Accident Overview
At approximately 1140 mountain standard time on May 15, 2009, an Engineering and Research (Ercoupe) 415C, registration N2339H, experienced a total loss of engine power while in cruise flight. The sole occupant, a student pilot who owned the aircraft, executed a forced landing onto a rough dirt strip near San Manuel, Arizona. The pilot was not injured, but the airplane sustained substantial damage to the fuselage and wings during the landing rollout and subsequent impact with desert vegetation.
Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 cross-country flight, which had departed from a private dirt strip in Punkin, Arizona. The intended destination was San Manuel Airport (E77). No flight plan had been filed.
Post-Accident Inspection
The incident was upgraded to an accident on May 19, 2009, following an inspection by a Federal Aviation Administration (FAA) airworthiness inspector. The inspector reported broken engine mounts, a wrinkled firewall and fuselage, and deformation of both wings.
In an interview with the FAA inspector, the pilot stated 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 sustained 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), but did not include a written statement regarding the circumstances. However, the pilot provided 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.
Pilot Records and Maintenance History
FAA inspectors reviewed the student pilot's logbook and student pilot certificate. Both documents showed endorsements for 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, occurred on May 9, 2006.
Engine Examination
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 and blades sustained damage. 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; 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.