Skyranger Nynja Build Manual
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Nynja Build Manual 1.4d
Nynja Build
manual
Version 1.4d
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Nynja Build Manual 1.4d
Figure 1 tube numbering scheme.
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Nynja Build Manual 1.4d
Figure 2 Basic frame (Skyranger).
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Nynja Build Manual 1.4d
Figure 3 uncovered Skyranger frame.
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Nynja Build Manual 1.4d
Figure 4 Uncovered Nynja frame
Figure 5 Nynja fuselage with rear fairings removed
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Nynja Build Manual 1.4d
Figure 6 Nynja fuselage with rear fairings removed – rear view
Figure 7 simply assemble thus!
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Nynja Build Manual 1.4d
Contents
Introduction ............................................................................................................. 10
1.1 How to Build Your Aircraft .................................................................................................... 10
1.2 The BMAA Homebuilt Aircraft System ....................................................................................... 12
1.3 General Assembly Notes ........................................................................................................... 14
1.4 Finish .......................................................................................................................................... 18
1.5 Weight ........................................................................................................................................ 20
2. Forward Fuselage ............................................................................................ 21
2.1 Tube Numbering .................................................................................................................. 21
2.2 Fuselage frame assembly overview ........................................................................................... 23
2.3 Lower Cabin Triangle .................................................................................................................. 25
2.4 Upper Cabin Triangle ................................................................................................................. 30
2.5 Rear Cabin Frame ................................................................................................................ 33
2.6 Rear cabin frame bracing. .................................................................................................... 34
2.7 Engine Supports ................................................................................................................... 37
2.8 Floor ..................................................................................................................................... 46
2.9 Rudder Pedals ..................................................................................................................... 48
2.10 Control Stick Assembly ........................................................................................................ 49
2.11 Finishing the Forward Fuselage ........................................................................................... 52
3 Rear Fuselage .................................................................................................. 54
3.1 Tail End ................................................................................................................................ 54
3.2 Bracing Frame ............................................................................................................................. 56
3.3 Front End.............................................................................................................................. 57
3.4 Fuselage bracing cables ............................................................................................................. 58
3.5 Tailplane Front Mounting ..................................................................................................... 63
3.6 Fuel Tank Support and Flap Handle ........................................................................................... 64
Not Tightening the Bolts and cables! ................................................................................................ 66
4 Undercarriage .................................................................................................. 67
4.1 Wheels ................................................................................................................................. 67
4.2 Main Undercarriage .............................................................................................................. 69
4.3 Nose Gear ................................................................................................................................... 73
4.4 Brakes .................................................................................................................................. 77
5. Tail Surfaces ....................................................................................................... 80
5.1 Tensioning the Rear Fuselage ............................................................................................. 80
5.2 Elevator Trim Tab ................................................................................................................. 81
5.3 Tailplane ...................................................................................................................................... 83
5.4 Rudder .................................................................................................................................. 87
5.5 Control Cables ..................................................................................................................... 90
6 Fitting the Rear Fuselage Fairings ............................................................... 100
6.1 Preparing the rear fuselage fairings ................................................................................... 100
6.2 Fitting the rear fuselage fairings ......................................................................................... 101
7. Engine Installation Rotax 912UL/912ULS .................................................... 105
8. Wings .............................................................................................................. 110
8.1 Wing Frame ........................................................................................................................ 110
8.2 Aileron Horn Assembly ....................................................................................................... 119
8.3 Attaching the Wings to the Fuselage ................................................................................. 121
8.4 Aileron Control Cables ....................................................................................................... 122
8.5 Flaps ................................................................................................................................... 126
8.6 Covering the Wings ............................................................................................................ 128
8.7 Inserting the Battens .......................................................................................................... 135
9. Windscreen Frame and Throttles ................................................................. 138
9.1 Windscreen Frame ............................................................................................................. 138
9.2 Throttles ............................................................................................................................. 143
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10. Floor pan, firewall and cowlings .................................................................. 147
10.1 Floor pan ............................................................................................................................ 147
10.2 Firewall and scuttle moulding ............................................................................................. 150
10.3 Engine cowlings ................................................................................................................. 153
11. Engine Ancillaries ......................................................................................... 158
11.1 CKT twin outlet exhaust fitting ........................................................................................... 158
11.2 Oil cooling ................................................................................................................................ 160
11.3 Water cooling ..................................................................................................................... 164
12 Fuel System ................................................................................................... 167
12.1 Fuel lines and connections ...................................................................................................... 167
12.2 Engine compartment ............................................................................................................... 168
12.3 Fuel Tanks............................................................................................................................... 169
