Accident Details
An experimental amateur-built Hawk Aero Tandem airplane sustained substantial damage during an emergency landing. The pilot reported that he lost engine power after restarting the engine twice. During the landing, the aircraft impacted a mound with its nose landing gear. A witness observed liquid in the fuel tank when the airplane was disassembled.
Engine and Fuel Information
The airplane was powered by a Hirth 2706 fuel-injected engine. The Blue Max two-cycle oil's recommended fuel and oil ratio was 100:1. However, an engine manual supplement noted that the recommended fuel and oil mixture was 90:1 for fuel-injected engines. The pilot reported that he used a 100:1 fuel/oil ratio.
A representative of the engine repair facility stated, "This engine experienced a piston seizure of the mag[neto] end piston. ... The PTO side piston is undamaged and from inspection of this cylinder it appears that possibly there was too lean of an oil mix in the fuel."