LAX96FA275

The pilot departed San Jose, California, on a cross-country flight to Sisters, Oregon. He obtained a standard preflight weather briefing. Visual flight was not recommended. Cumulus buildups were reported to the pilot. The pilot indicated that he may be overflying the cloud tops. He did not file a flight plan. The pilot's wife was driving to the same location and they talked by cell phone while en route. When the pilot failed to arrive at the destination a search was started. According to radar data, the aircraft was at 15,400 feet when it started a rapid descent. Radar was lost at 11,800 feet. Witnesses reported seeing the aircraft descending near vertically out of broken clouds with the engine at full power. When the aircraft was found, the right outboard wing panel from about station 110 outboard was missing. About a month later the outer wing panel was found. Analysis of the failed structure indicated a positive overload of the wing and the horizontal stabilators.

History of flight

On July 17, 1996, about 1415 hours Pacific daylight time, a Piper PA-24-260, N9324P, was destroyed after an uncontrolled descent into terrain near Tennant, California. The pilot and passenger were fatally injured. Marginal visual meteorological conditions had been forecast along the pilot's route of flight and no flight plan was filed. The flight originated at San Jose, California, about 1230 on the day of the accident and was destined for Sisters, Oregon.

The pilot's wife was driving to the same location. They talked by cell phone while en route. When the pilot failed to arrive at the destination a search was started.

According to recorded radar data, the aircraft was observed at 15,400 feet msl, at which time it started a descent. About 1 minute later it was lost from radar at 11,800 feet msl. There were three witnesses that observed the aircraft descending into the general area of the accident site. Two witnesses stated that it was descending vertically out of the clouds, and one said it was descending at a 45-degree angle with a loud engine sound. The witnesses reported that there were breaks in the overcast with bases about 3,000 feet above ground level.

Personnel information

The pilot's flight logbook was not recovered. According to the pilot's last third-class flight physical which was conducted on July 29, 1994, he had accumulated 2,800 total flight hours with 86 hours in the last 6 months.

Aircraft information

At the time of the accident the aircraft had accumulated about 4,229 total flight hours according to an examination of the airframe logbook. The last documented annual inspection was performed on March 8, 1996. At that time, the aircraft had a total flight time of 4,192 hours with 1,007 hours since an engine major overhaul. During the wreckage examination the recording tachometer indicated 3,509.27 hours. The aircraft had flown about 37 hours since the last annual inspection.

Meteorological information

The pilot called for and received a preflight weather briefing from OAK AFSS from San Jose, California, to Bend, Oregon. The pilot received a standard briefing and was advised that VFR was not recommended.

The pilot contacted the Oakland En Route Flight Advisory Service (EFAS) while he was over Red Bluff, California. He requested the weather to Klamath Falls, Oregon, and was advised that there were no flight advisories. He was informed that the clouds over the Siskiyou mountains were 7,000 feet broken with some cumulus buildups. The Klamath Falls weather was given as a few clouds at 4,000 feet and scattered clouds at 8,000 and 18,000 feet.

Satellite data indicated cumulus buildups in the area of Klamath Falls, with precipitation north. There were no pilot reports available. The pilot was advised of the cumulus buildups. The pilot stated to the briefer that he may be going over them. The briefer said that their may be higher en route buildups. The Redmond, Oregon, weather was given as 8,000 and 9,000 foot broken clouds. The terminal forecast for Redmond for 1800 local time was: 6,000 feet broken clouds; 10,000 feet overcast clouds; with occasional rain and possible thunderstorms.

The pilot was provided with a pilot report over The Dalles, Oregon. A Cessna 172 reported moderate turbulence at 5,000 and 8,000 feet.

The winds aloft data indicated that winds at 14,000 to 15,000 feet in the Tennant area were likely about 220 degrees at 50 knots around the accident time. Mt. Shasta (14,162 feet msl) is located about 13 to 15 nautical miles downwind of the accident area.

The National Weather Service (NWS) Surface Analysis chart for 1400 hours indicated a moderate cold front extending southward from eastern Washington through eastern Oregon, and then curving southwestward through northern California. The map showed generally visual meteorological conditions (VMC) south and east of the front. The chart showed most stations north and west of the front reporting marginal VMC and light rain.

Wreckage and impact information

Examination of site photographs, wreckage distribution diagrams, and interviews of FAA personnel present were used to describe the accident site. The accident site is on a forested level plain about 4,800 feet msl, and is populated by 30-foot pine trees and scrub brush. An initial ground disturbance was noted just south of a 30-foot-tall pine tree consisting of two crater-like depressions on a magnetic bearing of 171 degrees and separated by a 4-foot distance. The first crater was small and shallow, while the second was about 2 feet by 3 feet deep in diameter.

The propeller assembly was found just south of the second crater and was separated from the engine crankshaft flange. One blade remained attached to the hub. The second blade was fractured and separated at the shank just outboard of the hub. Minor leading edge damage, chordwise scoring, and tip end twist deformation was observed.

A trail of debris and ground scars was observed leading from the second crater on a magnetic bearing of 159 degrees to the main wreckage. The debris field between the crater and wreckage contained left wing components, left aileron, and it's associated balance weight/bell crank assembly.

The entire aircraft sustained accordioning crush from the nose cone to the tail cone, with extensive fragmentation noted to all components. The remains of the left and right wings were found on the west side of the wreckage. Approximately 75 inches of the outboard right wing and it's associated aileron, the aileron balance weight and bell crank assembly were not located. An area encompassing a radius of 100 yards from the main wreckage was examined for components with none found.

The wreckage was recovered from the site and examined at Plain Parts in Pleasant Grove, California, on August 7 and 8, 1996. During the examination, the wreckage was schematically reconstructed. All structural and skin wreckage components were positively matched to their location on the aircraft structure. Following the reconstruction, no components from the outboard 75-inch right wing section were found.

No oxygen system components of any kind were observed in the wreckage. The cockpit and cabin were fragmented and destroyed. The fuel selector was located and found in the detent for the left main tank position. The cabin heater, defroster, and right side air vents were found off; the left side air vent was destroyed. The throttle quadrant was crushed and separated from the instrument panel; the throttle, propeller, and mixture controls were full aft. The control system components behind the instrument panel and under the cabin floor were examined with no unusual operating condition noted.

The cabin door was separated from its hinges. The door locking handle was found in the closed-locked position. The door bolt and upper latching pins and hook were found in the extended positions and were bent and distorted. The corresponding door frame pin sleeve, hook recess pin, and bolt receptacle were observed to be distorted.

The fuselage aft of the cabin to the vertical stabilizer leading edge and the empennage was distorted and fragmented. No unusual condition was observed to any control system components in these sections.

The crushed and distorted vertical stabilizer remained attached to the empennage. The rudder remained attached to it's associated hinge and hangar assembly, with a distortion pattern matching the vertical stabilizer. The rudder balance weight was present on the structure. The rudder cables remained attached to the rudder bell crank, with no battering observed to the limit stops.

The right horizontal stabilizer separated from it's torque tube, but was found adjacent to the empennage at the accident site. Leading edge accordioning signatures were observed to the outboard half and were oriented 30 degrees to the leading edge.