CAUTION

NOTE

1

5

7

38

5

33

5

7

22

APPLICABLE SERVICE INSTRUCTION
(SI) OR MAINTENANCE MANUAL
SUPPLEMENT (MMS) FOR KIT
COMPONENTS SCHEDULE.

SOME PARTS ARE INSTALLED AS
ORIGINAL EQUIPMENT ON BOTH
MILITARY AND COMMERCIAL
HELICOPTERS AND MAY HAVE A
LOWER AIRWORTHINESS LIFE AND/OR
OVERHAUL SCHEDULE WHEN USED
ON A MILITARY HELICOPTER. IN
ADDITION, CIRCUMSTANCES
SURROUNDING THEIR USE MAY CALL
FOR OPERATION OF THE MILITARY

The airworthiness life given or the failure to
give an airworthiness life to a component
does not constitute a warranty of any kind.
The only warranty applicable to the
helicopter or any component is the
warranty included in the Purchase
Agreement for the helicopter or the
component.

HELICOPTER OUTSIDE OF THE
APPROVED COMMERCIAL FLIGHT
ENVELOPE. CONSEQUENTLY, PARTS
THAT HAVE BEEN USED ON MILITARY
HELICOPTERS SHOULD NOT BE USED
ON COMMERCIAL HELICOPTERS.

The airworthiness lives given to the components and
assemblies are determined by experience, tests and
the judgement of Bell Helicopter engineers. The
airworthiness lives and inspection intervals cannot be
changed without the approval of the FAA.

Prior to disposing of unsalvageable helicopter parts
and materials, caution should be exercised to ensure
that the parts and materials are disposed of in a

manner that does not allow them to be returned for
AIRWORTHINESS LIFE OF SOME KIT
COMPONENTS MAY NOT BE COVERED
IN THIS SCHEDULE. REFER TO

service. Refer to FAA Advisory Circular 21-38 for

guidance on the disposal of unsalvageable aircraft

parts and materials.

Table 4-1. Airworthiness Limitations Schedule

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

MAIN ROTOR HUB

Y oke Assembly 412-010-101-109 700 hours
Y oke Assembly 412-010-101-123 5000 hours
Y oke Assembly 412-010-101-137 4500 hours
Y oke Assembly 412-010-101-139 3000 hours
Spindle Assembly 412-010-156-105 5000 hours
Spindle and Damper Bearing Assembly 412-010-190-101 5000 hours
Spindle and Damper Bearing Assembly 412-010-190-103 10,000 hours
Spindle and Shear Bearing Assembly 412-310-102-101 10,000 hours

4-00-00
Page 6 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

1

27

224

4

4

2

32

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

MAIN ROTOR HUB (CONT)

Pitch Horn Assembly 412-01 0-149-105 5000 hours
Pitch Horn Assembly 412-010-149-111 15,000 hours
Retention Bolt 412-010-124-105 5000 hours
Retention Bolt (Expandable) 412-010-137-103 5000 hours
Damper Bridge 412-010-104-101 5000 hours
Damper Bridge 412-010-183-101 10,000 hours
Damper Bridge 412-010-183-109 15,000 hours
Damper Bridge 412-010-185-101 10,000 hours
Damper Bridge 412-010-185-109 15,000 hours
Damper Bridge 412-018-068-101 10,000 hours or

180 months

Damper Bridge 412-010-170-101 10,000 hours or

180 months
Pivot Bearing 412-010-106-101 On condition
Fitting 412-010-111-101 5000 hours
Damper Yoke Set 412-010-145-101 On condition
Damper Yoke Set 412-310-146-103 On condition

MAIN ROTOR DROOP RESTRAINT

Bolt (8) MS-21250-H05-006 120 months

MAIN ROTOR SIMPLE PENDULUM ABSORBERS

Bolt, Bracket (16) EWB0420D-7-36 15,000 hours

MAIN ROTOR CONTROLS

Rephasing Lever Assembly 412-010-403-109 1250 hours
Rephasing Lever Assembly 412-010-403-113 5000 hours
Drive Link Assembly 412-010-405-101 5000 hours
Swashplate Outer Ring 412-010-407-105 2500 hours

4-00-00

Export Classification C, ECCN EAR99

25 SEP 2018 Rev. 27 Page 7

BHT-412-MM-2 FAA APPROVED

1

24

363537394019282930

282930

2930282930

282930

29

30

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

MAIN ROTOR CONTROLS (CONT)

Swashplate Outer Ring 412-010-407-1 17 10,000 hours
Pitch Link Rod End Bearing 412-010-412-101 5000 hours
Pitch Link Rod End Bearing 412-010-438-101 5000 hours
Swashplate Link Rod End Bearing 412-010-412-101 5000 hours
Swashplate Link Rod End Bearing 412-010-448-101 5000 hours
Swashplate Link Rod End Bearing 412-310-400-103 5000 hours
Swashplate Support Assembly 412-010-409-105 5000 hours
Swashplate Support Assembly 412-010-443-101 5000 hours
Swashplate Support Assembly 412-010-453-101 5000 hours
Swashplate Support Assembly 412-010-453-105 15,000 hours
Gimbal Ring Assembly 204-010-404-001 9000 hours
Gimbal Ring Assembly 212-010-416-101 9000 hours
Collective Sleeve 204-011-408-003 9000 hours
Collective Sleeve 212-011-412-101 9000 hours
Collective Lever Assembly 412-010-408-101 10,000 hours
Collective Lever Assembly 412-010-408-105 2500 hours
Collective Lever Assembly 412-010-464-101 20,000 hours
Collective Lever Pin 412-010-465-101 20,000 hours

MAIN ROTOR CONTROL SYSTEM BOLTS

Pitch Horn to Pitch Link (4) 20-057-5-25D 2500 hours
Pitch Horn to Pitch Link (4) 20-057-5-28D 2500 hours
Pitch Link-to-Rephasing Lever (4) 20-057-6-36D 2500 hours
Pitch Link-to-Rephasing Lever (4) 20-057-6-52D 2500 hours
Drive Link-to-Rephasing Lever (4) 20-057-6-36D 2500 hours
Swashplate Link-to-Rephasing Lever (3) 20-057-6-38D 2500 hours
Swashplate Link-to-Rephasing Lever (2) 20-057-6-52D 2500 hours

4-00-00
Page 8 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

1

282930

282930

252829

30

282930

2829302829

30

282930

2930282930

31

645789

7

810789

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

MAIN ROTOR CONTROL SYSTEM BOLTS (CONT)

Swashplate Link-to-Rotating Ring (2) 20-057-6-36D 2500 hours
Gimbal Ring-to-Swashplate Support (2) 204-011-463-105 2500 hours
Gimbal Ring-to-Swashplate Inner

204-011-463-001 1000 hours

Ring (2)
Gimbal Ring-to-Swashplate Inner

204-011-463-109 2500 hours

Ring (2)
Collective Lever-to-Swashplate

20-057-8-92D 2500 hours

Support (1)
Boost Tube-to-Universal (3) 20-057-5-24D 2500 hours
Universal-to-Boost Cylinder (3) 20-057-5-24D 2500 hours
Boost Cylinder-to-Lower Support (3) 212-001-323-001 2500 hours
Rephasing Lever-to-Hub (4) 20-057-6-82D 1250 hours
Rephasing Lever-to-Hub (4) 20-057-8-84D 2500 hours

MAIN ROTOR SUPPLEMENTAL CONTROL SYSTEM BOLTS

Swashplate Inner Ring-to-R.H.

20-057-5-24D 2500 hours

Cyclic Boost (1)
Swashplate Inner Ring-to-L.H.

20-057-5-24D 2500 hours

Cyclic Boost (1)
Collective Lever-to-Collective Boost (1) 20-057-5-24D 2500 hours

PROPULSION AND DRIVE SYSTEM

Planetary Spider 204-040-785-003 On condition
Planetary Spider 412-040-785-101 2500 hours
Planetary Spider 412-040-785-103 On condition
Main Rotor Mast Assembly 412-040-101-105 10,000 hours or

80,000 RIN
Main Rotor Mast Assembly

(used on helicopters with Mast Torque

412-040-101-121 10,000 hours or

60,000 RIN
Systems)

Main Rotor Mast Assembly 412-040-101-127 10,000 hours or

80,000 RIN

4-00-00

Export Classification C, ECCN EAR99

25 SEP 2018 Rev. 27 Page 9

BHT-412-MM-2 FAA APPROVED

1

7

8

10

7

8

14

7

8467

8

144747

47811

12810

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

PROPULSION AND DRIVE SYSTEM (CONT)

Main Rotor Mast Assembly
(used on helicopters with Mast Torque

412-040-101-129 10,000 hours or

60,000 RIN

Systems)
Main Rotor Mast Assembly

(used on helicopters with Mast Torque

412-040-101-135 5000 hours or

60,000 RIN
Systems and with BHT-412 -SI-62, Slope
Landing Kit)

Main Rotor Mast Assembly 412-040-114-101 2,500 hours or

25,000 RIN
Main Rotor Mast Assembly

(used on helicopters with Mast Torque

412-704-012-105 5000 hours or

60,000 RIN
Systems and with BHT-412 -SI-62, Slope
Landing Kit)

Cap Retention 412-010-161-101 10,000 hours
Cap Retention 412-010-171-101 10,000 hours
Cap Retention 412-010-171-103 10,000 hours
Mast Cap 412-010-171-105 5,000 hours
Cone 412-010-165-101 10,000 hours
Cone 412-010-165-103 5,000 hours
Drive Pin 412-010-166-101 10,000 hours
Drive Pin 412-010-166-103 5,000 hours
Upper Cone Seat 412-010-164-101 10,000 hours
Upper Cone Seat 412-010-174-101 10,000 hours
Upper Cone Seat 412-010-186-101 10,000 hours
Upper Cone Seat 412-010-186-107 5,000 hours
Upper Cone Seat 412-010-286-101 2,500 hours
Splined Plate Assembly 412-010-177-101 Life limited

(see notes)
Splined Plate Assembly 412-010-177-105 10,000 hours or

60,000 RIN

4-00-00
Page 10 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

1

8

9

8

14

8108

46

8

111247

777

773

41

17

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

PROPULSION AND DRIVE SYSTEM (CONT)

Splined Plate Assembly 412-010-177-109 10,000 hours or

80,000 RIN

Splined Plate Assembly 412-010-177-121 5,000 hours or

60,000 RIN

Splined Plate Assembly 412-010-177-113 10,000 hours or

60,000 RIN

Splined Plate Assembly 412-010-277-101 2,500 hours or

25,000 RIN

Splined Plate Assembly 412-010-167-105 Life limited

(see notes)
Cone 412-010-169-103 10,000 hours
Cone 412-010-179-101 10,000 hours
Cone 412-010-179-105 10,000 hours
Cone 412-010-179-107 5,000 hours
Lower Cone Seat 412-010-168-105 10,000 hours
Lower Cone Seat 412-010-178-101 10,000 hours
Lower Cone Seat 412-010-056-101 2,500 hours
Lower Cone Seat 412-018-056-103 10,000 hours
Lower Cone Seat 412-018-056-109 5,000 hours

ELEV ATOR AND CONTROLS

Horn Assembly 205-001-914-103 On condition

AIRFRAME

Upper Aft Beam Cap 212-030-191-001 On condition

TAIL ROTOR INSTALLATION

Blade Assembly 212-010-750-009 5000 hours
Blade Assembly 412-016-100-1 11 5000 hours
Y oke Assembly 212-011-702-001 5000 hours

4-00-00

Export Classification C, ECCN EAR99

25 SEP 2018 Rev. 27 Page 11

BHT-412-MM-2 FAA APPROVED

1

153442

153442

18344234424344220

2

20

20

202020212121162020

26

20220

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOMENCLATURE PART NUMBER AIRWORTHINESS LIFE

LANDING GEAR

High Aft Crosstube Assembly 412-050-011-101 10,000 events
High Aft Crosstube Assembly 412-050-045-107 20,000 events
High Aft Crosstube Assembly 412-321-104 20,000 events
High Aft Crosstube Assembly 412-321-901 12,000 events

FIRE EXTINGUISHER CARTRIDGES

HTL Industries P/N 13083-5 209-062-908-015 6 years service life/

9 years total life

HTL Industries P/N 30900400 209-062-908-019 6 years service life/

9 years total life
W. Kidde and Co. P/N 804943 209-062-908-013 6 years total life
W. Kidde and Co. P/N 804944 209-062-908-017 6 years total life
W. Kidde and Co. P/N 895408-1 209-062-908-113 10 years total life
W. Kidde and Co. P/N 895409-1 209-062-908-115 10 years total life

FLOATS

Float Hose 70-072M000C144 6 years calendar life
Float Hose 70-072M000C222 6 years calendar life
Float Hose 412-073-800-115A

6 years calendar life

(uses hose P/N

70-072L000B204)
Squib Cartridges, Floats 30908 15 years total life
Squib Cartridges, Floats 29022968 15 years total life
Cylinder Assembly, Floats 212-073-920-107 10 years total life

INTERNAL HOIST KIT

Cable Cutter Assembly (Squib) 1810-033-01 5 years service life/

10 years total life

4-00-00
Page 12 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

1

234

56789

10

111213

14

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOTES :

The airworthiness life or inspection interval for any part number contained in this schedule applies to all
the successive dash numbers for that component unless it is otherwise specified.

In-service life begins the day the component is entered into service. In-service life only remains in effect
while the component is installed on the helicopter.

Fail safe, refer to Chapter 5 for detailed 100-hour inspection.
On-condition subject to daily or 25-hour visual inspection interval (as applicable) per scheduled

inspections (Chapter 5).
The bushing 412-010-222 is installed on the main rotor yoke assemblies 412-010-101-127/-129/-133

-135/-137/-139. The bushing is assigned an unlimited ai rworthiness life. If removed, it is not reusable.
An on-condition retirement is assigned to spider 204-040-785-003 subject to passing a magnetic particle

inspection every 3100 hours per ASB 412-91-52A.
An additional 4 hours must be logged for each hoist operation performed within penalty CG region

(Figure 4-1). Refer to Chapter 5 and BHT-412-FM.
RIN (Retirement Index Number) is the retirement life based on fatigue damage from normal helicopter lifts

and takeoffs. New components will begin with an accumulated RIN of zero that will be increased as lifts
and takeoffs are performed. Operators mu st record the number of lifts and takeoffs and increase the
accumulated RIN accordingly. When the maximum RIN or retirement flight hours is/are reached,
whichever occurs first, the component will be removed from service. Refer to Information Letter
GEN-94-54/Information Letter GEN-03-94.

