Service difficulty report · Check Valve · Boeing 7377H4

Difficulty date
January 8, 2026
Submitted
January 12, 2026
Operation
Air carrier
Aircraft
N445WN
Make and model
Boeing 7377H4
Aircraft serial
29841
Aircraft time
70,818 hours, 42,590 cycles
Part
Check Valve
Condition
Faulted
Location
Nr 1 Engine
Stage of operation
CR
How discovered
O
Nature of condition
R, J
Precautionary procedure
O

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

What was found

SUSPECTED COMPRESSOR STALLS (X3) ON NR 1 ENG UPON LEVEL OFF. ACCOMP BY FLUCTUATING EGT MOMENTARILY. STABILIZED WITHOUT REPEAT FOR DURATION OF FLT. CREW NOTED EVENT HAPPENED WITH AUTOTHROTTLES ENGAGED. REMOVED ENG 1 HAND CRANK PAD IAW AMM 72-63-01-000-801-F00. C/W REQUIRED BOROSCOPE INSPECTIONS IAW AMM 71-00-00-210-801-F00. NO FINDINGS NOTED. PERFORMED FIM 71-05, TASK 805 UP TO E6 STEP B1. REMOVED & INSTALLED BORESCOPE PLUGS 1, 2, 4, 5, 8, 9, 17, & 18 IAW AMM 72-00-00. REMOVED & INSTALLED LT & RT IGNITER PLUGS FOR BORESCOPE INSPECTION IAW AMM 74-21-02. IGNITER TEST PASSED FOR BOTH LT & RT. PERFORMED 5TH STAGE CHK VALVE INSP IAW FIM 71-05 805 & FOUND NO DEFECTS. INSTALLED 5TH STAGE CHECK VALVE IAW AMM 36-11-0209. R & R 5TH STAGE CHECK VALVE ON NR 1 ENG IAW AMM 36-11-02 REF TTG8Q019T24D. PERFOMED REMAINING STEPS OF FIM 71-05 TASK 805; IAW TSR 202600162. PERFORMED POWER ASSUANCE CHK IAW AMM 71-00-00. ALL PARAMETERS NORMAL, NO DEFECTS NOTED.

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