Service difficulty report · Control Valve · Boeing 737890

Difficulty date
October 19, 2008
Submitted
October 23, 2008
Operation
Air carrier
Aircraft
N570AS
Make and model
Boeing 737890
Aircraft serial
35185
Aircraft time
6,612 hours, 1,964 cycles
Part
Control Valve
Part number
32895625
Part serial
10171
Condition
Faulty
Location
Nr 1 Engine
Part time
6,612 hours, 1,964 cycles
Stage of operation
CL
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

UPON DEPARTURE FROM HNL AIRFLOW FROM GASPERS WAS EXCESSIVELY HIGH NOISE LEVEL WAS 120 DBT AND TEMPERATURE IN CABIN WAS VERY COLD. AFTER APPROX 5 MIN AIRFLOW DB LEVEL AND TEMPERATURE RETURNED TO NORMAL. SUSPECT THAT A 9TH STAGE BLEED VALVE STUCK OPEN. NO OTHER DISCREPANCIES. PERFORMED FIM TASK 36 10 00 810 809 AND FOUND PRECOOLER CONTROL VALVE ON THE NR 1 ENGINE BAD. REMOVED AND REPLACED NR 1 PRECOOLER VALVE. OP CHECK GOOD REF MM 36 12 02 PRECOOLER VALVE VERIFIED BY SEAMC MARK. BITE ON PACK CONTROLLERS PRODUCED NO FAULTS. PERFORMED ENGINE BLEED CROSSOVER OP TEST, CK'D GOOD. VERIFICATION FLIGHT SATISFACTORY.