Retire when the part has 10,000 flight hours or when the accumulated RIN = 80,000, whichever
occurs first. For manual tracking, increase the RIN count by 1 for each takeoff/lift recorded. If logging,
increase RIN count by 2 for each lift recorded.

Retire when the part has 10,000 flight hours or when the accumulated RIN = 60,000, whichever
occurs first. For manual tracking, increase the RIN count by 1 for each takeoff/lift recorded. If logging,
increase RIN count by 2 for each lift recorded.

This splined plate assembly can be used on all 412 models. When used on 412 HP/EP, it will be
vibroetched “412 HP" and will be retired when part has 10,000 flight hours or when the accumulated
RIN = 60,000, whichever occurs first. For manual tracking, increase the RIN count by 1 for each
takeoff/lift recorded. If logging, increase RIN count by 2 for each lift recorded (see Note 12).

This splined plate assembly can be used on all 412 models. When used on 412/412SP, it will not be
vibroetched "412 HP". Retire when part has 10,000 flight hours or when the accumulated RIN = 80,000,
whichever occurs first. For manual tracking, increase the RIN count by 1 for each takeoff/lift recorded. If
logging, increase RIN count by 2 for each lift recorded (see Note 11).

Deleted.
Retire when the part has 5000 flight hours or when the accumulated RIN = 60,000, whichever occ urs fir st.

For manual tracking, increase the RIN count by 1 for each takeoff/lift recorded. If logging, increase RIN
count by 2 for each lift recorded.

4-00-00

Export Classification C, ECCN EAR99

25 SEP 2018 Rev. 27 Page 13

BHT-412-MM-2 FAA APPROVED

15

161718

192021

22232425262728

29

303132

33

343536

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOTES (CONT):

Per ASB 412-99-97.
Contained in inflation valve 30905. 30908 includes squib 944 55 and o-ring 568-905.
Per ASB 412-96-89, the tail rotor flapping stop/yield indicator 212-011-713-103 must be used with the tail

rotor yoke. The stop/yield indicator 212-011-713-103 must be inspected every 25 hours and at each
incident involving a hard landing, sudden stoppage , or any other incident involving excessive tail rotor
flapping. Refer to Chapter 5.

Manufactured by Aeronautical Accessories, Inc. Refer to AAI Report No. ICA AA-01136 Rev. C, or
subsequent, Inspection and Maintenance Instructions. Recurring visual inspection per
AAI Bulletin AA-07109 and ASB 412-08-129.

As per ASB 412-98-92, bolt 20-057-5-25D is replaced by 20-057-5-28D.
Total life begins from the date of component manufacture and cannot be interrupted.
Calendar life begins the day the component is entered into service and cannot be interrupted.
Not applicable to subsequent dash numbers.
Deleted.
Replacement bearing cartridges 412-310-400-107 are on-condition. Refer to IL 412-IL-03-49.
As per ASB 412-02-110, bolt 204-011-463-001 is replaced by 204-011-463-109.
29022968 contained in valve assembly 20022988 Rev. E and refurbishment kit 29022971.
As per ASB 412-93-73, bolt 412-010-124-105 is replaced by 412-010-124-109.
Included in bolt kit 412-704-112-101. Bolt kit 412-704-112-101 is replaced by bolt kit 412-704-112-105.
Included in bolt kit 412-704-112-103. Bolt kit 412-704-112-103 is replaced by bolt kit 412-704-112-105.
Included in bolt kit 412-704-112-105.
Not included in bolt kits 412-704-112-101/-103/-105.
Life reduction to 2500 hours per ASB 412-08-131; remove from service by 1 June 2009.
Refer to ASB 412-08-128.
Use aft crosstube retention strap kit per BHT-412-SI-58 when towing helicopters with a gross weight of

8900 pounds or greater.
Swashplate support assembly 412-010-443-101 was removed from service by ASB 412-93-71. All

subsequent dash numbers remain in service.
Swashplate support assembly 412-010-409-105 was removed from service by ASB 412-93-71.

4-00-00
Page 14 Rev. 27 25 SEP 2018

Export Classification C, ECCN EAR99

FAA APPROVED BHT-412-MM-2

37

383940

4142434445

46

47

Table 4-1. Airworthiness Limitations Schedule (Cont)

NOTES (CONT):

Swashplate support assembly 412-010-453-101 was removed from service by ASB 412-92-61. All
subsequent dash numbers remain in service.

500-hour penalty to be applied in accordance with AD 99-23-23 and ASB412-98-93.
AD 2012-22-11 imposes on collective lever 412-010-408-101 a visual inspection at in tervals not to excee d

100 hours Time-In-Service (TIS) (ASB 412-11-148 Rev. A).
Visual inspection at intervals not to exceed 100 hours Time-In-Service (TIS). Inspection requirements

same as listed in ASB 412-11-148 Rev. A.
AD 2000-18-09 imposes on the upper aft beam cap 212-030-191-001 a recurring visual inspection at

intervals not to exceed 100 hours Time-In-Service (TIS) (ASB 412-00-100). All aircraft with serial
numbers 38001–38999 and 39101–39999 require a visual inspection in intervals not to exceed
9 hours Time-In-Service (TIS), in accordance with AD 2000-18-09 pr ocedures.

For manual tracking, increase the event count by 1 for each takeoff r ecorded.
Part manufactured and part number assigned by AAI of Bristol, Tennessee. Retire part when event =

12,000 (event life).
1000-event penalty to be applied against accumulated events of high aft crosstube assembly if used with

increased gross weight kit 412-706-140 (BHT-412-FMS-74.5). 1000 event penalty to be applied on high
aft crosstube assembly 412-321-901 on all aircraft serial numbers 38001–38999 and 39101–39999.

On Condition indicates that there is no retirement life (i.e., unlimited). Any required inspections will be
addressed by additional specific notes.

Retire when the part has 2,500 flight hours or when the accumulated RIN is 25,000, whichever occurs
first. For manual tracking, increase the RIN count by 1 for each takeoff/lift recorded. If logging,
increase RIN count by 2 for each lift recorded.

Apply a one time 7,500 hours penalty for all aircraft with serial numbers 38001–38999 and 39101–39999
on retention cap, cones, and drive pins.

4-00-00

Export Classification C, ECCN EAR99

25 SEP 2018 Rev. 27 Page 15

BHT-412-MM-2 FAA APPROVED

Figure 4-1. Longitudinal/Lateral CG Envelope for Hoist Operations

4-00-00
Page 16 Rev. 24 15 SEP 2016

Export Classification C, ECCN EAR99

BHT-412-MM-2

TABLE OF CONTENTS

Paragraph Chapter/Section Page
Number Title Number Number

CHAPTER 5 — INSPECTIONS

INSPECTIONS

5-1 General.......................................................................................... 5-00-00 3

5-2 Inspection Requirements............................................................... 5-00-00 4

5-3 Crash Damage............................................................................... 5-00-00 4

5-3A Types of Inspections.......................................... ... ... ... .... ... ... ... ... ... 5-00-00 4

5-3B Definitions...................................................................................... 5-00-00 5

5-3C Inspection and Overhaul Tolerance................... ... ......................... 5-00-00 6

SCHEDULED INSPECTIONS

5-4 Scheduled Inspections................................................................... 5-00-00 7

5-5 Daily Inspection — Part A.............................................................. 5-00-00 9

5-6 100 Hour/12 Month Inspection — Part A.................... .... ... ... ... ... ... 5-00-00 27

5-7 1000 Hour Inspection — Part A ..................................................... 5-00-00 49

5-8 5000 Hour/5 Year Inspection — Part A.......................................... 5-00-00 51

5-9 25 Hour/30 Day Inspection — Part B............................................. 5-00-00 57

5-10 300 Hour/12 Month Inspection — Part B................. ... .... ... ... ... ... ... 5-00-00 79

5-11 600 Hour/12 Month Inspection — Part B................. ... .... ... ... ... ... ... 5-00-00 93

5-12 5000 Hour/5 Year Inspection — Part B.......................................... 5-00-00 101

SPECIAL INSPECTIONS

5-13 Special Inspection.......................................................................... 5-00-00 107

5-14 Daily/10 Hour Inspection, Whichever Occurs First

Until 250 Hours.............................................................................. 5-00-00 109

5-15 Between 1 and 5 Flight Hours After Main Rotor Hub Installation... 5-00-00 113
5-15A Between 1 and 25 Flight Hours After Expandable Blade Bolt

Installation...................................................................................... 5-00-00 114A

5-16 Between 5 and 10 Hours of Flight After Each Installation.............. 5-00-00 115

5-17 Each 25 Hours for the Next Four Inspections................................ 5-00-00 117

5-18 Each 25 Hours of Tail Rotor Operation.......................................... 5-00-00 119

5-19 50 Hours After Installation of Components .................................... 5-00-00 123

5-20 100 Hours After Installation of Tailboom........................................ 5-00-00 125

5-21 Each 100 Hours of Collective Lever Operation ............................. 5-00-00 127

5-22 Each 150 Hours of Starter Generator (200SG119Q) Operation.... 5-00-00 131

5-22A Each 300 Hours or 6 Months of Expandable Blade Bolt

Operation....................................................................................... 5-00-00 132A

5-23 Each 600 Hours of Tail Rotor Driveshaft Operation or 12 Months 5-00-00 133

5-24 Each 600 Hours of Main Driveshaft Operation or 12 Months ........ 5-00-00 136

5-25 Each 1000 Hours of Component Operation................................... 5-00-00 138

5-26 Each 12 Months or 2500 Landings of Aft High Crosstube

Operation....................................................................................... 5-00-00 140

5-27 Each 24 Months of Control Bolt Operation .................................... 5-00-00 148

5-27A Each 24 Months of Main Rotor Mast Operation............................. 5-00-00 150A

5-28 Each 2500 Hours of Main Rotor Hub Assembly Operation............ 5-00-00 151

Export Classification C, ECCN EAR99

01 JUN 2018 Rev. 26 Page 1

5-00-00

BHT-412-MM-2

TABLE OF CONTENTS (CONT)

Paragraph Chapter/Section Page
Number Title Number Number

FIGURES

Figure Page
Number Title Number

5-29 Each 2500 Hours of Main Rotor Blade Operation.......................... 5-00-00 153

5-30 Each 2500 or 3000 Hours of Main Rotor Mast (4 12 - 04 0- 3 66 -1 09

and Subsequent) Operation........................................................... 5-00-00 155

5-31 Each 2500 Hours of Tail Rotor Drive System Operation ............... 5-00-00 159

5-32 Each 3000 Hours of Main Rotor Mast

(412-040-366-103 and -105) Operation ........................................ 5-00-00 169

5-33 Each 3000 Hours of Transmission (412-040-002) Operation.. ...... 5-00-00 173

5-34 Each 3000 Hours of Transmission (412-040-004) Operation.. ...... 5-00-00 177

5-35 3600 Hours Total Airframe Time and Each 300 Hours/12 Months

Inspection....................................................................................... 5-00-00 185

CONDITIONAL INSPECTIONS

5-36 Conditional Inspection.................................................................... 5-00-00 187

5-37 After Hard Landing......................................................................... 5-00-00 189

5-38 Sudden Stoppage — Power On or Off .......................................... 5-00-00 195

5-39 After Overspeed............................................................................. 5-00-00 203

5-40 After Overtorque ............................................................................ 5-00-00 207

5-41 After Compressor Stall or Surge.................................................... 5-00-00 213

5-42 After Lightning Strikes.................................................................... 5-00-00 219

5-43 After Engine Combining Gearbox Clutch Non-engagement,

Misengagement, or In-flight Slippage ............................................ 5-00-00 225

COMPONENT OVERHAUL SCHEDULE

5-44 Component Overhaul Schedule..................................................... 5-00-00 233

5-1 Collective Stick Tube — Part A........................................................................... 59

5-1A Cabin Frame Inspection — Part A ...................................................................... 60

5-2 Collective Stick Tube — Part B........................................................................... 109

5-2A Cabin Frame Inspection — Part B ...................................................................... 110

5-3 Tail Rotor Blade — Special Inspection ............................................................... 121

5-4 Collective Lever — Special Inspection................................................................ 129

5-4A Expandable Blade Bolt — Special Inspection..................................................... 136

5-5 Aft High Crosstube — Special Inspection........................................................... 146

5-6 Fuselage Tailboom Attachment Inspection......................................................... 229

5-7 Spiral Bevel Gear Inspection .............................................................................. 230

5-00-00
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Export Classification C, ECCN EAR99

BHT-412-MM-2

TABLES

Table Page
Number Title Number

5-1 Component Overhaul Schedule.......................................................................... 234

Export Classification C, ECCN EAR99

2 SEP 2014 Rev. 20 Page 2A/2B

5-00-00

INSPECTIONS

WARNING

NOTE

BHT-412-MM-2

5-1. GENERAL

This chapter contains the requirements for Scheduled,
Special, and Conditional Inspections, and a
Component Overhaul Schedule.

FAILURE TO CORRECT CONDITIONS
SUCH AS, BUT NOT LIMITED TO,
CORROSION, EROSION, MECHANICAL
DAMAGE, OR OBVIOUS WEAR FOUND
DURING A SCHEDULED INSPECTION
COULD SERIOUSLY AFFECT THE
AIRWORTHINESS OF THE HELICOPTER.

These inspection requirements constitute an approved
inspection program designed and recommended by
Bell Helicopter Textron for the Model 412 Series. They
can be utilized by registered owners or operators who
desire to develop a progressive inspection system to
be used as part of the complete maintenance
program. A written request for approval to use the
progressive inspection system shall be submitted to
the governing civil aviation authority having jurisdiction
over the area in which the owner or operator is
located. Relief from the requirements in this chapter
can be requested through the local aviation authority.
For the convenience of the operator, two separate
scheduled inspections are provided as follows:

• Part A Scheduled inspections consist of a
daily inspection, 100 hour/12 calendar month
inspection, 1000 hour inspection, and
5000 hour/5 year inspection.

• Part B Scheduled inspections consist of a
25 hour/30 day inspection, 300 hour/
12 month, 600 hour/12 mo nth inspection, and
5000 hour/5 year inspection.