12.4 Fitting instructions for HADS Optional Mod 33 – Large diameter balance pipe between fuel
tanks ................................................................................................................................................ 170
Overview ......................................................................................................................................... 170
Parts: ............................................................................................................................................... 170
Fitting ............................................................................................................................................... 171
12.5 Fuel tank load spreader bars .................................................................................................. 172
12.6 Fuel tank securing straps ........................................................................................................ 172
12.7 Fuel tank connections ........................................................................................................ 173
12.8 Fuel filler .................................................................................................................................. 175
13 Instrument panel .............................................................................................. 176
14 Throttle and Choke cables .............................................................................. 180
15 Instruments .................................................................................................... 184
15.1 Pitot-Static System ............................................................................................................. 184
16 Electrical System ........................................................................................... 186
16.1 Soft start wiring .................................................................................................................. 190
16.2 Wiring General Points ........................................................................................................ 191
16.3 Low Current and Instrument Wiring ................................................................................... 191
16.4 Battery ................................................................................................................................ 193
17 Windscreen and rear windows ..................................................................... 195
17.1 Windscreen ........................................................................................................................ 195
17.2 Rear windows ..................................................................................................................... 202
18 Doors .............................................................................................................. 205
18.1 Keeping out the drafts. ....................................................................................................... 205
18.2 One Piece Door .................................................................................................................. 207
18.3 Two Piece Door .................................................................................................................. 213
19 Tail surfaces again ........................................................................................ 224
19.1 Trimmer system ................................................................................................................. 224
20 Centre console. ............................................................................................. 230
21 Seats and Seatbelts....................................................................................... 234
21.1 Seats .................................................................................................................................. 234
21.2 Seatbelts ............................................................................................................................ 237
22 Wheel Spats – Standard ................................................................................ 238
22.1 Nose Wheel ........................................................................................................................ 238
22.2 Main Wheels ...................................................................................................................... 239
23 Fitting the teardrop spat option. .................................................................. 241
Nose Wheel ..................................................................................................................................... 241
Main Wheel spats ............................................................................................................................ 242
24 Fairings .......................................................................................................... 246
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24.1 Lower Fin Fairing ............................................................................................................... 246
24.2 Upper Fin Fairing ............................................................................................................... 246
24.3 Wing Root Fairings ............................................................................................................. 248
24.4 Cable Exit Fairings ............................................................................................................. 248
24.5 Tailplane Leading Edge Fairings ....................................................................................... 249
24.6 Wingstrut end Fairings (Socks) .......................................................................................... 249
24.7 Wingtip Fairings ................................................................................................................. 250
25 Aerofoil Profile Support Blocks ................................................................... 252
26 Fitting the heater option ............................................................................... 254
27 Fitting the storage side pockets................................................................... 256
28 Preparing for Flight ....................................................................................... 257
28.1 Airframe .............................................................................................................................. 257
28.2 Aerofoil Jury struts ............................................................................................................. 257
28.3 General checks .................................................................................................................. 259
28.4 Baggage Bag ..................................................................................................................... 259
28.5 Controls .............................................................................................................................. 260
28.6 Powerplant ......................................................................................................................... 263
28.7 Weight and Balance ........................................................................................................... 265
28.8 Placards ............................................................................................................................. 266
28.9 Test Flying .......................................................................................................................... 266
27 Additional Information .................................................................................... 268
27.1 Example BMAA Homebuilt Registration Form ........................................................................ 268
27.2 Wire-locking........................................................................................................................ 270
28 Index ................................................................................................................. 274
28 Amendments .................................................................................................. 277
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Introduction
1.1 How to Build Your Aircraft
Building the Nynja is a fairly straightforward process, but it can be made much more
difficult than necessary if one basic rule is not followed:
READ THE INSTRUCTIONS!
Figure 8 A rare sight, but essential for successful building (the manual that is, not Rob)!
The Build Manual
Reading the whole manual before starting is suggested. Reading ahead by at least
the section being worked upon, as each section is reached, is recommended.
Reading the instructions for the components under your spanners is essential! It is
remarkable how often the instructions are over-looked or misread, remembering that
you are going to fly in your finished aircraft!
Instructions, however, are never as good as they could be, and so corrections and
suggestions for improving the instructions are welcome, preferably in writing by
email. These can then be included in future updates of the manuals.
If you have errata or receive updates to the manual, mark these immediately in
your copy of the manual so that you do not forget them when you reach that
stage.
