History of Flight
On May 9, 2010, at 1028 Pacific daylight time, N56626, a Piper PA-28-235, collided with trees and terrain approximately 8 miles northeast of Livermore Municipal Airport, Livermore, California. The pilot was operating the airplane under Title 14 Code of Federal Regulations Part 91. The private pilot and passenger, who also held a private pilot certificate, were fatally injured. The airplane sustained substantial damage. Witness information indicated that instrument meteorological conditions prevailed at the accident site. The pilot departed in visual flight rules (VFR), requested and received flight following after departing from Auburn Municipal Airport, Auburn, California, about 0945, and was destined for San Carlos Airport, San Carlos, California.
According to family members, the pilot and passenger were visiting family in the Auburn area and wanted to return home for an afternoon meeting. A witness near the accident site heard the airplane but did not see it due to fog. The witness stated that the airplane sounded lower than usual and the engine sounded normal, followed by the sound of impact.
The pilot was in communication with Northern California Terminal Radar Approach Control. The pilot had requested flight following to San Carlos and was authorized to fly at an altitude of the pilot's discretion. No distress calls were made.
A Safety Board Air Traffic Control specialist plotted radar data. The flight track showed a descent to 2,600 feet and a turn to the south-southeast when reaching hilly terrain. The last radar target was at 2,799 feet at 1028. The accident site was about 10 miles southeast of the straight-line path from Auburn to San Carlos.
Personnel Information
The pilot, age 75, held a private pilot certificate for airplane single-engine land and a third-class medical certificate issued December 4, 2008, with a limitation to wear corrective lenses. The pilot's logbook showed 983 flight hours, with 751 hours in the accident airplane. She had flown 3 hours in the past 90 days, 2 hours in the past 30 days, and 1 hour in the past 24 hours.
The passenger, the pilot's husband, was also a rated pilot with a current medical, but family members indicated he no longer flew as pilot-in-command.
Aircraft Information
The four-seat, low-wing, fixed-gear airplane, serial number 28-7410016, was manufactured in 1973. It was powered by a Lycoming Engines O-540-B4B5 250-hp engine and equipped with a Hartzell HC-C2YK-1BF fixed-pitch propeller. An annual inspection was completed on April 1, 2010, at a tachometer reading of 3,171.74 hours. The tachometer read 3,175.65 hours at the accident site. The airplane was equipped with a Garmin (Apollo) CNX 80 GPS unit, and the main software was upgraded on April 19, 2010.
Meteorological Information
No weather services were provided by Lockheed Martin Flight Service, and no record of a weather briefing from DUAT providers existed. A Safety Board meteorologist completed a weather study. The closest official weather observation station was Livermore. At 1053, a METAR reported wind from 210 degrees at 7 knots, visibility 10 statute miles, few clouds at 2,200 feet, broken clouds at 4,000 feet, temperature 14°C, dew point 9°C, and altimeter 30.02 inHg.
The National Weather Service Surface Analysis Chart for 1100 PDT depicted a shortwave trough in northern California. Station models indicated generally westerly flow with overcast skies west of the accident site. Light rain was reported north of the accident site. WSR-88D radar data indicated light rain in limited areas of the San Francisco Bay Area, with no severe weather. The closest radar, KMUX, was about 40 miles south at an elevation of 3,469 feet. Radar imagery at 1013 PDT indicated light precipitation passed through the accident airplane’s flight path about 12-15 minutes prior. At 1025 PDT, no precipitation was falling at the accident site near the accident time.
Wreckage and Impact Information
The first identified point of impact was an area of 50-foot tall trees at an elevation of 2,412 feet mean sea level. Pieces from the left wing were located in the trees. The debris path continued in a direction of about 100 degrees magnetic. The first ground impact was approximately 110 yards from the trees. The debris field included large sections of both wings, the main wreckage, empennage, and engine, spanning about 290 yards.
Medical Information
The Contra Costa County Coroner completed an autopsy on the pilot. The cause of death was multiple blunt impact trauma. Forensic toxicology by the FAA Bioaeronautical Sciences Research Laboratory detected fluoxetine, norfluoxetine, and quinine. No carbon monoxide or ethanol was detected. The blood provided was "cavity blood," and the blood was not tested for quinine.
Tests and Research
Examination of the airframe revealed both wings in multiple pieces. The left wing had circular indentations consistent with tree branches. The right wing had separated into four sections with no circular indentations. All control surfaces were accounted for. Control cables to the ailerons had broomstrawed separations. Flap control surfaces appeared retracted with no trailing edge damage. Control cables from cockpit attach points were secure.
The engine was examined. Mechanical continuity was obtained via manual rotation of the propeller. Thumb compression was obtained on all cylinders. Magnetos produced spark at all posts. The engine-driven fuel pump was not found. Spark plugs had similar electrode gapping; plugs 2, 4, and 6 were oil coated. No evidence of catastrophic malfunction or fire was found. Cylinders showed no foreign objects or detonation. The carburetor contained approximately 3 ounces of fuel consistent with 100 low lead, with no water. Floats were intact.
Examination of recovered airframe and flight control system components revealed no evidence of pre-impact mechanical malfunction.