Either series of inspections may be utilized. However,
once a helicopter has been started on either
inspection program, it shall be maintained on that
program except as follows:

to the Part B inspection program, a complete
Part A 1000 hour inspection shall be
accomplished. The helicopter may then be
changed to the Part B inspection program
beginning with a 25 hour/30 day inspection.

• If a helicopter is being inspected on the Part B
inspection program and it is desired to change
to the Part A inspection program, a complete
600 hour inspection shall be accomplished.
The helicopter may then be changed to the
Part A inspection program beginning with a
daily inspection.

The inspection intervals given in this chapter are the
maximum permitted. Do not exceed these intervals.
The owner/operator is responsible for increasing the
scope and the frequency of the inspections as
necessary. Make sure the helicopter is maintained
safely during all unusual local changes, such as
environmental conditions, helicopter use, etc. You can
request changes to the requirements in this chapter
through the local aviation authority.

The inspection intervals and the component overhaul
schedule provided in this chapter a re applicable only
to Bell Helicopter Textron approved parts.

The time period given for the overhaul of a
component (or the failure to give a time
period for the overhaul of a component)
does not constitute a warranty of any kind.
The only warranty applicable to the
helicopter or any component is the
warranty included in the Purchase
Agreement for the helicopter or the
component.

The Time Between Over haul (T BO) a nd the inspection
periods are determined through experience, tests,
Lead The Fleet (LTF), or any other special programs
and the judgement of Bell Helicopter Textron
engineers. They are subject to change only by Bell
Helicopter Textron or an approved Airworthiness
Authority.

• If a helicopter is being inspected on the Part A
inspection program and it is desired to change

Export Classification C, ECCN EAR99

Changes to the TBO will be introduced by either
revisions to this chapter or a Technical Bulletin.

5-00-00

2 SEP 2014 Rev. 20 Page 3

BHT-412-MM-2

WARNING

Every calendar and hourly inspection is a thorough
visual inspection to determine the airworthiness of the
helicopter and the components. Qualified persons
must do the inspections in accordance with quality
standard aircraft practices and the applicable
maintenance manuals. Bell Helicopter Textron
considers that it is mandatory to obey all the
applicable Alert Service Bulletins (ASB) and the
Airworthiness Directives (AD).

Component operating time records are necessary for
components that have scheduled maintenance
procedures, which are different from those of the
airframe. It is the owner/operator’s responsibility to
keep the Historical Service Records (HSR) for the
applicable component and to do the necessary
maintenance procedures.

Before each inspection, remove or open the
necessary cowlings, fairing, inspection doors, and
panels.

ALL PARTS REMOVED, DUE TO
REACHING THEIR LIMITS OR AS A
RESULT OF AN ACCIDENT/INCIDENT
INSPECTION AND DEEMED
UNAIRWORTHY, SHALL BE
PERMANENTLY MARKED AS SCRAP OR
PHYSICALLY DESTROYED TO THE
EXTENT THAT THERE IS NO CHANCE
OF REPAIR OR INSTALLATION ON ANY
HELICOPTER OR COMPONENT.

5. Make sure all limited life parts that have
completed their published operating limits are
replaced.

6. Make sure all of the components that have
completed their published overhaul periods are
overhauled.

5-2. INSPECTION REQUIREMENTS

This manual does not include specific inspections
required by the FAA or other government regulatory
authorities. These specific inspections are given by
your government regulatory authority. Refer to their
requirements for these specific inspectio ns .

The owner/operator of the helicopter is responsible for
the maintenance done on the helicopter. It is the
owner.operator’s responsibility to:

1. Establish, maintain, and review the log books for
discrepancies.

2. Make sure the Alert Service Bulletins (ASB), the
Airworthiness Directives (AD), and the special
inspections are done when they are required to be
done.

3. Make sure the scheduled inspections, the special
inspections, and the required tests for all of the
installed kits are complied with.

7. Make sure all of the maintenance that is done on
the helicopter is done by an approved maintenance
organization.

The maintenance organization/person doing the
maintenance is responsible for the quality of the
maintenance done.

The owner/operator may choose to ask the
maintenance organization/person doing the
maintenance to perform the tasks listed by prior
arrangement through a separate formal agreement.

5-3. CRASH DAMAGE

Because of the many possible co mbinations that can
result from crash damage, it is not possible to include
the specific repair tasks in this category. The
helicopter mechanic must make an analysis of the
crash damage for each situation. Do the repair in
accordance with the degree of damage to the sp ecific
part and the applicable repair procedures in this
manual. Call Product Support Engineering with your
analysis of the crash damage.

4. Make sure all parts and components for which
Historical Service Records are required have
documented traceability to their original installation in
the helicopter.

5-00-00
Page 4 Rev. 19 30 AUG 2013

5-3A. TYPES OF INSPECTIONS

1. The maintenance procedures may include

scheduled inspections, special inspections, conditional

Export Classification C, ECCN EAR99

BHT-412-MM-2

inspections, component interim inspections, and
component overhaul inspections.

a. Scheduled inspections must occur at specifie d
operating intervals. The intervals may be in operating
time (hours), cycles, torque events (RIN), calendar
(days, months, years) or other assigned units. This
ensures the helicopter is airworthy.

• Scheduled inspections — Part A consists of:

– Daily inspection — Accomplish daily before

flight operation.

– 100 hours/12 calendar months — Accomplish

each 100 hours of flight operation or
12 calendar months, whichever comes first.

– 1000 hours — Accomplish ea ch 100 0 hours of

flight operation.

– 5000 hours/5 years — Accomplish each

5000 hours of flight operation or each
60 calendar months, whichever comes first.

• Scheduled inspections — Part B consists of the

following:

– 25 hours/30 days — Accomplish each

25 hours of flight operation or each 30 days,
whichever comes first.

d. An interim inspection occurs between

overhauls.

e. The component overhaul schedule gives the
elapsed operating time at which a component must be
removed, disassembled, examined for condition, and
overhauled, in accordance with data approved by Bell
Helicopter Textron.

2. Airworthiness limitations — Replace components
in accordance with Airworthiness Limitations Schedule
(Chapter 4).

3. Lubrication and servicing requirements are in
addition to those stated in this chapter (Chapter 12).

4. For corrosion control, refer to the Corrosion
Control Guide, CSSD-PSE-87-001 and the
BHT-ALL-SPM.

5. For the PT6T Series engines, refer to the
applicable Pratt & Whitney Canada Engine
Maintenance Manual for the scheduled inspections,
special inspections, conditional inspections, and
component overhaul schedule.

6. For the common Bell Helicopter Textron approved
optional equipment that is integrated into this
maintenance manual, refer to this chapter for the
scheduled inspection, conditional inspection,
component interim inspection, and component
overhaul inspection.

– 300 hours/12 month inspection — Accomplish

each 300 hours of flight operation or each
12 calendar months, whichever comes first.

– 600 hours/12 months — Accomplish each

600 hours of flight operation or each
12 calendar months, whichever comes first.

– 5000 hours/5 years — Accomplish each

5000 hours of flight operation or each
60 calendar months, whichever comes first.

b. Special inspections are of a temporary nature
or of a special interval that is not consiste nt with the
scheduled inspections.

c. Conditional inspections do not occur at a
specified time. A conditional inspection is the result of
known or suspected unusual event, known or
suspected malfunctions, or defects.

Export Classification C, ECCN EAR99

7. For all other Bell Helicopter Textron approved

equipment, refer to the applicable Service Instruction
for the scheduled inspection, special inspection,
conditional inspection, component interim inspection,
and component overhaul inspection.

8. For the inspection requirements for optional
equipment approved under Supplement Type
Certificate (STC), refer to the applicable STC
documentation. Maintenance and inspection of these
items are the responsibility of the owner/operator.

5-3B. DEFINITIONS

• Inspect, check, examine — Determine condition

relative to an established standard.

• Condition — The state of being of an item as
related to serviceable or unserviceable standard.

5-00-00

7 NOV 2016 Rev. 25 Page 5

BHT-412-MM-2

WARNING

NOTE

• Security — The presence of attaching parts that

are properly tightened or appear to be, and the
presence of properly installed (as required)
locking devices such as lockwire, cotter pins, or
other.

• Standard — An established rule or measure to
determine condition.

• Damage — Physical deterioration whereby the
standard renders the condition or an item
acceptable or not acceptable for continuous use.

• Discard — Reject a component that has damage
that cannot be repaired. To permanently remove
from service.

• Preventive maintenance — Simple or minor
preservation and the replacement of small
standard parts not involving complex assembly
operations.

• Maintenance — Inspection, overhaul, repair,
preservation, and the replacement of parts, but
excludes preventive maintenance.

• Operating time — Time required to be recorded in
historical record sheets or helicopter logs.
Operating time to be recorded may be identified
as follows:

– Time in service — Time from the moment a

helicopter leaves the surface of the earth until
it touches down at the next point of landing.
Time during which the engine and rotor are
turning with the helicopter on the ground is not
taken into account.

– Calendar time — Elapse time starts the day

the inspection is accomplished, the
component is installed, or the rotor is turned
for the first time and ends on the last day of
the month that the time limit expires. Calendar
time shall be recorded without interruption.
Removal of the component or storage of the
helicopter etc. does not stop calendar time.

• Planned event — Occurrence of interval in which
a specific action is to be taken as in the case of
preventive maintenance, scheduled overhaul, or
replacement in accordance with maximum
airworthiness life guidelines.

• Lead The Fleet (LTF) Program — This is a
program to validate the performance of an
approved product improvement or a change to a
maintenance interval. The engineering aspects of
this change are approved. The program is closely
monitored by Bell Helicopter Textron in an
operational environment with selected operators.

• Special Programs — These are approved
programs that may be initiated under certain
special conditions to meet specific requirements.
These programs will be clearly defined through a
plan and the engineering and maintenance
aspects will be approved by the regulatory
authorities.

5-3C. INSPECTION AND OVERHAUL

TOLERANCE

DO NOT APPLY THESE TOLERANCES
TO PARTS WITH A LIMITED
AIRWORTHINESS LIFE (CHAPTER 4).

The Bell Helicopter Textron approved tolerance for
scheduled inspections, special inspections, interim
inspections, and overhaul intervals, unless otherwise
stated, is 10% or up to a maximum of 100 hours
operating time/30 days calendar time, whichever is
less. The tolerances are established for maintenance
scheduling convenience only.

Scheduled inspections, special inspections, interim
inspections, or overhaul intervals required beyond the
stated tolerances must be approved by Product
Support Engineering.

The following is only applicable for those
operators whose governing aviation
authority requires to specifically approve
the inspection and overhaul tolerance.

If approval of the inspection and overhaul tolerance is
required by the applicable governing aviation authority,
this is the responsibility of the owner/operator.

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Page 6 Rev. 19 30 AUG 2013

Export Classification C, ECCN EAR99

BHT-412-MM-2

1

1

1

1

Refer to the applicable Pratt & Whitney Canada
Engine Maintenance Manual for inspection and
overhaul tolerances.

The following provides examples of when hourly,
calendar, or hourly/calendar inspection tolerances
have been applied:

Hourly Example (10% or up to a maximum of 100 hours, whichever is less):

300-HOUR

INSPECTION

DUE A T:

MAXIMUM ALLOWED

TOLERANCE

INSPECTION CARRIED

OUT A T:

3400 Hours 10% of 300 hours = 30 hours 3430 Hours

(10% tolerance applied)

3730 Hours 10% of 300 hours = 30 hours 3750 Hours

(within 10% tolerance)

4050 Hours 10% of 300 hours = 30 hours 4050 Hours

(tolerance not applied)

Calendar Example (10% or up to a maximum of 30 days calendar time, whichever is less):

12-MONTH

INSPECTION

DUE ON:

MAXIMUM ALLOWED

TOLERANCE

INSPECTION CARRIED

OUT ON:

NEXT 12-MONTH

NEXT 300-HOUR

INSPECTION

DUE A T:

3730 Hours

4050 Hours

4350 Hours

INSPECTION

DUE ON:

June 10, 2010 10% of 12 months = 1.2 months

(maximum allowed is 30 days)

July 31, 2011 10% of 12 months = 1.2 months

(maximum allowed is 30 days)

June 30, 2012 10% of 12 months = 1.2 months

(maximum allowed is 30 days)

July 8, 2010
(within 30 day tolerance)

June 15, 2011
(completed early)

June 30, 2012
(tolerance not applied)

NOTE:

The last day of the month applies for the next inspection (paragraph 5-3B, calendar time).

July 31, 2011

June 30, 2012

June 30, 2013

5-00-00

Export Classification C, ECCN EAR99

7 NOV 2016 Rev. 25 Page 6A

BHT-412-MM-2

1

111

Hourly/Calendar Example (10% or up to a maximum of 100 hours operating time/30 days calendar time,
whichever is less):

5000-HOUR/

5 YEAR

INSPECTION

DUE AT:

6000 Hours/
December 31,
2010

11,000 Hours/
January 31,
2016

16,100 Hours/
January 31,
2021

NOTE:

The last day of the month applies for the next inspection (paragraph 5-3B, calendar time).

MAXIMUM ALLOWED

TOLERANCE

10% of 5000 hours = 500 hours
(maximum allowed is 100 hours)
or
10% of 60 months = 6 months
(maximum allowed is 30 days)

10% of 5000 hours = 500 hours
(maximum allowed is 100 hours)
or
10% of 60 months = 6 months
(maximum allowed is 30 days)

10% of 5000 hours = 500 hours
(maximum allowed is 100 hours)
or
10% of 60 months = 6 months
(maximum allowed is 30 days)

INSPECTION CARRIED

OUT AT:

6000 Hours/January 15, 2011
(within 30 day calendar
tolerance)

11,100 Hours/January 2, 2016
(100 hour tolerance applied)

16,175 Hours/February 20,
2021
(within 100 hour and 30 day
calendar tolerance)

NEXT 5000-HOUR/

5 YEAR

INSPECTION

DUE AT:

11,000 Hours/
January 31,
2016

16,100 Hours/
January 31,
2021

21,175 Hours/
February 28,
2026

5-00-00
Page 6B Rev. 20 2 SEP 2014

Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

BHT-412-MM-2

5-4. SCHEDULED INSPECTIONS

Part A — Inspect helicopter daily, each 100
hours/12 months, each 1000 hours, each 5000
hours/5 years.