An electronic copy of the build manual is available on request via dropbox, and any
updates will be published there as soon as they are made.
Don’t rush things, work carefully, and don’t forget to enjoy building your aeroplane!
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Nynja Build Manual 1.4d
In case of difficulty
If you cannot find a part, ensure that you have determined what it looks like, and that
it is not already attached to a sub-assembly in the area you are working on. Often
parts are hidden by the packaging, or lurking in the bottom of a box of bits in the
corner of the garage, rather than being missing from the kit.
If you have a problem that you cannot resolve by a careful read of the instructions
with the appropriate parts in front of you please have a look in the Skyranger internet
discussion group, send an email, or if all else fails ring:
01604 494459
Note that most enquiries can be answered by a careful read of the manual, so
do give it some thought before calling.
Email is preferred and more convenient than the telephone, as it makes it simple to
communicate answers to other builders and allows time for a better more researched
reply to your questions. Please use paul@flylight.co.uk
Figure 9 We await your call on the Nynja Hotline! – but consider email please!
Photographs
The manual has lots of drawings and photographs to help you build your aeroplane.
The photographs are chosen to illustrate each point, but often include other areas of
the aeroplane in the background. However, due to the number of modifications made
during the UK certification phase you should be cautious about assuming that
background items are shown as they should be on UK specification aircraft. Many
parts are common to the Skyranger and Skyranger Swift, and these may be shown in
some of the photos and drawings where commonality exists.
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Nynja Build Manual 1.4d
1.2 The BMAA Homebuilt Aircraft System
Before starting the build of your Nynja you must register the project with the BMAA.
The required forms are downloadable from the BMAA website at www.bmaa.org, go
to the Technical Information section, click on Forms, and download form
BMAA/AW/022.
An example form for a Nynja fitted with a Rotax 912ULS and standard Kiev prop 283
is shown towards the end of this manual.
You will have to find a BMAA Inspector to oversee the project. A list of Inspectors is
available from the BMAA if required. Fill in the form with information about your
aircraft and Inspector.
Send this form, along with the certificate of conformance for the aircraft, engine and
propeller, with the current fee to the BMAA.
The BMAA will then register the project and issue you with a project number. They
will send you a pack of paperwork with information about building a BMAA homebuilt,
and a stage inspection form to be completed during the build by yourself and your
Inspector.
Please read all the paperwork that the BMAA send you when you receive it –
this may prevent stress later!
You can also register the aircraft with the CAA and order registration letters
(available from Flylight) to save time later.
Your Inspector is required to visit prior to commencing any real building to inspect
your workshop and the kit. This forms the first stage inspection.
Your Inspector has to sign off several key stages of the build. Get his signature on
the form at the time, just in case! He can be a very useful source of knowledge and
advice, and should be your ‘mentor’ during the build. Also, a second pair of eyes and
an experienced mind can often solve problems for you in an instant.
Inspectors will vary somewhat in their likes and dislikes, and so requirements may
vary from what you may consider to be adequate. It is best to listen to your
inspector’s views, but in case of specific queries either you or your inspector may
contact Flylight or the BMAA directly to discuss matters.
Please respect the stage inspections and do not present him with a fully built aircraft
for the first visit! It is not his fault if you have to undo a lot of building to make right
something that should have been checked in a stage inspection before continuing
further. If there is a delay in having an inspection it is better to get on with building
bits and pieces like wheels and wing frames than to continue adding to the main
assemblies.
When your aircraft is complete and to your Inspector’s satisfaction, the completed
stage inspection form is sent to the BMAA. Also required to be sent at the same time
is the Engine Installation Check Sheet (either the Rotax version or the generic BMAA
version for non-Rotax engines). This details tests required to ensure correct
installation and set up of the engine, such as the fuel-flow test described towards the
end of this manual. Again your inspector has to witness the tests and sign the form.
The BMAA will then process the paperwork and raise a BMAA AW029 giving
permission to test fly, along with a draft MAAN (Microlight Aircraft Approval Note) for
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Nynja Build Manual 1.4d
specific clearance and flight testing of your aircraft. This will require checking and
returning to the BMAA for an authorisation signature to make it valid.
Initially your aircraft must be flown by a BMAA Test Pilot, or a specially authorised
check pilot. He/She will fly the aircraft to the flight test schedule to ensure that your
aircraft is set up and flying as it should. You can accompany them for the flight tests
as observer / secretary. When the aircraft is flying satisfactorily (some trimming /
adjustments may be required), then if you have suitable experience you may fly the
aircraft. 5 hours of flying are required to prove reliability and debug the aircraft,
before an application can be made for a full permit to fly. Whilst waiting for this to
arrive you are normally permitted to fly the aircraft, continuing to obey the restrictions
of the test flying clearance contained in the AW029.
