SDR CALA2013090991139

Service difficulty report · Relay · Boeing 747422

Difficulty date: September 8, 2013
Submitted: September 10, 2013
Operation: Air carrier
Aircraft: N199UA
Make and model: Boeing 747422
Aircraft serial: 28717
Aircraft time: 64,804 hours, 7,525 cycles
Engine: Pwa PW4056
System (JASC): 2121 · Air Distribution Fan
Part: Relay
Condition: Failed
Location: E&E Bay
Stage of operation: IN
How discovered: O
Nature of condition: J
Precautionary procedure: O

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

What was found

ON DEPARTURE EE COOLING SUPPLY FAN STATUS MESSAGE. UNABLE TO RESET, EE SUPPLY FAN DEF INOPERATIVE HIS & TIME. REPLACED FAN, VERIFIED FAN IS WORKING, MESSAGE STILL PRESENT AFTER GROUND TEST. SUSPECT SENSE RELAY T1591 PCN 585-1484 BAD IAW MEL. 2158J PARTS, 563-9043 MR21271, 585-148 & 285T0177-3 SENSOR.