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

Page: 64 / 95

P&M QUIK-GTR Manual, ref. QUIK-GTR Man 1.0.doc
Page 64
11. TUNING THE WING
11.1. NEW AIRCRAFT
11.2. WING TUNING
A well tuned wing will fly in a straight line hands-off and will respond to control inputs equally in each direction.
However, fabric can stretch slightly with age and ribs can alter shape and get bent or distorted. The most
common problem with flexwings is the tendency for the wing to acquire a turn one way which can be irritating and
tiring on a long flight. Turns like this can be tuned out and are invariably due to rib shape or tip setting problems.
However, it may be that airframe damage has occurred so if a turn becomes apparent the first thing to do is to
check the frame carefully, inspecting for bends and distortion particularly in the leading edges. If the frame is
alright, you should check the ribs against the template and adjust accordingly. In fast cross-country flight the
nosewheel can be used as a trimmer (nosewheel right = slow left turn in flight). With a well tuned machine, in
smooth conditions it should be possible to cruise with arms folded, making course corrections using the
nosewheel.
With the STARS system, it has been found best to move the tip adjuster plugs symmetrically, only for trim speed
adjustment. Instead of adjusting the tips asymmetrically, the STARS cords can be used to tune out low speed
turns and the wing rib reflex technique used for high speed turns.
Prior to delivery to the customer all new aircraft are flown and set up by either the Factory or by Appointed
Dealers. A full check flight is carried out and adjustments made to the wing to ensure that it is properly
trimmed out and flies hands off at the right speed. Owners are discouraged from making any adjustments. If
you feel your new P&M aircraft is not performing as it should, it is essential that your dealer is immediately
informed.
The following notes are for guidance only. Since tuning of flexwings is a specialised technical procedure, no
adjustment should be made without a full understanding of the principles involved. Please observe the
following simple guidelines:
1. Before making any adjustments check for correct rib profiles against the rib plan supplied. If the aircraft is
not new, then also check the airframe components, particularly the outer leading edges.
2. Never exceed the adjustments specified in this Tuning Guide.
3. Make notes of every adjustment made. Only ever make one adjustment at a time, and carry out a flight test
to gauge the effect before making further adjustments.
4. When the exercise is complete, you should discuss any adjustments made with your Instructor or Dealer
and then enter them in the Aircraft Technical Log.
5. If you cannot get the aircraft to fly as it should, then first return all the settings to standard and reassess the
situation. If this cannot be made to work, contact your Dealer immediately.
WARNING
!
Those operators who wish to tune the GTR wing should contact a P&M Aviation agency for
additional advice. Before any tuning is attempted, a careful and thorough check of the airframe is
essential. A sudden indication that the wing requires tuning may be the result of damage caused in
an unreported accident or from a heavy landing. Unless your are an experienced flexwing pilot, you
should ask your Instructor/Dealer or Check Pilot to assist with all tuning operations and have
him/her carry out the flight tests.
WARNING
!