Service difficulty report · Priority Valve · Boeing 767322

Difficulty date
December 11, 2011
Submitted
December 14, 2011
Operation
Air carrier
Aircraft
N654UA
Make and model
Boeing 767322
Aircraft serial
25392
Aircraft time
82,148 hours, 13,320 cycles
Engine
Pwa PW4060
Part
Priority Valve
Part number
79027013
Part serial
280
Condition
Faulted
Location
Bleed System
Stage of operation
DE
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

CREW REPORTED NO RT HIGH STAGE BLEED AT 80 PERCENT N1. RT BLEED DUCT OSCILATES BETWEEN 20-40 PSI DURING CLIMB. IN DESCENT RT DUCT 20 PSI LESS THAN LEFT. VALVE IN LOCKED IN INTERMEDIATE POSITION. FAULTING FAN AIR TEMP SENSOR. ON TAKEOFF AND CLIMBOUT RIGHT DUCT PRESSURE RAPIDLY FLUCTUATED BETWEEN 20 AND 40 PSI. ACCOMPLISHED PNEUMATIC HEALTH CHECK ON PRSOV, PRSOV FAILED TEST. REPLACED PRSO VALVE. ACCOMPLISHED LEAK CHECK OF VALVE AND ENGINE RUN, STILL FLUCTUATES. REPLACED HPC AND PRV AND PRV SENSE LINE, RAN ENGINE AT IDLE AND TAKE OFF AND ALL INDICATIONS NORMAL.