Service difficulty report · Hmu · Boeing 737890

Difficulty date
January 15, 2014
Submitted
January 21, 2014
Operation
Air carrier
Aircraft
N531AS
Make and model
Boeing 737890
Aircraft serial
35199
Aircraft time
14,439 hours, 4,395 cycles
Engine
Cfmint CFM567B273
Part
Hmu
Part number
442597
Part serial
BECW5167
Condition
Malfunctioned
Location
Nr 1 Engine
Part time
21,098 hours, 7,402 cycles
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

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

What was found

WHILE ACCOMPLISHED, FOUND NR 1 ENG WITH FAULT 73-10351, FMV POS SIGNALS DISAGREE - SHORT TIME FAULT. ACFT GROUNDED. PERFORMED ACTUATORS TEST REF MM 71-00-00-700-807-F00 AND EEC TEST REF MM 73-21-00-700-804-F00 BOTH TESTS PASSED. ACCOMPLISHED RESISTANCE CHECKS AT RECEPTACLES DP0601 AND DP0501 OF THE HMU FOUND RESISTANCE AT PINS 35 TO 36 AT 106.1 OHMS, IT SHOULD BE 130 TO 230 OHMS. ACCOMPLISHED T/C N8473000, HMU REMOVAL NR 1 ENGINE. COMPLETED INSTALLATION IAW T/C N8473001, NO FAULTS NOTED.