SDR UALA2008121106842

Service difficulty report · Shutoff Valve · Boeing 767322

Difficulty date: December 8, 2008
Submitted: December 12, 2008
Operation: Air carrier
Aircraft: N664UA
Make and model: Boeing 767322
Aircraft serial: 29236
Aircraft time: 36,425 hours, 10,289 cycles
Engine: Pwa PW4056
System (JASC): 3610 · Pneumatic Distribution System
Part: Shutoff Valve
Part number: 7732887810
Condition: Faulty
Location: Lt Engine
Stage of operation: IN
How discovered: O
Nature of condition: W
Precautionary procedure: O

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

What was found

LEFT ENGINE HIGH STG SYSTEM FLUCTUATES WILDLY FROM 15-40 PSI AT 75-77 PCT N2. ABOVE 80 PCT N2, PNEU STEADY AT ALL POWER SETTINGS. REPLACED HI STAGE VALVE AND CONTROLLER. FAILED TEST AFTER VALVE REPLACEMENT. ACP'D PNEUMATIC HEALTH CK ON PRV & PRC, HPSOV & HPC, FAMV, AND PRSOV. PRSOV FAILED HEALTH CK. REPLACED PRSOV BLEED SHIFT & OPS CHECK PERFORMED, ALL NORMAL.