Accident Overview
On November 7, 2020, at approximately 0830 central standard time, an ERCO Ercoupe 415-C airplane, registered as N331BW, sustained substantial damage during an accident near Ardmore, Oklahoma. The commercial pilot sustained serious injuries, and the two passengers suffered minor injuries. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight Details
The purpose of the flight was for the pilot to take two passengers on a local flight to photograph a house. The pilot reported that the airplane departed with a full fuel load. The pilot occupied the left seat, while the two passengers shared the right seat. Both seats were equipped with lap belts.
Accident Sequence
The pilot completed two passes by the house. He then felt a “slight shudder” and announced to the passengers that he thought they were flying through the airplane’s own propeller wash. Immediately after, the engine began “vibrating so bad” that the pilot feared the engine would separate from the airframe. He attempted to control the vibration by adjusting the throttle, but the vibration persisted. He did not activate carburetor heat. The pilot configured the airplane for a glide, at which point the airplane banked left. Despite applying full right aileron, the left turn could not be arrested. While attempting to land in a field, the airplane contacted a tree and came to rest inverted.
Postaccident Examination
The airplane sustained substantial damage to the fuselage, both wings, and the empennage. A postaccident examination of the engine and airframe, including the flight controls, revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation.
Meteorological and Weight Considerations
Review of local meteorological data indicated that at the time of the accident, the airplane was likely operating in conditions conducive to the formation of serious carburetor icing at cruise power, as defined by FAA Special Airworthiness Information Bulletin CE-09-35. Additionally, weight and balance calculations showed that the airplane was 48 pounds over its maximum takeoff weight at engine start.
Seating Compliance
According to ERCO Ercoupe Information Letter Number 2, the model 415-C does not have a flight manual. FAA Type Certificate Data Sheet A-718 limits the airplane to two seats but does not address two passengers sharing a single seat. The FAA has issued a clarification stating that multiple occupants per seat are permitted only if the seat usage conforms to the approved Airplane Flight Manual limitations, and the pilot must verify that the seat belt is rated for such use and that seat structural strength is not exceeded. The clarification emphasizes that each person should have a separate seat and seat belt whenever possible.