Accident Details
On July 22, 2023, at approximately 1940 central daylight time, an Ercoupe 415-D, registration N415JC, sustained substantial damage during a forced landing near Waupun, Wisconsin. The pilot suffered serious injuries, while the pilot-rated passenger was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
According to statements from the pilot and passenger, they had been en route for about two hours when the engine rpm decreased. The pilot activated the carburetor heat and cycled the throttle, but the engine sputtered and lost power completely. The passenger noted that the sight gauge on the center (header) fuel tank indicated it was empty.
The pilot determined the engine was likely starved of fuel and executed a forced landing to a marsh. The airplane came to rest upright with substantial damage to the fuselage, both wings, and the empennage.
Fuel Management
The flight originated in Conroe, Texas, destined for Oshkosh, Wisconsin. The passenger stated they stopped for fuel in Cedar Rapids, Iowa. During fueling, the center tank was filled with six gallons, both main tanks with nine gallons each, and each auxiliary tank received two gallons. They estimated having over four hours of fuel onboard at departure, consistent with their previous fuel loads.
After fueling, the pilot observed that the line technician had placed the vented fuel cap on the outboard tank backwards. The pilot estimated it would take about an hour to reposition the cap without damaging the airplane and decided to address the issue after arrival in Oshkosh.
Postaccident Findings
Law enforcement reported both main fuel tanks were empty at the scene, but a strong smell of fuel was present in the marsh. The auxiliary tanks were not inspected on site. The passenger and a first responder experienced chemical burns on their feet and legs after standing in the marsh adjacent to the airplane. The left main fuel tank was compromised, and the gascolator sustained impact damage.
A postaccident examination of the engine found no mechanical anomalies that would have prevented normal operation. All fuel tanks were empty. Inspection of the fuel system revealed the fuel cap on the left auxiliary tank was installed backwards, with the vent facing the trailing edge of the wing.