Amateur-built HAWK AERO II N4513S accident near Holland, Michigan

Probable cause

The improper installation of quick release connectors in the fuel lines, which was not in accordance with the engine manufacturer's maintenance instructions and allowed air to be introduced into the fuel system and resulted in a partial loss of engine power. Also causal to the accident was the pilot's failure to maintain adequate airspeed and exceedance of the airplane's critical angle of attack, which resulted in an aerodynamic stall and impact with power lines.

NTSB analysis

The private pilot stated that the experimental light sport airplane experienced a partial loss of engine power during climb after takeoff about 80 to100 ft above ground level. The airplane entered an aerodynamic stall, so the pilot decreased the pitch attitude to recover, but the airplane then impacted power lines.

Postaccident examination of the engine revealed numerous items that had not been performed in accordance with the engine manufacturer's maintenance instructions, one of which was the correct installation of a quick release connector in the fuel lines. When the quick release connector was tested, it leaked a substantial amount of air into the fuel system; therefore, it is likely that air entered the fuel system during the flight and resulted in the partial loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN16LA363 for the full record.