Fox Composites BAe Hawk User manual

Fox Composit s Co., Ltd.
April 2008 version: 1
Fox Composites BAe Hawk

Instruct on Manual for BAe Hawk model a rplane k t
Thank you for purchasing the BA Hawk kit (58"/147cm span) manufactured by Fox Composites.
These instructions are available as a full-colour freely down-loadable Adobe Acrobat .pdf file from
our website (www.fox-composites.com), and also on a CD-Rom in every kit box. In addition, we
have included high resolution versions of all the photos used in the Manual, and some extra pho-
tos showing detailed construction areas, on the CD for your assistance.
We strongly advise that you read this Instruction Manual completely, and make sure you under-
stand all of it, before commencing assembly of the Hawk kit.
Please remember that our Hawk kit is based on the original hand-made plugs from the ducted-fan
version flown since 1983 and, although fully re-engineered for the new full-composite 'turbine' ver-
sion, we are aware that it is not perfectly symmetrical in a few areas. However, these small dis-
crepancies have no affect on the accurate and docile flying characteristics of the plane.
We hope you have much enjoyment and many safe flights with your Hawk, and always welcome
feedback from Customers, and photos of your completed plane. If you have any technical ques-
tions about this product, or require spare parts, please contact us at:
email: [email protected] alternative email: [email protected]
website: http://www.fox-composites.com
address: Fox Composites Co., Ltd. 19/88 Moo 5. Soi 53, Nongprue. Banglamung.
Pattaya. Chonburi 20150. Thailand.
L ab l ty Exclus on
You have acquired a kit which can be assembled into a fully working and flying radio-controlled
model airplane when properly fitted with suitable equipment and accessories, and constructed ac-
cording to the current instructions provided by Fox Composites Co., Ltd. for the kit.
However, as the manufacturers of this kit, Fox Composites Co,. Ltd cannot influence the manner
in which the model is built, fitted out and operated, and we are unable to control the methods and
equipment you use to install, operate and maintain the radio control system components. There-
fore we are obliged to deny all responsibility and liability for any direct, or consequential, injury, loss,
damage or costs involved due to the incorrect or incompetent assembly, use or operation of this
product, or any circumstances connected with it. When operating this product you must assume
all responsibility for any resulting consequences.
Unless otherwise determined by binding law, Fox Composites Co,. Ltd. are excluded from paying
any compensation with regard to operation of our products. The maximum liability of Fox Com-
posites Co., Ltd with regard to this product is limited to the amount that you actually paid for the
kit in all circumstances.
Fox Composites Co.,Ltd are unable to monitor whether you follow our instructions with regard to
assembly, operation & maintenance of the model airplane. Therefore we are not able to guaran-
tee or provide any contractual agreement with the operator or owner of the product that it will func-
tion correctly and safely. The operator of the product must rely on their own judgement in obtaining,
constructing and operating this model airplane.
Fox Composit s Co., Ltd.
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Safety
All model airplanes can provide a potential hazard for personal injury or damage to property if not
operated with care, and assembled and used in accordance with the instructions of the manufac-
turers of all the parts contained within it. It is your responsibility to operate and fly your Hawk in
accordance with all current laws & regulations governing model flying in the country of operation.
Before the first engine run, make sure that the motor, control surfaces, R/C gear and all servos with
their associated linkages are all attached securely. Double-check that heavy items, like batteries,
are attached very securely in the plane and cannot move at all.
Make absolutely sure that the Centre of Gravity is in the position shown at the end of this manual.
Carry out a proper range check with your R/C system, in both motor 'running' and motor 'off' states,
and ensure that the range achieved before fail-safe occurs is at least in accordance with the R/C
manufacturers minimum recommendations.
When starting and running the motor on the ground, make sure that the plane is firmly secured so
that it cannot move and ensure that all spectators are at least 15 metres behind or to the sides, or
far in front of the plane.
Adhes ves
Gluing composite parts together does not require any special types of glue, but due to the high
flight speeds attainable with a jet model it is absolutely necessary to use high quality adhesives
and proper gluing techniques to ensure airframe integrity, and therefore increased safety.
For a strong glue joint it is equally important to use high-quality glue
and to prepare both parts to be joined properly. When joining any com-
bination of fibreglass and wood parts together you must lightly sand
both parts (to provide a mechanical 'key' for the glue) and clean off
the dust caused by sanding before joining them. You can use many
cleaning agents for this, however some of them may damage the 2-
pack polyurethane paint used to colour the parts in the mold. There-
lighter-fluid, such as 'Ronsonol'. This is what we use at the factory,
and it can also be used to wipe uncured glue off painted surfaces, with-
out damaging the paint.
When sanding the inside surface of the foam vacuum-sandwich parts (eg: wings, fins and sta-
bilisers) don’t sand right thru' the lightweight glasscloth on the inner surface, as this will reduce the
rigidity of the parts. Only a light sanding with 120 - 240 grit is necessary, followed by cleaning.
Be careful if using thin CA on foam sandwich components, as it can soak into the foam and ex-
pand as it cures and heats up - causing a blemish (bump) on the outer skin. The use of Activator
(‘Kicker’) increases the chance of this even more!
The fuselage is a fibreglass and epoxy moulding, without a foam sandwich, and we strongly sug-
gest that you sand the complete inside surface of it before starting any assembly - using 180 or
240 grit, or red Scotchbrite pad. This will also remove any loose glass strands that might otherwise
get into your hands! At Fox Composites we only use 1st quality slow (24hr) laminating epoxy
mixed with micro-balloons, ZAP 30 minute epoxy (mixed with micro-balloons) and Hysol 9462
thixotropic epoxy for assembly and important joints, and can highly recommend these types. Micro-
balloons are added to all epoxy mixtures to increase the gap-filling ability, without adding weight.
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Milled fibre is added to epoxy to increase the strength of the adhesive. Do not use any polyester-
based glues under any circumstances, as they will not bond properly to the epoxy parts.
Before starting assembly it is also wise to give the complete outer surface of all the parts at least
2 coats of clear car wax (not silicone-based as very difficult to completely remove) wiped on with
a soft cloth. This usually makes it possible to remove any accidental small spots of glue or finger
marks that get on there during building. Of course you must make sure to remove this wax com-
pletely before doing any painting or adding trim and markings/decals to your model at the finish-
ing stage. Fortunately the wax is easy to remove using 'Ronsonol' lighter fluid, or equivalent.
Take Care
The vacuum-cured foam sandwich construction used for the flying surfaces gives a very light-
weight, but torsionally stiff and strong structure. However it is relatively easy to 'dent' the outer
surface, and so it is necessary to protect the model during assembly by covering your workbench
with soft carpet or foam. Included in the kit are protective foam bags for the complete fuselage,
wings, vertical fin and horizontal stabs - and these should always be used during storage and
transport to protect your plane.
Included n the K t
Shown above is a view of the complete (turbine) kit contents as shipped, except for the CD-Rom
that is also included, with this Instruction manual & additional photos. A full list of kit contents, in-
cluding wood parts and hardware is included at the end of this manual.
‘Turbine’ and ‘ lectric ducted-fan’ kit versions are available, and the differences between the kit
contents are shown at the end of this manual, which describes the assembly of the turbine ver-
sion. All control surfaces are now elastic-hinged for your convenience.
Fox Composites reserve the right to make changes to the kit for reasons of improvement, or pro-
duction reasons, so it is possible that your moulded parts or hardware might not look exactly as
Fox Composit s Co., Ltd.
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shown in the photos in this manual. Therefore, please check our website for any instruction
changes, or important updates, before commencing assembly of your Hawk.
Equ pment and Accessor es
In addition to the kit contents you will need some accessories, R/C, additional equipment and