Part B — Inspect helicopter each 25 hours/30 days,
each 300 hours/12 months, each 600
hours/12 months, each 5000 hours/5 years.

Export Classification C, ECCN EAR99

5-00-00

2 SEP 2014 Rev. 20 Page 7/8

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A

DATE: __________________W.O. _____________________

FACILITY: __________________________________________

HELICOPTER S/N: ___________________________________

REGISTRY NO.: _____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:________________________________________

NOTE

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

For helicopters on the Part A inspection program,
accomplish the following checks daily before flight
operation.

GENERAL

INITIAL

MECH OTHER

1. Each listed inspection item or maintenance function is to

be performed in accordance with the BHT-412-MM chapter
specified or the BHT-412-CR&O.

2. Refer to the applicable Pratt & Whitney Canada Engine
Maintenance Manual for engine inspection requirements.

PRELIMINARY REQUIREMENTS

Corrosion Control
Guide,
CSSD-PSE-87-001.

Chapter 4 2. Replace all finite life components that have completed

Chapter 5 3. Overhaul all components that have completed published

Chapter 12 4. Lubricate and service helicopter as required.

Export Classification C, ECCN EAR99

1. Use medium helicopter corrosion control guide to establish

helicopter corrosion control program.

published operating limitations.

overhaul periods.

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7 NOV 2016 Rev. 25 Page 9

BHT-412-MM-2

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 5 5. Review Special Inspections and carry out applicable

inspections.

6. Examine all inspection windows and sight glasses for
cracking, crazing, and discoloration. If any of these conditions
are present, the part must be removed and replaced prior to
returning helicopter for service.

Service Instruction
(SI)

Chapter 21 BLEED AIR HEATING SYSTEM COMPONENTS

7. Ensure all required inspections of installed BHT kits not
covered in this inspection have been performed, as applicable.

1. Visually inspect heater compartment for cleanliness,
condition, and security of heating system components, wiring,
ducts, supports, and structure for damage and corrosion.

2. Visually inspect overhead ventilating system components
for condition and security.

3. Visually inspect heat/vent air ducts for condition and
security.

INITIAL

MECH OTHER

4. Visually inspect ventilation/defog components for condition

and security.

Chapter 25 CREW/PASSENGERS SEATS

1. Visually inspect crew seats for condition, security, and
operation.

2. Visually inspect crew seats restraints for condition,
security, and operation.

3. Crew seat attenuator for compression — inspect witness
line. If line is not visible, repair attenuator assembly.

4. Visually inspect passenger seats for condition and security.

5. Visually inspect passenger seats restraints for condition

and security.

5-00-00
Page 10 Rev. 25 7 NOV 2016

Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 25 MISCELLANEOUS FURNISHINGS

Visually inspect miscellaneous furnishing (map and data case,
first aid kit, and emergency equipment) for condition and
security.

Chapter 26 FIRE EXTINGUISHERS

Visually inspect cockpit and cabin portable fire extinguishers
and engine compartment fire extinguishers containers for
security and condition.

Chapter 28 FUEL SYSTEM

Visually inspect fuel samples for contamination.

Chapter 29 HYDRAULIC SYSTEMS

1. Visually inspect the following:

a. Hydraulic system 1 and 2 filter bypass indicator buttons

— not extended.

INITIAL

MECH OTHER

b. Collective and cyclic servoactuators and boost tubes for

leaks, damage, and security.

c. Hydraulic system 1 and 2 pumps for leaks, damage,

and security.

d. Hydraulic system 1 and 2 valve and filter modules for

leaks, damage, and security.

e. Hydraulic system 1 and 2 lines, hoses, and fittings for

leaks, damage, chafing, kinking, and security.

f. Hydraulic system 1 and 2 reservoirs for proper fluid

levels, damage, corrosion, and security.

g. Tail rotor hydraulic actuator and hoses for leakage,

corrosion, and security.

2. Remote hydraulic filter bypass indicator (located in right
nose window) — confirm not tripped.

Export Classification C, ECCN EAR99

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26 FEB 2013 Rev. 16 Page 11

BHT-412-MM-2

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 30 WINDSHIELD WIPER

Visually inspect windshield wiper blades for serviceability and
security.

Chapter 32 LANDING GEAR SYSTEM

1. Visually inspect landing gear as follows:

a. Forward crosstube and cap fittings for condition and

security of attachment.

b. Aft crosstube, cap fittings, and wear strips for condition

and security of attachment.

c. Aft crosstube support beam for wear, cracks, damage,

corrosion, and security of attachment.

d. Skid tubes and skid shoes for condition and security of
attachment. Replace skid shoes that are worn into shoe
surface. Repair weld beads as required.

INITIAL

MECH OTHER

e. Fuselage supports for wear, damage, and security of

attachment.

f. Deleted.

g. If installed, landing gear forward crosstube crew step

fittings for corrosion, damage, and security in area of
attachment. If edge sealant is damaged or missing, remove
crew step and inspect crosstube for corrosion or damage.

h. Emergency float reservoir pressure indicator for proper
charge indication (if installed).

i. Floats for proper stowage and condition (if installed).

2. Visually inspect tail skid for deformation and security of

attachment.

Chapter 52 DOORS, WINDOWS, AND EMERGENCY EXIT

1. Visually inspect nose door for obvious damage, security of
attachment, proper latching, and seal for condition.

5-00-00
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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

2. Visually inspect all windows for damage. Crew door

windows, cargo hinged door window, passenger sliding door
windows, cabin roof windows, cabin lower nose windows, and
windshields.

3. Visually inspect crew door emergency release pins for
security.

4. Visually inspect cabin doors for condition, security, and
freedom of operation.

5. Avionics/electrical and heater compartment doors for
condition and security of attachment. Latches for proper
operation.

Chapter 53 FUSELAGE

1. Visually inspect fuselage exterior for cond ition an d damage
to protective finish.

2. Visually inspect fuselage underside for evidence of fuel
and hydraulic fluid leakage

INITIAL

MECH OTHER

3. Visually inspect all cowlings and fairings for condition and

security, missing fasteners, cracks, and proper operation of
latches.

4. Inspect fuselage tailboom attachment points for security.

5. Visually inspect pitot tubes and static po rts for obstruction

and damage.

6. Visually inspect fuselage interior for evidence of water
entrapment in following areas:

a. Nose compartment

b. Pilot and passenger cabin

c. Electrical compartment

d. Heater compartment

Export Classification C, ECCN EAR99

5-00-00

26 FEB 2013 Rev. 16 Page 13

BHT-412-MM-2

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

e. Baggage compartment

Chapter 53 TAILBOOM

1. Inspect tailboom exterior structure for general condition.

Chapter 52 2. Inspect baggage compartment interior for condition and

cleanliness.

3. Check baggage compartment door for damage, proper
operation, and security.

4. Inspect driveshaft and intermediate gearbox covers for
damage and security.

Chapter 62 MAIN ROTOR BLADES

Visually inspect main rotor blades for condition, damage,
security, and cleanliness.

Chapter 62 MAIN ROTOR HUB

INITIAL

MECH OTHER

1. Visually inspect main rotor hub assembly for condition and

security, paying particular attention to the condition of
elastomeric components, and the integrity of sealing.

2. Visually inspect pitch horns for condition, security, and
cracks in areas surrounding torque transfer pin holes. No cracks
permitted.

3. Inspect pivot bearings and damper yoke set for elastomeric
bearing delamination, cracking, and elastomer degradation.

Chapter 62 MAIN ROTOR CONTROLS

1. Visually inspect swashplate and support assembly and
collective lever for condition and security.

2. Visually inspect hub and sleeve assembly for condition and
security.

5-00-00
Page 14 Rev. 16 26 FEB 2013

Export Classification C, ECCN EAR99

NOTE

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Use swashplate link and drive link bearings — Work
aid (Chapter 62) to assist with deter mining condition
of main rotor control bearings.

3. Visually inspect drive hub and rephasing levers for bearing
looseness and security of attachment.

4. Visually inspect pitch links for condition, security, and
bearing looseness.

5. Visually inspect mast assembly for corrosion and
mechanical damage. Mast seal for leakage.

Chapter 63 ENGINE-TO-TRANSMISSION (MAIN) DRIVESHAFT

1. Visually inspect main driveshaft for condition and security.

INITIAL

MECH OTHER

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

2. Visually inspect main driveshaft forward and aft couplings,
boots, seals (and surrounding area), for grease leakage,
damage, corrosion, and evidence of overheat as indicated by
TEMP-PLATES or coupling discoloration. A change in color of
any yellow bordered TEMP-PLATE, from white/off-white to
black, will indicate a possible overheat condition and/or
component degradation (step 3). If one of more of the red
bordered TEMP-PLATE dots change from white/off-white to
black, an overheat condition is present and may require
replacement of both outer and inner couplings.

3. Visually inspect overheat TEMP-PLATES for condition and
security. TEMP-PLATES must not show evidence of
overtemperature indication, deterioration, debonding, or
excessive discoloration of the epoxy overcoating.

Export Classification C, ECCN EAR99

5-00-00

26 FEB 2013 Rev. 16 Page 15

BHT-412-MM-2

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 63 TRANSMISSION

1. Check for proper oil level.

2. Check external oil filter for bypass indication.

3. Visually inspect transmission cases for damage, condition,

and evidence of leaking.

4. Visually inspect accessories for condition, damage, and
security of attachment.

5. Visually inspect external oil lines and hoses for condition,
damage, chafing and leaks, paying particular attention to lines
running aft of the thermostatic relief valve.

6. Visually inspect mast assembly for corrosion and
mechanical damage, and mast seal for leakage.

7. Transmission mount dust boots for condition.

INITIAL

MECH OTHER

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

8. Visually inspect transmission tail rotor output quill coupling
(and surrounding area) for grease leakage, damage, corrosion,
and evidence of overheat as indicated by TEMP-PLATES or
coupling discoloration. A change in color of one or more of the
red bordered TEMP-PLATE dots from white/off-white to black,
indicates an overheat condition, and may require replacement
of both outer and inner couplings (step 9).

9. Visually inspect overheat TEMP-PLATES for condition and
security. TEMP-PLATES must not show evidence of
overtemperature indication, deterioration, debonding, or
excessive discoloration of the epoxy overcoating.

5-00-00
Page 16 Rev. 16 26 FEB 2013

Export Classification C, ECCN EAR99

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 63 ROTOR BRAKE QUILL AND BRAKE ASSEMBLY

1. Visually inspect rotor brake assembly for condition,

damage, and security.

2. Visually inspect rotor brake quill for conditio n, damage, and
leakage.

3. Visually inspect rotor brake disc for warpage.

Chapter 63 TRANSMISSION OIL COOLING AND COMBINING

GEARBOX

1. Visually inspect oil coolers for leaking, damage, and

obstruction.

2. Visually inspect oil cooler hoses and tubes for leaking,
chafing, fraying or other damage.

3. Visually inspect oil cooler blowers for damage and
obstruction.

INITIAL

MECH OTHER

Chapter 64 TAIL ROTOR HUB AND BLADE ASSEMBLY

NO CRACKS ARE PERMITTED ON ANY SURFACE
OF THE T AIL ROTOR BLADES.

1. Tail rotor blades for condition of bond lines, cracks,
corrosion, leading edge erosion, damage, security, and
cleanliness. Clean blades are required to maintain enhanced
visibility for safety.

2. Tail rotor hub for security, corrosion, and condition.

3. Flapping bearings and pitch change bearings for excessive

looseness and freedom of movement through full range of travel
with anti-torque pedals positioned full right and then full left.

Export Classification C, ECCN EAR99

5-00-00

26 FEB 2013 Rev. 16 Page 17

BHT-412-MM-2

NOTE

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

4. Tail rotor pitch change links, crosshead, pitch horns,

counterweight arms, and links for security, corrosion, and
condition.

5. Pitch link bearing and counterweight link bearing
looseness shall not exceed 0.015 inch (0.381 mm) axial. Check
freedom of movement through full range of travel with antitorqu e
pedals positioned full right and then full left.

6. Pitch change links for binding with tail rotor blade moved to
both full flapping positions. Binding is not acceptable.

Chapter 65 TAIL ROTOR DRIVESHAFT

Step 1 through s tep 5 pertain to helicopters S/N
33001 through 33213 and 36001 through 36019 not
modified by 412-570-001-003 or Pre BHT-412-SI-74
(412SP to 412HP Upgrade).

INITIAL

MECH OTHER

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

1. Hanger assemblies — bearings and surrounding areas for
evidence of grease leakage, condition, damage, security,
corrosion, and overheating. Discoloration of bearing (color
change to blue to blue/black in color) or multi-color appearance
of hanger that darkens adjacent to bearing is evidence of
overheating. Brown color of bearing shield is normal and is not
evidence of overheating.

2. Driveshaft sections for cracks, rivet failure, distortion,
dents, corrosion, and for damage to anodized finish.

3. Clamp sets for condition, security, and proper installation.

5-00-00
Page 18 Rev. 16 26 FEB 2013

Export Classification C, ECCN EAR99

WARNING

NOTE

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

4. Flexible couplings and surrounding areas for grease
leakage, damage, corrosion, and evidence of overheat as
indicated by TEMP-PLATES or coupling discoloration. A change
in color of one or more of the red bordered TEMP-PLATE dots
from white/off-white to black indicates an overheat condition and
may require replacement of both outer and inner couplings
(step 5).

5. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of over temperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

INITIAL

MECH OTHER

Step 6 through step 10 pertain to helicopters
S/N 36020 through 36999, S/N 37002 through
37999, S/N 38001 through 38999, S/N 39101
through 39999, and helicopters modified by
412-570-001-103 or Post BHT-412-SI-74 (412SP to
412HP Upgrade).

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

Export Classification C, ECCN EAR99

5-00-00

01 JUN 2018 Rev. 26 Page 19

BHT-412-MM-2

WARNING

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

6. Hanger assemblies — bearings and surrounding areas for

evidence of grease leakage, condition, damage, security,
corrosion, and overheating. Discoloration of bearing (blue or
blue/black in color) or multi-color appearance of hanger that
darkens adjacent to bearing is evidence of overheating. Brown
color of bearing shield is normal and is not evidence of
overheating.

