Amateur-built KR2 N886MJ accident near Poplar Grove, Illinois

Probable cause

The loss of engine power due to vapor lock of the throttle body injection system.

NTSB analysis

Shortly after departure, the pilot smelled oily smoke and noted a loss of engine oil pressure and an increase in oil temperature. The engine lost power, and the pilot performed a forced landing to a corn field. During the landing, the nosewheel dug into the field and the airplane nosed over, resulting in substantial damage to the wings and vertical stabilizer.

An examination of the engine revealed no mechanical anomalies that would preclude normal operations. The source of the oil leak was not identified.

The pilot later reported that, after researching and consulting with other pilots who operated the engine type installed on the accident airplane, he believed that the loss of engine power was the result of vapor lock in the throttle body injection (TBI) system. His research indicated that other airplane owners provide “blast cooling” on the TBI to fix the issue. The pilot said that the vapor lock issue likely started at the same time as the engine heated up due to the extra lean mixture. He added that the rear seal might leak and spray oil on the exhaust pipe. He stated that enriching the mixture might have corrected the issue inflight.

Text from the NTSB. Open the NTSB docket for CEN19LA152 for the full record.