Service difficulty report · Thermocouple · Boeing 737890

Difficulty date
December 18, 2012
Submitted
December 24, 2012
Operation
Air carrier
Aircraft
N589AS
Make and model
Boeing 737890
Aircraft serial
35686
Aircraft time
19,301 hours, 6,078 cycles
Part
Thermocouple
Part number
MS280341
Condition
Malfunctioned
Location
Apu
Stage of operation
IN
How discovered
V
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

APU TREND DATA SHOWS A SHIFT IN EGT. INSPECTED APU INLET AND PLENUM REF AMM 49-11-00-200-801. NO OBSTRUCTIONS FOUND. PERFORM APU BITE CHECK IAW AMM 49-61-00-700-801. NO MX MESSAGE FOUND. R & R THE INLET TEMP SENSOR T2 IAW M/M 49-61-31-401. REPLACED BOTH EGT THERMOCOUPLES IAW MM 49-71-21-401. OPS CHECK GOOD REF AMM 49-11-00-860-801. APU BITE CHECK SHOWS NO CURRENT FAULTS NOTED.