Aero Commander 680 F N900L accident near Lapine, Alabama

Probable cause

The pilot's failure to maintain directional control during takeoff after a total loss of left engine power due to fuel contamination, which resulted in impact with trees. Contributing to the accident were the mechanic's failure to properly flush the fuel system during the annual inspection.

NTSB analysis

The commercial pilot reported that he had recently purchased the airplane and that he had completed two full-stop takeoffs and landings. Just as he began to rotate the airplane during a third takeoff, the left engine lost all power, and the airplane veered left and struck trees, which resulted in substantial damage to both wings and the fuselage.

Postaccident examination of the airplane revealed that both fuel selectors were set to the "center" tank position. Examination of the left engine and its accessories revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. When power was applied to the left engine's electric boost pump, it was not operational. Fluid that smelled like automotive gasoline and a small amount of water were drained from the fuel line between the electric boost pump and the fuel controller. Additionally, a dark-colored fluid that smelled like automotive gasoline was drained from the fuel strainer bowl located between the electric boost pump and the fuel controller.

The airplane had not been flown for about 13 years before the pilot bought it. Two days before the accident, a mechanic completed an annual inspection of the airplane. The previous owner reported that he told the mechanic that the left engine fuel controller had been malfunctioning, that the boost pump had to remain on until the engine warmed up, and that he believed that the fuel controller needed to be overhauled or replaced. A review of the airplane's maintenance logbooks revealed that there were no entries indicating which tasks were performed during the inspection, including whether the fuel lines had been flushed. A review of the left and right engines' logbooks revealed entries in both that stated, "checked fuel injectors and inspected fuel system." No entries were found indicating that any fuel system components were replaced.

The mechanic reported that he added 100LL aviation gasoline to the center and auxiliary fuel tanks before the flight, and the previous owner said that he observed the mechanic sump "a great deal of fuel" before the flight. Both the mechanic and the pilot said that they ran the engines after the annual inspection and conducted several high-speed taxi checks, and they noted no anomalies. The pilot also said he flew the airplane for 30 minutes the day before the accident; however, this contradicted the time noted on the hour meter between the time that the annual inspection was completed and the time of the accident, which was about 0.2 hour (or 10 to 15 minutes).

Although fresh fuel was added to the center fuel tank, given that no entries were found in the maintenance logbooks indicating that the fuel lines had been flushed or that any fuel components had been replaced when the airplane was inspected and that contaminated fuel was found in the fuel lines going to the left engine, the loss of engine power was likely due to contaminated fuel.

Although the pilot held a commercial pilot certificate with a multiengine land rating, he had not flown in the airplane make and model in about 25 years. He also said that he did not use the checklist for an engine failure during takeoff and that he was not provided a checklist when he purchased the airplane.

Text from the NTSB. Open the NTSB docket for ERA18LA073 for the full record.