Service difficulty report · Valve · Boeing 747230B

Difficulty date
July 6, 2006
Submitted
July 14, 2006
Operation
Air carrier
Aircraft
N512MC
Make and model
Boeing 747230B
Aircraft serial
21220
Aircraft time
111,894 hours, 20,692 cycles
Engine
Ge CF650E2
Engine time
55,418 hours, 11,211 cycles
Part
Valve
Part number
73836222
Part serial
JC38022
Condition
Leaking
Location
Nr 3 Engine
Stage of operation
CR
How discovered
O
Nature of condition
M, J
Precautionary procedure
O

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

What was found

WHILE CRUISING AT FL LEVEL 310, NR 3 ENG OVERHEAT LIGHT CAME ON. ACCOMPLISHED PROCEDURES AS PER FHB 3.35.5.6. OVERHEAT LIGHT EXTINGUISHES WHEN THROTTLE WAS RETARDED, ALSO WITH THE BLEED AIR VALVE SWITCH IN CLOSED POSITION VALVE LIGHT FAILED TO COME ON. THERE WAS PRESS DROP, UNTIL ENGINE WAS TOTALLY AT IDLE. THE LIGHT CAME ON, THROTTLE WAS ADVANCED AGAIN AND THE OVERHEAT LIGHT CAME ON WHEN EVER 761.N1 WAS REACHED. ALSO, THE OVERHEAT LIGHT CAME ON WHEN THE AIRCRAFT ENCOUNTERED ANY TURBULENCE. XRERRED TO DPG 83153 DMI M06-098 MEL 36-05 PER MEL 36-5-1. REMOVED AND REPLACED NR 3 ENG PYLON VLV IAW MM 36-11-06. REMOVED AND REPLACED NR 3 ENG OVERHEAT TEMP SWITCH IAW MM 36-22-01. DMI CLOSED.