Beech F33 N711JA accident near Land O Lakes, Florida

Probable cause

The partial loss of engine power due to a contaminated fuel system and the pilot’s improper decision to attempt a takeoff with a known deficiency in engine power.

NTSB analysis

Twice before the accident takeoff, the pilot performed an engine run-up successfully; however, when he advanced the engine to full power, the engine ran rough, and the pilot elected not to attempt the takeoffs. During a third attempt, the engine ran rough again, but the pilot continued the takeoff. The airplane travelled more than half the distance of the 3,541-ft-long runway before it lifted off, barely cleared trees at the end of the runway, and made a left turn. A witness radioed the pilot and advised that he had a rough running engine; the pilot acknowledged the rough running engine and stated that he was returning to the airport. He subsequently stated that he was going down.

The airplane came to rest upright in the back yard of a vacant residence about 1/2 mile from the departure end of the runway. A postcrash fire consumed most of the cockpit, cabin, and right wing. The left wing had separated during the impact and was also located in the back yard of the residence. Subsequent examination of the wreckage revealed corrosion and loose material associated with corrosion inside the fuel manifold. The fuel lines leading to the fuel manifold had partially melted during the postcrash fire, preventing any water from entering the fuel manifold after the accident. The corrosion and material likely resulted in a partial power loss at high power settings (increased fuel demand).

Toxicological testing revealed the pilot had been taking two disqualifying and potentially impairing medications used to treat depression. Due to limited information on the status of the pilot’s depression or symptoms from his use of these medications, whether his medical condition or use of medications contributed to the accident could not be determined from the available information.

Text from the NTSB. Open the NTSB docket for ERA20LA179 for the full record.