hardware items to complete your Hawk. The list below can act as a 'Check-list' to remind you of
the main items that will be needed, and our recommendations - based on our own experience, and
that of several respected customers who have been operating our Hawk successfully.
Tu bine: (4.5 - 7kg thrust) and installation kit with CU, mounting strap, fuel pump and so-
lenoid valves etc. (eg: Wren MW44, MW54, PST600, Jetcat P60). This model is designed to op-
erate with turbines up to a maximum of 7kg (16lbs) thrust, and the fitting of a more powerful turbine
could cause excessive speed and structural failure, and consequentially injury or damage to per-
sons or property.
EDF: The fitting of lectric Ducted Fan units is not described in these instructions, as
there are so currently many different systems being tried, but there is a good building thread about
both the turbine and electric versions (by Paul Gray) on the internet at RCUniverse at: www.rcu-
niverse.com/forum/m_5453789/mpage_1/key /tm.htm or just search for “Fox Composites”.
Th ust Tube: You will need to supply a suitable thrust tube for your turbine. A good source of
lightweight, well-designed, thrust tubes is Wren Turbines (www.wren-turbines.com). An alterna-
tive is PST Jets (www.pstjets.com) and their thrust tube is shown in this manual.
Ret acts: The kit was designed around Spring-Air 300 (or 700) series main gears (90 de-
gree) and Spring-Air 100 or 300 series (90 or 100 degree) nose gear but, of course, many other
units of a similar size can be used. Main landing gear units of up to 35mm height can be installed,
with the wire leg and wheel still fitting inside, or flush, with the bottom wing surface. A 100 or 105
degree retracting nosegear (firewall style) also allows you to fit the ‘scale’ forward-retracting nose-
leg, but it is far easier to fit a 90 degree rearward-retracting unit, as described below.
Wheels: We used a Ø 50mm nosewheel (2"). A soft foam type helps to prevent bouncing
during landing. Main wheels should be Ø 56 - 67mm (2.5 - 2.75"). The Robart type main wheel
shown in the photos is Ø 67mm.
Se vos: For the ailerons we recommend that you use 'wing-servos’, with integral side-
mounts - such as the (10.5mm thick) JR DS161 or Hitech 5125MG, or the (15mm thick) JR DS-
3301 or Graupner DS-3328, due to the limited space inside the wing. In any case you should use
digital types with a minimum torque of 4kg.
The flaps are large surfaces on the Hawk, and therefore we highly recommend using standard
sized servos, with a minimum of 5kg torque. Many servos will be adequate for these - for exam-
ple the digital JR/Graupner 5391, 8231 or 8311 shown here.
The horizontal stabilisers are controlled by a single servo mounted in the fuselage, and this should
be a standard sized digital servo with at least 8kg torque. (eg: JR DS8311, DS8411). Fitting the
highest quality unit possible here will reward you with a responsive plane with good centering.
Any mini-servo of minimum 3kg and 15mm thickness (eg: JR 3301, 3401 or Graupner 3328) will
fit easily inside the vertical Fin for rudder control. We recommend a standard sized servo for
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nosegear steering, as the larger gears (preferably metal) can handle any shock-loads better.
Retract valves, etc., can normally use any mini servos of at least 2kg torque.
Fuel System: A pair of fibreglass moulded conformal main tanks (approx. 875cc each) are in-
cluded in the kit, which fit into the fuselage. Included is basic stopper hardware for these, but you
need to provide the brass tubing (1/8" O.D), kerosene stoppers (Dubro part #400), clunks and I.D
3 - 3.5mm Tygon tube.
We recommend a small 'hopper' tank between the main tanks and fuel pump, to prevent air bub-
bles getting to the turbine that could cause a 'flame-out'. Suitable tanks can easily be made from
any small 3 - 4oz tank, or you could use a BVM UAT, or the excellent small 'air-trap' from Intairco.
In addition you will need kerosene-proof fuel tube to suit your turbine, fuel filters etc.
If fitting a turbine at the higher end of the thrust range you can fit an additional tank of about 300cc
(10 fl.oz) in the fuselage, immediately in front of the rear cockpit bulkhead (under the hopper tank)
which will give you extended flight time.
Batte ies/Switches: The Hawk has no tendency to be tail-heavy, and with a 6-cell CU/pump
battery (sub-C cells) and two 5-cell 600 mAH (AA sized) NiMH receiver packs no additional weight
was needed in the nose of the factory PST 600 powered Hawk. Depending on the recommenda-
tions of your R/C manufacturer, be sure to use a voltage regulator to limit the max. current to your
receiver ! One simple way to achieve this is to use the excellent (small & lightweight) Powerbox
'Sensor' switch which combines dual electronic 'fail-ON' switches for dual Rx batteries, with dual
inputs and outputs, and an integral 5.9v voltage regulator.
Bu ld ng Instruct ons
There is no special sequence necessary for construction of the Hawk, and you can work on sev-
eral areas at the same time if you wish, making it a very quick plane to build. However it is nec-
essary to complete the wing joiners and wing bolts before installing the stabilisers, so that you
can use the wings as a guide to set the correct alignment of the stabs.
If you complete the assembly in the order shown below you will have no access problems, and by
fitting the nosegear unit last you can adjust the position and leg length as necessary to obtain the
correct ground angle (wing incidence) for easy take-offs and bounce-free landings.
W ng:
The wings are laminated from a lightweight fibreglass and foam sandwich, cured under vacuum,
and are painted in the molds in a single colour. Ailerons and flaps are elastic-hinged for your con-
venience. The hatches in the bottom skin for the servos are also elastic hinged and already cut out
for you at the factory. Likewise the main landing gear bays are already trimmed, and separate
molded covers are supplied.
The instructions below refer to the larger 2-piece ‘Sport’ wing, whereas the smaller ‘Scale‘ wing is
a one-piece type, so no wing joiners are needed. However, the assembly and servo installation is,
otherwise, similar for both wing versions.
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W ng Jo n ng
The left and right wing panels are connected to-
gether with a rectangular fibreglass rod (10 x 12 x
220mm long) and a Ø 7 x 90mm anti-rotation dowel
at the trailing edge. The joined wing is attached to
the fuselage with 2 more (factory-fitted) fibreglass
dowels in the leading edge, that fit into matching
holes in the fuselage bulkhead, and a pair of M4 x
25mm allen bolts at the back that screw thru' the
wing into T-nuts in the fuselage. All 3 dowels fit into
fibreglass tubes that are installed in the wing during
manufacture. You only need to glue in the rectangu-
lar wing joiner, the rear anti-rotation dowel, and fit
the wing bolts and T-nuts.
Check the fit of the rectangular wing joiner in the
tube in the wing. If it is too tight you can sand it a lit-
tle with 600 grit sandpaper. Temporarily join the
wings, wit out gluing the joiners in, fit onto the fuse-
lage and drill Ø 4mm holes thru’ the moulded dim-
ples in the underside of the trailing edge for the wing
bolts, perpendicular the the bottom wing surface,
right thru’ the 6mm balsa/fibreglass plate inside the
fuselage. Counterbore the holes in the bottom sur-
face of the wing for the M4 washers, Ø 10mm and
approx. 4mm deep, until you reach the factory-in-
stalled plywood plate inside the wing, so that the
washers will fit inside and the bolt heads will be al-
most flush with the surface. Open up the holes in the
balsa plate in the fuselage only to Ø 5.5m for the T-
nuts. Reinstall the wings, screw the T-nuts onto the
wingbolts and then secure them to the plate with a
little 30 minute epoxy & micro-balloons mixture.
When cured, remove the wings.
The rectangular joining rod should be glued into one
panel, and the Ø 7mm dowel into the other panel, in
both cases with 50% of their length projecting out of
the wing roots. Glue the rectangular joiner into the
wing that it has a looser fit in, to reduce any play.
Lightly sand the outer surface of both joiners for half
their length, to provide a good key for the glue, and
wax the other half that will be exposed. Wax the sur-
face of both wing roots. If the joiners can slide too far
into the wings that they will be glued into, then drop
a small scrap of balsa stick in the wing tubes first to
prevent that.
Apply a little slow (minimum 30 minute) epoxy and micro-balloons mixture into the 2 tubes in the
wings, and slide half the length of the wing joiners into them. Wipe off any excess epoxy that seeps
out with lighter-fluid, and re-wax the exposed joiners as necessary.
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(abov ) T-nuts for th wing bolts ar
glu d onto th composit plat (ar-
row d). You can also s th T-nuts for
th turbin mounting h r .
(b low) Count rbor hol s in wing un-
d rsid for th M4 bolts & wash rs.
(abov ) Wing pan ls ar join d with a
r ctangular fibr glass rod and a Ø 7mm
dow l just in front of th trailing dg .

