SDR 97UAL900205

Service difficulty report · Sequence Valve · Boeing 747122

Difficulty date: March 7, 1997
Submitted: March 26, 2000
Operation: Air carrier
Aircraft: N4735U
Make and model: Boeing 747122
Aircraft serial: 19928
Engine: Pwa JT9D7A
System (JASC): 3230 · Landing Gear Retraction/Extension System
Part: Sequence Valve
Part number: 60B00253426702
Condition: Malfunctioned
Location: Lt Mlg Ww
Stage of operation: CL
Nature of condition: N
Precautionary procedure: A

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

What was found

AFTER TAKEOFF, LEFT BODY GEAR DOOR AND LEFT WING DOOR OPEN LIGHTS ILLUMINATED. AIRCRAFT RETURNED TO FIELD. *S/D* REPLACED LBLG UPLOCK SEQUENCE VALVE, LEFT BODY GEAR DOOR SEQUENCE VALVE, AND LWG DOOR SEQUENCE VALVE. GEAR SWUNG SEVERAL TIMES, OPERATION CHECKS NORMAL.