History of Flight
On April 1, 2009, about 0735 Pacific daylight time, a Piper PA-22-150, N9996D, collided with terrain near Sherwood, Oregon. The private pilot and one pilot-rated passenger were killed; the airplane sustained substantial damage. The cross-country personal flight departed Lusardi Field, Salem, Oregon, at 0711, with a planned destination of Hillsboro, Oregon. Visual meteorological conditions prevailed at Aurora State Airport, which was 8 nautical miles from the accident site; however, instrument meteorological conditions prevailed within the vicinity of the accident site. No flight plan had been filed.
Witness Reports
A witness standing in his driveway heard an airplane circling overhead but could not see it due to fog. He estimated the airplane was about 100 feet above him, with lateral visibility about 30 feet. The engine was sputtering and backfiring, then went quiet. The airplane suddenly appeared, and he saw only the wing and a light, estimating a 90-degree bank. He ducked, and the airplane flew less than 10 feet over his head before striking the ground less than 50 feet away. Another witness about 1/4 mile away did not hear the airplane until just before impact, when the engine raced up.
Radar Data
Recorded radar data showed a target on a secondary beacon code of 1200 on a northerly course at 0721, maintaining a straight track toward the accident area. At 0725:53, the mode C altitude was 1,600 feet mean sea level (msl), varying by plus or minus 100 feet. It then descended to 1,400 feet for about 1 minute, climbed to a peak of 2,400 feet, and began a left turn. After a figure-8 pattern at altitudes between 2,100 and 2,300 feet, the target continued a right turn and descended during the last 30 seconds. The last altitude recorded was 1,800 feet; the final two targets were in coast mode with no altitude, the last at 0734:52.
Personnel Information
The 49-year-old pilot held a private pilot certificate with airplane single-engine land rating and a third-class medical certificate issued June 11, 2008, requiring corrective lenses. He reported 490 total flight hours, with 90 hours in the previous 6 months. The 53-year-old pilot-rated passenger held a private pilot certificate with airplane single-engine land rating and a third-class medical certificate issued August 30, 2007, with 249 total hours and 30 hours in the previous 6 months.
Aircraft Information
The airplane was a Piper PA-22-150, serial number 226789. Its logbooks were not located. A mechanic with inspector authorization provided records from the two previous annual inspections. At the last annual inspection on June 7, 2008, total airframe time was 3,349 hours; tachometer time was 713 hours. The tachometer read 893 at the accident site. The engine was a Textron Lycoming O-320-A1B, serial number L-9618-27, with total time 3,349 hours and time since major overhaul 1,518 hours.
Meteorological Information
The accident site was at an estimated elevation of 940 feet. The homeowner reported light rain, drizzle, and fog with low clouds; he could not see the airplane despite hearing it about 100 feet above. He estimated lateral visibility about 30 feet. The closest official weather station at Aurora State Airport (KUAO) reported: at 0653 PDT, wind 180° at 6 knots, visibility 7 statute miles, light rain showers, broken clouds at 2,100 feet, overcast at 2,800 feet; at 0753 PDT, wind 170° at 8 knots, visibility 6 miles, light rain showers and mist, scattered clouds at 2,600 feet, overcast at 3,400 feet; at 0802 PDT, wind 180° at 9 knots, visibility 7 miles, light rain showers, broken clouds at 2,600 feet, overcast at 3,400 feet.
Wreckage and Impact Information
The debris field extended about 150 feet beyond the initial impact site, with most wreckage within 20 feet. Fire department personnel had cut through portions of the structure for victim extraction, preventing flight control continuity verification. On-site visibility varied from 500 feet to 50 feet with steady drizzle to light rain. The propeller was intact and attached; all four cylinders intact; engine case intact. Starter ring gear crushed and displaced. Baffling smashed flat; components broken loose from aft engine. No oil striping or puddling. Strong fuel odor, but all fuel tanks ruptured with no visible fuel. Fuel selector in left position; throttle at full throttle.
Medical and Pathological Information
Autopsies of both occupants determined deaths resulted from massive blunt force injuries. Toxicology testing of the pilot found no tested drugs; ethanol (10 mg/dL) detected in muscle but not in brain, possibly postmortem formation. No ethanol or drugs detected in the pilot-rated passenger. Tests for carbon monoxide and cyanide were not performed.
Tests and Research
Investigators from the Safety Board, Piper, and Lycoming examined the wreckage. The fuselage sustained severe crush damage; most instruments separated. Left wing separated; aileron and flap cables remained attached. Right wing separated with upward bending at tip; control cables attached. Empennage control surfaces remained attached. Elevator trim drum indicated a slight nose-down trim setting (six threads, eight is neutral). The engine was removed and inspected; spark plugs were clean with normal appearance per Champion chart. Intake and exhaust tubes showed ductile bending. Borescope inspection revealed no mechanical deformation. Crankshaft would not rotate, displaced aft by about 3/16 inch, binding internal components. Connecting rods attached; camshaft lobes not misshaped or discolored. Both magnetos separated but produced spark when manually rotated. Carburetor crushed and breached, packed with mud; metal floats crushed. Oil sump crushed and breached; oil filter separated with angular fractures; mud compacted. One propeller blade bent aft; the other had leading edge gouges, trailing edge buckling, and tip twisted toward low pitch/high rpm. Investigators identified no mechanical anomalies with the airframe or engine that would have precluded normal operation.