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SDR FDEA201107232914

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Service difficulty report · Thermal Switch · Boeing 727277

FAA SDR system

Difficulty date
July 23, 2011
Submitted
July 25, 2011
Operation
Air carrier
Aircraft
N245FE
Make and model
Boeing 727277
Aircraft serial
22016
Aircraft time
42,186 hours, 33,391 cycles
System (JASC)
7500 · Engine Bleed Air System
Part
Thermal Switch
Condition
Failed
Location
Nr 3 Engine
Stage of operation
CR
How discovered
O
Nature of condition
J
Precautionary procedure
B, G

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

What was found

DURING CRUISE AT FL360 ENGINE 3 BLEED AIR TRIP OFF LIGHT ILLUMINATED AND THE NR 3 BLEED AIR VALVE CLOSED, SYS WOULD NOT RESET VIA QRH PROCEDURES ( LIGHT STAYED ON ). CABIN ALTITUDE WAS RAPIDLY INCREASING THROUGH 10000FT AND AFTER DONNING OXYGEN AND DESCENDING, ABLE TO ESTABLISH PRESSURATION WITH NR 2 BLEED AIR. AFTER 10 MINUTES WE WERE ABLE TO RESET THE NR 3 BLEED TRIP OFF LIGHT, BUT WE USED NR 2 BLEED FOR THE REMAINDER OF FLIGHT. REPLACED NR 3 ENGINE BLEED THERMAL SWITCH IAW MM 36-22-001-4. OPS CHECKS NORMAL ON GROUND AT THIS STATION.