7. Driveshaft sections for cracks, rivet failure, distortion,
dents, corrosion, and damage to anodized finish.

8. Disc pack couplings for separation, deflection, distortion,
cracks, or missing sections, and correct installation of bolts and
washers.

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

INITIAL

MECH OTHER

9. Coupling assembly at first hanger and adjacent to

transmission and surrounding area for grease leakage,
damage, corrosion, and evidence of overheat as indicated by
TEMP-PLATES or coupling discoloration. A change in color of
one or more of the red bordered TEMP-PLATE dots from
white/off-white to black indicates an overheat condition and ma y
require replacement of both outer and inner couplin gs (step 1 0).

10. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of over temperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

5-00-00
Page 20 Rev. 16 26 FEB 2013

Export Classification C, ECCN EAR99

NOTE

WARNING

NOTE

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 65 INTERMEDIATE GEARBOX

Step 1 through step 4 pertain to helicopters S/N
33001 through 33213 and 36001 through 36019 not
modified by 412-570-001-103 or Pre BHT-412-SI-74
(412SP to 412HP Upgrade).

1. Gearbox assembly for security, condition, corrosion,
damage, and oil leaking.

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

INITIAL

MECH OTHER

2. Input and output quill flexible couplings (and surrounding

area) for grease leakage, damage, corrosion, and evidence of
overheat as indicated by TEMP-PLATES or coupling
discoloration. A change in color of one or more of the red
bordered TEMP-PLATE dots from white/off-white to black
indicates an overheat condition and may require replacement of
both outer and inner couplings (step 3).

3. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of over temperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

4. Gearbox for proper oil level and oil for evidence of
contamination.

Step 5 through step 8 pertain to helicopters S/N 3602 0
through 36999, S/N 37002 through 37999, S/N 38001
through 38999, S/N 39101 through 39999 and
helicopters modified by 412-570-001-103 or Post
BHT-412-SI-74 (412SP to 412HP Upgrade).

Export Classification C, ECCN EAR99

5-00-00

01 JUN 2018 Rev. 26 Page 21

BHT-412-MM-2

WARNING

NOTE

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

5. Gearbox assembly for security, condition, corrosion,

damage, and oil leaking.

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

6. Output quill outer couplings (and surrounding area) for
grease leakage, damage, corrosion, and evidence of overheat
as indicated by TEMP-PLATES or coupling discoloration. A
change in color of one or more of the red bordered
TEMP-PLATE dots from white/off-white to black indicates an
overheat condition and may require replacement of both outer
and inner couplings (step 7).

7. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of over temperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

INITIAL

MECH OTHER

8. Gearbox for proper oil level and oil for evidence of

contamination.

Chapter 65 TAIL ROTOR GEARBOX

Step 1 though step 4 pertain to helicopters S/N
33001 through 33213 and 36001 through 36019 not
modified by 412-570-001-103 or Pre BHT-412-SI-74
(412SP to 412HP Upgrade).

1. Gearbox assembly for security, condition, corrosion,
damage, and oil leaking.

5-00-00
Page 22 Rev. 16 26 FEB 2013

Export Classification C, ECCN EAR99

WARNING

NOTE

SCHEDULED INSPECTIONS

5-5. DAILY INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

CAUSE OF ANY DISCOLORATION SHALL BE

DETERMINED AND CORRECTED PRIOR TO

NEXT FLIGHT.

2. Input quill flexible coupling (and surrounding area) for
grease leakage, damage, corrosion, and evidence of overheat
as indicated by TEMP-PLATES or coupling discoloration. A
change in color of one or more of the red bordered
TEMP-PLATE dots from white/off-white to black indicates an
overheat condition and may require replacement of both outer
and inner couplings (step 3).

3. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of overtemperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

INITIAL

MECH OTHER

4. Gearbox for proper oil level and oil for evidence of

contamination.

Step 5 and step 6 pertain to helicopters S/N 36020

through 36999, S/N 37002 through 37999, S/N

38001 through 38999, S/N 39101 through 39999,

and helicopters modified by 412-570-001-103 or

Post BHT-412-SI-74 (412SP to 412HP Upgrade).

5. Gearbox assembly for security, condition, corrosion,
damage, and oil leaking.

6. Gearbox for proper oil level and oil for evidence of
contamination.

Chapter 67 FLIGHT CONTROLS

1. Inspect flight control tubes for condition, corrosion, and
security.

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2. Visually inspect elevators for damage and security. Check

elevator control tube for positive spring action and freedom of
movement.

Chapter 71 LEFT POWER SECTION

1. Inspect gas generator case for cracks, buckled areas, and
hot spots.

2. Inspect oil and fuel hoses and tubes for chafing, leaking,
and security.

3. Inspect electrical wiring for fraying, chafing, and security.

4. Check for proper oil level.

Chapter 71 RIGHT POWER SECTION

1. Inspect gas generator case for cracks, buckled areas, and

hot spots.

INITIAL

MECH OTHER

2. Inspect oil and fuel hoses and tubes for chafing, leaking,

and security.

3. Inspect electrical wiring for fraying, chafing, and security.

4. Check for proper oil level.

Chapter 71 REDUCTION GEARBOX

1. Inspect hoses and lines for chafing, leaking, and security.

2. Check oil filter impending bypass indicator button — not

extended.

3. Check for proper oil level.

Chapter 71 ENGINE AND REDUCTION GEARBOX MOUNTS

Inspect mounts for loose bearings and security.

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BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 71 ENGINE FIREWALLS

Visually inspect firewalls for cracks, distortion, missing rivets,
broken spot welds, and deteriorating seals or gaskets.

Chapter 71 ENGINE AIR MANAGEMENT SYSTEM

1. Visually inspect exhaust ejectors and ducts for damage
and security.

2. Visually inspect air ducts and plenum for condition,
obstruction, and security.

Chapter 79 ENGINE OIL SYSTEM

Visually inspect oil coolers for damage and obstruction.

Chapter 95 INSTRUMENTS

1. Visually inspect instrument panel for cleanliness.

INITIAL

MECH OTHER

2. Visually inspect all instruments, placards, decals, and

markings for appearance and legibility.

3. Check magnetic compass for condition and security.

4. Visually inspect compass cards for validity.

Chapter 96 ELECTRICAL SYSTEM

1. Inspect electrical equipment in nose compartment for

condition and security.

2. Inspect pedestal mounted avionics/electrical equipment for
condition, cleanliness, and security.

3. Inspect overhead console for condition, cleanliness, and
security.

4. Inspect all instrument lights, integrally lit panels, secondary
lights, and map lights serviceability.

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DATA REFERENCE INSPECTION TASK DESCRIPTION

5. Inspect all caution and warning lights for proper operation

by using master caution, fire test, and baggage compartment
smoke detector press-to-test func tion s.

6. Check landing and search lights for condition and security.

7. Navigation and anticollission lights for condition and

security.

Chapter 96 BATTERY SYSTEM

1. Visually inspect battery and external connections for
condition and security.

2. Visually inspect battery vent and drain tubes for obstruction
and security.

Chapter 97 ANTENNAS

Visually inspect all antennas located on fuselage and tailboom
for condition and security.

INITIAL

MECH OTHER

Chapter 97 AVIONICS EQUIPMENT

Visually inspect all avionics located in fuselage and tailboom
for condition and security.

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SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A

DATE: __________________W.O. _____________________

FACILITY: __________________________________________

HELICOPTER S/N: ___________________________________

REGISTRY NO.: _____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:________________________________________

NOTE

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

For helicopters on the Part A inspection program,

accomplish each 100 hours of flight operation or after

12 calendar months, whichever comes first.

GENERAL

INITIAL

MECH OTHER

1. Each listed inspection item or maintenance function is to

be performed in accordance with the BHT-412-MM chapter
specified or the BHT-412-CR&O.

2. Refer to the applicable Pratt & Whitney Canada Engine
Maintenance Manual for engine inspection requirements.

3. Record all work accomplished during inspection in the
helicopter maintenance record.

4. Check helicopter records for recorded discrepancies.

5. Accomplish complete Daily Inspection — Part A.

Paragraph 5-13 6. Review special inspections and perform any special

inspection required.

Chapter 4 7. Replace all finite life components that have completed

published operating limitations.

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DATA REFERENCE INSPECTION TASK DESCRIPTION

Paragraph 5-44 8. Overhaul all components that have completed published

overhaul periods.

Chapter 12 9. Perform lubrication requirements.

10. Remove all panels, fairings, and cowlings required to
satisfactorily carry out the inspection.

The following step is to be performed every
12 calendar months.

11. Inspect all fuel system, oil system, and hydraulic system
filler caps for proper functioning and sealing. Make sure the
sealing O-rings within the filler caps are in good condition.
Repair or replace the filler caps or replace sealing O-rings as
required.

AFTER COMPLETION OF INSPECTION

INITIAL

MECH OTHER

1. Reinstall all panels, fairings, and cowlings removed during

inspection.

2. Carry out a ground run and leak check prior to releasing
the helicopter back to service.

Chapter 21 HEA T/VENT AIR DUCTS

1. Visually inspect all heating, ventilation, cooling ducts, and
controls for cracks, security, and for proper operation.

Every sixth 100 hour inspection (600 hours) or 12 months:

Chapter 96 1. Bleed air heating and ventilation/defog system

components:

a. Perform operational check of bleed air heating system

and components.

b. Perform operational check of defog blower.

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BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 25 MISCELLANEOUS FURNISHINGS

1. Check all safety equipment for inspection due dates and

operation.

Chapter 26 FIRE PROTECTION

1. Make sure fire extinguishers are properly charged.

2. Baggage compartment smoke detector for condition and

security.

Every sixth 100 hour inspection (600 hours) or 12 months:

Chapter 26 1. Weight check crew and passenger cabin portable fire

extinguishers.

ASB 412-12-152 2. Visually inspect the loop clamp installed on modified

discharge tubes 212-060-921-001FM and -002FM for condition
and security until Part III of referenced ASB is accomplished.

INITIAL

MECH OTHER

Chapter 96 3. Perform operational check of engine fire extinguishing

system.

4. Perform operational check of baggage compartment
smoke detector.

Chapter 4 5. Replace engine fire extinguisher container fir ing cartridg es

in accordance with specified service life.

Chapter 28 FUEL SYSTEM

1. Inspect all exposed fuel lines and connections for leakage,
damage, and security.

Every sixth 100 hour inspection (600 hours) or 12 months:

2. Remove four access doors, located just forward of the aft

crosstube, from the underside of the fuselage. Inspect fuel lines
for evidence of leakage, damage, and security.

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NOTE

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DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 29 HYDRAULIC SYSTEMS

1. Inspect all lines and hoses for security and general

condition.

Every sixth 100 hour inspection (600 hours) or 12 months:

Hydraulic filter elements 205-076-034-003 are
non-cleanable. It is recommended they be replaced
every 600 hours or 12 months. Filter elements
205-076-034-007 are cleanable. The -003 and -007
elements are interchangeable; intermixing of
different element types is not permitted.

1. Remove and inspect hydraulic filter elements.

2. Discard or clean filter elements as applicable.

3. Install hydraulic filter elements.

INITIAL

MECH OTHER

Chapter 63 4. Install 0 to 500 PSI (0 to 3447 kPa) gauge in quick

disconnect at rotor brake caliper. Slowly pull rotor brake handle
through travel. Cylinder should generate 240 to 260 PSI (1655
to 1793 kPa) at any handle velocity and shall maintain 150 PSI
(1034 kPa) minimum in over center position for 3 minutes.
Adjust as necessary.

5. Inspect brake linings for wear (minimum thickness

0.150 inch).

Chapter 32 LANDING GEAR

1. Inspect landing gear crosstube assemblies, skid tubes, and
skid shoes, for condition and security of attachment. Inspect
crosstube retention cap (rubber bumper pads) for condition and
security of attachment.

2. Aft crosstube assemblies support beam for cracks,
damage, corrosion, and security of attachment.

3. Crosstube to skid tube saddle bolts for tightness.

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BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

4. Torque forward and aft cross tube support fittings U-bolts to

80 to 100 inch-pounds (9.04 to 11.29 Nm).

5. Torque check ground handling wheel attachment eyebolts
on skid tubes 40 to 58 foot-pounds (54 to 79 Nm). Eyebolts that
rotate prior to reaching 40 foot-pounds (54 Nm) shall be
removed and inspected for evidence of bending. No bending is
permitted.

Every third 100 hour inspection (300 hours) or 12 months:

BHT-412-SI-58 6. If gross weight towing kit provisions are installed, inspect

fitting assembly for condition and security. Torque check
attachment bolts 160 to 190 inch-pounds (18.1 to 21.4 Nm). If
bolts are found loose, inspect for condition.

Chapter 52 DOORS AND WINDOWS

1. Crew and passenger doors structure for corrosion,
damage, distortion, and positive lockin g mechanisms. Seals for
adherence, tears, separations, and deterioration.

INITIAL

MECH OTHER

Every third 100 hour inspection (300 hours) or 12 months:

2. Crew door emergency jettison mechanism for condition

and security. Perform operational check.

3. Passenger door window retainers and fillers for damage.

4. Nose, electrical, and equipment compartment access

doors for corrosion, damage, distortion, and positive locking
mechanisms.

5. Baggage compartment door for corrosion, damage, and
positive locking.

6. Inspect heated windshield, if installed, for condition and
proper operation.

Chapter 53 FUSELAGE

1. Inspect fuselage tailboom attachme nt points for evidence
of fretting.

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DATA REFERENCE INSPECTION TASK DESCRIPTION

ASB 412-00-100 2. Inspect fuselage tailboom attachment components and

hardware for cracks with a 10X m a gn ifying glass. Pay particular
attention to interface between forward end of tail boom
attachment fitting and cap angle, and main beam web area
below cap angle (Figure 5-6).

3. Move pylon fore and aft, using mast as lever. Check friction
dampers for freedom of movement and smooth operation.

4. Inspect transmission mounts, mounting brackets, and
structure for cracked or broken parts.

5. Inspect lift link and fitting for cracks and security.

6. Cabin interior and exterior for corrosion and damage.

7. All compartments for evidence of water entrapment and

corrosion.

