Piper Cherokee LANCE, Service Manual

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PIPER CHEROKEE SIX / LANCE SERVICE MANUAL
07/15/06 IV - STRUCTURES
1F23
4-29. STABILATOR DRAIN HOLES. In order to prevent the accumulation of water or ice in the stabilator
when the aircraft is parked, it is recommended that drain holes be added in accordance with Figure 4-14.
4-30. CONTROL SURFACE BALANCING.
4-31. CHECKING CONTROL SURFACE BALANCE. The movable control surfaces have been statically
balanced at the time of installation at the factory and normally should not require rebalancing. Where
possible the control surfaces were set with the balance weight on the heavy side of the limits, to permit
limited repair or paint touch-up without adjusting the balance weight. It should be noted however, that
spare control surfaces are delivered unpainted and the static balance will not necessarily fall within the
limits provided, this is more pronounced on the stabilators and rudders. The completed control surface
including paint should be within the limits given in Table IV-II. If the surface is not to be painted, the
balance weight will probably require adjustment. Rebalance all replacement control surfaces, or surfaces
that have been repainted, according to the procedures given in paragraphs 4-33 thru 4-35. The static
balance of the surfaces must be as specified in Table IV-II.
Before balancing any control surface, it must be complete including tip, trim/servo tabs as applicable and
tab actuating arms or push rods with bearings as applicable, and all optional equipment which is
mounted on or in the control surface when it is flown, including paint, position lights and wiring, static
wicks, scuff boots, etc.
If optional equipment is added or removed after balancing the control surface must be rebalanced.
During balancing, trim/servo tabs must be maintained in their neutral positions.
4-32. CHECKING CONTROL SURFACES FREE PLAY. The following checks are recommended before
balancing to ascertain the amount of “free play” in the stabilator, stabilator trim tab and aileron:
a. Stabilator: Check the stabilator for any “free play” at its attachment points by grasping each half
near the tip and gently trying to move it up and down, fore and aft, and in and out. No play is
allowed.
b. Stabilator Trim Tab: Set the stabilator trim tab in neutral position. This neutral position is
determined with the airplane properly rigged per instructions given in Section V of this Service
Manual and the trim indicator at its neutral position. Obtain a straightedge long enough to extend
from the ground up to a few inches above the trim tab trailing edge. Place the straightedge next to
the trim tab inboard (center) trailing edge; secure the stabilator in neutral and grasping the tab,
gently move it up and down, mark the limit of tab free play on the straightedge. The overall travel
(free play) must not exceed 0.15 of an inch. The use of a dial indicator and fixed stand is
recommended.
c. Aileron: Set the aileron in its neutral position and secure. Obtain a straightedge long enough to
extend from the ground up to a few inches above the aileron trailing edge. Place the straightedge
next to the aileron trailing edge and gently move the aileron up and down, mark the limit of travel
(free play) on the straightedge. The overall travel (free play) must not exceed 0.24 of an inch.
Should free play exceed the limit stated make necessary repairs as required to eliminate excessive
free play. Grasp the aileron and move it spanwise inboard/outboard) to ensure maximum end play
of .035 is not exceeded.
4-33. BALANCING EQUIPMENT. (Refer to Figure 4-15.) Balancing must be done using a suitable tool
capable of measuring unbalance in inch-pounds from the centerline of the control surface hinge pin. See
the tool configuration in Figure 4-15. Other tool configurations may be used, provided accuracy is
maintained and recalibration capability is provided.