NTSB Factual Report

On May 15, 2009, about 1140 mountain standard time, an Engineering and Research (Ercoupe) 415C, N2339H, experienced a total loss of engine power during cruise flight and the pilot made a forced landing on a rough dirt strip near San Manuel, Arizona. The student pilot/owner, the sole occupant, was not injured. The airplane sustained substantial damage to the fuselage and wings during the landing roll out and subsequent impact with desert vegetation. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations (CFR) Part 91 cross-country flight that departed a private dirt strip in Punkin, Arizona. No flight plan had been filed for the flight that was destined for San Manuel Airport (E77), San Manuel.

The incident was upgraded to an accident on May 19, 2009, following an inspection of the airplane by a Federal Aviation Administration (FAA) airworthiness inspector. The FAA inspector reported that the engine mounts had broken, the firewall and fuselage were wrinkled, and there was deformation of the both wings.

In an interview with the FAA inspector, the pilot reported that he was on a solo flight when the engine lost power. He made the emergency landing on an abandoned dirt airstrip, and the airplane received substantial damage due to the rough, uneven terrain, and impact with desert vegetation.

The student pilot returned the Safety Board Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1); however, the report did not include a written statement as to the circumstances surrounding the accident. The pilot did however, provide a written statement to his insurance adjuster reporting that the engine lost partial power and then quit. According to that report, the pilot was able to restart the engine, but it only achieved 1,000 rpm's.

FAA inspectors reviewed the student pilot's logbook and his student pilot certificate. Both the logbook and certificate showed the same endorsements; a solo flight in the accident airplane on September 20, 2008, and a solo cross-country flight on September 29, 2008.

According to the maintenance records, the last annual inspection of the airplane, and the last 100-hour inspection performed on the engine, was on May 9, 2006.

An inspection of the engine was performed by a National Transportation Safety Board (NTSB) investigator, and a participant from Teledyne Continental Motors.

During the inspection, no obvious mechanical problems were noted. The propeller assembly along with the propeller blades sustained damaged. The induction system separated from the engine, and the fuel strainer was about 80 percent full with a cloudy liquid. Mechanical continuity was established throughout the engine. Crankshaft rotation produced thumb compression in each cylinder, with accessory gear and valve train continuity established. Both magnetos remained attached at their respective mounting pads. During rotation of the crankshaft, investigators noted impulse coupling engagement and spark visible at the terminal ends; they also reported that the ignition harness was not damaged. The fuel pump was disassembled, with no damage to the diaphragm present.

The upper spark plugs were removed and the cylinders were borescoped. The upper spark plugs exhibited light gray deposits consistent with normal operation. The combustion chambers and piston heads showed a heavy white deposit. The valve heads were not damaged, and no signs of abnormal thermal discoloration were noted. The carburetor was removed and disassembled. Manual operation of the carburetor throttle and mixture linkage arms revealed no binding. The inlet screen was removed with a light amount of debris noted; the bowl was free of debris. The fuel filter was also removed and had some restriction when air was blown into it. According to the engine manufacturer, there were no abnormalities found during the engine inspection that would have precluded normal operation.

NTSB Probable Cause

A loss of engine power during cruise flight for undetermined reasons, which resulted in a forced landing and impact with terrain.