At high speed the Hawk springs to life. It can perform any manoeuvre a real jet can do.
by Khalid Ally
The Hawker Sidley BAe Hawk was originally built in the early 1970's to meet the RAF requirements for a basic and advanced jet trainer. Fully aerobatic, it was stressed for +8 and -4g manoeuvres. A number of variants were built for specific roles and many were ordered by countries outside the UK. During the 1980's the premier aerobatic team in England was the Red Arrows, using the Hawk for spectacular displays at airshows. Recently the RAAF announced it will purchase the updated version of the Hawk for their jet trainers.
The Red Arrow Hawk is a semi-scale, prop driven model designed for .35-.46 two stroke motors. Construction is kept simple with ample flying surfaces for easy and safe handling. This model will appeal to the sport modeller who likes jets. I have been building models since 1948 starting with chuck gliders and rubber models.
Now retired from flying jet fighters in the Indian Air Force ( aircraft included the Hawker Hunter, Gnat Mk1 and MIG-21) the model Hawk was just the thing to fulfil my radio control model dreams.
Building The Model.
Start by cutting out all the parts into kit form. To mark out the parts onto balsa and plywood, I photocopied sections of the plan, then placed the photocopies face down onto the timber and pressed them down with a hot iron to transfer the image. Lay the plans over a flat building board and protect the plan with greaseproof or plastic lunch wrap.
Start by pinning the lower main spar onto the plan. Glue all ribs onto spar. Set W1 on an angle to allow for the dihedral. Glue the top spar into place, followed by the trailing edge spar and leading edge from W3-W10. The centre section leading edge is added on after joining the wing halves. While the wing is still on the board, glue in the vertical web shear webbing in front of the main spar. Allow to dry.
Join the wing halves by glueing the three dihedral braces over the inboard ribs with epoxy and lifting each wing tip off the building board by 30mm. Bevel the edges of D1 before adding on the remaining section of leading edge. Now install the main undercarriage mounting blocks into the wing using epoxy. Cut out a section of W1 for the aileron servo well. The top and bottom of the wing plus capping strips can then be glued ensuring no warps are introduced at this stage. Shape the strip ailerons and inboard trailing edge. Fit the aileron torsion rods and trial fit the ailerons onto the wing with hinges. Add the wing tips, sand the entire wing to shape.
Glue in the wing locating dowels, and also the ply trailing edge reinforcement plate. Build up the aileron servo tray and glue onto top centre of wing.
The tailplane, elevator, fin and rudder are all cut from 9.5mm balsa sheet. The tailplane halves are joined together with anhedral set by the tailplane brace. Sand the tail surfaces to shape. Install the hinges and control horns.
Cut out the fuselage sides from balsa sheet to outline shown on plan, join as required for the correct depth. Make up a left and right side with reinforcement doublers and longerons on the inside face.
Note grain directions. Epoxy the two pieces of F2 and F3, F5 and F5a to make up correct thickness. Using a pen mark the positions of the formers. Mount the steerable nosewheel assembly unit onto F3. Now glue formers F5, F6 and F7 at right angles onto the fuselage sides, then draw the ends together and glue in the rest of the formers.
Check alignment over plans. Using soft balsa blocks and sheets build up the top fuselage, plane and sand to shape. Make cut outs for fin and tailplane and then glue these into the fuselage. Trial fit the wing and fix bolt mounts onto F7. Check alignment.
Make up a ply wedge for the right thrust of the engine mount onto the firewall, then bolt the radial engine mount onto the firewall F2 and check for correct position of engine. There is no down thrust on this model. Trial fit the tank and fuel lines. Fit the cable onto the steerable nose wheel unit, then cover the underside fuselage between F2 and F5 with balsa sheet. Build up the nose cone around the engine using balsa blocks. Sand to shape to blend into fuselage.
Install the radio gear at this stage and make up pushrods and cables to suit controls. When satisfied complete the rear underside fuselage sheeting and tailpipe. Sand to shape. cut out for access hatch between F8 and F9. Add the fin strakes either side of hatch. Cut the cockpit floor to size and glue onto it the canopy frames. Paint and decorate the inside of the cockpit. Trim the moulded plastic canopy to shape and glue onto the frames. The canopy rear of C1 is removable for access to fuel tank. To complete the fuselage build up the dummy engine nacelles on the sides of the fuselage with planking. Sand to blend into fuselage shape. Re-check fit of wing, then trim engine nacelles as required. Bend the undercarriage legs to shape, strap onto wing. Attach wheels on with wheel collars.
Covering and Finishing.
The Hawk jet offers a wide choice of colour schemes for model builders. the Red Arrow aerobatic Hawk is perhaps the most striking but I chose a simpler RAF training colour scheme with orange, white and royal blue. I used heat shrink plastic film to cover the prototype. Paint the dummy jet engine intakes black, and also paint the canopy frames to suit. Add roundels and other markings to finish off the model. Thoroughly fuel proof the engine bay. Reinstall the engine with spinner. My prototype used and OS.32 FSR engine.
Fit the tank, fuel lines, wheels and all radio gear into the model. By positioning of battery in particular balance the model at the most forward C.G. position shown on plan. Move to rearward position for greater manoeuvrability after the first few flights. Check all controls move freely and test run engine for reliability.
Flying the Model.
The Hawk taxies well with the steerable nose wheel to line up for take off. With full power the Red Arrow Hawk roared to life and began its rather long take off run. After airspeed is built up , a touch of up elevator pulled the aircraft away from ground. Keep the climb out gentle, gradually building up height. A good .40 or .46 would provide ballistic power for the Hawk, however my tiny OS .32 was more than adequate to satisfy my flying needs. Once height is gained the engine can be throttled back. Low speed handling is very good, no sign of dropping a wing. The Hawk was flown safely at very low speeds at low altitude in figure 8 circuits for the benefit of the photographer. After the snaps were taken, it was full throttle again for some high speed action.
At high speed the Hawk springs to life looking very much like the real thing in the air. No change of trim was required. After a few speed runs, the Hawk was climbed up to test out its aerobatic capabilities. Loops were easy and quite tight. It rolls smoothly, axial or barrel, and snap rolls. It performs split "S", figure 8's, inverted and anything the real jet can do. The spins are exhilarating and recovery is quick and positive. It will even knife edge with the small size engine.
Landing the Hawk is straight forward, for round out the nose can be pulled up high just like the real thing.
I found this model very satisfying to fly having flown full sized jet fighters. Although not a beginners model the Hawk can be flown and aerobated in most realistic fashion in the hands of someone with moderate experience. It is a real pleasure to watch and fly.
SPECIFICATIONS Red Arrow HawkType: Sport Scale Prop Driven Jet Wingspan: 1.15 metre Engine: .35 - .46 two stroke 4 channel radio control required
Red Arrow Hawk plans are available from:
Airborne Plans Service
AU$33.20 plus AU$2.00 P&H2
Moulded Canopy: AU$27.50 plus P&H (AH$6.00 within Australia).
Plan No. 590
Click here to order this plan
To return to Airbornes home page
This page was last modified on the21-May-02