IMPORTANT: Wait a minute
before joining the wing panels
together - to make sure that the
glue does not slowly push the
joiners out of the wing they are
glued into. In this case you will
need to drill a very small (1mm)
hole through the sides of the
tubes at the outboard end (ac-
cess from the landing gear bay)
to release the hydraulic pres-
sure caused by the glue.
Now slide the wings together,
and bolt them to the fuselage,
which is supported upside-
down in a model stand, and
leave until the glue has com-
pletely cured. When the epoxy
has cured they should slide
apart easily. Remove the wax
from the exposed joiners and
wing roots with lighter-fluid. You can apply some soft pencil lead (graphite) to the exposed half of
the fibreglass wing joiner if it is a bit tight to make it slide smoothly into the other wing.
Servo Installat on
A leron servos
The ‘U-shaped’ milled lite-ply mounts for the aileron
servos are sized to suit the 30mm wide JR DS-161
or Hitech 5125 servos, but can be sanded to fit the
33mm wide JR DS-3301 or Graupner DS-3328 if
you prefer to use these - and they have slightly more
torque and larger gears. In any case we recommend
that you use aileron servos with a minimum of 4kg
torque. Fit the servos in the opposite orientation in
the 2 wings so that you can Y-lead them together,
and use a single Rx channel for operation.
Sand the upper surface of the 2 ply mounts and glue
them onto the 6mm thick balsa sheet doublers, as
shown, to position the servos closer to the lower
wing surface. Don’t forget to make a ‘left’ and a ‘right’
servo mount ! Sand the mounts and square-off the
radiused corners as necessary so that your servos
are snug fit. Centre the servos using your Transmit-
ter, fit short servo arms at 90° to the case, set trav-
els to 100%, and screw the servos onto the mounts.
Trial fit the mounts into the wing, and check that the
front of them fits up against the back of the wing
spar, and that the linkage will be exactly parallel to
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(abov ) Digital DS161 s rvo install d in
th mill d ply mounts suppli d in th kit.
Not th slot cut out for th s rvo arm,
th linkag lin mark d on th tap , and
th hol for th ail ron horn 10mm back
from th ail ron l ading dg . Th
ail ron horn must b install d xactly in
lin with th s rvo arm.
(abov ) Wing bolts & join rs compl t d. Not that th y ar
glu d into opposit pan ls for th b st fit, using slow poxy.

