No gyro is needed, but of course it’s always nice to have one on the rudder and nose-steering for
cross-wind take-offs and landings.
Ground angle:
With the main and noseleg lengths shown in the manual, and same diameter wheels, the Hawk
should have the close to the correct angle of incidence when fully fuelled on the ground. For nice
smooth takeoffs, and bounce-free landings, you can fine tune the main and/or nosegear landing
gear leg lengths a little if necessary so that the wing incidence at the root is between 0° to +1 de-
gree. With takeoff flap set then the ‘effective’ wing incidence will be a little more positive which gives
a smooth rotation.
This incidence gives nice easy takeoffs, and the plane settles down nicely on landing. If you are
flying from a grass strip you can increase the root incidence a little more if necessary, remember-
ing that the washout will give almost zero angle of attack at the wing tips.
In case you don’t have an incidence meter then the underside of the fuselage below the cockpit
should be almost level to the ground, which can be checked with a spirit level. At the noseleg po-
sition it should be about 8 - 9mm above the joint with the leading edge of the wing.
Flying the Hawk
As usual it is wise to make all your engine and fuel system checks before going to the field for the
first flight, and during these tests check that the back of the fuselage is not getting too hot. Cer-
tainly outer fuselage temperature should not exceed 60 degrees C at any position. In this case you
will normally need to move the turbine forwards a little, to increase the gap between the nozzle and
the bellmouth of the thrust-tube to induce extra cooling air to be sucked between the 2 tubes, and
also between the fuselage and outer tube, or ejector ring.
When you go to the field for the first flight it is always wise to have another experienced helper with
you to act as a spotter, advise and generally reduce your work-load. With the throws and Centre
of Gravity mentioned above the Hawk is quite docile with the new larger ‘sport’ (2-piece) wing,
and is a very nice flying model. However, if you are flying with the smaller ‘scale’ wing be gentle
with the elevator until you are comfortable with the flying characteristics.
All-up dry weight should be around 12 -13 lbs (5.5 - 6kg) with a turbine in the recommended range.
The prototype was a little heavier than this, and had the smaller ‘scale wing, at about 6.5kg - but
it still flew fine.
Check the CG again before takeoff, and make sure that it is at 140mm from the central leading
edge of the wing, with half full fuel tanks. You can check and fine tune this by flying the plane in-
verted, and if you have to hold in a lot of ‘down’ elevator to fly level - then the plane is too nose-
heavy. The Hawk should need just a little ‘down’ elevator to fly level when inverted. If the plane
climbs, or needs no ‘down’ elevator to fly level when inverted, then it is a bit tail-heavy and you
should land and adjust the position of your gear or batteries to correct it.
Takeoff presents no problems at all, but keep the nosegear steering travels to a minimum, and a
little toe-in on the main wheels definitely improves the tracking.
I believe that the full-size Hawk uses 15 degrees of flap for takeoff, and about 45° for landing, and
I used the same on the prototype model, although no takeoff flap is needed at all if there is a little
nose-wind. 40 - 45° landing flap tends to give some nose-down effect, which I adjusted out by
mixing about 3mm of ‘up’ elevator with full flaps. Another solution is to use crow-braking - where
Fox Composites Co., Ltd.
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