Service difficulty report · Monopole · Lear 35A

Difficulty date
January 27, 2012
Submitted
January 29, 2012
Operation
Air carrier
Aircraft
N72AX
Make and model
Lear 35A
Aircraft serial
419
Aircraft time
7,419 hours, 6,448 cycles
Engine
Garrtt TFE73122B
Engine time
7,369 hours, 6,284 cycles
System (JASC)
7603 · Power Lever
Part
Monopole
Part number
307072210
Condition
Shorted
Location
Rt Engine
Stage of operation
DE
How discovered
O
Nature of condition
X
Precautionary procedure
O

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

What was found

SHORTLY AFTER THROTTLING BACK TO FLIGHT IDLE TO DESCEND FROM 41,000 FT THE NR 2 ENGINE MOMENTARILY STAYED AT 80 PERCENT (APPROXIMATELY 15 SECONDS) AND THEN CONTINUED ROLLING DOWN AND FLAMED OUT. PILOT WINDMILL RESTARTED THE ENGINE AT APPROXIMATELY 26,000 FT AND HAD TO RESET THE FUEL COMPUTER TO TURN OFF THE COMPUTER LIGHT. SLIGHT ENGINE SURGE WHICH CREATED A SLIGHT YAW WAS NOTICED AT 6,000 FT. ONCE ON THE GROUND WITH THE ENGINES SHUT OFF THE NR 2 ENGINE FUEL COMPUTER LIGHT WAS REPORTED AS FLASHING. MAINTENANCE DISPATCHED TO THE AIRCRAFT WITH A LAPTOP AND UPON DOWNLOAD FOUND THE N2 MONOPOLE HAD CAUSED A FAULT WHICH WAS PICKED UP BY THE DEEC. A NEW N2 MONOPOLE WAS INSTALLED AND THE ENGINE WAS RAN WITH NO FURTHER PROBLEMS NOTED AND THE DEEC WAS CHECKED WITH NO FURTHER FAULT CODES FOUND.

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