Piper Navajo Chieftain PA-31-350 Service Manual page 242

NAVAJO CHIEFTAIN SERVICE MANUAL
21. Engage the flap motor circuit breaker and move selector to full UP position. When the flaps
stop moving (actuating arm may not engage the UP limit switch) record system voltages on a work sheet as
follows:
VC
VL
VR
DOWN Position
X.XX
XXX
XX
UP Position
X.XX
XXX
X.XX
22. The values at the DOWN position were established for VC, VL, and VR in step 17. Now
enter the reading for VC, VL and VR at the UP position. The work sheet will now resemble the following
example (voltage values used in this example are for illustrative purposes only. They are NOT system
requirements):
VC
VL
VR
DOWN
9.15
8.95
8.95
UP
4.06
4.38 (See
4.36 (See
steps c and d)
steps c and d)
CAUTION
No adjustments are to be made to the wing rheostats (RL and
RR) unless the flap motor circuit breaker is pulled.
c. If VL and VR differ by more than 0.50 volts, an out of syncronization shutdown has occurred due
to an actuator arm beinq loose on the rheostat shaft. In this event, place a jumper wire between RL and RR at
the amplifier and select flaps full DOWN. Readjust voltages at RR and RL as per step 17 and begin again.
d. If VL is within 0.04 volts of VC the system has shut down because the amplifier sees that the
position selected (VC) and the position sensed (VL) have been satisfied. In this event, select flaps to full
DOWN and readjust voltages at RL and RR per step 17, using greater spread between VL, VR and VC than in
the initial adjustment.
e. If the system has completed a full stroke (UP) limit switch has been engaged) and the flap position
indicator is correct, no further adjustment is necessary. It is acceptable if the indicator pointer center line is
tangent to the upper or lower edge of the indicator graduation mark, provided that VL and VR are within the
limits of step 17. Proceed to step h. If position and / or indicator criteria are not satisfied proceed as follows:
Calculate VC1 by the formula: VC1 = VC + (10 +0.10/-0.05).
1.
Calculate the voltage difference between VC1 and VL, VC1 and VR as measured in the UP
position. Multiply the voltage difference by 2 as shown in the following example:
Voltage Difference
Voltage Difference
between VC1 and VL
between VC1 and VR
Flap
VC
VC1
VL VR
Higher
Lower
Higher
Lower
UP
4.06
4.16 4.38
4.36
AVCL
AVCR
= 0.22V
= 0.20V
x2
x2
Adj. = .0.44
Adj. = .40
DOWN
9.15
N/A 8.95
8.95
Revised: 3/31/94
SURFACE CONTROLS
1K2