the wing root, in line with the
air-flow during flight. This only
a few degrees off the ‘ideal’ 90°
to the hinge line of the ailerons,
and is close enough that there
is no noticeable binding or lost
movement. If you want to add
‘scale’ linkage covers later you
will need the linkages at this
angle, and not at 90 degrees to
the aileron leading edge.
File or sand the 5mm x 20mm
notches on the inner edges of
the servo hatches, as shown,
for the servo arms to exit the
wing. Carefully sand the inside
surface of the wing skin and
back of the wing spar where
the mounts will be glued for a
good bond, and clean off the
dust. Glue the mounts into the
wing using a little 30 minute
epoxy and micro-balloons mix-
ture. When cured, remove the
servos and apply a fillet of glue
all around the mounts, also
making sure that they are firmly
glued to the back of the spar.
Tape the ailerons in the neutral
position. Carefully mark the line
(on masking tape) of the link-
age, exactly in line with the
servo arms and perpendicular
to the wing root. The control horns are made from the 35mm lengths of M3 threaded rod included
in the hardware. Insert the small plywood reinforcing strips (6 x 15 x 30mm) into the inboard ends
of the ailerons, in line with the linkage, and glue in place to the aileron leading edge and lower skin
with a little 30 minute epoxy and micro mixture.
Drill right thru' the aileron on the marked line, exactly 10mm behind the front edge of the aileron,
using a sharp Ø 2.2 or 2.3mm drill. Use a 90° square to keep the drill perpendicular to the bottom
surface of the elevators. The holes should be just behind, or against, the balsa elevator spars,
and must pass thru’ the ply reinforcing strips. Now thread these holes, right thru' the ailerons, using
an M3 tap. Sand both ends of the threaded rod flat, and screw on the plastic adapter provided.
Screw it into the tapped hole until the upper end is flush with the top surface of the aileron. The
M3 rod must now be secured in place, by applying glue through the open (root) end of the aileron.
Apply one drop of thick CA and, when cured, add some 30 minute epoxy and micro-balloons mix-
ture to fill the space between the ply reinforcing strips and upper skin.
Make up the linkages between the servos and aileron horns using M2, M2.5 or 2 x 56 UNC cle-
vises and threaded rods. The linkages will need to be approx. 55mm long, clevise pin-to-pin. Fit
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(abov ) Compl t d ail ron s rvo, linkag and horn.
(b low) W advis you to us ‘wing-mount’ s rvos with in-
t gral mounting tabs, lik th digital JR DS-161 and DS-
3301/3328 s rvos shown h r .

the clevise on the servo arm as close to the servo
centre as possible, and the clevise on the elevator
horn as far out from the elevator as possible - to
maximise the mechanical advantage, whilst still ob-
taining the maximum necessary aileron throws of
9mm up and down. Lengthen the servo arm exit slot
to clear the linkage on max. throws if needed.
IMPORTANT: Do NOT use ball-joints or ball-links on
the plastic horn adapters. They will cause twisting,
and almost certain flutter ! This also applies to the
rudder linkage.
When the linkages are finally adjusted the servo
hatches can be held closed with small strips of clear
tape. It is not necessary to secure them with screws.
Some small triangles of very thin ply or fibreglass
sheet glued inside the corners of the servo bays
keep the hatches flush with the wing skin.
Flap Servos
The flap servos require a little patience to install and
set up, but result in a very nice system that is com-
pletely hidden within the wing.
The servos are fitted in 6mm thick milled liteply
mounts that you glue into the wing, sized to suit
‘standard’ sized servos, and we recommend that you
use servos with not less than 6kg torque as the
Hawk flaps have quite a large surface area. We pre-
fer to use a digital servo with at least 8kg torque, and
have installed JR 8311’s here.
If you want to use a single Rx channel and Y-lead
for operating the two flap servos, then you must fit
them both in the same orientation. In this case, then
the left flap servo will be fitted at the inboard side of
the hatch, and the right flap servo at the outboard
side of the hatch, as shown in the photos here.
Of course it is even easier to use a ‘Matchbox’ (or
equivalent) on one servo so that you can reverse it,
and adjust centres and end-points to match the other
one perfectly - and in this case you can install the
flap servos in 'mirror-image' (like the aileron servos).
As with the aileron linkages, we also prefer to make the flap linkages parallel to the wing root - al-
though as they are fully hidden in the wing you can also choose to make them perpendicular to
the flap leading edges if you prefer. It’s your choice, and the angular difference is so small (6.5°)
that it does not affect the operation.
Carefully mark the line of both linkages on masking tape before starting. Centre both servos using
Fox Composit s Co., Ltd.
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(abov ) S cur flap s rvos to mounts
with all n-h ad scr ws for asy r moval.
(b low) Hold plywood mount at an angl
insid th hatch to scr w th s rvo into
plac wh n trial fitting. Right wing shown.
(b low) Notic that th s rvo is at a slight
angl to th hatch sid s, but parall l to
th wing root. Right wing shown.

