Service difficulty report · Hmu · Boeing 737890

Difficulty date
July 3, 2019
Submitted
July 5, 2019
Operation
Air carrier
Aircraft
N518AS
Make and model
Boeing 737890
Aircraft serial
35693
Aircraft time
39,577 hours, 11,775 cycles
Part
Hmu
Part number
442653
Part serial
BECW5077
Condition
Faulted
Location
Nr 2 Engine
Part time
40,755 hours, 14,389 cycles
Stage of operation
TX
How discovered
O
Nature of condition
J
Precautionary procedure
K

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

What was found

RIGHT SIDE ENG VALVE CLOSED LIGHT ILLUMINATED BRIGHT BLUE DURING PREFLIGHT BEFORE START. GROUNDED - YES. PERFORMED FIM 73-06 TASK 804, DISCONNECTED CONNECTOR DP1203, CONFIRMED PROPER OPERATION OF FIRE CONTROL PANEL SWITCH S9 AND PROPER OPERATION OF THE #2 ENGINE START LEVER SWITCH S1029 REF WDM 76-21-21. REQUIRES #2 ENGINE HMU CHANGE. REPLACED #2 ENG. HMU. IDLE LEAK CHECK, EEC BITE CHECK AND ACTUATORS TESTED OK. REF T/C N8473000, N8473001 THRU STEP J.(5). FOUND D46126P SHORTED AT PINS 5,6,7 WHEN CONNECTED. REMOVED AND REPLACED CONNECTOR D46126P AND VERIFIED CONNECTOR D46126J INSULATOR AND WIRING INTEGRITY REF WDM 76-21-21 AND SWPM 20-61-11. PINS 5,6,7 OF D46126P NO LONGER SHORTED. ALL OPERATIONAL CHECKS PASS FOR CONNECTOR D46126. PERFORMED MULTIPLE SUCCESSFUL ENGINE STARTS AND SHUTDOWNS OF THE #2 ENGINE. COMPLETED SUCCESSFUL REPAIR CONFIRMATION OF FIM 73-06 TASK 804 FOR THE #2 ENGINE. #2 ENG VALVE CLOSED LIGHT OPERATING AS REQUIRED. ETOPS GROUND VERIFICATION SUCCESSFUL.