SDR NOCA0199B

Service difficulty report · Valve · Boeing 75723A

Difficulty date
January 18, 1999
Submitted
March 26, 2000
Operation
Air carrier
Aircraft
N757NA
Make and model
Boeing 75723A
Aircraft serial
24567
Part
Valve
Part number
32896961
Condition
Inoperable
Location
Lt Pack
Stage of operation
CR
Nature of condition
O
Precautionary procedure
O

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

What was found

DURING FLIGHT, CABIN TEMP INCREASE, CREW ATTEMPTED TO REGULATE BY USING TRIM AIR SWITCH. TRIM AIR SWITCH HAD NO EFFECT. CABIN ALTITUDE STARTED TO CLIMB. CREW COMMENCED DESCENT. EVALUATION CONDUCTED TO PREVENT RECURRENCE WITH CHECKS OF TRIM AIR VALVE SYS TEST, ZONE TEMP SENSOR RESISTANCE CHK, PRESS SYS CHK, OUTFLOW VALVE INSP AND TEST, AND BITE CHK OF ZONE TEMP CONTROLLER. ALL CHKS ACCOMPLISHED, FOUND LT AND RT WATER EXTRACTOR NOZZLE SPRAY PATTERN NOT IAW MM 21-51-11. BOTH PACK WATER EXTRACTOR NOZZLES REPLACED. LOW LIMIT VALVE LT POSITION FAILED TEST. LT LOW LIMIT VALVE REPLACED. NO TEMPERATURE OR PRESS ITEMS REPORTED SINCE ORIGINAL DISCREPANCY DATED 1-18-98. (X)

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