Amateur-built Vampire N333SV accident near Findlay, Ohio

Probable cause

A total loss of engine power due to the failure of the reduction drive assembly as a result of excessive wear and high temperatures. Contributing to the accident were the pilot's lack of total experience in the airplane and the unsuitable terrain for a forced landing.

NTSB analysis

The airplane was an experimental amateur-built airplane that was a prototype for light sport aircraft certification. The flight test was conducted by the engine manufacturer, who also provided a pilot to fly the airplane. The pilot had not received flight instruction or a checkout in the airplane. The pilot learned to fly the airplane on his own by taxiing and performing local flights in the airport area. The pilot also had no training or experience in aircraft flight test. A larger radiator had been installed onto the airplane due to noted high engine temperature during previous flights. Prior to the accident flight, the pilot performed two taxi tests during which he performed short hops on the runway to get familiar with the aerodynamic forces that would be encountered during takeoff and landing. The engine temperature was reported as normal during this time. The pilot then attempted a takeoff for a flight that was to remain in the airport traffic pattern. Just after takeoff the airplane lost total engine power. The pilot attempted an engine restart without success, during which he did not hear the engine turn over. The pilot then executed a forced landing into a quarry located about 0.6 miles from the departure end of the runway. An examination of the reduction drive assembly needle roller bearing sidewall revealed a combination of wear and high temperatures leading to overstress. Circumferential wear marks on the separated cage sidewall and the presence of metallic debris suggested impingement of the rollers on the sidewall during engine operation. Heat tinting of the outer raceway in the vicinity of the failed sidewall and the cam that served as the inner raceway was also noted. The needle bearing malfunction could be attributed to misalignment of the needle bearing and insufficient lubrication.

Text from the NTSB. Open the NTSB docket for CHI08LA274 for the full record.