Amateur-built ADVENTURA II N32856 accident near Miramar, Florida

Probable cause

The pilot’s failure to remove the ECU select switch per the manufacturer’s service bulletin, which resulted in a loss of engine power.

NTSB analysis

According to a witness, the pilot and passenger reported that the experimental, amateur-built airplane had experienced engine issues in the days preceding the accident. According to the airplane and engine manufacturers, the passenger had reported an intermittent in-flight loss of engine power that occurred during a previous flight (both the pilot and passenger were employees of the airplane manufacturer). The pilot and passenger had been troubleshooting the power loss, and departed on a test flight. After takeoff, the pilot acknowledged air traffic control instructions to extend on the downwind leg of the airport traffic pattern, however, there were no further communications from the pilot. The accident site was located in a residential area about 1 mile south of the departure airport.

The investigation revealed that a service bulletin issued by the engine manufacturer had not been complied with. The bulletin required the removal of an "ECU select switch" connected to the engine’s control units. During postaccident functional testing of the engine, a loss of power occurred consistent with the malfunction of the switch. After the switch was removed, the engine operated normally.

Text from the NTSB. Open the NTSB docket for ERA23FA023 for the full record.