Service difficulty report · Sensor · Boeing 737990ER

Difficulty date
January 26, 2018
Submitted
January 29, 2018
Operation
Air carrier
Aircraft
N433AS
Make and model
Boeing 737990ER
Aircraft serial
41704
Aircraft time
16,945 hours, 5,568 cycles
Part
Sensor
Part number
11500021
Condition
Failed
Location
Lt Ram Air
Stage of operation
CR
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

LEFT PACK LIGHT ILLUMINATED AT FL340, OAT-49. COMPLETED QRH, THE PACK LIGHT EXTINGUISHED AFTER TRIP, RESET. LEFT PACK LIGHT ILLUMINATED THREE MINUTES LATER. COMPLETED QRH, LIGHT EXTINGUISHED, FLT DECK TEMP WENT OUT OF CONTROL, HOT, QRH CABIN TEMP HOT COMPLETED, LEFT PACK SECURED, TEMP AND PRESSURIZATION NORMAL. ACFT GROUNDED. THE PACK/ZONE TEMP BITE COMPLETED: THE RAM AIR ACTUATOR FAULTED IN HISTORY, BUT CLEARS WITH RESET. RAM AIR CONTROL TEMPERATURE SENSOR REMOVED AND REPLACED IAW AMM 21-51-50. PACK BITE DONE WITH NO FAULTS. REMOVED AND REPLACED THE LT PACK DISCHARGE OVERHEAT SWITCH IAW AMM 21-51-42. REMOVED AND REPLACED THE COMPRESSOR DISCHARGE OVERHEAT SWITCH IAW AMM 21-51-40. REMOVED AND REPLACED THE TURBINE INLET OVERHEAT SWITCH IAW AMM 21-51-41. ACCOMPLISHED POWER RUN, BOTH PACKS OPS NORMAL. RUN AND OPS CHECKED IAW EA 900ER-21EA-19773, STEP 17.