Composite ARF USE

Composite ARF USE
Thank you very much for purchasing our Composite-ARF ‘Hawk’ jet, made with the
revolutionary Total Area Vacuum Sandwich (TAVS) technology.
Before you get started building and setting-up your aircraft, please make sure you have read
this instruction manual, and understood it. If you have any questions, please don’t hesitate to
contact your Rep, or C-ARF directly. Below are the contact details:
Email: [email protected]
or [email protected]
Telephone: Phone your C-ARF Rep!!! He will be there for you.
Liability Exclusion and Damages
You have acquired a kit, which can be assembled into a fully working R/C model when fitted out
with suitable accessories, as described in the instruction manual with the kit.
However, as manufacturers, we at Composite-ARF are not in a position to influence the way you
build and operate your model, and we have no control over the methods you use to install,
operate and maintain the radio control system components. For this reason we are obliged to
deny all liability for loss, damage or costs which are incurred due to the incompetent or
incorrect application and operation of our products, or which are connected with such operation
in any way. Unless otherwise prescribed by binding law, the obligation of the Composite-ARF
company to pay compensation is excluded, regardless of the legal argument employed. This
applies to personal injury, death, damage to buildings, loss of turnover and business,
interruption of business or other direct and indirect consequent damages. In all circumstances
our total liability is limited to the amount which you actually paid for this model.
It is important to understand that Composite-ARF Co., Ltd, is unable to monitor whether you
follow the instructions contained in this instruction manual regarding the construction, operation
and maintenance of the aircraft, nor whether you install and use the radio control system
correctly. For this reason we at Composite-ARF are unable to guarantee, or provide, a
contractual agreement with any individual or company that the model you have made will
function correctly and safely. You, as operator of the model, must rely upon your own expertise
and judgement in acquiring and operating this model.
Attention !
This ‘jet’ aircraft is a high-end product and can create an enormous risk for both pilot and spectators,
if not handled with care & used according to the instructions. Make sure that you operate your ‘Hawk’
according to the laws and regulations governing model flying in the country of use. The engine, landing
gear, servos, linkages and control surfaces have to be attached properly. Please use only the
recommended servos and accessories. Make sure that the ‘Centre of Gravity’ is located in the
recommended place. Use the nose heavy end of the CG range for your first flights. A tail heavy plane
can be an enormous danger for you and all spectators. Fix any weights, and heavy items like batteries,
very securely into the plane. Make sure that the plane is secured properly when you start the engine.
Have a helper hold your plane from the nose before you start the engine. Make sure that all spectators
are far behind, or far in front, of the aircraft when running up the engine. Make sure that you range
check your R/C system thoroughly before the 1st flight. It is absolutely necessary to range check your
complete R/C installation first WITHOUT the engine running. Leave the transmitter antenna retracted, and
check the distance you can walk before ‘fail-safe’ occurs. Then start the engine, run at about half throttle
and repeat this range check. Make sure that there is no range reduction before ‘fail-safe’ occurs. If the
range with engine running is less then with the engine off, please DON’T FLY at that time. Check that the
wing and stab retaining bolts are tight, and that all linkages are secured. Please don’t ignore our
warnings, or those provided by other manufacturers. They refer to things and processes which, if ignored,
could result in permanent damage or fatal injury.
Important/General Notes
Elastic Hinges:
The ailerons, elevator, flaps and rudder are all hinged for you. The ailerons and flaps are laminated in the
mould and attached with a special nylon hinge-cloth, sandwiched between the outer skin and the foam.
This nylon hinge is 100% safe and durable. You will never have to worry about breaking it, or wearing it
out. There is no gap at all on the top side of the surface, and there is a very narrow slot in the bottom
surface, where the control surface slides under the skin during ‘down’ throw. This means that the hinge
axis line is on the top surface of the wing and stab, not in the centre. This is NOT a disadvantage, but you
need to program in about 10% NEGATIVE differential in your transmitter. This means that the ‘down’
throw needs to be about 10% more than the ‘up’ throw. Why? Because the axis of the hinge is not at the
centreline of the aileron/elevator, so it moves slightly in and out when operated, and the control surface
gets a little "smaller" in surface area when moving downwards. The slot needs some explanation, too. The
cut line is exactly in the correct position so that the control surface slides under the wing skin smoothly. If
the cut was a few mm forward or backwards, it would not work properly. So, make sure that the lip is not
damaged, and that the control surface slides under this lip perfectly. It will not lock at any time, as long as
the lip is not damaged. If damage occurs, you can cut a maximum of 2-3 mm off the lip on the wing in
front of the control surface, but you should never cut off more than this.The rudder is hinged with a metal
rod passing through factory fitted hinge plates. The all flying elevator hinges on a large carbon plate
fitted with ball-races, which pivots on a carbon tube that requires locking in position.
Servo Choice:
We strongly advise that you use the recommended servos and equipment listed in the manual.
Servo Screws:
Fix the all the servos into the milled plywood servo mounts using the 2.9 Ø x13mm or 16mm sheet metal
screws provided in the kit, not the standard screws normally supplied with servos by the servo manufacturer. This is because all the holes in our milled servo mounts are 2mm diameter, due to our CNC manufacturing process, and this is too big for the normal screws
Building Sequence:
The actual building sequence is your choice, but it is definitely most efficient to start at the back of the
fuselage and work forwards, in the same order as shown below.
Take Care:
Composite sandwich parts are extremely strong, but fragile at the same time. Always keep in mind that
these contest airplanes are designed for minimum weight and maximum strength in flight. Please take care
of it, especially during transport, to make sure that none of the critical parts and linkages are damaged.
Always handle your airplane with great care, especially on the ground and during transport, so you will
have many hours of pleasure with it. To protect the finished paint on the outside of the model from
scratches and dents during building, cover your work table with a piece of soft carpet, cloth or bubbleplastic. The best way to stop small spots of glue getting stuck to the outside painted surfaces is to give the
whole model 2 good coats of clear car wax first, but of course you must be sure to remove this 100%
properly before adding any additional paint, markings or trim.
