Service difficulty report · Actuator · Boeing 737890

Difficulty date
October 14, 2023
Submitted
October 18, 2023
Operation
Air carrier
Aircraft
N589AS
Make and model
Boeing 737890
Aircraft serial
35686
Aircraft time
57,328 hours, 16,977 cycles
Part
Actuator
Part number
38861883
Part serial
3503
Condition
Faulty
Location
Apu
Part time
2,927 hours, 4,150 cycles
Stage of operation
NR
How discovered
V
Nature of condition
J
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

APU BLEED AIR DUCT PRESSURE ZERO WITH APU RUNNING & BLEED ON. GROUNDED - YES. (RESOLVED ON W/O: 1973316 TASKCARD: N/R-00009 ) BITE OF APU ECU NO CURRENT FAULTS. APU MAINT HISTORY SHOWS 49-52190, 49-52192 MULTIPLE TIMES. PERFORMED RESISTANCE CHECKS OF T12, T4, IGV ACTUATOR AND SURGE VALVE ALL COILS WITHIN LIMITS. INSPECTED T12 AND T4 SENSORS FOR DEBRIS AND REMOVED SENSE LINES AND CLEARED WH 56474REMOVED AND REPLACED APU IGV ACTUATOR REFER AMM 49-52-12. PERFORMED OPERATIONAL CHECKS. NO LEAKS OR DEFECTS NOTED. APU BITE PROCEDURE SHOWS NO CURRENT FAULTS. NO ERRATIC OR SURGING OF APU WHILE BLEED APPLIED AND BOTH PACKS RUNNING. DUCT PRESSURE CHECKS GOOD. THIS CLEARS MEL 49-7C. MX PROCEDURES REVERSED, PLACARDS REMOVED SEAMC ASHRAF NOTIFIED.