Amateur-built CHALLENGER II N906WV accident near Port Orange, Florida

Probable cause

The total loss of engine power due to an out-of-temperature seizure of the PTO cylinder.

NTSB analysis

The pilot reported the engine lost power shortly after takeoff, while at an altitude of about 900 ft. The pilot established best glide speed and attempted to restart the engine several times; however, the engine did not regain power. The pilot then performed a forced landing. During the forced landing, the airplane impacted a tree followed by terrain and sustained substantial damage to the wings and fuselage.

Postaccident examination of the two-stroke engine revealed that the power take-off (PTO) cylinder had significant scoring along the cylinder walls, which was consistent with the cylinder being subjected to an out-of-temperature seizure. No further anomalies or mechanical failures were observed that would have prevented normal operation. Given that the visible signatures of a hot seizure and a cold seizure of a cylinder are the same, the type of seizure could not be determined with the available information.

Text from the NTSB. Open the NTSB docket for ERA23LA324 for the full record.