Adhesives and Solvents
Not all types of glues are suited to working with composite parts. Here is a selection of what we normally
use, and what we can truly recommend. Please don’t use inferior quality glues - you will end up with an
inferior quality plane, that is not so strong or safe. Jet models require good gluing techniques, due to the
higher flying speeds, and hence higher loads on many of the joints. We highly recommend that you use a
slow filled thixotropic epoxy for gluing highly stressed joints (eg: Hysol 9462). The self-mixing nozzles
make it easy to apply exactly the required amount, in exactly the right place, and it will not run or flow
onto places where you don’t want it! It takes about 1 - 2 hours to start to harden so it also gives plenty of
time for accurate assembly. Finally it gives a superb bond on all fibreglass and wood surfaces. Of course
there are many similar glues available, and you can use your favourite type.
1. CA glue ‘Thin’ and ‘Thick’ types. We recommend ZAP, as this is very high quality.
2. ZAP-O or Plasti-ZAP, odourless, or ZAP canopy glue 560 (for clear canopy)
3. 30 minute epoxy (stressed joints must be glued with at least 30 min & NOT 5 min epoxy).
4. Loctite Hysol 9462 or equivalent (optional, but highly recommended)
5. Epoxy laminating resin (12 - 24 hr cure) with hardener.
6. Milled glass fibre, for adding to slow epoxy for stronger joints.
7. Micro-balloons, for adding to slow epoxy for lightweight filling.
8. Thread-locking compound (Loctite 243, ZAP Z-42, or equivalent)
We take great care during production at the factory to ensure that all joints are properly glued, but of
course it is wise to check these yourself and re-glue any that might just have been missed. When sanding
areas on the inside of the composite sandwich parts to prepare the surface for gluing something onto it,
do NOT sand through the layer of lightweight glasscloth on the inside foam sandwich. It is only necessary
to rough up the surface, with 80/120 grit, and wipe off any dust with acetone or de-natured alcohol (or
similar) before gluing to make a perfect joint. Of course, you should always prepare both parts to be
joined before gluing for the highest quality joints. Don’t use Acetone for cleaning external, painted, surfaces as you will damage the paint. Tip: For cleaning small (uncured) glue spots or marks off the painted
surfaces you can use old-fashioned liquid cigarette-lighter fuel, like ‘Ronsonol’ or equivalent. This does not
damage the paint, as Acetone and many other solvents will, and this is what we use at the factory. At
Composite-ARF we try our best to offer you a high quality kit, with outstanding value-for-money, and as
complete as possible. However, if you feel that some additional or different hardware should be included,
please feel free to let us know. Email us: [email protected] We know that even good things
can be made better !
Did you read the hints and warnings above and the instructions carefully?
Did you understand everything in this manual completely?
Then, and only then, let’s start assembling your Composite-ARF Hawk
If not, please read it again before you continue.
This list will help you chose the main additional items needed to finish your Composite
Some of the recommendations are mandatory and some can be sourced and chosen by
you. The items we list here are highly recommended by C-ARF, and have been tested on
various prototype aircraft used during the development of this aeroplane.
1. Servos (minimum 8 high quality servos) All the main control surfaces require a
minimum 11kg digital servo (two matched servos for the elevator control) such as
the Gr/JR 8411/8711 metal geared servos. All the prototype Hawk models used
JR 8711 servos.
2. Heavy duty servo arms are recommended, for the JR servos we used JR part
JRPA215 or Graupner #Nr 3544. Two packets required.
3. A receiver power supply system like the excellent Powerbox units are
recommended using two separate batteries through separate regulators. The Hawk
requires some weight in the nose area, so the additional batteries all help.
4. Turbine set. Turbines in the 10-16kg (20-36lb) thrust range have been used in the
prototype aeroplanes. Turbines in the 16kg (36lb) 160N thrust class should be
seen as the maximum thrust for the aeroplane and should not be exceeded. Ideally
a 160N turbine should be turned down in RPM 5%. Comp ARF display aeroplanes
use JetCat turbines.
5. Retractable Landing Gear sets are available from Composite-ARF in sport and
scale sets (C-ARF product #200500-Sport) and (#200600-Scale). The Hawk was
designed specifically around the German manufactured AT high quality sets that
include three units, plus specifically manufactured trailing link legs with associated
ball raced wheels and high quality brake units. If you chose the sports scale gear
to start with you can upgrade at a later date using scale upgrade set (C-ARF
product #200650)
6. Landing Gear support equipment is available from Composite-ARF (#200550), or
can be sourced by you. The Hawk requires a minimum of three air rams to operate
the gear doors (four with a scale nose gear door set up). The retract valve chosen
needs to operate air up/down units and a suitable method of controlling the gear
door opening sequence. The Hawk has the gear doors stay open when the landing
gear is in the down position. C-ARF set features high quality parts including air
valves from Jet Tronic to control the gear and door opening, plus brakes. Suitable
air tubing and a large capacity air tank for landing gear/door operation. Filler
valves and quick disconnect joiners. We strongly recommend you use this proven
high quality set.
7. A radio system with a minimum of 7 channels is needed, but C-ARF recommend a
quality system with 9 or more channels to allow individual servo connections to the
receiver system (talk to your C-ARF rep for advice on a suitable system) High
quality extension leads are required and a guide to the sizes and quantities
required are listed below.
8. The Hawk features a large cockpit area which benefits from some additional
detail. Our Hawk is a perfect starting point for a scale aeroplane, adding
additional cockpit detail using products like the 1:5 scale ejector seats from
Graupner and canopy glass MDC from Taylor Made Decals will add to the
already impressive look of this iconic aeroplane.
Thrust Tube Assembly
The thrust tube is manufactured from an aluminium
outer “cool” tube and a stainless steel inner pipe
rolled and spot welded for you at the factory.
This tube is designed to work with the sizes of turbine
intended for the BAE Hawk. Turbines in the 22-35lb
thrust class are perfect.
The tail pipe is mounted in the fuselage between the
rear fuselage cut-out opening and aluminium
mounting brackets provided that fix to the carbon
bellmouth and turbine mounting rails.
Fig 1
The first job is to fix the carbon bellmouth to the
stainless inner tube. The bellmouth is designed to go
inside the tail pipe and be fixed by M3 cap head
screws or pop rivets if available to you.
The thrust tube can be fitted in any orientation, but
the neatest look is with the joint seam at the top
when the aeroplane is on its wheels.
