Service difficulty report · Bleed Valve · Boeing 777222

Difficulty date
October 28, 2000
Submitted
December 12, 2000
Operation
Air carrier
Aircraft
N790UA
Make and model
Boeing 777222
Aircraft serial
26943
Aircraft time
15,015 hours, 2,374 cycles
Engine
Pwa PW4090
Engine time
12,316 hours, 1,956 cycles
Part
Bleed Valve
Part number
339910030
Part serial
MR3621139
Condition
Failed
Location
Rt Engine
Stage of operation
CR
How discovered
O
Nature of condition
J
Precautionary procedure
A

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

What was found

FLT HAD RIGHT BLEED VALVE FAILURE. ALSO SATCOM MEL. DIVERTED ORD DUE TO COMBINED PROBLEMS. *S/D* ORIGINALLY, MAINT MSGS SHOWED THE PRSOV TO HAVE FAILED CLOSED, HPSOV FAILED OPENED & CLOSED (AT DIFFERENT TIMES), INTERMED. PRESSURE SENSOR FAILED & THE FAMV FAILED CLOSED. HPSOV & IP SENSOR WERE REPLACED. AFTER WHICH, THE BLEED MESSAGE RESURFACED. REPLACED THE HIGH PRESSURE FAN AIR CONTROLLER (HPFAC), THE PRESSURE SHUTOFF CONTROLLER (PRSOVC), & THE AIR SUPPLY CABIN PRESSURE CONTROLLER (ASCPC). NO FURTHER MSGS WERE GENERATED AFTER THESE COMPONENTS WERE RPLCD. SHOP FINDNGS INDICATE THAT HPFAC HAD HOLE IN DIAPHRAGM, PRSOVC NEEDED MINOR ADJMNT. THE HPSOV SHOWED UNABLE TO DUP.