P&M Aviation QUIK-GTR, Operator'S Manual

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P&M Aviation Quik-GTR Manual, Quik-GTR1.0doc
Page 80
Electric Trim and STARS system:
For the GTR wing a patented roll augmentation system has been introduced called STARS (stability and roll
system). Flexwings generally have light handling at high speed but become progressively more stable and
heavier to manoeuvre at lower speeds. The Stars system works with the trimmer so that the more nose-up (slow)
trim is applied, the more the STARS system works to increase roll response. The way it works is shown
schematically below.
Pitch axis
Fast trim:
In the fast trim condition the whole system is slack and has no effect on the wing. The wing trims fast because
the hangpoint is set to provide the maximum hands-off trim speed (approximately 90mph). The wing is shown in
the fast trim condition in figs 3 (side view) and 4 (rear view), where the sail is shown with minimum washout. The
minimum washout is held in by the washout rod system so as to produce positive pitch stability.
In the fast trim condition the STARS system must be set so that it becomes just taut as the control bar
approaches the pilot’s stomach.
Slow trim:
Referring to fig. 1, In the slow trim condition the trim motor 1 pulls the trim spring (bungee) 2 and tightens cord 3
which is attached to the keel by pulley 4.
At pulley 4 the cord splits into two, one running to each wing around pulleys 5. The cord continues into position 6
then around pulley 7 which is attached to the outboard washout rod 9. The cord continues from pulley 7 to
position 11 and is attached to the leading edge post 10.
Since the washout rods are connected to the leading edge by a universal joint and are prevented from moving
inboard by cord 8, tension in the trim cord 3 causes both washout rods to be pushed upwards, so increasing
washout. Increased washout improves pitch stability and also prevents the possibility of tip stalling. Tension in
cord 3 also applies a direct mechanical nose-up pitch relative to the trike. The combined effect is to slow the trim
speed and increase pitch stability.