Service difficulty report · Hmu · Boeing 737990ER

Difficulty date
October 25, 2021
Submitted
November 2, 2021
Operation
Air carrier
Aircraft
N435AS
Make and model
Boeing 737990ER
Aircraft serial
43292
Aircraft time
29,949 hours, 9,573 cycles
Part
Hmu
Part number
442653
Part serial
BECW4096
Condition
Failed
Location
#1 Engine
Part time
51,141 hours, 20,392 cycles
Stage of operation
TX
How discovered
V
Nature of condition
J
Precautionary procedure
O

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

What was found

DURING ENGINE #1 START FO NOTED SLIGHT DELAY FOR ENGINE EGT TO STABILIZE BUT OTHERWISE NORMAL AND WITHIN LIMITS. ACCELERATION SLOW ON 1ST APPLICATION OF POWER DURING TAXI BUT NORMAL. 2ND APPLICATION OF POWER PRODUCED NO N1 ACCELERATION. WITHIN 1 MINUTE MASTER CAUTION AND XFR BUS OFF ILLUMINATED WITH ENGINE FAIL INDICATION ON UPPER DU. RAN ENGINE FAILURE QRH TO SHUTDOWN. NO OTHER ABNORMAL / EXCEEDENCE INDICATIONS NOTED. GROUNDED - YES. EEC #1 SHOWS GND FAULT 74-30951 IGN L (IGN 1) IS FAILED. PERFORMED B737-900 FIM 73-05 TASK 805-E (S)(6) ENG. START LEVER CUTOFF / IDLE TEST SHOWED CORRECTLY W/NUMEROUS TESTS PRECAUTIONARY - PERFORMED #1 EEC GROUND SELF W/NO FAULTS 13422 10/26/2021. COMPLETED FIM TASK 73-05 TASK 805. PERFORMED ENGINE RUN FOR FUEL FILTER LK CK, NOTICED ENGINE N2 SPOOL UP FASTER THAN INITIAL RUN. FUEL PUMP AND HMU P/N VERIFIED SEAMC DARWIN ALL PARTS OK FOR ETOPS ACFT .....18294.... CHANGED HMU AND FUEL PUMP PACKAGE REF T/C NG8473001 B737-900 AMM 73-11-01-400-801-F ALL LEEK CHECKS GOOD.