Deicer System Inspection - Piper PA-44-180 SEMINOLE Maintenance Manual

INSPECTION.
A ground check of the entire deicer system should be made at least every 100 hours.
Before checking the system, all deicers should be inspected for damaged areas and repaired according to the
procedure in this section outlining the cold patch or vulcanized repairs. In order to check the system, refer to
Chart 3002 and the paragraph "Pneumatic Regulator Adjustment" for operating pressure and check procedures.
GROUND PROCEDURE.
After the test pressure range is established, connect an external source of air providing this pressure and a
pressure gauge to the pneumatic deice line at the manifold assembly. Disconnect the deice line from the manifold
to accomplish the test. The deicer system should be within one psig of the recommended operating pressure with
each inflation cycle.
If deicers do not reach the operating pressure, check the inflation time to ascertain that the solenoid valves are
open the specified length of time (six seconds). If this is not the cause of trouble or if the boots deflate slowly,
the lines or valves may be plugged; then the lines should be disconnected and blown clear.
Check the timing of the system through several complete cycles. Boots ON six seconds, then OFF. The wing
and empennage boots operate simultaneously. If cycle time is off the specified time, determine and correct the
difficulty.
Inflation must be rapid to provide efficient deicing. Deflation should be complete before the next inflation
cycle of the boots.
100 HOUR INSPECTION.
At each 100 hour inspection of the airplane, inspect and operate the deicer boots. Make checks as follows:
1. Carefully inspect the deicers for evidence of damage or deterioration, and repair or replace damaged boots.
2. Resurface boots which show signs of considerable wear or deterioration.
3. Inspect all hose connections which form a part of the pneumatic deicing system. Replace deteriorated
sections on non-kink hose.
4. Check the operation of the boots and the operating pressure of the system as outlined in this section.
5. If new or replacement boots have been installed, check the tube inflation to make sure that the air
connection stems have been properly connected.
6. Disconnect all drain lines in the system and check for proper drainage.
7. Check the on-off control switch for freedom of action. Check associated electric wiring.
8. Clean or replace the air filters.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
2D10
3 0 - 1 2 - 0 2
Page 30-06
Revised: May 15, 1989