8. Ensure all drain holes are open.

INITIAL

MECH OTHER

9. Inspect underside of fuselage:

a. Fuselage structure for damage, corrosion, and working

rivets.

b. Exterior finish for condition and cleanliness.

c. Evidence of excessive fluid leakage.

d. Structure around landing gear for condition.

e. Forward crosstube support structure for working

fasteners, cracks, corrosion, and excessive wear.

f. Aft crosstube support structure for working fasteners,

cracks, corrosion, and excessive wear.

10. Fuselage bonded panels for damage and delamination.

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SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

11. Inspect cabin roof structure:

a. Cabin roof structure, cowlings, and fairing for damage,

delamination, and general condition.

b. Cabin roof and cowling/fairing mounted antennas for

condition and security.

Every sixth 100 hour inspection (600 hours) or 12 months:

1. Inspect fuselage cabin structure:

a. Fuselage structure for corrosion and damage to finish

and sealant. Pay particular attention to edges of joints and
seams and around fastener heads.

b. Engine compartment floor and service deck, FS 155.06

to 241.22, for damage, delamination, and corrosion.

INITIAL

MECH OTHER

To adequately inspect the following, it will be

necessary to remove the auxiliary fuel tanks if

installed.

2. Pylon wall for damage, working fasteners, cracks,
delamination, and corrosion.

Chapter 53 TAILBOOM

1. Inspect tailboom attachment points for cracks and security.

2. Inspect tailboom exterior and interior structure for corrosion

and damage.

3. Ensure all drain holes are open.

Chapter 65 4. Torque check tail rotor gearbox mounting nuts by applying

torque in tightening direction, do not exceed 200 inch-pounds
(22.6 Nm). If any nut rotates under torqu e, inspect attachment
hardware and tail rotor gearbox for serviceability.

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NOTE

NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

5. Torque check intermediate gearbox mounting bolts by

applying torque in tightening direction, do not exceed
50 inch-pounds (5.65 Nm). If any bolt turns under torque,
inspect attachment hardware and intermediate gearbox for
serviceability.

Chapter 67 6. Inspect elevator attachment lugs at each end of elevator

horn for cracks and security of attachment. Check elevator horn
to elevator spar attaching bolts and surrounding joint for cracks
and security of attachment.

Chapter 53 7. Inspect vertical fin spar caps for cracks and corrosion.

8. Inspect vertical fin spar caps forward side and web from
upper tailboom skin to approximately 4.0 inches (101.6 mm)
below upper tailboom skin as follows: Remove aft tailboom
access door. Face aft and use bright light and small mirror to
inspect area for cracks, especially near rivets holes.

INITIAL

MECH OTHER

Step 9 and step 10 pertain to helicopters modified
with the BLR FastFin™ system kit 412-705-040-101.

For helicopters equipped with the Dual Tailboom
Strakes and FastFin™ system Supplemental Type
Certificate (STC), refer to the applicable BLR
Aerospace documents for inspection criteria.

9. Inspect upper and lower tail fairings for visible damage to
the exterior skin and cracks at the attachment points. If paint is
missing locally or has scratches, inspect the fairing for
delamination and voids with a tap hammer. Inspect fairings for
loose or missing attaching hardware.

10. Inspect upper and lower strakes for visible damage,
deformation, cracks at the attachment points, and loose or
missing rivets.

If necessary, clean area with cloth dampened with
MEK (C-309) or equivalent. Ventilate area to prevent
breathing fumes.

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NOTE

NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Every third 100 hour inspection (300 hours) or 12 months:

1. Inspect tailboom joints, splices, longerons, attach fittings,

and attaching hardware for corrosion, dam a ge , an d cra cks.

ASB 412-90-49 2. Remove plug button at BS 99.00.

Paint fissures are common in the splice area, cracks

will be evident by black powder emanating from

cracked area, and corrosion will leave evidence of

white powder.

3. Using a borescope or other suitable means, inspe ct inside
of longeron paying particular attention to cracking and/or
corrosion in area of splice.

4. Report any cracks to Product Support Engineering.

5. Install plug button with sealant (C-308).

INITIAL

MECH OTHER

Chapter 62 MAIN ROTOR BLADES

1. Wash main rotor blades.

2. Inspect main rotor blades’ upper and lower surfaces for

condition of bond lines and doublers. Leading edge for erosion.
Blade surfaces for corrosion, cracks, damage, and voids.

3. Inspect blade retention bolts for condition and security.

Waxing is not required for blades 412-015-300-109

and subsequent or for any blade finished with

polyurethane paint.

4. Apply a coat of wax to main rotor blades.

Chapter 62 MAIN ROTOR HUB

1. Inspect hub assembly for condition, corrosion, and
security, paying particular attention to the integrity of sealing.

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NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

2. Inspect pitch horns for corrosion and cracks in areas

surrounding torque transfer pin holes. No cracks permitted.

3. Inspect pivot bearings, spindle bearings, and damper set
for elastomeric bearing delamination, elastomer degradation,
shim cracks, crazing, cracking, or sheeting.

4. Inspect damper bearing bumper pads for deterioration or
deformation due to contact with yoke.

5. Torque check eight yoke a ssembly through bolt nu ts to 70
to 80 foot-pounds (95 to 108 Nm).

6. Make sure bolts EWB0420 are installed (16 places) for
simple pendulum absorber bracket. Torque check bolts. Apply
29 to 33 foot-pounds (39 to 45 Nm).

7. Functionally check arm and bearing (pendulum)
assemblies. Apply a minimum of 5 pounds (22.24 N) of force to
each arm and bearing assembly (force toward center of yoke).
Cycle arm and bearing through full travel.

INITIAL

MECH OTHER

8. Apply force away from center of yoke. Arm and bearing

assembly should cycle free and smooth. Roughness and
binding are not acceptable.

9. Functionally check droop restraint system. Check for
engagement of restraint arms in lower detent of cam window.
Relieve load on each blade and verify lower clevis moves freely
through cam window envelope. Binding and roughness in
inboard clevis is not acceptable.

Chapter 62 MAIN ROTOR CONTROLS

Disconnect pitch link upper rod ends from the pitch
horns to determine main rotor control bearing wear.

1. Swashplate and support assembly:

a. Inspect for condition and security with special attention

to gimbal ring attachment lugs.

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SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

The presence of black oxide powder will require

investigation to determine the cause.

b. Inspect gimble ring bearings, liners, and attaching
hardware for excessive looseness and wear. Gimble ring
bearing and attaching bolt axial or radial looseness shall not
exceed 0.005 inch (0.127 mm) with no binding allowed.

c. Inspect trunnion bearings and attaching hardware for
excessive looseness and wear. Trunnion bearings shall not
exceed 0.020 inch (0.508 mm) axial looseness.

2. Hub and sleeve assembly:

a. Inspect for condition and security.

b. Inspect drive hub and rephasing levers for wear and

bearing looseness.

INITIAL

MECH OTHER

c. Drive links spherical bearings shall not exceed

0.007 inch (0.178 mm) radial or 0.015 inch (0.381 mm) axial
looseness.

d. Swashplate link non-elastomeric bearing looseness
shall not exceed 0.015 inch (0.381 mm) axial.

3. Inspect collective lever for condition and security. Trunnion
bearing shall not exceed 0.020 inch (0.508 mm) axial
looseness.

4. Inspect pitch links for condition and security.
Non-elastomeric bearing looseness shall not exceed 0.007 inch
(0.178 mm) radial or 0.015 inch (0.381 mm) axial.

Every third 100 hour inspection (300 hours) or 12 months:

1. Torque check swashplate link elastomeric rod end bearings

(as applicable) attachments bolts to 165 to 200 inch-pounds
(18.65 to 19.74 Nm).

2. Torque check swashplate outer ring through bolts to 165 to
175 inch-pounds (18.65 to 19.74 Nm).

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DATA REFERENCE INSPECTION TASK DESCRIPTION

3. Torque check four hub and sleeve to rephasing lever

attachment bolts to 24 to 34 foot-pounds (33 to 46 Nm ) for
1/2 inch bolts or 160 to 200 inch-pounds (18.08 to 22.59 Nm) for
3/8 inch bolts (if installed).

4. Torque check drive link to rephasing lever attachment bolts
to 165 to 200 inch-bolts (18.65 to 22.59 Nm).

5. Torque check pitch link elastomeric rod end bearings (as
applicable) attachment bolts to 165 to 200 inch-pounds (18.65
to 22.59 Nm).

6. Torque check swashplate support to mast plate bolts
(AN5H-6A) to 130 to 140 inch-pounds (14.67 to 15.79 Nm).

Chapter 63 MAIN ROTOR MAST

1. Inspect mast assembly for security, corrosion, and
mechanical damage.

2. Inspect mast torque sensor (if installed) installation for
security and condition

INITIAL

MECH OTHER

3. Inspect for evidence of oil leaks at mast bearing cap.

Chapter 63 TRANSMISSION

1. Inspect mounts for damage and security. Check boots for

condition and ensure boots are in place.

2. Inspect lift link and attachments for corrosion, damage, and
security. Check bearings for looseness.

3. Inspect for evidence of oil leakage.

4. Check all transmission chip detectors for debris and clean.

5. Test all transmission chip detectors electrical circuits.

Every third 100 hour inspection (300 hours) or 12 months:

1. Check internal oil filter or full flow oil monitor for debris and

clean.

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CAUTION

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

2. Torque check top case to ring gear case nuts, ring gear

case to main case nuts, and main case to support case nuts to
230 to 250 inch-pounds (25.99 to 28.25 Nm). Retorque as
required.

Chapter 64 TAIL ROTOR HUB AND BLADE ASSEMBLY

COUNTERWEIGHT BELLCRANK RETENTION
NUT MS14145L6 OR ITS EQUIVALENT MS17826-6
IS DESIGNATED AS ONE TIME USE ONLY. IF
MAINTENANCE ACTION REQUIRES THAT IT BE
REMOVED, THE COUNTERWEIGHT BELLCRANK
NUT IS TO BE DISCARDED AND REPLACED
WITH A NEW NUT. OVERTORQUING OR
INCORRECT APPLICATION OF THE NUT COULD
CAUSE MECHANICAL FAILURE RESULTING IN
EXCESSIVE VIBRATION OR DAMAGE TO THE
TAIL ROTOR BLADES.

INITIAL

MECH OTHER

1. Inspect the tail rotor counterweight bellcrank

212-011-705-001 retention nuts for cracks, corrosion, and
security. Reapply corrosion preventive compound (C-101) if
nuts are not completely covered.

Every third 100 hour inspection (300 hours) or 12 months:

Chapter 18 1. Dynamically balance tail rotor.

2. Torque check nuts on tail rotor blade retention bolts.

3. Torque check tail rotor hub retaining nut.

Chapter 65 TAIL ROTOR GEARBOX

1. Inspect chip detector for debris. If metallic particles are

found, determine and correct cause.

2. Clean chip detector.

3. Test chip detector electrical circuit.

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5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 65 TAIL ROTOR DRIVESHAFT

1. Hanger assemblies for cracks at m ounting ea rs, corrosio n,

and security of attachment.

2. Hanger supports for condition and security of attachment.

3. Driveshaft sections and attaching hardware for condition

and security.

4. S/N 33001 through 36019 not modified by
412-570-001-103 or Pre BHT-412-SI-74 (412SP to 412HP
Upgrade) check:

a. Condition of clamps for tail rotor driveshaft coupling to

gearbox couplings (90

b. Inspect clamps for cracks in or near the bolt hole lugs.

5. For helicopters S/N 36020 through 36999, S/N 37002

through 37999, S/N 38001 through 38999, S/N 39101 through
39999, and helicopters modified by 412-570-001-103 or Post
BHT-412-SI-74 (412SP to 412HP Upgrade), check disc pack
couplings and attaching hardware for condition and security.

 apart).

INITIAL

MECH OTHER

Chapter 65 INTERMEDIATE GEARBOX

1. Inspect chip detector for debris. If metallic particles are

found, determine and correct cause.

2. Clean chip detector.

3. Test chip detector electrical circuit.

Chapter 67 FLIGHT CONTROLS

1. Inspect all control tube assemblies for clearance, security,

and general condition.

2. Inspect tube bellcranks, supports, and attaching hardware
for corrosion, security, wear , and damage.

3. Collective and cyclic flight control actuators, check:

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5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

a. Universal bearings for looseness.

b. Input lever bearings and bolts for wear and looseness.

c. Fasteners attaching cylinder lower supports to structure

for looseness.

d. Cylinder lower bearings for looseness.

e. Actuator assemblies for condition, leakage, and

security.

f. Cylinder extension tubes for condition and security.

g. Upper cylinder housing mounting bracket for condition

and security. Check mounting bracket cavity for corrosion.
Cavity drain hole for obstruction. Dust boot for condition.
Reapply corrosion preventive compound (C-104) as required.

h. Actuator linkage for wear and security.

INITIAL

MECH OTHER

i. Clean exposed area of actuator piston with hydraulic

fluid (C-002) or hydraulic fluid (C-072) and lint-free cloth.

j. Check cyclic and collective hydraulic cylinders’ piston
rods for evidence of excessive wear and scoring. Wear of the
piston rods indicates cylinder assembly is incorrectly aligned to
lower supports and requires adjustment.

4. Antitorque controls check:

a. Inspect tail rotor control tubes, bellcranks, supports, and

attaching hardware between tail rotor pedals and tail rotor
gearbox for corrosion, wear, and damage.

b. Inspect tail rotor hydraulic actuator for leaks, security of
attachment, damage, corrosion, wear, bearings, and linkages
for looseness.

Every third 100 hour inspection (300 hours) or 12 months:

1. Collective and cyclic flight control actuators:

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CAUTION

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

a. Torque check nuts attaching actuator cylinder to upper

supports.

b. Remove bolts attaching actuator to lower supports.
Check cylinder alignment to lower support. Rod end bearing
side loads are not permitted. Reinstall bolts.

2. Aerodynamically actuated elevator check:

a. Inspect elevator control tube between forward support

bracket and elevator horn for corrosion, wear, and damage.

b. Inspect elevator control tube support and attaching
hardware for security, corrosion, wear, and damage .

c. Inspect elevators and support structure for loose or
missing rivets, cracks in skin, and corrosion.

d. Inspect trailing edge tabs and tip caps for condition and
security.

INITIAL

MECH OTHER

e. Functionally check operation of control tube as follows:

DO NOT RELEASE ELEVATOR AND ALLOW THE
SPRING TO DRIVE ELEVATOR BACK TO
ORIGINAL POSITION.

