The private pilot and a pilot-rated passenger departed on a local flight to complete touch-and-go landings at a nearby airport. The Ercoupe 415D was in the traffic pattern when witnesses reported that it flew very low over their house and that the engine was “sputtering and backfiring.”
The airplane flew about 30 feet above them, made a steep left bank toward the airport, then hit the ground in a wooded area near Monmouth, Illinois. Both aboard the plane died in the crash.
A post-impact fire consumed a majority of the airplane. The propeller exhibited signatures consistent with a lack of engine power at impact.
Although impact and thermal damage precluded a detailed examination of the engine and fuel system, the examination did not reveal any evidence of preimpact mechanical malfunction or abnormalities that would have led to a loss of engine power.
The investigation was unable to determine the cause of the loss of engine power based on the available information.
Probable cause: A loss of engine power for reasons that could not be determined based on the available information.
NTSB Identification: CEN18FA235
This June 2018 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Have a friend with a Europe who has experienced two engine outs. Both due to failure of the single fuel transfer pump. Subsequently he installed a secondary fuel pump.
The design of the ercoupe has wing tanks that feed a 5 gallon header tank (22 gallons max as I remember). From the pictures they crashed in a area of some trees with both wings bent rearward, no real fuselage crushing, and everything in one area (quick dissipation of energy but not 0 feet).
1 Header tank would have been able to help start the fire with the hot engine
2 I think they came in at a significant angle (not straight down) because of the trees and bent wings
3 Contaminated fuel could account for the sputtering and backfire. The fuel in the header could have been good at the beginning of the flight with the contaminated fuel pumped in latter
Not a fun report to read
There was significant thermal damage. A polite way of saying it burned badly. Considering the construction of magnetos and the ignition system, they may very well have been unable to test for spark. Engine internals can survive some pretty extreme fire exposure. So maybe that’s all they had left to test.
Hey Wylbur, I see you have been down this road before. I saw another engine failure after losing both mags that was blamed on fuel starvation. This was later proved by an independent expert to be the mags. Not enough investigation was done by qualified technicians.
Engine reported to be missing and back-firing by several wittnesses. So the NTSB or FAA did not check the Mags to see if they had problems allowing them to get “in time” and then get “out of time”. The extended report did not show they even checked for spark.
Just because the valve train worked and they got compression/suction doesn’t mean that the accessory “drive” was working correctly.
I’ve dealt with auto engines that have had a problem like this and the distributor was not turning at the same speed as the engine. In one case because the shaft driving the distributor, the splines had worn off.
the photos in the NTSB docket include one of the engine. It was in pretty bad shape after the crash and fire. Would a mag reliably spark after that kind of mechanical and thermal damage? That the plane burned so vigorously after the crash suggests that several gallons of fuel was on board. Initiating a “steep turn” low to the ground and a slow speed as reported by multiple witnesses seems like a set up for a cartwheel. “Crash as slow as possible, at flying airspeeds, unstalled, wings level, in control” doesn’t seem to have happened here.