Service difficulty report · Pilot Valve · Boeing 757222

Difficulty date
January 3, 2013
Submitted
February 1, 2013
Operation
Air carrier
Aircraft
N555UA
Make and model
Boeing 757222
Aircraft serial
26647
Aircraft time
72,840 hours, 21,482 cycles
Engine
Pwa PW2037
Part
Pilot Valve
Part number
33990046U2
Part serial
214
Condition
Faulty
Location
Bleed Air Sys
Stage of operation
CR
How discovered
O
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

DURING CRUISE AT 85% N2 THE DUCT PRESSURE SPLIT R 45 PSI L 25 PSI. CREW REPORTED THAT AFTER CYCLING WAI, THE RIGHT SIDE WENT TO 25 PSI. MAINT TEXT: DUE TO HISTORY, SUGGEST HEALTH CHECK ON RIGHT ENGINE HIGH STG SYSTEM. IF NO PROBLEMS AND OR LEAKS FOUND, RECOMMEND TO REPLACE HIGH STG PILOT CONTROLLER AND ACCOMPLISH HIGH STG VALVE SHIFT AND REGULATION CHECK AT RUN UP PAD. PNEU LEAK CHECKED ALL PNEU LINES BETWEEN HIGH STAGE VALVE AND CONTROLLER, ALL CHECKED GOOD. REPLACED NR 2 ENGINE HIGH STAGE PILOT VALVE. ACP'D HI POWER PNEU CHECK, NO FAULTS NOTED.