For simplicity the Hawk was designed without full
ducting, hundreds of test flights in various conditions
have shown perfect operation and normal turbine
Fig 2
A trial fit of the carbon bellmouth should show any
areas that need sanding to allow a snug fit. The
carbon moulding process will undoubtedly lead to a
variation in thickness of the material. Some early tail
tubes show a reduction in diameter where the lip is
formed in the tail pipe tube, this needs to be worked
out before the carbon bellmouth will fit. Later pipes
have no lip.
Once the bellmouth can be inserted at least 12mm
drill four holes to suit the fixing you have chosen.
If using M3 x 8 Socket head cap screws use washers
under the screw heads on the inside (carbon)
Fig 3
Fitting the aluminium mounting angles to the bellmouth at approximately 3 and 9
o’clock is best done after the turbine has been mounted so that the inner tube is fixed
centrally on the turbine cone. This is important to avoid “hot Spots” in the pipe that can
lead to tube failures. Note that on early kits the tail pipe outer “cool” tube will get very
close to the elevator servo mounting plate restricting how high the pipe can be mounted
at the front. Later kits will have more clearance.
Alignment by eye is accurate enough when fitting the carbon cone.
The outer tube should protrude through the fuselage rear between 3 and 5mm. This sets
the position.
Access to the two front mounting screws (2.2 x 10mm) is improved if you drill two access
holes in the rear wing seating area. Holes drilled at 170mm centres approx and 10mm
in from the rear edge of the wing. The tail pipe front brackets should be screwed directly
to the turbine mounting rails. Be sure to centralise the carbon bell mouth between the
rails as the deflector duct fits outside of the carbon bell mouth.
Turbine Installation
Mounting the turbine is very straight forward on the Hawk, with excellent access to the
turbine through the wing opening. Mount the turbine directly on the bearers, higher
power turbines benefit from being mounted slightly higher in the fuselage. To achieve
this the motor mount could be fixed below the rails (when looking through the wing
Modern electric start turbines remove the need for
engine access hatches, as the operator does not need
to attach or detach anything from the turbine during
We recommend a turbine of 12-16kg thrust, the three
prototype aeroplanes have been flown with JetCat
P120SX and P160SX turbines.
Any turbine between 22 and 35lb thrust will give
adequate performance to the Hawk. For less
experienced pilots we recommend turbines over 35lb
thrust have the maximum RPM reduced to limit output.
Fig 4
designed for a maximum turbine thrust of 16kg-This
must not be exceeded. All installation pictures show a
JetCat P120SX, , which give more than scale
performance including huge vertical elements.
Many of the turbines available now feature off-set
mounts. The exact position of the turbine will affect the
thrust tubes vertical position, which can affect the
Hawk’s trim. On very early kits the elevator servo
plate is mounted 10mm lower in the fuselage,
requiring a small dent placing in the outer cool tube to
allow clearance for the correct bellmouth height. On
the prototype model 8mm of packing was required.
The exact position of the turbine fore and aft will
depend on your chosen turbine. With the JetCat
turbines we recommend a distance of 25mm between
the back of the turbines tail cone and the carbon
bellmouth/stainless tube joint. This relates to the front
Fig 5
Fig 6
of the turbine purple cover finishing just in front of the
wing fixing formers.
The carbon turbine deflector guard mounts to the
carbon bellmouth with three M3 x 10 Allen bolts,
washers and nuts. The guard features mounting ears
that sit between the turbine mounting lugs.
When you drill the fixing holes for your chosen
turbine it is very important that the turbine is centred
on the tail pipe tube. It is also important that the
turbine is not angled so that the hot gasses are being
directed onto the tail pipe walls. JetCat turbines are
installed with the cable connection towards the top of
the aeroplane, away from the wing. Drill the four
mounting holes ø4 one at a time, adding a screw into
the drilled holes in turn, help keep the turbine
position. Once drilled remove the turbine and open
the holes to ø5.5mm ready for the M4 T-nuts. These
can be pulled into position with the M4 Allen screws
and large spreader washers. The carbon deflector
guard may require a hole to accept the turbine cable,
with the shown JetCat turbine a single hole is
required for the power cable.
Fig 7
Fig 8
Fuel Tank Setup
Composite-ARF offer an optional moulded Kevlar fuel
tank of 4.1 ltr capacity, which is installed in the
fuselage on the C of G and a plastic tank that can be
used as a hopper tank in the cockpit area. If you wish
to fit smoke some of the C-ARF team pilots have used
Flash wing tanks mounted below the main fuel tank. If
this set up is chosen the wing services should exit the
wing through the leading edge/wing mount face,
with corresponding holes drilled in both faces. The
main tank is moulded with a deeper rear trough to
retain fuel towards the end of the tank.
Fig 9
Before starting assembly of the moulded tank it is
important that any debris left in the tank during the
manufacturing process is flushed out. Washing the
tank with warm water and some washing detergent
works well. Ensure the tank is completely dry before
you assemble it fully.
The tank comes factory joined and is tested in the
factory for leaks. The recommended hardware is
provided in the kit. Care when assembling the fuel
Fig 10
tank cap and tubing will reward you with a reliable
aeroplane. De-bur inside the brass tubing with a new
sharp scalpel blade and remove any raised edges on
the outside caused by cutting. To aid sealing and help
prevent the fuel tube coming off, solder the short
lengths of tube provided a few mm back from each
end of the feed line and on the outside of the breather
line only.
Use Tygone tube for the clunk line, where the clunkline
passes through the baffle insert a section of brass tube
as the glass fibre edge can easily cut through the
tygone tube. The supplied soft clunk will become
heavier when charged with fuel and easily reach all
areas of the fuel tank.
The fuel tank is designed to be easily removable,
retained by the aluminium tank cap at the front and
two fixing brackets at the rear. The tank cap is
inserted into a 60 x 60 3mm plywood plate that is
fixed to former F2. The two aluminium angles and 30
x 3 x 185mm plywood strip are bonded to the rear of
the tank. Two M4 Allen screws fix these angles to
plywood mounts bonded to the fuselage sides. Start
by laminating the four 40 x 45mm 3mm plywood
mounts into two pairs.