(1) Move elevator to extreme nose down position and
while holding allow to slowly return to original position. Failure to
return to original position, binding and/or lock-up are not
acceptable.

(2) If any of these conditions exist, replace tube.

f. Remove elevator control and measure spring breakout

force for 90 to 100 pounds (400.34 to 444.80 N).

g. Functionally check elevator rigging for proper travel.
Measure trailing edge for 16
surface of elevator.

 1/4 angle down from upper

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SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Every sixth 100 hour inspection (600 hours) or 12 months:

1. Inspect collective flight controls:

a. Flight control systems bellcrank and control tubes for

damage, chafing, corrosion, and security of attachment.

b. Friction shoes and liners for condition.

c. Check collective lever friction adjuster for operation.

d. Check for proper collective minimum fric tio n.

e. Check collective flight controls for smooth movement

throughout full range of travel.

2. Inspect flight controls:

a. Flight control systems bellcrank and control tubes for

damage, chafing, corrosion, and security of attachment.

INITIAL

MECH OTHER

b. Check cyclic stick friction adjuster for proper operation.

c. Check for proper cyclic minimum friction.

d. Check cyclic flight controls for smooth movement

throughout full range of travel.

3. Inspect anti-torque flight controls:

a. Flight control systems bellcrank and control tubes for

damage, chafing, corrosion, and security of attachment.

b. Check anti-torque friction adjuster for proper friction.

c. Check anti-torque flight controls for smooth movement

throughout full range of travel.

4. Aerodynamically actuated elevator:

a. Remove left and right elevators.

b. Clean elevator spars and inspect fo r cor ro sio n.

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BHT-412-MM-2

NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

c. Clean internal bore of elevator horn and inspect for

corrosion.

d. With elevator control removed, attach a spring scale to
hole in arm of horn where control tube is normally installed. Pull
scale at right angle to arm, verify friction is 26 to 32 pounds
(115.65 to 142.34 N). If friction is not within limits, adjust shim
thickness.

e. Install left and right elevators.

Chapter 71 POWER PLANT

Every third 100 hour inspection (300 hours) or 12 months:

Refer to the applicable Pratt & Whitney Canada
Engine Maintenance Manual for engine inspection
requirements.

INITIAL

MECH OTHER

1. No. 1 (left) engine power section:

a. Chip detectors for debris.

b. Clean chip detectors.

c. Test chip detector electrical circuits.

2. No. 2 (right) engine power section:

a. Chip detectors for debris.

b. Clean chip detectors.

c. Test chip detector electrical circuits.

3. Reduction (combining) gearbox:

a. Chip detectors for debris.

b. Clean chip detectors.

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NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

c. Test chip detector electrical circuits.

4. Engine electrical connections:

a. Power section 1 ignition leads for corrosion, chafing,

and security.

b. Power section 2 ignition leads for corrosion, chafing,

and security.

5. Starter generator:

a. Power section 1 starter generator brushes allowable

wear.

b. Power section 2 starter generator brushes allowable

wear.

c. Power section 1 starter generator cooling ducts for

obstruction, kinking, and security.

INITIAL

MECH OTHER

d. Power section 2 starter generator cooling ducts for

obstruction, kinking, and security.

6. Engine fire detection system elements for condition and
security.

If applicable, refer to BHT -412-SI-87 fo r installation of
adjustable seals or refer to Chapter 71 for seal
adjustment.

Chapter 71
ASB 412-10-140

Chapter 76 ENGINE CONTROLS

7. Inspect the left-hand and right-hand engine air inlet
cowlings for gaps between the lower surface of the cowling
firewall and the mating horizontal engine firewall.

1. Check controls for smooth movement through full range of
travel.

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BHT-412-MM-2

NOTE

NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Every third 100 hour inspection (300 hours) or 12 months:

1. Inspect engine fuel and power controls:

a. Engine control linkages for looseness, lost motion,

chafing, damage, and security of attachment.

b. Bellcranks, mounts, and jackshafts for looseness,
damage, and security of attachment.

Every sixth 100 hour inspection (600 hours) or 12 months:

Maximum NG topping check is not applicable to Pratt
& Whitney PT6T-9 engine.

Pratt & Whitney
Canada PT6T-3
Series Maintenance
Manual

1. Perform maximum N

topping check.

G

INITIAL

MECH OTHER

Chapter 96 ELECTRICAL SYSTEM

1. Check inverters for security of mounting and connections.

2. Check generator control units for damage and security of

mounting and terminals.

3. Inspect all exposed wire bundles, bundle supports, and
connectors for damage, corrosion, and security. Pay particular
attention to engine deck connectors and harnesses.

4. Inspect relays and main bus area for security of mounting
and connections.

5. Inspect bus insulation for damage and condition.

Chapter 95 INSTRUMENT SYSTEMS

Following checks are required every 12 months only.

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NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

1. Calibrate pilot, copilot compass systems, and standby

magnetic compass.

2. Drain pitot-static system of any accumulated moisture.

3. Test pitot-static system for leaks.

Chapter 96 BATTERY SYSTEM

1. Service battery in accordance with battery manufacturer’s

recommendation.

2. Inspect battery compartment for general condition.

3. Check battery mount for security and corrosion.

4. Perform functional test of battery temperature sensor

caution light.

Chapter 96 EMERGENCY BUS AND POWER DIODES

INITIAL

MECH OTHER

Every third 100 hour inspection (300 hours) or every
12 months:

1. Perform operational check of emergency bus system as

follows:

Helicopters S/N 33001 through 33107, except those
modified for CAA, remove screw, spa cer, and washer
installed in the emergency load switch guard.

a. Inspect EMERG BUS INTC circuit breaker for wear.
Operate circuit breaker manually and check by feel. Worn or
loose circuit breaker is not acceptable. Close circuit breaker.

b. Place all switches in OFF or NORM position and close
all circuit breakers.

c. Connect battery.

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BHT-412-MM-2

NOTE

SCHEDULED INSPECTIONS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

d. Place BATTERY BUS 1 switch and BATTERY BUS 2

switch in the ON position. Position INV 1 and INV 2 switches in
the ON position. Caution panel INVERTER 1 and INVERTER 2
segments should not be illuminated.

e. Check emergency bus power by p ressing the FIRE EXT
PRESS TO TEST button momentarily. Observe both FIRE
PULL handle warning lights illuminate.

f. Position emergency bus switch to EMERG LOAD
position. Check emergency bus power by pressing the FIRE
EXT PRESS TO TEST button momentarily. Observe both FIRE
PULL handles illuminate. Verify INVERTER 1 and INVERTER 2
segments are illuminated on the caution panel.

S/N 33108 through 33213 and 36001 through 36999
— Check INVERTER 1 light segment on the caution
panel is not illuminated and INVERTER 2 segment is
illuminated.

INITIAL

MECH OTHER

g. Position BATTERY BUS 1 and BATTERY BUS 2

switches off. Check emergency bus power by pressing FIRE
EXT PRESS TO TEST button momentarily. Observe FIRE
PULL handles illuminate.

h. Position INVERTER 1 and INVERTER 2 switches OFF.
Position emergency bus switch to NORMAL. Disconnect
battery.

2. Install screw, spacer, and washer in the emergency load
switch guard if removed.

3. Perform functional check of power diodes.

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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-7. 1000 HOUR INSPECTION — PART A

DATE: __________________W.O. _____________________

FACILITY: __________________________________________

HELICOPTER S/N: ___________________________________

REGISTRY NO.: _____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:________________________________________

NOTE

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

For helicopters on the Part A inspection program,
accomplish each 1000 hours of flight operation.

GENERAL

INITIAL

MECH OTHER

1. Each listed inspection item or maintena nce function is to

be performed in accordance with the BHT-412-MM chapter
specified or the BHT-412-CR&O.

2. Record all work accomplished during inspection in the
helicopter maintenance record.

3. Accomplish complete 100 Hour/12 Month Inspection —
Part A.

Chapter 62 SWASHPLATE AND SUPPORT ASSEMBLY — HUB AND

SLEEVE ASSEMBL Y

1. Disconnect drive and swashplate links from swashplate

outer ring, and drive plate set from hub assembly.

2. Disconnect pitch links from main rotor hub pitch horns.

3. Check swashplate duplex bearing and collective sleeve

hub bearing set for roughness and ease of rotation.

4. Purge lubricate bearings.

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BHT-412-MM-2

SCHEDULED INSPECTIONS

5-7. 1000 HOUR INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

5. Reconnect drive and swashplate links and tubes, and

drive plate set to hub assembly.

INITIAL

MECH OTHER

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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A

DATE: __________________W.O. _____________________

FACILITY: __________________________________________

HELICOPTER S/N: ___________________________________

REGISTRY NO.: _____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:________________________________________

NOTE

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

For helicopters on the Part A inspection program,
accomplish each 5000 hours flight time or
60 months, whichever comes first.

This inspection is meant to be a full visual inspection
of the airframe primarily for environmental damage
and corrosion.

INITIAL

MECH OTHER

GENERAL

Each listed inspection item or maintenance function is to be
performed in accordance with the BHT-412-MM chapter
specified or the BHT-412-CR&O.

PRELIMINARY REQUIREMENTS

1. All work accomplished during this inspection shall be

recorded in the helicopter maintenance records.

2. Remove all panels, interior coverings, fairings, and
cowlings required to satisfactorily carry out the inspection.

3. Remove the following items:

a. Main ba tt er y.

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BHT-412-MM-2

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

b. Electrical and avionics equipment from the nose area,

as required, to allow a full visual inspection of the nose area to
be done.

c. Main rotor transmission.

d. Intermediate gearbox.

e. Tail rotor gearbox.

f. Deleted

g. Tailboom (to allow a full inspection of the aft fuselage

bulkhead and forward tailboom bul kh ea d) .

h. Landing gear assembly (to allow a complete inspection

of the landing gear attachment points and support structure).

4. In addition to the 5000 Hour/5 Year Inspection — Part A
items, carry out the following:

INITIAL

MECH OTHER

a. Complete Daily Inspection — Part A.

b. Complete 100 Hour/12 Month Inspectio n — Par t A.

c. Complete 1000 Hour Inspection — Part A.

AFTER COMPLETION OF INSPECTION

1. Install the following items:

a. Ma in ba tt er y.

b. Electrical and avionics equipment on the nos e area .

c. Main rotor transmission.

d. Intermediate gearbox.

e. Tail rotor gearbox.

f. Deleted

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SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

g. Tailboom.

h. Landing gear assembly.

2. Install all panels, interior coverings, fairings, and cowlings

removed during inspection.

3. Do a ground run and leak check before you return the
helicopter to service.

Chapter 53 FORWARD FUSELAGE

1. Nose panels in area of pitot tube attachment, areas inside
and outside for disbonding and cracking.

2. Pitot tubes attachment for looseness.

3. Nose shelves for damage, corrosion, and disbonding.

4. Nose shelf attachment locations for damage, corrosion,

and cracking.

INITIAL

MECH OTHER

5. Right and left BL 14.00 main beams, forward of STA 23.00

for damage, corrosion, and cracking.

6. Instrument panel attachment structure for damage,
corrosion, and cracking, primarily in the door frame attachment
area.

7. Instrument panel glareshield for chafing and cracking.

8. Crew door hinge attachment structure for damage and

cracks.

9. Outboard cabin post (1, Figure 5-1A), cabin roof longeron
(2), and windshield frame (5) upper corner area for damage
and cracks.

10. Striker plates (3 and 4) attachment areas for dam age and
cracks.

11. Striker plates (3 and 4) for excessive wear, damage, and
corrosion.

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BHT-412-MM-2

NOTE

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

12. Cabin floor area under crew doors for chafing and

damage.

13. Crew door hinges for wear, damage, corrosion, and
security of attachment.

14. Crew doors for proper fit and operation.

15. Crew seat rails for excessive wear and damage.

16. Center and outboard bulkhead, below WL 22.00 at

FS 23.00, for cracks, deformation, and corrosion along
structure joints.

17. Collective and cyclic control jackshafts support
intercostals for cracks and corrosion.

18. Cyclic support for corrosion and cracks.

19. Collective, cyclic, and antitorque control system

bellcranks, levers, and support brackets for corrosion, cracks,
and indication of wear at attaching points.

INITIAL

MECH OTHER

20. Crew seat support beams, at BL 14.00 and 30.00 between

FS 23.00 and 74.30, for cracks and corrosion.

21. Forward crosstube attachment points and support
structure at FS 63.33 and 74.30 for damage, corrosion, and
cracks.

22. Aft crosstube attachment points and support structure at
FS 155.06 and 166.00 for damage, corrosion, and cracks.

23. Crew and passenger cabin floor, FS 23.00 to 155.06, for
corrosion and damage. Floor bonded panels for voids. Seat
fasteners and cargo tie-down rings for condition. Area around
pilot and copilot ICS foot switches for cracks.

In the following step, removal of the fuel cells is not
required unless there is evidence of fuel leakage or
damage to the fuel cells or structure is suspected.

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Export Classification C, ECCN EAR99

NOTE

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

24. All structure under floor panels and in forward fuel cell

cavities including caps, angles, transverse bulkheads, and
bonded panels between FS 74.30 and 155.06 for damage,
corrosion, cracks, and voids.

In the following step, removal of the fuel cells is not
required unless there is evidence of fuel leakage or
damage to the fuel cells or structure is suspected.
Structure that is hidden by the fuel cells on ly needs
to be inspected if the fuel cells are removed for
some reason or structural damage is suspected.

25. All structure under floor panels and in aft fuel cell cavities
including caps, angles, and panels between FS 155.06 and

200.00 for damage, corrosion, cracks, and disbonding.

26. Bottom skin, FS 23.00 to 243.937, for damage. Joints for
corrosion. Access panels and covers for condition and
attachment.

INITIAL

MECH OTHER

27. Main transmission compartment interior, FS 129.00 to

166.00 and WL 7.44 to 76.00, for corrosion. Bulkheads and
main beam panels for damage and corrosion. Attaching
supports and brackets for condition and security.

28. Fluid lines in transmission compartment for evidence of
leaks, condition, wear, and chafing. Clamps for condition (fluid
contamination and swelling) and security of attachment.

29. Lift beam fitting for condition and working rivets, lift link
attachment bolt hole bores for excessive wear, and bushings
for looseness.

