Deicer System Operating Pressures; Deicer System Operation Check - Piper PA-44-180 SEMINOLE Maintenance Manual

Recommended Operating Pressure
OIL WHICH REACHES THE DEICERS WILL CAUSE RAPID
DETERIORATION OF THE RUBBER.
IN COLD WEATHER, EXTREME CARE MUST BE TAKEN TO SEE THAT
ENGINE OIL DOES NOT COLLECT IN CRITICAL PA RTS OF THE
SYSTEM AND CONGEAL CONGEALED OIL WILL CAUSE STICKING OF
THE CONTROL VALVES AND DEFLATE VALVE. IF STICKING OF THESE
PA RTS IS ENCOUNTERED, REMOVE FROM AIRPLANE, CLEAN OR
REPLACE.
This operation may be omitted if the boots were installed on the airplane subsequent
to the last previous 100 hour check. On the other hand, if operations are being
conducted under cold weather conditions below 10° F (-1° C), the airfilters should be
cleaned out at each 100 hour check, or more often if difficulties are encountered with
valves sticking due to congealed oil.
OPERATION CHECK.
The pneumatic deicing system should be checked at least every 100 hours. This check can be done on the
ground. A visual inspection should be performed to determine the condition of the deicer boots, and any areas in
need of repair should be taken care of before continuing with the operation check of the system.
With one engine operating, activate the deicing system switch. Observe the operation of the deicers carefully
for evidence of malfunctioning. Look for tubes which leak or fail to inflate and deflate properly. Repeat the
procedure for the other engine.
Do not manually hold surface de-ice switch on "ON"position, as this switch is spring
loaded and holding switch on "ON"may induce system failure.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
CHART 3002. OPERATING PRESSURES
PSIG
15
18
— CAUTION —
MIN.
13
16
— Note —
— Note —
2D11
Test Pressure
in PSIG
MAX.
17
20
Page 30-07
Revised: May 15, 1989
3 0 - 1 2 - 0 3