Service difficulty report · Hmu · Boeing 737890

Difficulty date
February 20, 2016
Submitted
February 22, 2016
Operation
Air carrier
Aircraft
N529AS
Make and model
Boeing 737890
Aircraft serial
35198
Aircraft time
23,157 hours, 6,977 cycles
Engine
Cfmint CFM567B20
Part
Hmu
Part number
442369
Part serial
BECW3590
Condition
Failed
Location
Nr 1 Engine
Part time
40,788 hours, 14,512 cycles
Stage of operation
TX
How discovered
O
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

SHORTLY BEFORE TAKEOFF, NR 1 ENGINE CONTROL LIGHT COME ON. ACFT GROUNDED. PERFORMED ELECTRONIC ENGINE CONTROL BITE REF 73-00, TASK 801 FOUND FAULT CODE 75-10581. REF FIM 75-23, TASK 801. PERFORMED TEST 12 ACTUATORS TEST. TEST PASSED: NO FAULTS, FAULT IS INTERMITTENT. RE-PERFORMED ELECTRONIC ENGINE CONTROL BITE NO RECENT FAULTS GROUND VERIFICATION SUCCESFUL. TSR ACCOMPLISHED, REF FIM 75-23, TASK 801. ELECTRONIC ENGINE CONTROL BITE SHOWS NO CURRENT OR PAST FAULTS. ACTUATORS TEST SHOWS NO FAULTS. GVI SHOWS NO DEFECTS REF WDM 75-31-12. RESISTANCE CHECKS FROM DP909 TO TBV DP0907 CHANNEL A: D-R/31.6 OHMS, W-R/ 31.3 OHMS, D-W/ 62.8. DP1010 TO DP1007 RESISTANCE CHECKS CHANNEL B: D-R/31.4 OHMS, W-R/31.1 OHMS, D-W/62.0 OHMS. NO DEFECTS NOTED. HMU RECEPTACLES DP0501/DP0601 PINS 20-40 SHOW 15 OHMS. RE-ACCOMPLISHED ELECTRONIC ENGINE CONTROL GROUND TEST. NO FAULTS. R & R NR 1 ENGINE HMU IAW T/C 'S N8473000 & N8473001, NO FAULTS NOTED GROUND VERIFICATION ACCOMPLISHED.