your transmitter and fit short servo arms now, at 90°
to the servo case in the neutral position. Check that
the milled mounts fit inside the wing (with the front
edge against the spar) without being too tight, sand
the U-shaped slots as necessary to fit your servos,
and drill the holes for the mounting screws. If you
use allen-head sheetmetal screws for this it is much
easier to remove the servos later using a ball-ended
allen wrench, because of the angle needed to ac-
cess the screws thru’ the hatch. Cut holes as needed
for lightening and servo cable routes.
Note that the mount for the left wing is supplied
12mm longer to allow you to install them in the same
orientation, if you wish, as shown. If you use a 2
channels, a Matchbox, or one reversed servo, and
install the servos in mirror-image, then you can cut
the extra length off the front of the mount, and fit both
at the outboard side of the servo hatches.
We highly recommend that you install both mounts,
servos, linkages and horns and just tack everything
into place temporarily with very small drops of CA to
check for similar operation before gluing anything in
place permanently with epoxy and micro-balloons.
Install the flap horns before the servo mounts. They
should be close to the mid-span of the flap; we fitted
both 195mm outboard from the flap roots, so that the
servos are positioned at the edge of the servo
hatches - giving the shallowest angle for in-
stalling/removing the servo screws.
Take both the supplied fibre-
glass flap horns, lay them ex-
actly on top of each other (sand
to make the shapes identical if
needed) and drill the hole
through the front for the clevise
pins, in the position shown in
the photos. Keep the hole at
least 3mm from the edge of the
horns. Scuff up both sides that
will be glued inside the flaps.
Mark the flap horn position on
the leading edge of the flaps,
and file slots 3mm wide and
12mm high against the upper
skin of the flaps.
Insert the horns, with the
curved part upwards, and push
Fox Composit s Co., Ltd.
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(abov ) T mplat mad from scrap ply or card and a Ø
1.5mm drill s ts both flap horns in id ntical positions.
(b low) Flap horn glu d in, with curv d part at top, and
cl vis hol 7 - 8mm in front of ail ron top skin.
7 - 8mm
(abov ) Flap s rvo horn drill d for cl -
vis pin, and pr par d for installation.
(b low) Sand 6 x 12mm slot in th wing
trailing dg for th flap horn & linkag .

them into the flaps until the holes for the clevises are
7- 8mm in front of the leading edge of the flap.
specially if you want to connect the servos together
on a Y-lead and use a single channel it is important
to have the horns in identical positions on both flaps.
Make a small template from scrap plywood and an
old drill bit to copy the position of the first flap horn
to the other flap, as shown here. Tack glue both
horns in place with a small drop of thick CA. File
matching slots (approx. 6 x 12mm) in the trailing
edge of the wing for the horn & linkage to pass thru’.
Carefully prepare the inside of the wing skins where
the mounts will be glued in place. Insert the ply servo
mounts (only) into the wing, and hold them at an
angle so that you can insert the servos and screw
them into place thru’ the hatches. Just 2 servo
screws is enough for trial fitting. Twist the mounts
vertical again, push them forward to make contact
with the wing spar, and set the angle of the servo
arm parallel to the flap horns. Tack in place with a
drop of thick CA. Make up the linkages from your
preferred hardware - we used M3 threaded rod and
steel clevises, and they will need to be approx.
100mm long, clevise pin-to-pin.
NB: To obtain the best mechanical advantage (and
holding power) for the flaps you must set your servo
throws to the maximum possible and fit the clevise
into a hole on the servo arm as close as possible to
the servo centre !
Connect the linkages to the hole approx. 10mm from
the centre of the servo horn, with the servo horns
angled approx. 45° forward for
the ‘up’ flap position, and check
the flap travel by hand. You
only need 40° - 45° max. travel
for landing. When you are sat-
isfied with both flap travels,
carefully remove the servos
and permanently glue the
mounts into place with slow or
30 min. epoxy and micro-bal-
loons, making sure they are se-
cured to the wing spar.
Also glue the flap horns se-
curely to the inside surface of
the flaps, inserting the glue on
the end of a thin stick.
Fox Composit s Co., Ltd.
11
(b low) Compl t d flap s rvo installa-
tion in right wing, at th outboard sid
of th hatch, with flap in th fully down
(‘landing’) position, and th s rvo arm
angl d backwards at about 45°.
(abov ) Ply mounts s cur d with a fill t
of poxy/micro-balloons all around.
(b low) Flap s rvo install d in l ft wing,
at inboard sid of hatch, using th 12mm
long r plywood mount suppli d.

Re-install the servos and linkages,
not forgetting to ‘Loctite’ one clevise
and add a locknut to the other end.
The servo hatches can be held
closed with small strips of clear tape.
Some small triangles of thin ply or fi-
breglass glued inside the corners of
the servo bays keep the hatches
flush with the wing skin.
Ma n Land ng Gear
The Fox-Composites Hawk was de-
signed to use Spring-Air 300 or 700
series main retracts (89° or 90° re-
traction angle), or similar sized units.
The maximum internal depth avail-
able in the wing at the outer end of
the retract mounting plate is 35mm.
The retract units are bolted onto
milled 6mm composite plywood/fibre-
glass plates that you must glue onto the fibreglass
sleeves that are factory-installed in the wings. Ad-
just the milled slots in the plates to suit your chosen
retracts and secure them with small (M3 or equiva-
lent) bolts and T-nuts, as shown. The set-up here
shows straight wire-legs, but if you chose to fit trail-
ing-link main legs then you will need to adjust the
position of the slots (forward), so that the wheels are
in the same position.
Sand the back edge of the mounting plates a little if
necessary, so that you can just insert them into each
retract bay at an angle, and then straighten them to
fit onto the fibreglass flanges. Check that both re-
tracts are the same distance from the centreline and
the trailing edge of the wing, and adjust the ply
mounts if necessary.
Make sure that there is at least a 1mm gap between
the top of your retract units and the fibreglass sleeve
that is factory-bonded to the upper wing skin - so
that you won’t damage the wing surface in the case
of a ‘bouncy’ landing! Shown installed here are
Spring-Air 700’s (same as 300 series, but drilled for
3/8” oleos), which are 29mm high, and it is just pos-
sible to install these and still fit the (2mm thick)
moulded retract bay covers over the retracts, flush
with the wing skin, but you will need to use counter-
sunk bolts to secure the retracts.
Fox Composit s Co., Ltd.
12
(abov ) R tract units s cur d to ply
mount with M3 bolts & T-nuts.
(b low) Pr par ply plat & fibr glass
sl v prop rly b for gluing in plac .
(abov ) Compl t d Spring-Air 700 s -
ri s r tract installation in th right wing.

