Piper Navajo PA-31 Service Manual page 242

PIPER NAVAJO SERVICE MANUAL
5-69. WING FLAP CONTROLS. (CALCO SYSTEM.) (S/N 317912001
and up.) (Refer to Figure 5-18.)
5-70. DESCRIPTION AND OPERATION. The wing flap control system
provides continuous control and
monitoring of flap position and condition over its full range. In addition to the
limiting of both up and down
overtravel. the system will shut the driving mechanism off in the event of a
5
°
or more differential between right
and left flap position and it will self-monitor and automatically react appropriately
in the event of critical
component failure in the control circuitry.
Preselection of any desired flap position from full up (0) to full down
(40) is possible thru the
positioning of the selector control which has an 80 stroke analog lever.
(That is. 2
°
of lever movement
represents 1 of wing flap movement.) The selector incorporates a friction type
drag brake to hold the lever at
any desired intermediate position as well as ball block detents at 0
°
, 15
°
, and 40
°
of flap extension. Flaps are
deployed mechanically by a single motor driven thru two flexible shafts connected
to individual ball screw
actuators.
Selection of the desired flap position moves the control rheostat wiper relative
to the left wing flap
rheostat wiper with a resultant amplifier output which will operate the flap
motor through contactors K1 and
K2 to move the left and right flaps to the desired position. If at any time the amplifier
sees a differential voltage
in excess of 0.55 VDC between the left wing flap rheostat wiper and the
right wing flap rheostat wiper, the
amplifier will shut the system off. This condition corresponds to a maximum
differential of 5 offlap position.
A flap fault test switch is provided to check the control circuitry for asymmetrical
flap protection as well
as the operation of the fault lamp switching transistor. The activation of this
switch while flaps are in motion
will give a false signal to the right side follower potentiometer, simulating an
out-of-sync condition causing the
amplifier to shut the system off and illuminate the fault light. Release of the switch will clear the
simulated fault
and allow the system to respond normally to selector position command.
All adjustments are made with the motor circuit breaker pulled (OFF) and the
flaps in the down position.
Adjustment procedures will require some special equipment such as a digital
voltmeter and flap transmission
tools.
5.71. REMOVAL OF FLAP ACTUATOR MOTOR. (Refer to Figure 5-20.)
a.
Remove the center floor panel located in the main cabin area. The flap actuator
motor(5) is located on the
forward side of the fuselage bulkhead at station 174.
b.
Disconnect the electrical leads from the motor.
c.
Cut the safety wire (12) and disconnect the flexible drive shaft ends (4 and
6) from the motor.
d. Remove the clamp (9) that holds the motor on its mounting bracket (13).
Remove the motor.
e.
If desired to replace the shock grommets in the bulkhead, the motor with its mounting
bracket may be
removed together by removing the bracket mounting bolts at the bulkhead.
Revised: 10/12/83
SURFACE CONTROLS
Effectivity
CALCO
1K2
1K2