SDR 96ZZZX2245

Service difficulty report · Diode · Cessna 550

Difficulty date
April 10, 1996
Submitted
March 26, 2000
Operation
General aviation
Aircraft
N777FL
Make and model
Cessna 550
Aircraft serial
5500070
Part
Diode
Part number
1N1201825
Condition
Burned
Location
Aoa Heater
Part time
7,033 hours
Stage of operation
CL
Nature of condition
B
Precautionary procedure
A

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

What was found

AIRCRAFT RETURNED TO MAINTENANCE WHEN COCKPIT FILLED WITH SMOKE SHORTLY AFTER TAKEOFF. AOA HEATER CIRCUIT BREAKER TRIPPED AND WOULD NOT RESET. INVESTIGATION REVEALED TWO DIODES IN AOA HEAT CIRCUIT TOUCHING GROUND THROUGH RIGHT PITOT STATIC HEAT SWITCH. A REPLACEMENT SWITCH WAS INSTALLED AND DIODES WERE REMOVED FROM THE CIRCUIT IAW WIRING DIAGRAM NOTE AT THE BOTTOM OF THE DIAGRAM. NO OTHER INFORMATION REGARDING REMOVAL OF THESE DIODES COULD BE FOUND. SUBMITTER RECOMMENDS REMOVAL OF THESE DIIODES IF STILL INSTALLED ON OLDER MODEL CITATIONS.

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