Piper Navajo Chieftain PA-31-350 Service Manual page 241

NAVAJO CHIEFTAIN SERVICE MANUAL
NOTE
The following are the flap rigging limits:
UP 0
°
+ 1°/-0
°
(0
°
to 1° down)
APPROACH 15
°
+/-1
°
DOWN 400 +/-1
°
6A. Adjust the UP limit actuating bolt so that the UP limit switch is actuated when the flap is
moved (manually) to the 0 degree position as indicated by the rigging tool.
7A. Adjust the DOWN limit actuating bolt on each flap so that the DOWN limit switch is actuat-
ed when the flap is moved (manually) to the full DOWN position as indicated by the rigging tool.
8A. Install the left flap horn. Support the left flap in the full DOWN position as indicated by the
rigging tool. Turn the transmission sleeve for the left flap out from its forward stop (recording the number of
turns) until the attachment hole in the sleeve aligns with the corresponding hole in the flap horn. Temporarily
install the attachment bolt.
9A. Install the right flap horn. Support the right. flap in the full DOWN position as indicated by
the rigging tool. Turn the transmission sleeve for the right flap out from its forward stop the same number of
turns as were required for attachment of the left sleeve. If this number of turns (plus or minus one half turn)
does not provide alignment of the attachment hole in the sleeve with the corresponding hole in the flap horn
(such that the attachment bolt may be inserted), loosen the bolts attaching the horn to the flap sufficiently to
permit movement of the horn by tapping to achieve proper alignment. Temporarily install the attaching bolt
Torque the horn attaching bolts. Supporting means for the flaps should now be removed, since flaps will be
held in place by the sleeve attaching bolts.
10A. Install castellated nuts on sleeve attaching bolts and tighten the nuts so as to allow 0.030 of
an inch thrust play for the bolts. Safety with cotter pins
11. Connect the flexible drive shafts to the transmissions. Be sure that the splines are properly
engaged and run the shaft attaching nut on finger tight. Safety with MS20995C32 wire.
12. Remove the covers from RT2 and RT3 on the flap control amplifier and ascertain that both
trimmers are in their full clockwise position (maximum resistance).
13. Insert a 30 amp fuse (for test purposes only) in the flap motor electrical power connection.
14. Apply external power to the aircraft and establish bus voltage at 28 +/-.5 volts.
15. Place the flap selector in the DOWN position.
16. Engage flap control circuit breaker - DO NOT engage flap motor circuit breaker at this time.
Allow five minutes warm-up time.
17. Measure voltage at VC and adjust voltages of RL and RR by rotating the shafts at the wing
pots as follows:
(a) VL shall be 0.10 + 0.10/-0.05 below VC in the DOWN position and 0.10 +.0 10/-0.05
above VC in the UP position.
(b) VR may be adjusted to within 0.01 volt of VC to allow the indicator to read correctly.
(Suggest using a difference between VR and VC of 0.1 volt for initial adjustment)
18. Lock actuator arms on potentiometer shafts. Remeasure VC, VL and VR to be sure they are
still the same values. Readjust if necessary. Record voltages on work sheet.
19. Move flap selector to the UP position. Listen for audible click of the motor solenoid. If sole-
noid does not actuate check wiring for proper interconnect.
20. Move nap selector back to full DOWN position.
Revised: 31/94
SURFACE CONTROLS
1K1