If you are the first with a new engine or propeller type, or have made any major
modifications to your aircraft, then 25 hours of reliability testing are usually required.
If you plan any modifications then it is essential that the BMAA is informed at the
beginning of the project, so that a technical investigation can be made and approval
for you to go ahead can be given.
It is likely that you are keen to begin construction, and are waiting impatiently for the
paperwork and your inspector to allow you to do so. However, this short delay can be
used very productively to familiarise yourself with the instructions and the
components, and prepare them for use.
Modifications
You may desire to install equipment such as a radio, strobes etc.. These will
constitute modifications to the standard aircraft and therefore must be done in
accordance with BMAA procedures. Details of the most common modifications are
included in the TIL’s, and Standard Minor Mods (SMM) available on the BMAA
website ( www.bmaa.org ) . If these are done at the time of construction no additional
modification fees are payable.
For modifications not covered by the TIL’s, or SMM’s, it is probably better to
complete the standard aircraft and commence flying before proceeding with the
modification. This is because non-standard modifications will introduce complexity
and delays into getting you aircraft flying, and so these are best done at leisure when
you already have your aircraft in the air.
Note that the Nynja succeeds in providing a capable aeroplane at an excellent price
by following the principle of simplicity. Some areas may look basic at first glance, but
meet the stringent requirements of BCAR Section S without adding cost and weight.
Any modifications you make must also meet Section S, but it is up to you how much
cost you are willing to bear and where you spend your weight. However, increased
cost and less fuel carrying capacity are difficult to avoid.
Do not begin any modifications without first speaking to your inspector, the
BMAA, or Flylight Airsports.
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1.3 General Assembly Notes
Before starting to assemble anything, read the whole of this manual to get an overall
impression of the order and methods of assembly. The sequence of construction is
the one used to build the importer’s aircraft, and should be adhered to. If you wish to
change the sequence, you may find difficulty in fitting other parts later, so read ahead
carefully to determine the effects of your changes. Flylight Airsports cannot advise
on, nor be responsible for, the consequences of not following the instructions, as if
we have not tried something we cannot comment upon it with any experience.
Unpacking
To familiarise yourself with the kit components it is useful to unpack the kit and sort it
into groups for each assembly stage, such as wing parts, fuselage parts,
undercarriage etc.. Do this in conjunction with the packing list and the instruction
manual to determine that you have all the required parts.
If you cannot find a part, check under the packaging on related assemblies,
and make sure you know what it is that you are looking for, as parts may be
rolled up or transported inside other parts. For instance smaller tubes may be slid
inside larger ones.
Don’t forget to check all the boxes, in case you’ve put a box aside somewhere. Some
small parts may be hidden within packaging foam ‘snow’ in the bottom of boxes, so
don’t throw any boxes or packaging away until you have ascertained for certain that
you have all the parts – we have stories of unloading skips to retrieve parts that have
gone with the rubbish!
We also pack some parts in the engine box – so remember to look in there.
This may all sound obvious, but we know from past experience that even big parts
like propellers can be thought missing when they are there all the time!
Don’t try and remove the glassfibre parts from the big wood box without first
removing at least one of the metal side rails on the box – or the gap will be too
small and you will flex and crack the big side panels!
Initial assembly with non locking nuts
During initial assembly it may be helpful to use wing nuts or normal nuts (wing nuts
are preferred as they are more obvious and less likely to be forgotton!) rather than
Nyloc nuts for test fitting pieces, or on pieces which need to be removed later to fit
the coverings or other parts. Alternatively, only tighten the Nyloc nuts up to the Nyloc
section until ready to apply threadlock and tighten properly.
Assembly
If in doubt about a part, or an assembly, read ahead and pay particular attention to
drawings and photographs. Note that the direction of bolts (up/down, pointing
forwards/backwards) may differ between drawings and photographs. Normally, the
bolts will be inserted from the top or the front, unless other considerations apply,
such as coverings or access.
Remember to replace any non locking nuts with Nyloc nuts before final assembly,
and also:
REMEMBER TO USE LOCTITE 243 ON ALL NUTS.
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Nynja Build Manual 1.4d
This is usually available from your local fastenings company, look them up in the
Yellow Pages under “Fixings and Fasteners”, and you will never be stuck for nuts
and bolts again!
