Accident Overview
On April 19, 2008, at approximately 1855 Pacific daylight time, a Cessna C175A Skylark, registered as N6868E, experienced a loss of engine power and collided with transmission wires. The accident occurred following a departure from Pine Mountain Lake Airport in Groveland, California. The pilot, a commercial pilot who owned the aircraft, was the sole occupant and sustained serious injuries. The airplane sustained substantial damage. The flight was a local personal flight originating from Groveland. Visual meteorological conditions prevailed, and no flight plan had been filed.
Pilot Report and Witness Accounts
According to a written statement from the pilot, he was conducting a high-speed taxi test when the airplane encountered a gust of wind and inadvertently became airborne. The engine then lost power, and the airplane struck power lines. An FAA inspector interviewed friends of the pilot based at Groveland. One friend stated that the pilot was performing a series of high-speed taxi tests. The airplane's groundspeed became excessive, and it encountered a gust of wind, causing an unintentional lift-off. The airplane continued to climb, and the pilot appeared to attempt a return to the airport. After the airplane made a 90-degree turn, the engine momentarily lost power, then briefly regained power before quitting entirely. The airplane then collided with a telephone pole and descended nose-low onto the road below.
Post-Accident Examination
The FAA inspector, along with representatives from Cessna and Teledyne Continental Motors, conducted a post-accident examination. The inspector discovered that the pilot had recently installed a newly purchased engine. As part of the installation, the pilot had fabricated and fitted a new fuel line just before the accident flight. The examination of the engine and airframe disclosed no mechanical malfunctions or failures that would have precluded normal operation, except for the following: during disassembly of the fuel line connecting the gascolator to the carburetor, a "flapper valve" was observed at both end fittings. The inspector noted that flapper valves can occur when fittings are installed without using a mandrel, causing the fitting to cut the inside of the hose and create a valve that obstructs fuel flow. The inspector opined that this flapper valve created an obstruction sufficient to prevent fuel flow.
Maintenance and Certification Issues
The last annual inspection recorded in the airframe logbook was on October 1, 2006, at a total time of 2,733.4 hours. No records were found for the engine or its installation. Furthermore, the airplane had not been approved for return to service and did not have an airworthiness certificate.
Weather Conditions
A routine aviation weather report (METAR) from Merced Municipal Airport/Macready Field, located about 38 nautical miles southwest of the accident site, indicated that approximately two minutes before the accident, winds were from 260 degrees at 15 knots, gusting to 25 knots.