Service difficulty report · Regulator Valve · Boeing 737890

Difficulty date
May 5, 2011
Submitted
May 10, 2011
Operation
Air carrier
Aircraft
N558AS
Make and model
Boeing 737890
Aircraft serial
35177
Aircraft time
18,319 hours, 5,380 cycles
Part
Regulator Valve
Part number
32145525
Part serial
6334
Condition
Defective
Location
Bleed Air Sys
Part time
33,620 hours, 13,415 cycles
Stage of operation
CR
How discovered
V
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

INFLIGHT DUCT PRESSURE SPLIT OF 22.0 PSI. AT FL350 BOTH PACKS IN AUTO NI 84.5 N2 89.6 LEFT DUCT PRESSURE IS 20 PSI AND RIGHT DUCT PRESSURE IS 42.0 PSI. DURING CLIMB FROM FL350 TO FL370 DUCT PRESS SPLIT AT N1 98.9 IS 29 PSI: LEFT AT 17 PSI RIGHT AT 46 PSI. ACCOMP BLEED AIR HEALTH CHECK ON NR 1 ENG FOUND PCCV (KISS) SEAL DEFORMED & LEAKING. REPLACED NR 1 ENG PCCV KISS SEAL. REF AMM 36 12 02 ALSO FOUND NR 1 PRSOV RATCHETING & NOT FULLY CLOSING. REPLACED NR 1 PRSOV REF AMM 36 11 04. OPS & LEAK CHECKS NORMAL. AS PRECAUTION CHANGED NR 1 ENG PRECOOLER SENSOR & TEMP SENSOR REF AMM 36 12 03 & 36 11 05. LEAK CHECK NORMAL. ACCOMP ENGINE BLEED AIR CROSSOVER OPS TEST FOR NR 1 ENG OPS GOOD. GROUND VERIFICATION SUCCESSFUL. VERIFICATION FLIGHT SUCCESSFUL.