Loctite should be used very sparingly. A common mistake is to overuse it. Loctite
smeared over the outside of fasteners acts as a corrosive agent. Any surplus should
be immediately removed with a soft cloth.
A good tip is to paint a red stripe across the nut and bolt end after final tightening.
This way it will be easy to inspect and spot any nuts not finally tightened.
Main tools needed for assembly
Spanners and sockets in the range of: 6, 8, 10, 12, 13, 14, 17mm
Allen keys: 4, 6, 8mm
Metal saw
Drill and bits for metal
Rivet pliers
Cutting pliers
General pliers
Screwdrivers, flat and cross-head
Hammers, metal and rubber/plastic
Mouse tail file with diameter less than 6mm
Flat file
Engineers Rule
Tape measure
6mm reamer (desirable)
Wire-locking pliers (desirable)
Cleco’s or Skin pins for 4mm holes
Dremel Multi tool or equivalent small cutting / sanding tool
Soft faced clamps
Rivnut installation tool and 4 and 5mm Rivnuts (these can be really useful to make a
tidier alternative to nuts or captive nuts on things like instrument panel fixings)
Products needed for assembly
Loctite 243, to be used on all bolts
Silicon grease
Oil for general use
Oil for engine and gearbox, see engine documents
Epoxy adhesive (Araldite or similar)
Lock-wire
Holes
All the holes have been drilled to a high accuracy, however it may sometimes be
necessary to use a round file or reamer to ease the insertion of some bolts. Be
careful not to make a hole too large however, sometimes all that is required is to
loosen other bolts nearby, or to apply pressure to some other part. Generally bolts
should not be tightened up until all the parts in a particular sub-assembly are
assembled, to avoid the common problem of the final bolt not fitting!
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Washers
Metal washers should be used to prevent scratching of the surface as a nut is
tightened.
Nylon washers, or similar plastic washers, should be used to:
a) fill spaces between parts, such as between tubes and U-brackets
b) avoid friction between two moving metal parts, such as the stick and its
supporting bracket
c) avoid contact between parts of different materials, especially stainless-steel
and aluminium
The final point above is primarily to prevent the hard steel wearing through the soft
aluminium due to vibration, rather than for electrolytic reasons, as the bolt passing
through both materials will still complete the electrical connection.
Saddle washers
Normally they are shown on the drawings and photos.
Generally they are used between two crossed tubes or between a tube and a flat
bracket.
Take care not to overtighten bolts which pass through plastic saddle washers as you
may cause them to split.
Nuts and washers
Standard nuts and washers in the main kit are metric zinc plated steel. An acceptable
alternative is to use A2 stainless nuts and washers. These can be purchased from a
fastener supplier for relatively low cost and provide protection form corrosion. Note
that bolts supplied are a mix of 8.8, 10.9 and 12.9 and Eastern European Mil spec
and some smaller bolts are stainless steel. These may NOT be changed for other
specification or to stainless steel as strength, malleability and dissimilar metal
corrosion can be problems.
Bolts
Generally all bolts should bear on their unthreaded lengths, not on the threaded
portions.
It is also important that nuts are not screwed on so far as to become ‘threadbound’
by reaching the limit of the threaded portion. You can use an extra washer or two to
adjust the effective length and prevent this where required.
Turn nuts, not bolts whenever possible, when tightening, as this may damage the
plating and encourage corrosion. Washers are only needed under nuts to allow them
to be turned, whereas bolt heads should not be turned.
Do not over-tighten bolts, avoid deformation of tubes or brackets.
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IMPORTANT: tubes must not be visibly deformed.
Figure 10 Left - WRONG – squashed tube, thread in tube. Right – RIGHT – tube still round,
thread stops in washer(s).
Every wing nut has to be fastened by a security ring or aviation ‘nappy pin’.
Nyloc nuts should be used only once.
When cutting bolts short, a minimum of two threads should protrude from the nut.
Paint the cut end to prevent rusting.
Bolts subject to rotation should be drilled and locked with a split pin. Examples
include stick pivot bolt, torque-tube pivot bolt, rudder link bolts.
Wire-locking
Certain parts require securing with lock-wire, such as engine bolts and turnbuckles. If
you have not done this before, discuss how to do it with your inspector. A basic guide
to wire-locking bolts and turnbuckles is included at the end of this manual.
Stainless-steel parts
A number of tubes have flattened steel end-fittings which may require slight “tweaks”
to align them as required. This should be done carefully in a vice, with wooden jaw
pieces to protect the surfaces.
