Table of Contents
Advertisement
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. Position and Warning
1. Description and Operation - Position and Warning
A squat switch on the landing gear and a dynamic pressure q sensor must operate this latch
before the landing gear selector control can be moved upward. The landing gear control knob is in
the shape of a wheel to differentiate it from the flap control, which has a knob in the shaft of an
airfoil.
A differential pressure q sensor is installed in the copilot's pitot/static system which senses
dynamic pressure (q). The sensor is set to actuate at 100 ± 4 KIAS on increasing airspeed and
100 plus 4 KIAS minus 10 KIAS on decreasing airspeed. The q sensing system is provided as an
alternate (backup) means of controlling major circuits which are operated through the landing gear
squat switches; ground cooling fan solenoid, cabin pressure dump solenoid, ice protection selector
switch, gear lock solenoid and high/low selection for the stall recognition system lift detector heat.
2. Fault Isolation - Position and Warning
CHART 1
FAULT ISOLATION (POSITION AND WARNING) (Sheet 1 of 2)
Fault
Cause
Remedy
No red light on panel
when gears are in
transit.
Circuit breaker out.
Check circuit breaker.
Replace indicator light.
Check wiring.
Indicator light burned out.
Circuit wire broken.
No green light on panel
when gears are down.
Circuit breaker out.
Indicator light burned out.
Check circuit breaker.
Replace indicator light.
Lock switch defective
or out of adjustment.
Gear not locked in down
position.
Replace and / or adjust lock switch.
(refer to 32-30-00)
Adjust the gear. (refer to 32-30-00)
Gear refuses to retract
above 100 _ 4 knots
increasing, 100 + 4 -10
knots decreasing.
Gear selector refuses to
unlock above 100 ± 4
knots.
"q" pressure switch
inoperative - stuck in
closed position.
Failure of K2 relay.
Replace as required.
Replace component.
EFFECTIVITY:
040-999
PAGE
1
32-60-00
Jan 10/90
Advertisement
Chapters
Table of Contents
