Service difficulty report · Pressure Switch · Boeing 747251B

Difficulty date
October 14, 2014
Submitted
October 17, 2014
Operation
Air carrier
Aircraft
N795CK
Make and model
Boeing 747251B
Aircraft serial
23111
Aircraft time
96,002 hours, 14,923 cycles
Engine
Pwa JT9D7R4G2
Part
Pressure Switch
Part number
21SN4149
Part serial
P241
Condition
Defective
Location
Start Valve
Stage of operation
CL
How discovered
O
Nature of condition
J
Precautionary procedure
E, A

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

What was found

NR 1 START VALVE OPEN LIGHT ILLUMINATED IN FLIGHT. ENGINE SHUTDOWN. ENGINE CONDITION STABLE PRIOR TO SHUTDOWN. AFTER SHUTDOWN NORMAL WITH N1 AT 31.5 N2 AT 26.9 11 PSI OIL PRESSURE. ENGINE SHUTDOWN IAW START VALVE OPEN LIGHT ILLUMINATION CHECK LIST. TOTAL WINDMILL TIME 34 MINUTES. AOM 3-114, PROCEDURE ACCOMPLISHED 20 MINUTES AFTER ENGINE SHUTDOWN. START VALVE OPEN LIGHT ILLUMINATED DURING CLIMB, CONFIGURATION NORMAL WITH ENGINE IGNITION OFF AND ENGINE ANTI-ICE OFF. RESTART NOT ATTEMPTED. R & R START VALVE PRESSURE SWITCH IAW MM 80-11-05. R & R START VALVE PRESSURE SWITCH CONNECTOR PLUG IAW BSWPM 20-61-00. IN FLIGHT OPS CHECK OF START VALVE LIGHT GOOD.