Service difficulty report · Hmu · Boeing 737990ER

Difficulty date
July 13, 2021
Submitted
July 15, 2021
Operation
Air carrier
Aircraft
N491AS
Make and model
Boeing 737990ER
Aircraft serial
44109
Aircraft time
20,888 hours, 6,681 cycles
Engine
Cfmint CFM567B27E
Part
Hmu
Part number
1853M56P16
Part serial
BECWD310
Condition
Faulty
Location
#2 Engine
Part time
20,888 hours, 6,681 cycles
Stage of operation
TX
How discovered
V
Nature of condition
M
Precautionary procedure
D

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

What was found

ENG #2 OVERTEMP ON STARTUP, RED BOX ILLUMINATED ABORTED START. GROUNDED - YES. REF LOG 60230329 FOR ENG INSP. AFTER ENG OPERATION ABOVE THE LIMITS AND HIGH STRESS . NO DEFECTS NOTED. ACCOMP B737-900 FIM 80-05 TASK 807 STEPS A THROUGH E , NO FAULTS FOUND . ACCOMP FIM TASK 80-05 TASK 802 STEPS A THROUGH E 6 NO FAULTS FOUND. REMOVED AND REPLACED HMU ON #2 ENG. REF T/C N8473000 AND N8473001 ALL ITEMS ON MIG 2C-40-0043974 CLOSED ETOPS PN VERIFICATION COMPLETED AND VERIFIED APPLICABILITY, THIS CLEARS THE MCT SEAMC MARK NOTIFIED.