NTSB Factual Report

HISTORY OF FLIGHT

On December 22, 2006, about 1035 Pacific standard time, a Piper PA-28-140, N8001H, collided with terrain near Bridgeport, California. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The non-instrument rated private pilot was killed; impact forces destroyed the airplane. The cross-country personal flight departed Yerington, Nevada, at an undetermined time, with a planned destination of Lone Pine, California. Visual meteorological conditions prevailed, and no flight plan had been filed.

A family member reported to the Federal Aviation Administration (FAA) that the pilot had not arrived at his intended destination. The FAA issued an Alert Notification (ALNOT) at 1400. The Civil Air Patrol commenced search and rescue operations in the vicinity where FAA radar showed a few primary targets that matched the airplane's estimated flight path. Aerial units located the wreckage at 0900 on December 23, in mountainous terrain.

A review of radar data provided by the FAA revealed a primary target that was tracking on a southerly course along the California and Nevada state line at an altitude of 11,500 feet mean sea level (msl) and a ground speed of 105 knots. The target descended to 9,900 feet as it initiated a right turn followed by a loss of radar contact. A second primary target appeared approximately 11 minutes later, about 10 miles west of where the first primary target lost radar contact. The radar data depicted the second primary target on a northerly heading with a ground speed of 65 knots. The last radar return was about 6 to 8 miles southeast of the accident site, at 11,300 feet, which was about 3,000 feet above ground level (agl).

PERSONNEL INFORMATION

A review of FAA airman records revealed that the 57-year-old pilot held a private pilot certificate with a rating for airplane single-engine land that was issued on September 28, 2006. The pilot held a third-class medical certificate issued on September 9, 2006, with the limitation that he must have glasses available for near vision. A review of the pilot's logbooks revealed that the pilot had accumulated a total flight time of 132.4 hours.

AIRCRAFT INFORMATION

The airplane was a Piper PA-28-140, serial number 28-21470. A review of the airplane's logbooks revealed that the airplane had a total airframe time of 2,707.4 hours at the last annual inspection. It had an annual inspection on July 25, 2006.

The engine was a Textron Lycoming O-320-E3A, serial number L-16097-27A.

METEOROLOGICAL CONDITIONS

The closest official weather observation station was at the Mammoth Yosemite Airport (MMH), Mammoth Lakes, California, located about 45 miles southeast of the accident site at an elevation of 7,128 feet. At 1054, MMH reported wind from 270 degrees at 6 knots; visibility 10 statute miles; overcast cloud layer at 2,900 feet above ground level; temperature -1 degree Celsius; dew point -6 degrees Celsius; and an altimeter setting of 30.27 inches of mercury.

The FAA reported that there was an Airmen's Meteorological Information (AIRMET) for mountain obscuration by clouds, precipitation, mist, and fog that included the area of the Sierra Nevada mountains near Bridgeport. The Area Synopsis for northern Nevada was for scattered clouds at 11,000 feet. The synopsis for southern Nevada was for isolated light showers of rain and snow. There were no radar reports of any precipitation. Bishop winds aloft at 12,000 feet were forecast to be from 350 degrees at 41 knots. Bishop weather was clear at the time, but there were broken clouds at 6,500 feet agl (about 10,600 feet msl) at 1255.

WRECKAGE AND IMPACT INFORMATION

The National Transportation Safety Board investigator-in-charge (IIC) examined the wreckage on scene. The airplane came to rest at a GPS estimated elevation of 8,100 feet msl. There were no ground scars leading to the wreckage, and trees within a few feet did not have any broken branches. The cabin was in a nose down vertical attitude, and the propeller and engine were underneath it. The airframe buckled about 180 degrees down at the aft end of the cabin. The sides and top separated at this point; the floor remained attached. The airframe buckled 90 degrees in front of the empennage, which was in a horizontal attitude. The empennage was relatively undamaged. Both wings maintained their position relative to the airframe, and exhibited leading edge crush damage that went aft to the spar.

The IIC observed that the control cables remained attached to the control surfaces, and were continuous to the deformed cabin area.

MEDICAL AND PATHOLOGICAL INFORMATION

The Mono County Coroner completed an autopsy, and ruled the cause of death as multiple traumatic injuries. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide, cyanide, volatiles, and tested drugs.

TESTS AND RESEARCH

Investigators examined the wreckage at Aircraft Recovery Service, Littlerock, California, on February 14, 2007.

Investigators removed the engine. They slung it from a hoist, and removed the top spark plugs. All spark plugs were clean with no mechanical deformation. The spark plug electrodes were gray, which corresponded to normal operation according to the Champion Aviation Check-A-Plug AV-27 Chart.

A borescope inspection revealed no mechanical deformation on the valves, cylinder walls, or internal cylinder head.

Investigators manually rotated the crankshaft with a tool in an accessory drive gear. The crankshaft rotated freely, and the valves moved approximately the same amount of lift in firing order. The gears in the accessory case turned freely. Investigators obtained thumb compression on all cylinders in firing order.

Investigators manually rotated the magnetos, and both magnetos produced spark at all posts.

The vacuum pump drive gear remained unbroken. All vacuum pump vanes fractured.

The oil sump screen was clean and open.

The fuel pump's rubber diaphragm was unbroken.

Investigators established control continuity for the elevator and rudder. They established continuity from the aileron control surfaces to the cockpit; the chains were off their respective sprockets.

The fuel selector valve was in the left main position.

NTSB Probable Cause

The pilot's attempted VFR flight into instrument meteorological conditions and subsequent failure to maintain aircraft control due to spatial disorientation. Contributing to the accident was mountain obscuration.