Avoid bending the parts back and forth repeatedly, and avoid bending them at
the hole position.
The finish on the stainless-steel parts is quite varied. If desired these parts can be
polished to a shiny finish, although those positioned in the pilot’s line of sight may be
covered in anti-reflection black coatings or plastic sleeving if desired. Scotchbrite
pads can be used to provide a pleasing, even, cosmetic finish.
Coverings
Handle the coverings with care, pay attention to the risk of bolt heads, corners and
reinforcements/stiffeners damaging the covering as it is put on.
Dacron coverings need care to avoid getting dirty and becoming stained. Keep your
hands and tools clean and oil-free when working with or near these coverings.
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You can remove most dirty marks on Dacron with a sponge soaked with tepid water
and a mild detergent, followed by rinsing using only tepid water.
Part numbering
Numbers in bold italics refer to a part number, either as shown on the relevant
drawing or a universal part number with a prefix. Prefixes refer to the following:
tu tube
tual aluminium tube
tuac steel (acier in French) tube
u U-bracket
ual aluminium U-bracket
me metal plate piece
meal aluminium metal plate piece
meac steel (acier) metal plate piece
ca cable, wire rope
The material-type part of the number is not always used.
During assembly follow the drawings and photographs corresponding to the text.
Drilling and cutting
When drilling holes or cutting parts be very careful to measure and mark the correct
positions. Check these a second time before proceeding to cut or drill.
The old adage of measure twice, cut once still applies!
Otherwise, you won’t be the first to ring up to order a new bit, having chopped
something too short!
If you find a part which you think is wrong, in terms of size etc., be very sure that this
is so before cutting or drilling etc. to correct the problem. For instance, over-long
bolts may have extra parts to be fitted later. Leave irreversible actions until the end of
the build!
When drilling holes in metal, use a centre punch to prevent the drill wandering, and
start with a small pilot drill working up to the required hole size.
It can be useful to use masking tape on fibreglass gel surfaces to help prevent
cracking, and to reduce the risk of marking the surface if the drill should slip.
1.4 Finish
All Aluminium parts are supplied anodised or powder coated. Do not be alarmed if
some marks are present in the finish of the tubular parts, this is a result of the
suspension method at the anodising plant. You may also notice areas on tubing that
may appear to have fine sanding marks. This is done prior to the anodising process
to polish out any small scratches. It is also not unusual to find small areas of silver
paint applied at the final stage over any small remaining marks prior to leaving the
factory. Some light scuff marks may be present as a result of storage and transit.
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Nynja Build Manual 1.4d
This is normal. Deep scratches or dents are not acceptable – ask you inspector for
advice, and refer the problem to the importer.
Aluminium plate parts may be painted to improve their cosmetic appearance if
desired. Use a Scotchbrite pad or lightly sand with fine wet and dry before using a
suitable aluminium primer and top coat. Ensure that all painting operations result in a
thin covering that will not hide defects from inspection.
Steel components are all supplied plated and / or powder coated, for corrosion
resistance. Again they may be painted for extra protection or cosmetic reasons if
desired.
Further protection from corrosion can be beneficial for longevity, and to resist the
ravages of operation near the sea or storage in damp hangars. Aluminium and steel
parts can be treated with corrosion protection products such as the excellent ACF50.
This should be squirted in all tube ends and around fittings and applied to the outside
with a soft cloth. An initial thorough application before covering is recommended
(don’t do this if you have Dacron covers that you intend to paint), followed by periodic
repeat application.
‘Wax oil’ or similar propriety products may also be used inside tubes and around
fittings.
Glassfibre fairing parts are supplied in a white finish. This can be polished with T cut
or similar to a high sheen. Alternatively they can be painted, but avoid using dark
colours on the rear fuselage fairings as strong sun can generate high temperatures
that will soften the glass fibre. None of the fairings carry structural loads so this does
not have any safety implications, but this may result in cosmetic damage in the form
of permanent distortion / waves in the fairings.
Self adhesive vinyl graphics may be applied, but again avoid large areas of dark
colour.
Dacron coverings may be lacquered with a special process using Automotive
Polyester or Acrylic Lacquer mixed with a flex agent. Refer to the importer for more
information. Advantages are stronger colours and a sealed shiny finish which allows
oil etc to be wiped off without leaving marks. Disadvantages include extra weight and
the loss of the ability for the coverings to be re-used in the event of removal for
damage repair.