Drill ø 4.1 holes centred on one each of the aluminium
angle faces. Drilling small holes in the opposite face
will help improve the bond to the Plywood spreader
plate and a small screw can be added for additional
security. Assembly of the rear mount is simplified if
you tack glue each part in position with a spot of Slo
Zap cyanoacrylate glue. Start by fixing the plywood
cross piece to the rear of the tank. Gently lay the
tank in the fuselage with the 60 x 3 x 60mm front
mount in plate to set the for/aft position of the tank.
Even moulded Kevlar tanks expand slightly during
filling, so it is important that the tank is not pushed
down into the fuselage before fixing. Tack glue the 40
x 45 x 6mm side mounts to the fuselage side against
the former F3 approximately 8mm down from the
fuselage contour change, using a few spots of thick
CA glue. Tack glue the aluminium mounting angle to
the plywood spreader plate with the ø 4.1mm hole
against the plywood mounts. Using a pen, mark the
fixing position on the 40 x 45 x 6mm plywood plates.
Remove the tank and break free the angles. Mark the
Fig 11
Fig 12
Fig 13
Fig 14
plywood spreader position on the rear face of the tank and sand the area ready for
bonding. Break free the side mounts and drill the marked position ø5.1 to accept M4
T-nuts. The T-nut face will require recessing slightly to allow the mounts to fit flush on the
fuselage side. Bond the T-nuts in position with a small amount of CA or epoxy,
squeezing the nuts fully home in a vice. Ensure you make a pair. Bond the plywood
spreader plate to the tank and allow it to dry.
Mix enough epoxy to fix the 40 x 45 side mounts and aluminium angles in position, put
a small amount of grease on the M4 x 10 Allen head screws to stop them sticking to the
T-nuts. Loosely screw the angles to the side mounts
and place the tank in position locating the angles
against the spreader plate and the side mounts
against the fuselage side and former. Tighten the
screws enough to hold everything in position while
the glue sets.
Remove the tank and reinforce the mount as
Canopy Frame and Canopy Glass
Fig 15
The moulded canopy frame has been factory trimmed
and the retaining system completed. The BAE Hawk
features a large canopy where the fixing and canopy
rigidity is critical. A pair of canopy hooks at the rear
and a single M4 cap head screw at the front holds
the canopy in position with two location tabs halfway
along the frame.
The fixing nut is factory installed and the frame test
fitted before leaving the factory.
The Hawk canopy glass is quite large, this makes
fitment a little harder.
It is important to sand the inside gluing surface to
remove any high spots and it is worth looking along
the frame edge to check for any areas that have
been moulded thicker than ideal. Pay particular
attention to the joint seam line where additional tape
is added. This should be thinned with a Dremmel type
drum sander before the clear glass is fitted.
Fig 16
To ensure the clear glass meets the canopy loop, the
front edge contact lip contact should be kept to a
To protect the clear glass, it is good practice to cover
it completely with masking tape. This protects the
glass while it is being trial fitted and makes it easier
Fig 17
to mark cut lines on.
Trim the front and rear end plate areas off the clear glass with a pair of curved cutting
Tip, do this when the canopy has been sitting in a warm room for some time.
Lay the canopy glass carefully over the canopy frame and mark the rough cut lines with
a marker pen. Mark this line level with the lower edge of the canopy frame-this will
ensure a little excess is left.
Test fit the glass inside the canopy frame and note any areas that need further trimming.
Small notches might be required around the canopy hooks and tabs.
Many modellers have their own favourite method of
gluing the canopy glass in position. We have had
good results with Zap 560 canopy glue and or Zap
CA Note: Do not use kicker which generates excess
heat and can cause the clear glass to fog.
The long sides on the Hawk frame are flat, this allows
the use of straight edge packers to help clamp the
clear glass against the frame. We cut a length of
scrap balsa to use inside the glass and charger power
clips to clamp the glass in position while the glue
Fig 18
Tailplane Assembly
The Hawk features an all flying tailplane (elevator
control) that is easily removable for transport.
Access to the tailplane mount/hinge support is
through a factory fitted rear fuselage hatch held in
position by two pins at the front and a single M4
screw at the rear. Removal of the cover requires the
tail being manually driven to the full up position,
allowing clearance to slide the cover back around
12mm to disconnect the front carbon pegs.
Fig 19
The carbon tail mount and bearing support are
factory installed, making tailplane installation easy.
The carbon pivot tube is not fixed to allow removal
during the build. The method of fixing this tube is left
to the builder as there are several options open to
you. A small cross pin inside the bearings is one
Four M4 x 25 Allen screws hold the tailplane in
position, the mounting holes are drilled and fixing
nuts factory installed on the carbon mount. On early
kits the two double control horns require fitting. Later
Fig 20
kits will have these factory installed.
Fitting the horns on the early kits is a straightforward job, requiring four slots cutting in
the top surface of the cross brace. This brace is hollow in the centre where the centre
pair of horns fit and filled where the outer pair fit. The centre pair of horns should
protrude through to the lower skin. The outer pair should be inserted a minimum of
Mark the control horn centres, working from the left hand pair of mounting holes mark a
line parallel to the two holes 8mm to the left. Then measure across and mark a second
line 51mm to the right. These lines match the pushrod line from the centrally positioned
ball ends. The control horns are fixed with an 8mm gap between. Mark 4mm either side
of the two lines you have made. Outside of these, mark two more lines allowing for the
thickness of the horns-approx 2mm. You will slot between these two lines. The fore/aft
position is measured from the front edge of the cross brace, mark a line 17mm back
from the front edge and a second line a further 17mm behind this. Slotting the brace is
easy using either chain drilled holes or a Dremel type cutter.
The control horn centres should be 16mm above the top surface of the brace and 18mm
back from the front face, these figures are not as critical as the two sets of horns
Two matching elevator servos are required. Composite ARF recommend the JR 8711
servo for this important control. Careful matching of the two servos using your radio or
a servo tester is imperative. Using the recommended super servo arm (JRPA215,
JRC46015 or Graupner Nr 3544) it is possible to match the servo neutral very closely
by checking the mould numbers on the underside of each arm and trying both 180
degree positions. The different moulds (5) feature different spline positions reducing any
sub trim required.