Carefully sand and prepare the ply mounting plates,
the fibreglass flanges and the surface of the wing
spars where the plates will be glued. Glue in se-
curely using a slow epoxy and micro-balloon mixture
- making sure of good contact to the fibreglass and
the wing spars at the front and back of the retract
bays. An alternative is to use silicone adhesive, and
this has the advantage that it remains slightly flexi-
ble, and can be be cut out with a sharp knife if you
have to replace the mounts after an ‘accident’ !
Note: Depending on the depth of your retract units
you may be able to glue the plywood retract mount-
ing plates inside the fibreglass sleeves, but in this
case you must be careful to get a very good glue
bond between the ply and the fibreglass because all
landing loads will be directly on the glue joint.
We recommend that you fit 2.5 - 2.75” diameter (Ø
63 - 69mm) wheels. Shown here is a Robart 2.75”
wheel, which fits fully inside the wing when retracted.
For the Spring-Air units shown, with a 2.75” diame-
ter wheel, the total leg length from the end of the
brass adapter to the centre of the wheel axle needs
to be 97mm. If it is shorter, then the wheel may foul
on the air nipple and tube on the end of the retract.
Carefully align the
sides of the wheels
exactly parallel with
the wing centreline
and secure firmly in
the adapters - or even
better is with about 1
degree of ‘toe-in’ on
each wheel for best
ground handling.
Route the air tube (&
servo extension ca-
bles) to the front cor-
ner of the gear bay
and secure in position
with a drop of silicone,
or equivalent, so that it
cannot foul the re-
tracted wheel. Trim
the molded retract
covers provided in the
kit as shown to make
covers for the retracts.
Small plywood tabs
Fox Composit s Co., Ltd.
13
(abov ) Clamp ply mounts firmly to fibr -
glass sl v s whil th glu cur s.
(b low) LG cov rs trimm d and tap d in
plac . Us count rsunk bolts to s cur
r tracts for max. cl aranc if n d d.
(abov ) Und rsid vi w of th compl t d right wing, with ail ron
and flap s rvo hatch s & r tract cov rs s cur d with cl ar tap .
SpringAir 300/700 s ri s r tract, plain wir l g and Robart 2.75”
wh l shown. If you chos to fit trailing-link l gs you will n d to
r position th r tracts forward a littl so that th wh ls ar in sam
position as shown h r .

glued inside the edges of the retract bay keep them
flush. You can use clear tape, or small screws, to
hold the covers in position as shown.
We have not designed this model to have any gear
doors, but an enterprising modeller could cut out the
retract covers to make operating inner gear doors if
wished, and even outer doors or strut covers. A sim-
ple spring-loaded mechanical linkage could be used,
so that the wheel pulls the inner door closed - with-
out having to use separate servos, pneumatic cylin-
ders, valves or door sequencing units.
The retract tubing, together with the aileron and flap
servo extension cables, can pass up into the fuse-
lage thru’ a hole in the upper surface of the wing near the root, immediately behind the main wing
spar, and then enter the cockpit area thru’ the same hole as the turbine services. Don’t forget to
protect these from the sharp edges of the composite sandwich by installing rubber grommets in
the holes. Make sure to secure all of these vital connections for flight, so they cannot flap around
in the high-speed air that is going into the turbine compressor.
W ng Fences
Included in the hardware bag are 2 small fibreglass
wing fences, which can be glued onto the leading
edge of the wings - exactly in line with the joint be-
tween the flaps and ailerons (scale position) if you
wish.
However, we noticed no difference to the flight char-
acteristics with them on, or off, and they are very
easy to break off when you put the wings in the pro-
tection bags for transport or storage !
Fuselage:
The fuselage is a fibreglass and epoxy moulding, without a foam sandwich, painted single-colour
in the moulds. We recommend that you lightly sand the complete inside surface of the fuselage
now, with 120 - 240 grit sandpaper - and this is especially important in the nose area as access is
more difficult after the nosegear is fitted and you may want to fit supports for batteries etc in there
later. This operation will also remove any loose glass strands that might get in your hands later.
Generally you can follow the assembly sequence shown below for simplest access, and we like
to work from the back of the fuselage forwards to the nose and install the gear and extension leads
etc as we progress. If installing one of the turbines recommended, or one of similar weight, and a
Fox Composit s Co., Ltd.
14
(abov ) Th mill d fibr glass wing f nc s
suppli d in th kit can b glu d on to th
top surfac in lin with Ail ron/Flap joint.
97mm
2.75” wh l
(abov ) For th Spring-Air 300/700 units
and 2.75” wh ls th l g l ngth is 97mm
from th nd of th brass adapt r (or
wir l g) to th c ntr of th axl .