Xlam coverings can be decorated with Vinyl graphics. Take care to degrease the
surfaces prior to application and use good quality Vinyl with good adhesive
properties. Application in low temperatures is to be avoided, and some work with a
heat gun and application of pressure will be required to work the Vinyl into the weave
and stitching to ensure good long term adhesion. Seek specific advice before
application.
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1.5 Weight
The UK prototype Nynja with Xlam coverings, Rotax 912ULS and standard ‘console’
dash, basic analogue instrument fit, installed intercom box, aerial and radio, and
including doors (see note below***), has been found to have a basic empty reference
weight of approximately 258kg. Options such as, wheel spats, spinner, thick carpet,
etc will have a weight penalty. Painting metal parts, cowlings and applying lacquer to
Dacron coverings will have a weight penalty. Additional avionics or strobes are also
surprisingly heavy.
It may be necessary to make choices in these options to ensure that the weight
remains inside the maximum permitted Zero Fuel weight (ZFW) for the aircraft. The
ZFW will vary according to the fuel burn of the chosen engine option. Max ZFW for
the 912ULS engine Nynja is 268Kg
Refer to the Homebuilt Aircraft Data Sheet (HADS) or the BMAA for further
information on the rules regarding weight for this class of aircraft.
Below is an approximate guide to the weight of specific options:
Wheel spat kit + 4.0Kg
Nynja wingtip fairings + 2.0Kg
Skyranger wing tip fairings (alternative to above) +1.5Kg
Carb heat (912 engines) +0.7Kg
Heater option + 1.0Kg
Spinner +0.5Kg
912UL engine - 1.5Kg
Slipper Clutch on 912/912ULS gearbox +1.5Kg
Large starter motor on 912 / 912ULS +0.5Kg
****Items that are non essential for flight and are easily removable may be eligible for
non inclusion in the ZFW calculation and be considered as payload. These items
may include:
Baggage hammock 1.5Kg
Doors 5.5Kg
Other items may be eligible – See latest version Of HADS or refer to BMAA.
If a total aircraft parachute recovery system is fitted, then the max permitted MTOW
rises to 472.5Kg and Max ZFW also rises 22.5Kg to 290.5Kg. These systems can
typically be installed for around 12 - 15kg, allowing the remainder of the allowance to
be used for payload, or additional fixed items.
Weight is surprisingly cumulative and dividends will be gained by ‘thinking light’
during every stage of the build. The benefits of an aircraft kept well under the
maximum permitted weight will be better performance and payload capacity.
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Nynja Build Manual 1.4d
2. Forward Fuselage
Note: During assembly of the fuselage, hand tighten the bolts only as far as the
Nyloc section. After the fuselage is complete and you are sure it is correct, you
can go back and tighten all of the nuts.
If you wish plain nuts, or even better wing nuts, can be used in the initial construction,
to be replaced with Nylocs when the time comes to tighten the nuts up. However,
note that it is often beneficial to have the nuts loose anyway, to ease any alignment
difficulties.
2.1 Tube Numbering
Refer to these drawings for tube numbers throughout the forward fuselage assembly
sequence.
Figure 11 cabin lower and upper triangle tube numbering.
Figure 12 cabin viewed from port side, and rear cabin frame viewed from rear.
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Nynja Build Manual 1.4d
Figure 13 forward fuselage from front quarter.
Figure 14 Cabin upper rear corner
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Nynja Build Manual 1.4d
2.2 Fuselage frame assembly overview
Lower triangle assembly Attaching TU14
Upper triangle assembly Attaching upper triangle to TU14
Attaching rear cabin uprights TU6 Attaching Upper triangle to uprights
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Nynja Build Manual 1.4d
Cabin diagonals TU27 attached Twin TU19 tubes in position
Front seat support TU15 and braces Forward engine mount assembly fitted
Assembling tailcone Tailcone fitted to cabin
Figures 15 – assembly overview
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Nynja Build Manual 1.4d
2.3 Lower Cabin Triangle
2.3.1 Orienting the main undercarriage cross-beam tu9.
The main undercarriage cross-beam tu9 is made of steel.
Flip the beam over until satisfied that the holes are in the correct positions.
The holes in the steel main undercarriage cross-beam tu9 are drilled at
an angle through the beam so that the tail section of the fuselage,
which attaches to the third set of holes in from the ends, tilts upwards
from the beam whilst the lift-strut attachment bolts, nearest the ends,
remain horizontal.