The two elevator servos mount in milled wood frames mounted on a CNC milled
removable plate that is held in position with three M4 Allen screws. It is important that
the centre screw is not over long as it will touch the tail pipe outer tube. The two servos
are mounted with both outputs facing the left hand side of the aeroplane and positioned
to the rear of the fuselage. Use the supplied 2.9 x 13mm sheet metal screws to mount
the servos-not screws supplied by the servo manufacturer. When you have finished the
set up, be sure the servo arm screws are fully tightened with a suitable large Phillips
screw driver.
The twin elevator linkage is assembled from two pieces of M3 all-thread fitted with a
steel 3mm clevis and lock nut at each end. It is important that the two servos do not fight
each other as the servo current draw is increased massively in this situation and will
lead to early servo failure. The tailplane neutral position is with the TE underside 6mm
above the cover split line.
Fin and rudder
Very little work is left for you to complete on the vertical fin and rudder, the single M4
Allen screw fixing is completed in the factory and the rudder servo mount, control horn
and hinging are all factory installed for you. The fin will accept any standard size servo
with a minimum torque of 8kg. We highly recommend a metal geared servo like the JR
8411/8711. It is important to use the screws supplied in the kit and not the screws
provided with the servos, which are too small in diameter to provide resistance to
If you received one of the early kits the servo cut-out
in the lower skin may not have been completed. The
cut-out should be made 32mm forward of the fin spar
centre and be 60mm in length, leaving a 5mm lip
along each edge.
Before installing the servo you need to cut a slot for
the rudder servo horn. The easiest method of locating
the arm position is to fit the servo with a short arm
that will just make contact with the fin skin when
Fit the servo mounting grommets and eyelets before
installing the servo with four 2.9 x 13mm sheet metal
screws with the output closest to the rudder. Mark the
servo output spline centre position on the left hand
skin, before rotating the arm enough to defect the
skin. Mark the horn centre line with a pen and remove
the servo. Draw two parallel lines 5mm apart centred
on this mark and the rudder horn position. Cut a slot
5mm wide and 30mm long
The rudder linkage is made up from a length of M3 x
100mm all-thread fitted with a steel M3 clevis and
locking nut at the servo end, and an M3 ball-link fixed
by an M3 x 16 Allen bolt and locknut through the
dual control horns.
Fig 21
Fig 22
If the fin is to be regularly removed the servo
extension lead socket could be mounted in the
fuselage top using a scrap piece of plywood.
Fig 23
Fig 25
Fig 24
The wing fixing system has been completed for you in
the factory. Two carbon pegs locate into the fuselage
front wing former, and two M4 x 60 high-tensile steel
socket head caps screw into the pre fitted wing fixing
nuts that are bonded into the wing fixing loop formers.
The aileron and flap surfaces are cut free and hinged
ready for installation of the servos and linkages.
Wooden mounting rails are factory installed to accept
the Composite ARF Hawk gear which was specifically
developed for the Hawk. The design allows either
Scale or Sports sets to be installed with minimal
adjustment. The landing gear openings are factory
cut, but may require a small amount of trimming to
clear the struts or wheels. Pre cut gear door covers
are pre painted to match your chosen colour scheme.
The aileron servos are screwed into CNC milled
plywood servo mounts that must be bonded to the
servo covers. The Flap servo mounts are factory
installed as part of the wing structure. All commonly
used servos will fit the openings in either mount. If you
use the recommended JR servos two 650mm long
leads are needed for the aileron servos and two
180mm leads for the flap servos.
Fig 26
Fig 27
Assemble the ailerons servo mounts from the milled
plywood parts provided. Ensure you bond the frame
onto the cover plate making a left and right plate.
We strongly recommend JR 8411/8711 servos for the
ailerons. Before fitting the servo frame prepare the
servo and fit with a JR super servo arm to allow
accurate positioning of the servo arm in the pre cut
slot. Use your radio or a known servo tester to centre
the servo arms before installation. JR servo arms can
be rotated 180 degrees to gain better centring with
minimal sub trim use.
Fig 28
Before bonding the mounts onto the cover plate sand
the gluing area to provide a good key. Tack glue the
frame in place with CA and test fit the servo to ensure
correct positioning. Once satisfied, reinforce the joint
with 30 minute epoxy or Hysol.
The servo should be mounted with 2.9 x 13mm sheet
metal screws provided (not with the servo
manufacturer supplied items) Some servos require a
small amount of the frame support gusset trimming to
Fig 29
clear the servo wire as it exits the servo case.
The aileron servo extension should run along the wing
in front of the main wing spar before passing through
the spar around the centre section. The extension lead
must be restrained where it runs past the flap linkage.
The Aileron linkage is assembled from the 42mm
length of M3 all-thread fitted with a locking nut at
each end and an M3 steel clevis. Fit this on the outer
hole of a 20mm radius arm.
Finally fix the servo cover plate using four 2.9 x
10mm sheet metal screws.
Fig 30
The flap servos are mounted into the servo cut-out pre
cut in the wing rib accessible through the main gear
opening in the wings lower surface. The servo is
mounted with the servo arm nearest the wing trailing
We recommend a servo with minimum 9.0kg torque
as the Hawk flaps are quite large and the actuating
horn offset from the hinge point is relatively small.
C-ARF strongly recommends using the JR 8411/8711
servo for the flaps, fitted with a heavy duty servo arm.
Very little movement is needed for total flap travel, so
Fig 32
Fig 31
Fig 33
the arm can be cut leaving only the inner two holes.
The flap servos are fitted using four 2.9 x 13 sheet metal screws-note do not use the
stock servo mounting screws
Some time should be spent cleaning up the factory cut openings for the flap linkage with
a file to remove any material left around the opening. This will stop any binding of the
linkage during flap operation. At least 60mm of flap movement is required in landing
The flap linkage is assembled using two M3 x 200mm all-thread rods fitted with a
locking nut at each end and a steel M3 clevis. This benefits from some additional
support in the form of a tube slipped over the all thread between the clevis fixing nuts.
