Service difficulty report · Clamp · Boeing 767238

Difficulty date
May 7, 2008
Submitted
May 21, 2008
Operation
Air carrier
Aircraft
N250MY
Make and model
Boeing 767238
Aircraft serial
23306
Aircraft time
68,795 hours, 27,528 cycles
Engine
Pwa JT9D7R4E
Engine time
47,853 hours, 19,591 cycles
Part
Clamp
Part number
2703550
Condition
Failed
Location
Duct
Stage of operation
CR
How discovered
O
Nature of condition
M
Precautionary procedure
O

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

What was found

THE CREW REPORTED THAT AFTER A NORMAL TAKEOFF AND CLIMB, AND AFTER GOING INTO CRUISE THE LEFT ENGINE WOULD NOT PRODUCE GREATER THAN 70 PERCENT N1, 80 PERCENT N2 AND 1.00 EPR. THEY ALSO REPORTED THAT EICAS REPORTED A LEFT ENGINE OVERTEMP OF 451 DEGREES. THE CREW FOLLOWED THE QRH WHICH INSTRUCTED THEM TO SHUTOFF THE BLEED, AFTER THIS ACTION THEY REGAINED NORMAL OPERATION OF THE ENGINE. UPON ARRIVAL AND FURTHER INVESTIGATION BY MAINTENANCE IN MZJ, MAINTENANCE DISCOVERED THE 8TH STAGE BLEED AIR DUCT V BAND CLAMP LAYING IN THE COWLING FOR THE INBOARD THRUST REVERSER. THE BLEED LEAK THAT WAS CAUSED BY THE FAILURE OF THE V BAND CLAMP HAD ALSO DAMAGED THE FAN AIR MODULATING VALVE. THE INVESTIGATION REVEALED THAT THE BLEED LEAK HAD CAUSED THE LEFT ENGINE EGT OVERTEMP AS WELL. MAINTENANCE REPLACED THE V BAND CLAMP, ACCOMPLISHED AN INSPECTION OF ALL OTHER ASSOCIATED V BAND CLAMPS, REPLACED THE FAN AIR MODULATING VALVES AND ACCOMPLISHED HIGH POWER ENGINE RUNS TO VERIFY THE SOLUTION. NO EMERGENCY PRECAUTIONS WERE TAKEN BY THE CREW AND NO OTHER DAMAGE OCCURRED.