Figure 16 Tu9 (The big white tube), looking from above, front of aircraft to left
2.3.2 Fitting the sides of the lower cabin triangle to the main
undercarriage cross-beam.
a) Assemble the aluminium linking plates 9 onto the pair of lower cabin triangle
tubes tu12, including the seat support brackets (Figure17)
The linking plates are drilled with three 6mm holes, not at equal
intervals. The centre hole is offset away from the single mounting hole.
Remember the anti-crush spacers on the bolts (inside the tubes).
The middle bolts have the seat support bracket, an L-shaped piece, on
their upper ends, with the upstanding part of the bracket in front of the
bolt. A piece of fuel tube may be slit to fit over the support, and secured
with silicone sealant, to make a better rest for the seat base later.
The bolts should pass from bottom to top (contrary to the drawing, but
as per the photographs), to clear the undercarriage legs later.
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Nynja Build Manual 1.4d
11,,,SKR.254
Figure 17 lower cabin triangle, rear of tube tu12 (note, find SKR254 in assembly bag A9)
b) Assemble the pair of lower cabin triangle tubes tu12 to the main undercarriage
cross-beam tu9 using the fourth set of holes inwards from the ends of tu9.
The front ends of the lower cabin triangle tubes tu12 should have the
cut-outs on the inside, visible in Figure 19.
Bolt spacers are not needed in the steel undercarriage tube.
The bolts should pass upwards, to clear the undercarriage legs later.
Figure 18 starboard end of tu9, looking from front.
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Nynja Build Manual 1.4d
2.3.3 Fitting the front vertical to the lower cabin triangle.
Figure 19 forward ends of the lower cabin triangle viewed from below and above. Note non-
UKMOD nose leg lower guide.
a) Fix the lower guide SKR90 for the nose-leg to the lower part of the front
vertical tu14, between the two U-brackets SKR76.
Note these U-brackets are slightly different from those used elsewhere
in the kit, with the holes on the side parts further from the end (16mm
from the end to the hole centre).
The front vertical tu14 has a row of three 6mm holes at its upper end
(amongst others), and a row of three 8mm holes at the lower end.
UKMOD: a spacer tube is used on the U-bracket and nose leg guide
securing bolt as it passes through the front vertical tu14.
UKMOD: The guide SKR90 has additional webs welded onto it top and
bottom, Figure 20
Figure 20 UKMOD nose leg lower guide.
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Nynja Build Manual 1.4d
Figure 21 forward end of lower cabin triangle.
Note: Stud shown
may also be
supplied as a bolt,
and should be fitted
head up.
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Nynja Build Manual 1.4d
b) Apply threadlock to the bolt securing guide SKR90 to the front vertical tu14
and tighten firmly, but take care not to distort or crush the tube.
This should be done at this stage as the bolt holding this bracket is not
easily accessible later.
Whilst the spacer should prevent crushing of the tube, it is better not to
rely on it. It is permissible for the spacer to remain slightly loose, as
under load it will still prevent excessive deformation of the tube.
Do not distort the tube.
c) Mount the U-brackets SKR76 to the lower cabin triangle tubes SKR12
Note the use of a spacer sleeve in the tubes.
The studs should be long end downwards to mount the bottom of the
firewall and the front of the fuselage covering later.Discard the curved
metal washer if fitted – as this is a Skyranger part not used for the
Nynja.
If the bolt thread sticking out of the nut securing the U brackets to the
TU14 fouls the TU12 end file the end of the TU12 to provide clearance
d) Mount the steel diagonal-brace SKR43 to the bottom of the stud through the
port tube. Use thin plastic washers W.FL-1-6-24 and steel washers
SKR456.001
The other end of the brace will be attached to the rudder pedal mounts
later. The brace may be supplied attached to the mounts, have a look
under the packaging.
Thin plastic washers may be used to take up any slack between the
tubes and U-brackets.
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Nynja Build Manual 1.4d
2.4 Upper Cabin Triangle
2.4.1 Fitting the sides of the upper cabin triangle to the upper rear cabin
cross-piece.
Refer to Figure 23 and 24.
a) Fix the aluminium linking-plates SKR60 on the upper rear cabin cross-piece
tube tu7, which links the trailing-edges of the wing.
These linking plates are drilled at one end with an 8mm hole and at the
other with two 6mm holes.
The row of small holes should point forwards, whilst the bolts point
rearwards.
The bolts will be tilted down and backwards compared to the vertical
bolt holes for the cabin upper triangle and tail cone tubes, as the rear
cabin frame is raked backwards.
Figure 22 Port end of the upper rear cabin cross-piece.
Figure 23 upper rear cabin cross-piece.
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