Service difficulty report · Hmu · Boeing 737990ER

Difficulty date
July 24, 2019
Submitted
August 12, 2019
Operation
Air carrier
Aircraft
N435AS
Make and model
Boeing 737990ER
Aircraft serial
43292
Aircraft time
22,845 hours, 7,432 cycles
Engine
Cfmint CFM567B27E
Part
Hmu
Part number
1853M56P16
Part serial
BECWB304
Condition
Failed
Location
Nr 1 Engine
Part time
22,988 hours, 7,470 cycles
Stage of operation
TX
How discovered
V
Nature of condition
J
Precautionary procedure
D

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

What was found

ENG VALVE CLOSED LIGHT DID NOT ILLUMINATE BRIGHT BLUE FROM DIM WHEN START LEVER WAS RAISED TO IDLE; INSTEAD LIGHT IMMEDIATELY EXTINGUISHED. GROUNDED - YES. REMOVED AND REPLACED #1 ENGINE HMU REF ASA T/C N8473000 &1. IDLE-POWER LEAK CHECK, GOOD. NO LEAK NOTED. ACTUATOR TEST, GOOD. NO FAULT ON EEC BITE CKS ENG VALVE CLOSED LT, OPERATED NORMAL.