30. Pylon (transmission) support structure for wear and
cracks. Pay particular attention to right and left horizontal
supports, forward vertical supports, and aft vertical webs.

31. Aft cabin bulkheads, FS 166.00, for damage, upper aft
flange for cracks, and bulkhead panel for damage and
disbonding.

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15 DEC 2015 Rev. 23 Page 55

BHT-412-MM-2

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

32. Electrical/avionics compartment, FS 166.00 to 243.937,

doors for condition and security. Door frames for cracks and
corrosion. Compartment interior for condition and joints for
corrosion. Skin for damage and cracks.

33. Oil cooler compartment, FS 166.00 to 243.937, doors for
condition and security. Main beam panels and bulkheads for
condition and corrosion.

34. Engine deck below the reduction gearbox, FS 211.00 to

238.00 for damage, cracks, and disbonding.

35. Firewalls, FS 155.06 to 241.22, for damage, cracks,
security of attachment, seals for condition, an d se al a tta ch ment
angles for cracks.

36. Cabin roof, FS 35.00 to 166.00 above WL 68.00, BL 50.00
left and right side, for damaged skin and joints for corrosion,
bonded panels for disbonding and corrosion. Structure above
overhead console (circuit breaker panels) for cracks and
corrosion.

INITIAL

MECH OTHER

37. Cargo door tracks for wear, cracks, and corrosion.

38. Engine and transmission cowlings and fairings for

evidence of chafing, cracks, corrosion, and seals for condition.

39. Bulkhead, FS 241.22, for damage, corrosion, and cracks.
Tailboom attachment fittings for damage, cracks, and loose
fasteners. Tailboom attachment bolt holes for damage and
corrosion.

40. Tailboom attachment bolts for damage, wear, and
corrosion.

Chapter 53 TAILBOOM

1. Bulkhead, BS 17.42, for corrosion and cracks. Fuselage
attachment bolt holes for damage and corrosion.

2. Tailboom and fin driveshaft covers for condition and
attachment.

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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

3. Tailboom and fin external skin for damage, corrosion, and

cracks.

4. Tailboom access panels and covers for condition and
attachment. Tail rotor driveshaft cover hinges for wear.

5. Tailboom baggage compartment door for condition,
attachment, and door handle operation.

6. Tailboom baggage compartment interior for damage,
panels for disbonding, and corrosion. Longerons above roof
panel for corrosion and cracks. Longerons below floor panel for
corrosion and cracks.

7. Tailboom interior bulkheads and stringers for cracks and
corrosion.

8. Intermediate gearbox mount pad for damage, cracks,
fretting, and corrosion.

9. Tail rotor gearbox support fitting assembly for damage,
cracks, fretting, and corrosion. Pay particular attention to
mounting holes and lugs.

INITIAL

MECH OTHER

10. Tailboom exterior bonded panels adjacent to baggage

compartment for damage, delamination, and corrosion.

11. With a borescope or equivalent, inspect interior structure
of vertical fin for cracks, corrosion, fretting, and damage.

12. Control tube fairleads (grommets and guides) for wear and
security of attachment.

Export Classification C, ECCN EAR99

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15 DEC 2015 Rev. 23 Page 56A

BHT-412-MM-2

SCHEDULED INSPECTIONS

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 67
BHT-412-CR&O
BHT-412-SI-44
TB 412-87-60

FLIGHT CONTROLS

1. Disassemble pilot and copilot (if installed) collective

stick(s) to the extent necessary to remove throttle twist grips.

2. Referring to Figure 5-1, visually inspect stick tube for
cracks using a 3X magnifying glass and a bright light. Pay
particular attention to the base of the throttle slots that form the
twist grip stops.

3. If a crack is found, replace stick tube.

4. Reassemble pilot and copilot (if installed) collective

stick(s).

5. Check throttle controls for proper operation.

INITIAL

MECH OTHER

6. Check collective controls for proper operation.

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Export Classification C, ECCN EAR99

BHT-412-MM-2

412_MM_05_0002

UPPER THROTTLE SLOT

STICK TUBE

AREA TO BE INSPECTED

AREA TO BE INSPECTED

LOWER THROTTLE SLOT

Figure 5-1. Collective Stick Tube — Part A

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2 SEP 2014 Rev. 20 Page 56C

BHT-412-MM-2

412_MM_05_0004+

1

3

4

5

2

A

VIEW A

1.

2.

3.

4.

5.

Outboard cabin post
Sticker plate (aft)
Cabin roof longeron
Sticker plate (forward)
Windshield frame

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Page 56D Rev. 20 2 SEP 2014

Figure 5-1A. Cabin Frame Inspection — Part A

Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B

DATE: __________________W.O. _____________________

FACILITY: __________________________________________

HELICOPTER S/N: ___________________________________

REGISTRY NO.: _____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:________________________________________

NOTE

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

For helicopters on the Part B inspection program,
accomplish the following checks each 25 hours of
flight operation or 30 days, whichever occurs first.

GENERAL

INITIAL

MECH OTHER

1. Each listed inspection item or maintena nce function is to

be performed in accordance with the BHT-412-MM chapter
specified or the BHT-412-CR&O.

2. Refer to the applicable Pratt & Whitney Canada Engine
Maintenance Manual for engine inspection requirements.

PRELIMINARY REQUIREMENTS

Corrosion Control
Guide,
CSSD-PSE-87-001.

Chapter 4 2. Replace all finite life components that have completed

Chapter 5 3. Overhaul all components that have completed published

Chapter 12 4. Lubricate and service helicopter as required.

Export Classification C, ECCN EAR99

1. Use medium helicopter corrosion control guide to

establish helicopter corrosion control program.

published operating limitations.

overhaul periods.

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BHT-412-MM-2

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 5 5. Review Special Inspections and carry out applicable

inspections.

6. Examine all inspection windows and sight glasses for
cracking, crazing, and discoloration. If any of these conditions
are present, the part must be removed and replaced prior to
returning helicopter for service.

Service Instruction
(SI)

Chapter 95 1. Pitot tubes and static ports for visible obstruction and

Chapter 52 2. Nose doors for damage, corrosion, security of attachment,

Chapter 53 3. Fuselage:

7. Ensure all required inspections of installed BHT kits not
covered in this inspection have been performed, as applicable.

FUSELAGE — NOSE SECTION

damage.

and for missing or damaged twist fasteners, seal for condition.

INITIAL

MECH OTHER

a. Forw ard fuselage area structure an d skin for damage,

corrosion, cleanliness, and damage to protective finish.

b. Avionics and electrical compartment for water

entrapment.

Chapter 96 4. Bat tery installation:

a. Battery and external connections for security,

corrosion, and condition.

b. Battery vent and drain tubes — unobstructed.

c. Every fourth 25 hour/30 Day Inspection (100 hours),

check battery mounts for corrosion and service battery in
accordance with battery manufacturers recommendation.

Chapter 96 5. Electrical equipment for condition, corrosion, and security.

Chapter 97 6. Avionics equipment for condition and security.

Chapter 52 7. All windows for damage and cleanliness.

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SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 30 8. Windshield wiper arms and blades for serviceability and

security.

Chapter 29 9. Remote hydraulic filter bypass indicator-check for bypass

indication.

Chapter 97 10. Antennas for condition and security.

Chapter 52 11. Crew doors (and surrounding structure) for damage,

corrosion, and proper operation, emergency release pins for
security.

FUSELAGE — CABIN SECTION

Chapter 53 1. Fuselage structure and compartments for condition,

corrosion, water entrapment, and damage to protective finish.

Chapter 53 2. Fuselage underside for evidence of fuel and hydraulic fluid

leakage.

Chapter 28 3. Visually inspect fuel samples for contamination.

INITIAL

MECH OTHER

Chapter 32 4. Landing gear:

a. Forward crosstube and cap fittings for condition,

corrosion, and security of attachment.

b. Aft crosstube, cap fittings, and wear strips for condition,

corrosion, and security of attachment.

c. Aft crosstube support beam for wear, cracks, damage,

corrosion, and security of attachment.

d. Skid tubes and skid shoes for condition, corrosion, and
security of attachment. Replace skid shoes that are worn into
shoe surface. Repair weld beads as requir ed.

e. Fuselage supports for wear, damage, and security of
attachment.

f. Deleted.

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BHT-412-MM-2

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

g. If installed, landing gear forward crosstube crew step

fittings for corrosion, damage, and security in area of
attachment. If edge sealant is damaged or missing, remove
crew step and inspect crosstube for corrosion or damage.

h. Tail skid for deformation and security of attachment.

i. Emergency float reservoir pressure indicator for proper

charge indication (if installed).

j. Floats for proper stowage and condition (if installed).

5. Deleted.

Chapter 97 6. Antennas for damage, cleanliness, and security.

Chapter 52 7. Passenger/cargo doors (and surrounding structure) for

damage, corrosion, and proper operation. Window seals for
condition.

Chapter 25 8. Crew seats:

INITIAL

MECH OTHER

a. Seats for condition, security, and proper operation.

b. Cushions and backs for cleanliness, excessive

deterioration, and tears.

c. Crew seat restraint assemblies for condition, security,

and proper operation.

d. Crew seat attenuator for compression; inspect witness

line. If line is not visible, repair attenuator assembly.

Chapter 25 9. Passenger seats:

a. Seats for condition and security.

b. Cushions and backs for cleanliness, excessive

deterioration, and tears.

c. Passenger seat restraint assemblies for condition,

security, and proper operation.

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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 95 10. Instruments:

a. Instrument panel for cleanliness.

b. All instrument, placards, decals, and markings for

appearance and legibility.

c. Check magnetic compass for condition and security.

d. All compass cards for validity.

Chapter 96
Chapter 97

11. Avionics and electrical equipment:

a. Pedestal mounted avionics/electrical equipment for

condition, cleanliness, and security.

b. Overhead console for condition, cleanliness, and
security.

c. All instrument lights, integrally lit panels, secondary
lights, and map lights for serviceability.

INITIAL

MECH OTHER

d. All caution and warning lights for proper operation by

using master caution, fire test, and baggage compartment
smoke detector press to test functions.

e. Landin g an d se ar ch lights for co nd itio n an d security.

f. Navigation and anti-collision lights for condition and

security.

g. Every fourth 25 Hour/30 Day Inspection, operationally
check cabin heater system, bleed air shutoff, and line check
valve.

Chapter 26 12. Two portable fire extinguishers for condition, mounting,

and valid inspection certificate.

Chapter 21 13. Cabin heating and ventilating system:

a. Ventilating system components for condition and
security.

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WARNING

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

DATA REFERENCE INSPECTION TASK DESCRIPTION

b. Heat/vent air ducts for condition and proper operation.

c. Ventilation/defog components for condition and

security.

Chapter 25 14. Miscellaneous furnishings (map and data case, first aid kit,

and emergency equipment) for condition and security.

Chapter 63 15. Main rotor transmission:

a. Proper oil level.

b. External oil filter for bypass indication.

c. Cases for damage, corrosion, condition, and evidence

of leakage.

d. Accessories for condition, corrosion, damage, and

security of attachment.

e. External oil lines and hoses for condition, damage,
chafing, and leaks, paying particular attention to lines running
aft of the thermostatic relief valve.

INITIAL

MECH OTHER

f. Transmission mount dust boots for condition.

CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.

g. Transmission tail rotor output quill coupling (and
surrounding area) for grease leakage, damage, corrosion, and
evidence of overheat as indicated by TEMP-PLATES or
coupling discoloration. A change in color of one or more of the
red bordered TEMP-PLATE dots from white/off-white to black,
indicates an overheat conditio n, and may require replacement
of both outer and inner couplings (see step h).

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Export Classification C, ECCN EAR99

SCHEDULED INSPECTIONS

5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)

BHT-412-MM-2

DATA REFERENCE INSPECTION TASK DESCRIPTION

h. Overheat TEMP-PLATES for condition and security.

TEMP-PLATES must not show evidence of overtemperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.

Chapter 29 16. Hydraulic systems:

a. Hydraulic system 1 and 2 filter bypass indicator buttons

— not extended.

b. Collective and cyclic servoactuators for leaks,

corrosion, damage, and security.

c. Deleted.

d. Hydraulic system 1 and 2 valve and filter modules for

leaks, damage, and security.

e. Hydraulic system 1 and 2 lines, hoses, and fittings for

leaks, damage, chafing, kinking, and security.

INITIAL

MECH OTHER

17. Flight control tubes for condition, corrosion, and security.

FUSELAGE AFT OF CABIN LEFT AND RIGHT SIDE

Chapter 52 1. Avionics/electrical and heater compartment doors for

condition and security of attachment. Latches for proper
operation.

Chapter 53 2. Fuselage structure:

a. Avionics/electrical and heater compartments for

evidence of water entrapment.

b. Engine decks for condition and evidence of

delamination.

Chapter 96
Chapter 97

Chapter 21 4. Heater compartment for cleanliness, condition, and

3. Avionics and electrical equipment for security and
condition.

security of heating system components, wiring, ducts and
supports. Structure for damage and corrosion (including
connections and fasteners).

Export Classification C, ECCN EAR99

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SCHEDULED INSPECTIONS

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DATA REFERENCE INSPECTION TASK DESCRIPTION

Chapter 29 5. Tail rotor hydraulic actuator and hoses for leakage,

corrosion, and security.

Chapter 67 6. Tail rotor control tubes for condition, corrosion, and

security.

Chapter 63 7. Transmission oil cooling system:

a. Oil coolers for leakage, damage, and obstruction.

b. Oil cooler hoses and tubes for leakage, damage,

chafing, and fraying.

c. Oil cooler blowers for damage, corrosion, and
obstruction.

Chapter 79 8. Engine oil system:

a. Oil coolers for leakage, corrosion, damage, and
obstruction.

INITIAL

MECH OTHER

b. Oil cooler hoses and tubes for leakage, damage,

chafing, and fraying.

c. Reduction gearbox oil filter impending bypass indicator
button — not extended.

d. Power section 1 for proper oil level.

e. Power section 2 for proper oil level.

f. Reduction gearbox for proper oil level.

Chapter 26 9. Engine compartment fire extinguisher containers for

proper charge, condition, and mounting.

Chapter 71 10. Engine and reduction gearbox mounts for loose bearings

and security.

Chapter 71 11. No.1 (left) engine power section:

a. Exhaust ejector and duct for damage and security.

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Export Classification C, ECCN EAR99