On early kits, the factory linkage access hole through the main wing spar needs
adjusting for pushrod clearance. Fitting the linkage from the flap control horn will show
you the required direction of slotting to allow clearance. It is possible on early kits that
the control horn will also need adjusting if it does not align with the servo arm. This is
simple using a pair of large grips to crack the horn into position, before rebonding with
Fig 35
Fig 34
Fig 36
Fig 37
Fig 38
Fig 39
To allow perfect flap operation it is important to set the two flap servo arm neutral (take
off Flap) from your radio in the centre position of any control switch or lever.
Main gear door installation.
The main gear doors are supplied moulded in one piece. These should be separated
into three pieces, the larger inner section is hinged using the milled phenolic hinges and
the supplied rod and tube. The centre section will be fitted to the struts and the small
base piece notched to clear the strut, or hinged if you chose.
Fig 40
Fig 41
Fig 42
Fig 43
Fig 44
Fig 45
Operation of the inner doors requires two large bore approx 1.5” stroke air rams. These
can be bought as part of the optional Composite ARF air pack #200550 or sourced
individually. We recommend Robart 3/8” air cylinders F-RB165. These are angled and
overlap each other in the wing centre section.
The hinges need separating from the phenolic sheet and the retaining tags sanding off.
It is good practise to tack glue the hinges and tubes in position to allow easy adjustment
and ensuring perfect operation before final fixing.
With the door pieces separated spend some time sanding the door recess to remove any
high spots and chamfer the door edges so that they seat fully in the recess.
Fig 46
Fig 47
Fig 48
Fig 49
For the doors to operate properly the hinge tubes need to be bonded to the wing skin
directly. The moulding process means it is possible that the foam skin could encroach
into the hinge tube area. This is no real problem as the foam easily sands away using a
round file.
Access to the hinge wire is through the wings leading edge centre section. Drill two 3mm
holes at 88mm centres and 31mm down from the wings seam/joint line.
To check the foam board position use a small mirror, if necessary clean away the foam
to allow the plastic hinge tubes to be bonded onto the wing skin.
Tack glue the hinges onto the gear doors with the rear hinge 13mm from the back
corner and 82mm between the two hinges.
The hinges require slots cutting in the wing gear door shut. Use the doors complete with
hinges as a reference and mark the wing slot positions.
Carefully cut the slots, ensuring they are only fractionally wider than the phenolic
hinges. Cut three pieces of the white 3mm dia plastic tube provided, one long length to
match the distance between the hinges fitted to the doors and two 20mm long lengths
for outside each hinge. The Hawk has such a large gear opening and thick wing it is
easy to work on one door at a time and access the hinges through the opposite door
opening. The use of a mirror will help with the hinge tube installation.
When satisfied with the hinge positioning, and opening angle, the hinges and tubes can
be fully bonded in position. On a Hawk the main doors open to around 85 degrees.
To aid cylinder clearance fitting ball link ends will allow one cylinder to be attached to
the inside and the opposite attached to the outside of the hinges. The Robart cylinders
require 2-56 threaded studs and suitable ball ends. The bases of all Robart cylinders are
conveniently fitted with a mounting base. This should be screwed to a scrap of 3mm
plywood approx 20 x 20mm.
The air cylinders should be fully extended and the gear door open position set before
bonding the cylinder mounts to the wing upper skin. This process should allow the
cylinders remaining stroke to act on the gear doors holding them shut against air
pressure in flight.
Main Landing Gear installation
Fig 50
Fig 51
Fig 52
Fig 53
Assemble the struts and retract units leaving the pin loose enough at this time to allow
adjustment of the wheel alignment.
The main units are installed with the cylinders pointing towards the wing tips. Slide the
units along the mounting rails until the wheels clear the door opening edges. The scale
struts feature larger diameter 114mm wheels than the sports struts, which have 100mm
wheels. If you think you might upgrade to scale struts allow for the additional 7mm
clearance required.
The close proximity of the gear opening may require trimming and half round notches
filing for mounting screw access. Drill the four mounting holes ø4 in the wood mounting
rails and remove the retract units. Open the four holes to ø5.5mm to accept the M4
Some of the T-nuts will require trimming for structure clearance. Before installing the
nuts apply a small amount of grease into the threads to stop glue locking the screws in
Fig 54
Fig 55
position. Apply a small amount of 30 minute epoxy onto the nuts and partially pull into
position using an M4 x 15 cap head screw and a large M4 washer. Do not pull them
fully home to allow final seating with the retract units in position. Working quickly re
install the units and pull the T-nuts fully home by tightening the retract units fully. Allow
the epoxy to fully cure before removing the units.
The steel retract/oleo pins require flats grinding to stop the hardened pins slipping in the
oleo leg. Insert the pin leaving 18mm protruding from the oleo leg and mark the four
grub screw positions to aid grinding the flats. Ensure the flats do not have sharp corners
as these create stress points where the pin can crack.
Use a thread locking compound like loctite to install the four set screws in each leg.
Install the oleo legs back in the retract units and nip the clamp screw just tight enough to
hold the leg in position.
With both legs installed ‘eye ball’ the wheels and use a straight edge held on the
Fig 57
Fig 56
outside edge of the tyre to check alignment.
Aircraft tracking is better with a very slight ‘toe in” on the wheels, but straight wheels
are better than ‘toe out’ which can lead to instability on the ground. Test the wheel
clearance during retraction and check that the main wheels clear the gear doors when
Fig 59
Fig 58
fully retracted. If tyre clearance is tight a thin plywood shim under the retract unit to
lower the wheel when in the retracted position should be added. Once you have found
the perfect position fully lock the legs by tightening the lock screws fully.
The wing structure features convenient openings to allow the air tube to be easily routed
through the wing to the centre section. The services (air and servo) can exit the wing
either through the top surface, or if you may fit a smoke system it is best to exit the
wings leading edge between the wing pegs.
The lower leg gear door covers are mounted using a shaped piece of wood glued to the
gear door with epoxy, and bonded to the oleo leg using a silicon adhesive. Additional
security is gained by drilling through the door and spacer and tapping the alloy leg M3
to accept two M3 screws.
The small door that covers the retract unit can either be notched to clear the leg or
hinged as the full scale Hawk.
Nose gear
The nose unit on the Hawk is specially designed with a large strong mounting frame,
perfect angles up and down, plus a positive, slop free and snag free steering system.
Fig 61
Fig 60
The steering servo moves with the nose leg removing the chance of snagged steering
cables and twisted jammed legs.