rearward-retracting nosegear
you will have no problems set-
ting the correct Centre of Grav-
ity as you can fit the batteries
right in the nose. If you chose
to fit a more scale forward-re-
tracting nosegear you may
need to be a little more careful
as it fills the useful space in the
nose - but you still should not
have to add any additional
weight to balance the plane
correctly.
Hor zontal Stab l sers
The anhedral stabilisers are laminated from a fibre-
glass and foam sandwich (2mm thick), cured under
vacuum, and painted in the molds in a single colour.
The stabs should be permanently glued onto the pair
of Ø 7mm composite rods, which are supported in a
pivoting fibreglass horn/bellcrank, and are controlled
by a single servo mounted centrally in the fuselage.
If installed as described here this simple system is
extremely strong and will certainly handle any nor-
mal flying loads that can be placed on it by turbines
in the recommended thrust range.
ach stab has pair of I.D. 7mm fibreglass tubes in-
stalled in it during manufacture, to take the Ø 7 x
180mm rods. These fit into the factory-assembled
Yoke, and the rear rod pivots in a pair of ball-bear-
ings that fit into moulded pockets in the side of the
fuselage. These items are pre-assembled for you
before shipping so that you can easily understand
the assembly. Note that the rear rod may have been
sanded at the factory, to give an easy sliding fit in
the bearings.
Just as with the flap linkages, it is wise to ‘dummy’
assemble the complete stab system, including the
servo & linkage, to check travels and proper opera-
tion before gluing anything permanently in place.
Fox Composit s Co., Ltd.
15
(abov ) S rvo fits in ply mount with out-
put shaft towards front, and cl vis as
clos to c ntr of arm as possibl . M3
cl vis s and linkag shown.
(b low) N utral l vator position is with
th top of th stab trailing dg s flush
with top of r ar fus lag , as shown.
(abov ) G n ral ass mbly vi w of th all-flying stabilis rs,
s rvo & linkag . Yok is paint d r d h r for clarity only !

Sand or file the 6 x 30mm long
slot in the top of the raised part
of the fuselage for access to
the clevise connection now.
This slot will be hidden by the
rudder at neutral when it is in-
stalled later.
Remove the bearings and rods
from the yoke. Fit the bearings
into the fuselage pockets - it is
not important which way
around they are fitted, and they
do not need to be glued in
place. Trial fit the yoke inside
the fuselage, and adjust the
length of the rear (longer) tube,
if necessary, so that it just fits
between the fuselage sides,
and it is centred on the slot in
the top of the fuselage.
Slide the rear (sanded) Ø 7mm
rod thru’ the bearings and back
tube of the yoke, and also the
front rod thru’ the curved slots
in the fuselage sides, and the
front tube of the yoke. Slide the
stabs onto the 2 rods, with the
chamfered surface of the roots
towards the underside. Now
check the travel available, with
the curved slots that are al-
ready milled in the fuselage for
you - and lengthen these if nec-
essary to obtain at least 10mm
‘up’ and 10mm ‘down’ move-
ment at the trailing-edge with-
out any binding.
Note that the elevator ‘neutral’ (level flight) position is with the top of the stab trailing edge flush
with the top of the fuselage moulding, and that is the position you must set for the first flight.
Mass-balanc ng
It is your choice whether to add a little lead into the leading edges of the stabs to achieve either
partial, or full, mass-balancing. We, and many customers, have flown hundreds of flights both with
- and without - balancing, and none of us has ever experienced any flutter.
Nevertheless, we recommend at least partial balancing, especially if you will fit a turbine at the
upper end of the thrust range. If you wish to balance, even just to reduce the loads on the stab
servo, then drill a 6mm hole in the root leading edge of both stabs and glue approx. 20 grams (3/4
oz.) of lead strip/fishing weight into each.
Fox Composit s Co., Ltd.
16
(abov ) B arings fit into mould d pock ts in th fus lag .
Adjust curv d front slots for 10mm up & 10mm down throws.
Cut a 6 x 30mm slot in th rais d part for cl vis acc ss.
(b low) Stabs must b spac d 1 - 1.5mm off fus lag whil
glu cur s, for cl aranc . Compl t d linkag also s n.
25mm 30mm

When satisfied with the stab throws, remove the
yoke and drill the hole in the top of it for the pin of
your chosen clevise, keeping the hole at least 4mm
from the edge of the fibreglass horn. We suggest
that you use M3 or 4 x 40 UNC hardware for this im-
portant control.
Apply clear car wax to the outsides of the fuselage
in the area of the stabs, and the stab roots, in case
you get some glue on there during the next steps.
Lightly sand inside the tubes that are factory-in-
stalled in the stab roots, and clean out any dust. In-
stall the wing onto the fuselage, and set the fuselage
up level on a flat table - with enough space so that
you can step back about 4 or 5 metres from it to ‘eye’
the alignment between the stabs and the wing be-
fore taping and clamping in position while the glue
cures.
Now reinstall the yoke and the 2 rods, and lightly
sand and clean the exposed ends that will be glued
into the stabs. You will need 4 thin spacers 1 -
1.5mm (1/16”) thick to tem-
porarily insert between the stab
roots and the fuselage while
you glue them onto the rods - to
maintain a small gap between
them and the fuselage. Be-
cause of the dual pivot rod sys-
tem there is no chance that the
stabs can blow-back at speed,
and therefore this gap can be
kept to a minimum. The spac-
ers shown in the photo here are
made from 1/16” plywood. An
alternative is to permanently in-
stall 4 thin plastic or nylon
washers between the stab
roots and fuselage.
Apply a little slow epoxy and micro-balloons mixture into the 4 tubes in the stabs, slide them onto
the rods in the fuselage, and wipe off an excess epoxy that seeps out. Be careful that the 2 rods
stay centred in the yoke when you slide the stabs on - you can even tack them into the yoke tubes
with a small drop of CA if you wish. At least 38mm length of both the Ø 7mm rods should project
out of both sides of the fuselage, and be glued into each stabiliser. Now view carefully from the rear
to check that both stabs have exactly the same incidence, are not twisted, and are equidistant to
the wing trailing edge, and then firmly tape them in position while the glue cures.
When the glue has fully cured turn the fuselage upside down, and add a small drop of 5 or 30
minute epoxy on the joints between the front yoke tube and the front rod, if not done previously -
to prevent any slight side-to-side movement.
Fox Composit s Co., Ltd.
17
(abov ) A small drop of poxy h r pr -
v nts sid -to-sid mov m nt of stabs.
(b low) Th s rvo mount is glu d b -
tw n th 2 bulkh ads, s n h r in th
l ft fus lag half - shown in th mould
b for joining for clarity.

