Amateur-built LANCAIR EVOLUTION N38DM accident near Iola, Kansas

Probable cause

Water contamination of the fuel due to the pilot’s inadequate preflight inspection, which led to a total loss of engine power. Contributing to the accident was the pilot’s failure to complete the engine-out checklist, which resulted in an excessive loss of altitude and the inability to glide to the intended airport.

NTSB analysis

The pilot was flying the airplane in cruise flight at 11,000 ft when the engine lost power. He attempted to restart the engine by switching fuel tanks, turning on the igniters, and holding down the start button but was unsuccessful. He elected to turn back toward the departure airport and feathered the propeller. During the descent, the pilot decided he was unable to make it back to the airport and conducted a forced landing on a dirt road. During the landing rollout, both wings struck trees, which resulted in substantial damage.

Examination of the flight controls, engine, and fuel systems revealed no mechanical malfunctions or failures that would have precluded normal operation. However, fuel samples recovered from the airplane tested positive for water. Data recovered from the engine monitor showed an abrupt power loss that coincided with a loss of fuel flow. The flight instructor who completed transition training with the pilot reported the pilot did not sump the fuel before every flight. Thus, it is likely that the pilot did not perform an adequate preflight inspection and water remained in the fuel system, which led to a total loss of engine power.

The pilot's operating handbook (POH) recommended that the configuration for a forced landing is landing gear up, flaps up, propeller feathered, and airspeed at 110 knots to achieve maximum glide performance. This configuration provides a maximum glide performance of about 500 ft per minute (fpm) descent and about 3.5 nautical miles glide distance per 1,000 ft of altitude lost. Data from the engine monitoring system revealed that, about 3 minutes after the fuel flow stopped and about 2-3 minutes before the accident, the flaps were extended to takeoff position, the airplane achieved 110 kts, and the propeller was feathered. During this time, the rate of descent exceeded 1,000 fpm and was, at times, in excess of 4,000 fpm. The pilot did not mention of the use of an emergency engine-out checklist or consultation of the POH during the event. The pilot's failure to accomplish all of the steps in the emergency engine-out checklist promptly after the loss of engine power led to an accelerated loss of altitude and the subsequent inability to glide to the airport.

Text from the NTSB. Open the NTSB docket for CEN17LA009 for the full record.