What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 10/31/2013 at approximately 10:35 am aircraft N757JX, a Cessna 152, experienced an induction fire during start-up. The flight instructor and student pilot were able to successfully evacuate the aircraft and with assistance from ground personnel extinguish the fire with minimal damage to the aircraft. The fire damaged the induction air filter and subjected the carburetor to extreme heat.
Flight instructor, privacy data omitted, with a student, privacy data omitted, attempted to start the aircraft prior to flight. During the start-up procedures the instructor directed the student to prime the engine with fuel utilizing the accelerator pump in the carburetor instead of the factory installed primer system. This procedure is contrary to the pilot?s operating handbook. The instructor stated he ?told [airman privacy data omitted] to defer the use of primer and merely open and close the throttle two times which I felt from experience would be sufficient to start the engine.? This procedure requires actuating the engine throttle; in this event the throttle was actuated twice prior to start-up. The design of a lycomimng 0-235 engine, incorporates an up-draft carburetor with an accelerator pump. When the accelerator pump is actuated it sprays fuel out of the carburetor into the induction. If the engine is not turning the fuel can, and in this case did, drain back down through the carburetor and into the carburetor airbox. Maintenance personnel inspected the engine after the fire and discovered the ignition timing was advanced by 2 degrees. This may have contributed to the fire by producing a spark while the intake valve was open, thus igniting the fuel in the induction.
As the FAA filed it
ON 10/31/2013 AT APPROXIMATELY 10:35 AM AIRCRAFT N757JX, A CESSNA 152, EXPERIENCED AN INDUCTION FIRE DURING START-UP. THE FLIGHT INSTRUCTOR AND STUDENT PILOT WERE ABLE TO SUCCESSFULLY EVACUATE THE AIRCRAFT AND WITH ASSISTANCE FROM GROUND PERSONNEL EXTINGUISH THE FIRE WITH MINIMAL DAMAGE TO THE AIRCRAFT. THE FIRE DAMAGED THE INDUCTION AIR FILTER AND SUBJECTED THE CARBURETOR TO EXTREME HEAT.
FLIGHT INSTRUCTOR, ^PRIVACY DATA OMITTED^, WITH A STUDENT, ^PRIVACY DATA OMITTED^, ATTEMPTED TO START THE AIRCRAFT PRIOR TO FLIGHT. DURING THE START-UP PROCEDURES THE INSTRUCTOR DIRECTED THE STUDENT TO PRIME THE ENGINE WITH FUEL UTILIZING THE ACCELERATOR PUMP IN THE CARBURETOR INSTEAD OF THE FACTORY INSTALLED PRIMER SYSTEM. THIS PROCEDURE IS CONTRARY TO THE PILOT?S OPERATING HANDBOOK. THE INSTRUCTOR STATED HE ?TOLD [AIRMAN ^PRIVACY DATA OMITTED^] TO DEFER THE USE OF PRIMER AND MERELY OPEN AND CLOSE THE THROTTLE TWO TIMES WHICH I FELT FROM EXPERIENCE WOULD BE SUFFICIENT TO START THE ENGINE.? THIS PROCEDURE REQUIRES ACTUATING THE ENGINE THROTTLE; IN THIS EVENT THE THROTTLE WAS ACTUATED TWICE PRIOR TO START-UP. THE DESIGN OF A LYCOMIMNG 0-235 ENGINE, INCORPORATES AN UP-DRAFT CARBURETOR WITH AN ACCELERATOR PUMP. WHEN THE ACCELERATOR PUMP IS ACTUATED IT SPRAYS FUEL OUT OF THE CARBURETOR INTO THE INDUCTION. IF THE ENGINE IS NOT TURNING THE FUEL CAN, AND IN THIS CASE DID, DRAIN BACK DOWN THROUGH THE CARBURETOR AND INTO THE CARBURETOR AIRBOX. MAINTENANCE PERSONNEL INSPECTED THE ENGINE AFTER THE FIRE AND DISCOVERED THE IGNITION TIMING WAS ADVANCED BY 2 DEGREES. THIS MAY HAVE CONTRIBUTED TO THE FIRE BY PRODUCING A SPARK WHILE THE INTAKE VALVE WAS OPEN, THUS IGNITING THE FUEL IN THE INDUCTION.
Other reports on N757JX · 1
Matched to the same aircraft by N-number and date.