The stabilisers should be
controlled by a full-size
servo of minimum 8kg
torque (eg: JR8311,
8411, or Futaba equiva-
lent). We strongly advise
fitting the best servo you
can here, and a digital
type of at least 8kg gives
peace-of-mind!
Adjust the size of the
cutout in the milled 6mm
liteply servo mount to fit
your servo, and screw it
in place, with the open
end of the cutout towards
the bottom of the fuse-
lage - again using allen-
head sheetmetal screws
to make it easier to re-
move the servo later.
Centre the servo with
your Tx, and fit a heavy-
duty servo arm onto the
output shaft at 90° to the servo case. The servo mount fits vertically between the 2 bulkheads in
front of the Fin position, with the servo output arm on the centreline of the fuselage, projecting
thru’ the factory-milled slot in the top of it.
Trial fit the mount and servo, and adjust the mount as necessary. Prepare all surfaces for gluing
properly. We find that the easiest way to glue the mount in place is with the fuselage upside-down
in a cradle, and connected to the yoke with the final linkage to ensure correct alignment. Tack glue
the mount (and servo) in place with 2 small drops of thick CA first, then carefully remove the servo
with a short ‘L-shaped’ allen wrench - and securely bond the mount to both bulkheads and the
upper surface of the fuselage with a slow epoxy and milled fibre mixture.
Re-install the servo, and refit the M3 or 4 x 40 pushrod linkage as shown. Fit the clevise as close
to the servo arm centre as possible, and use at least 100% servo travels to maximise the me-
chanical advantage. You will need to file a narrow slot in the base of the fin to clear the linkage later.
NB: Do NOT use a single-sided ball-link to connect the elevator linkage to the Yoke - it could
cause twisting and dangerous flutter !
There is plenty of space between the stab servo and the top of the thrust-tube, but you can sili-
cone glue a thin ply shield to the bottom of the servo, and cover it with aluminium tape if you are
worried about heat. Check carefully that the bottom of the fibreglass stab yoke does not touch the
top of the outer thrust tube in the elevator ‘up’ position.
During gear installation be careful to route the elevator servo extension cable as far away from the
(hot) thrust tube as possible, and we strongly recommend that you additionally protect them by
wrapping the cables with self-adhesive aluminium tape and fixing them securely to the sides of the
fuselage. This also applies to the servo extension cable for the rudder servo.
Fox Composit s Co., Ltd.
18
(abov ) Compl t d stab and rudd r linkag s, with Ø 7mm fin
join rs glu d into fus lag . H avy duty plastic s rvo arm us d on
stab s rvo, with M3 cl vis on 2nd hol . Slot in fus lag und r
rudd r allows asy conn ction of cl vis onto stab yok , and r g-
ular saf ty insp ction. Not that r ar fin join r is offs t, and a slot
must b fil d in back of fin bas to cl ar stab linkag .

F n and Rudder
The vertical fin and elastic-
hinged rudder is laminated
from a lightweight fibreglass
and foam sandwich, cured
under vacuum, and painted in
the molds in a single colour. It
has been fitted to your fuselage
at the factory, to check align-
ment, but small directional ad-
justments can be made when
gluing in the 2 joiner rods and
installing the retaining bolt at
the front. Note that the rear
tube for the fin spar/joiner is
offset to the (pilots) left side to
allow clearance for the stab
linkage on the centreline.
The 2 joiners (Ø 7mm x 90mm) must be perma-
nently glued into the fuselage, not into the fin, inside
the 2 tubes that are bonded to the rear bulkheads.
Apply 2 coats of clear wax to the root of the fin and
the top of the fuselage, in case you get some glue on
there in the next steps. Prepare the 2 joiner rods by
lightly sanding the end 35mm length of the front rod,
and 25mm length of the rear rod - which will be glued
into the fuselage. Lightly sand the inside of the tubes
in the fuselage. Wax the remaining length of the
rods, and push them into the Fin, leaving just the
correct lengths projecting. If they are a bit too loose
in the fin tubes, you can spray a coat of ‘clear’ or
paint a thin coat of laminating epoxy on the rods.
Apply a little thick mixture of slow epoxy and micro-
balloons inside the fuselage tubes and on the joiner
rods, and fit the fin into position. With the wings and
stabs fitted, view carefully from the back, and
measure from the wing tips - to ensure that the
fin is vertical and straight - and then tape se-
curely in position until the glue has cured.
Some tissue or rag laid in the bottom of the
fuselage under the fin joiners catches any glue
that seeps out.
When fully cured, remove the fin and wipe off
the wax with Ronsonol, or equivalent. The fin
is secured to the fuselage for flight with a M4
x 25 bolt at the front, that screws into an M4 T-nut that has been factory-fitted into the fin base al-
ready. The hole has been drilled in the fuselage for the bolt, but can be adjusted if necessary. Cut
a small reinforcing plate of 3mm plywood, approx. 20 x 30mm, and drill a 4mm hole in the centre
Fox Composit s Co., Ltd.
19
(abov ) Fin is s cur d with 2 x Ø 7mm join r rods, which
must b glu d into th fus lag , and an M4 bolt at th front.
Back join r has 25mm glu d into th fus lag , and front has
35mm. R ar join r is offs t to giv cl aranc for stab linkag .
(abov ) Linkag is parall l to fin bas .
Hol for horn is 10mm back from rudd r
L.E and approx. 10mm up from root. Drill
right thru’ rudd r and tap M3 thr ad.
(b low) Mini-s rvo install d in mill d
6mm ply mount, and glu d into Fin.