Amateur-built E-RACER N345JM accident near Big Rock, Illinois

Probable cause

The pilot's failure to maintain airplane control after experiencing excessive engine cylinder head temperatures during the initial flight test of the experimental amateur-built airplane.

NTSB analysis

The accident occurred during the first flight test of the recently completed experimental amateur-built airplane. The tower controller cleared the flight to orbit the airport at 2,500 feet mean sea level (msl) and to make left turns. As the airplane was completing its first orbit of the airport, the pilot told the tower controller that the airplane was experiencing excessive engine cylinder head temperatures and that he would like to land. According to radar track data, the airplane was at 2,700 feet msl and had a ground speed of about 145 knots at that time. The tower controller replied that the wind was calm and that the flight was cleared to land. The pilot acknowledged the landing clearance, and no additional communications were received from the pilot. Radar track data indicated that the airplane began a left descending turn as its ground speed decreased from about 170 to 105 knots, and its descent rate increased from 650 to 2,400 feet per minute. The last radar return was about 2 miles west-southwest of the airport about 400 feet above the ground. A witness observed the accident airplane traveling about 125 feet above the ground at a high speed while in a slight left turn with its landing gear retracted. The airplane leveled its wings momentarily before it entered a left-wing-low, wings-near-vertical descent and then collided with power lines and a cornfield. The postaccident examination of the airplane revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. No evidence of an in-flight fire was found. The extent of damage to the engine compartment and associated baffling precluded a determination of why the engine developed excessive cylinder head temperatures during the accident flight. However, excessive engine cylinder head temperatures would not have resulted in a flight controllability issue and, therefore, the pilot should have been able to maintain control of the airplane throughout the flight. The pilot had accumulated about 365 hours of flight experience in a comparable airplane.

Text from the NTSB. Open the NTSB docket for CEN11FA537 for the full record.