Mount the steering servo in the CNC machined frame using four M3 x 12 Allen screws
with the arm furthest from the steering arm. The steering servo requires a strong servo
arm at least 18mm between centres, using your radio set the servo arm neutral position
parallel to the steering arm fixed to the nose leg, with the wheel straight. Assemble the
Fig 62
Fig 63
linkage from two plastic ball-Links and a single length of M3 x 30 all-thread. Fix the
ball-links to the steering and servo arm with M3 x 16 Allen screws and M3 loc nuts. The
mounting plate is notched to clear the up line air connection nipple. Some units have
been assembled with the nipple on the opposite side, you can either notch the mounting
plate or switch the cylinder over. There are six mounting holes in the retract frame, but
only four are required. Before drilling the mounting holes place the nose leg in the
down position and check there is 2-3mm clearance between the back of the leg and
nose former. Drill four holes ø 4mm adding a screw into each hole as you drill, this
helps ensure the holes all match. Remove the nose unit and open each hole to ø5.5mm
ready for M4 T-nuts. The position of the rear fixing close to the nipple notch may break
into the cut-out, in this case the T-nut will require part of the flange removing. Install the
T nuts with some slow setting epoxy glue, pull them partially home with an M4 screw
and washer before installing the nose unit and tightening until fully seated. Installation of
the nose unit is made easier if you remove the rear nose former cross link section of
Fig 65
Fig 64
Nose Gear Door
The Full scale Hawk features twin “bomb” door style nose doors, plus a single small
“leg” door. Your Hawk kit includes sufficient hinges to allow the scale set up to be
Fig 66
Fig 67
This method will require two nose gear cylinders for operation, and a spring to close the
small door. As the Composite-ARF Hawk is intended as a sports scale aeroplane many
of the team have decided to use a single nose gear door, hinged on one side only. This
method is much simpler than the twin set up and in flight the appearance is not
The process and hinges are the same for either set-up,
you could even split the door at a later date and add
a cylinder to drive the second door.
The first job is to clean up the nose gear opening,
filing the two sides to be parallel just outside of the
panel line marks. The nose door is supplied moulded
to shape with a double curve front section to match
the nose area. Cut and sand the door near the
marked lines and then finally sand the door to fit
inside the opening with a 0.5mm gap all-around. If the
Fig 68
door is to be split cut the end small leg door off and
then cut down the centre marked lines and sand to leave the same 0.5mm gap once the
doors are hinged. Fabricate some door close stops from scrap material and place
around the nose opening. These should protrude no more than 3mm to avoid fouling the
nose leg and wheel during operation.
Before fitting the hinges it is worth opening the nose unit/leg enough to allow marks to
be made denoting the areas to avoid with the hinges. On the airframe shown the hinges
Fig 70
Fig 69
are positioned at 35mm, 126mm and 180mm back from the front edge with the nose
cylinder attached to the front pair. It may be necessary to trim the rear hinge to clear
the nose wheel steering servo which sits in the door opening in with the leg in the down
position. This depends on the depth of servo case on your servo choice. The curved
nature of the nose door may require some additional bracing to maintain the shape. We
used some scrap 3mm hard balsa as shown. The supplied hinge rod should remain
straight even though the nose door area is heavily curved. The front and rear hinge
tubes will touch the fuselage skin, the centre tube will require supporting with some
scrap balsa. By design the Hawk doors must move away from the fuselage immediately
they start opening to guarantee smooth operation and clearance while opening.
Sanding a small radius on the inside edge of all doors will reduce the chance of them
catching on the fuselage surface.
The recommended Robart air cylinders can be mounted near vertical in the height of the
Fig 71
Fig 72
Fig 73
Fig 74
Fig 75
Fig 76
fuselage. Whether you chose a single door or scale twin doors the cylinders base mount
to the top inside face of the fuselage shell. The angled face will require a packing piece
approximately 10mm thick before shaping. The cylinders should be fully extended with
the doors open, this will leave a few mm of travel when the door (or doors) close,
helping to resist opening from air pressure in flight.
Inlet ducts
The intakes are moulded separately for accurate scale appearance and allowing
additional access during the construction. Your chosen scheme will be factory painted to
match the fuselage detail making the job of fitting very simple. The fuselage shape can
benefit from a fixing screw adding in the splitter front corner. Use a piece of scrap wood
Fig 77
Fig 78
from the provided sheet and add a single self tapping screw from inside the cockpit. The
rear face of the inlet is glued with epoxy after removing the shine from both surfaces.
Note the lower 40mm or so does not require glue as it forms part of the front wing joint.
Equipment bay installation
Experience with the three prototype Hawk models confirms that the Hawk benefits from
as much weight kept forward in the cockpit area as possible. You are aiming for a
balance point between 190mm and 200mm back from the fuselage/wing joint. If you
intend using a scale cockpit set some adjustment of the battery position maybe required.
The equipment tray provided can be positioned to suit your preferred set-up, but is
probably best kept towards the front of the cockpit opening. With such a large canopy
glass area painting the cockpit area in a dark colour will help give the impression of a
scale cockpit, even with minimal detail added.
The radio plate has several cut-outs factory cut. The notch in one end can either be used
for a header tank or ECU battery placement on the floor. Either side of this, slots and
holes are formed for the Rx and turbine ECU allowing Velcro ties to secure them firmly.
If you are fitting the recommended Powerbox unit (Evolution, Competition or Champion)
the plate includes two cut-outs for the unit and wiring.
Composite ARF recommend that you fit a Powerbox unit using a true duel battery system
and featuring signal boosting electronics. This product is available through C-ARF.
We placed the header tank in front of the wing former to keep the tube from the main
tank to the header as short as possible. If you chose to fit the tank at the forward end of
the tray ensure large bore tubing is used to keep the pump load low.
If your intention is to fit a scale cockpit, thought should be given to keeping the
equipment mounted low within the cockpit area. The Hawk features staggered pilot
seating with the rear pilot mounted higher than the front, this allows you a little more
height close to the inlet area of the cockpit.
The photos included in this section give you several ideas on the equipment layout, but
the many different turbines available will require specific requirements.
A semi scale cockpit is available from C-ARF , this can be ordered through the
CARF-models site. Several manufacturers offer full scale cockpit sets that could be fitted
should you wish to “scale” the Hawk up.
If you intend fitting a cockpit now or possibly in the future it is a good idea to fit the air
tanks serving both the undercarriage and brake system above the main fuel tank as
there is ample space.
The plates either side of the undercarriage nose formers make perfect platforms for
mounting the receiver system twin battery packs.
Even with 2.4 GHz systems it is good practise to keep a reasonable separation between
ECU, fuel pump and valves. Avoid crossing the receiver aerials with power cables.
When you plumb the fuel system, keep all tubing as short as possible. Ensure the tube
ends are cut square, especially when used with any quick connect device. When using
larger tube like Tygone, cutting a short (5mm) length and sliding this over the tube end
by stretching with pliers will improve the seal by adding additional grab.
Fit the fuel system overflow outlet in the fuselage just in front of the wing break former,
positioning to one side will lessen the chance of damage in the event of a touch down
without landing gear.
Additional Fences and covers
Your Hawk kit includes various parts cut from a colour coded glass sheet. The wing
fences are an important feature on the Hawk. The glassfibre fences are fitted to the
wing leading edge just outboard of the aileron/flap break line. If you project a line
forward from the aileron inner edge there is a rectangular panel approximately 12mm
wide and 60mm long marked 45mm back from the leading edge. The wing fence is
mounted centrally on this panel using thick CA or epoxy.
Another feature of the Hawk are the fuselage fins mounted either side of where the
airbrake would be positioned. Two parallel lines are marked on the fuselage making
installation easy. The fins are given additional support by cutting two slots to accept the
location lugs. The fins should be firmly fixed using epoxy. The fins should be fixed with
an angle of approx 115 degrees on the inside edge.
To hide the openings in the tailplane cover sides around the elevator joiner, two shaped
cover plates that attach to the cross brace are provided. Ensure these plates cannot
cause binding with full and free movement on the tailplane.
The remaining vanes and plates are optional in their fitment, study a full size Hawk to
position these scale additions.
Setting up and Balancing
The final weight of your Hawk will vary with your turbine and radio equipment choice,
the prototype models varied between 11 and 12.5kg dry.
Set the Centre of Gravity at 190mm from the fuselage/wing break for the first flight with
the main tank empty and the header tank full. Further improvements in flight
performance will be seen if you laterally balance your aeroplane also.
Control throws
Experience has shown us that different pilots prefer different response “feel” so the
movements and expo figures quoted should be taken as a guide only. The all flying
tailplane (elevator control) requires extra care setting up the twin servo linkage. If you
carefully matched your servos in the earlier steps, little or no binding should occur. Note
when using digital servos some noise is normal when the control surface is moved, the
pitch of the sound will raise if the servos are under extreme load. A good tip is to
operate the elevator control with each linkage in turn only connected and listen to the
servos. When you connect the second linkage the sound should only change slightly.
Using a Powerbox unit with matchbox facility allows additional adjustment through the
centre and extremes of movement. A range of Powerbox products are available through
Starting point movements
Aileron travel 16mm up and 18mm down Expo 25-35% (Positive JR/Spectrum-Negative
Elevator travel 30mm up and 25mm down 25-45% (Positive JR/Spectrum-Negative
Rudder 35mm left and right 15-35% (Positive JR/Spectrum-Negative Futaba)
Flaps. Take-off 25mm and Landing 65mm with the recommended Centre of Gravity there
is no elevator compensation required with flap deployment.
All dimensions are measured at the root trailing edge of any surface.
BAE Hawk Hardware Bags
Rear Fuselage/Rudder/Stab
Sheet Metal Screw 2.9 mm
Servo screw
M4 x 12 allen bolt
stab servo frame mount
M4 washer
stab servo frame mount
M4 T-Nut
stab servo frame mount
Control horn (3mm hole) (later will be installed)
stab and rudder
Ball links M3
stab and rudder
Steel Clevises M3
stab and rudder Servo
M3 x 16 mm allen bolt
for ball link fixture
M3 lock nut
for ball link fixture
M4 x 25 allen bolt
for stab mounting
M3 all thread (100 mm long)
rudder linkage
M3 all thread (60mm long)
elevator linkage
200 x 100 mm fiberglass sheet
stab spades (covers)
M4 x12 allen bolt
rear hatch mount
2mm steel pin 250 mm long
gear door hinging
3mm plastic tube 250 mm long
gear door hinging
milled phenolic board
nose gear door hinges
M4 x 16 allen bolts
gear mounting
M4 T nuts
gear mounting
M3 ball link
nose gear steering
all thread M3 (25 mm long)
nose gear steering
M3 x 16 mm allen bolt
nose gear steering
M3 lock nuts
nose gear steering
M4 x 16 allen bolts
canopy fixing screw
carbon axle, ball bearings and carbon stab mount are pre-installed in fuselage
Allen bolt M4x20 for fin fixture is pre-installed in fin
milled wood parts for stab servo frame, not assembled
Sheet Metal Screws 2.9 mm
Servo screw
sheet metal screws 2.2mm Servo hatch screw
steel clevis M3 aileron and flap linkage
M3 nuts aileron and flap linkage
all thread M3 (42 mm long)
aileron linkage
all thread M3 (200 mm long)
flap linkage
servo hatch (maybe taped on the wing?)
aileron servo
M4 x 60 mm allen bolts wing bolts
allen bolts M3 x 20
gear door leg cover mount
aluminum tube ID 3mm, 100 mm long
gear door leg cover spacer
2mm steel pin 250 mm long
gear door hinging
3mm plastic tube 250 mm long
gear door hinging
milled phenolic board
main gear door hinges
M4 x 16 allen bolts
Gear mounting
M4 T-nuts
Gear mounting
servo hatch wood mounting frame part of CNC wood plate
Turbine installation
M4 x 20 allen bolts
Turbine mounting
M4 T-nuts
Turbine mounting
2.2 mm sheet metal screws
thrust tube mount
Small aluminium angles Bell mount mounting angles
M3 x 10 allen screws
Carbon deflector fixing screws
M3 nuts Carbon deflector fixing nuts
Carbon Deflector Duct
Double wall tail pipe tube
Carbon Bell mouth
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