Phoenix, AZ, USA
N9566U
Grumman AA-5A
Following a loss of engine power after takeoff, the airplane banked left, hit power lines, and went nose down vertically into a mobile home. The pilot departed downwind, and a few minutes later the pilot reported to the air traffic control tower that he was returning with a problem. The pilot made a second transmission, and said that he had no oil pressure. Then he transmitted that he was landing just west of a freeway near the airport. Witnesses along the flight path heard the engine backfire, and saw the propeller stopped at the 3-o'clock and 9-o'clock positions. An intense post crash fire consumed the airframe and severely damaged the engine, with most accessories and fluid lines destroyed. The top and bottom spark plug electrodes were circular, not mechanically damaged, and the gaps were similar. The magnetos could not be tested, and the magneto to engine timing could not be established. The steel quick oil drain was closed and the o-ring was in place. All oil lines, including the pressure line to the gauge, were accounted for and all oil line B-nuts on the accessory housing were secure. Fire consumed the oil cooler. The oil pump had metal material burnished and extruded at the drive gear thrust surface; however, there was no scoring on the internal housing, the gears were undamaged, and the pump drive meshed with the crankshaft interface. The main oil pressure screen was clean. None of the combustion chambers, valves, or pistons exhibited mechanical damage. The camshaft was intact, and each of the camshaft lobes appeared similar in shape. The crankshaft remained intact. The main bearings' tangs were undamaged, and the bearings were on their respective dowels. There was no discoloration, fretting, or mechanical damage to the bearing surface. All four connecting rods remained secure at each of their respective crankshaft journals and rotated freely on the crankshaft, but all had fore and aft movement as well as lateral play. All four journals exhibited discoloration. All connecting rod bearings exhibited some extrusion and metal transfer from the bearing to the journal. Cylinder No. 1 connecting rod bearing extruded the most; it had the most metal transfer. Cylinder No. 3 bearing sustained the next worse damage. Cylinders No. 1 and 4 were the least damaged. Investigators found no obvious obstructions or preimpact contaminates in the oil passages of the engine. Despite exhaustive examinations, the exact nature of the lubricating system problem and its underlying cause could not be determined.
HISTORY OF FLIGHT On October 12, 2002, at 0840 mountain standard time, a Grumman AA-5A, N9566U, crashed into a mobile home park about 1 mile west of the Deer Valley Airport (DVT), Phoenix, Arizona. The pilot was operating the borrowed airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, sustained fatal injuries; the airplane was destroyed. One ground victim suffered minor injuries from smoke inhalation. The flight departed Deer Valley at 0832; the purpose of the flight and the destination were unknown. Visual meteorological conditions prevailed, and no flight plan had been filed. The primary wreckage was at 33 degrees 41.202 minutes north latitude 112 degrees 06.857 minutes west longitude. Deer Valley air traffic control tower (ATCT) personnel reported that the pilot asked for a right downwind departure, and they cleared him for takeoff at 0832. A few minutes later the pilot reported that he was returning with a problem, but he did not declare an emergency. The pilot made a second transmission, and said that he had no oil pressure. At 0840, the pilot transmitted that he was landing just west of a freeway. ATCT personnel did not hear another transmission from the pilot. A ground witness about 4 miles from the airport reported that he observed the airplane at low altitude, and the engine was backfiring. A ground witness about 2 miles from the airport observed the airplane at low level. The propeller was not turning; its blades were at the 3-o'clock and 9-o'clock positions. Witnesses observed the airplane bank left, the tail catch power lines, and go nose down vertically into a mobile home. The airplane caught fire, which spread to adjacent mobile homes. One witness stated that the pilot extricated himself from the airplane and moved away from the wreckage, but he was engulfed in flames. The witness soaked a blanket in water and went to assist the pilot. He got the pilot away from the flames and covered the pilot with the blanket; however, the pilot succumbed to his injuries. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed that the pilot held a private pilot certificate with an airplane single engine land rating. The pilot held a third-class medical certificate issued on June 19, 2002. It had the limitations that the pilot must wear lenses for distant vision, and possess glasses for near vision. An examination of the pilot's logbook indicated that the last flight logged was on September 2, 2001. As of that entry, the pilot had an estimated total flight time of 1,480 hours. This logbook contained entries for over 200 hours in a Grumman AA-5B. AIRCRAFT INFORMATION The airplane was a Grumman AA-5A, serial number AA5A-0066. The logbooks contained an entry for an annual inspection dated March 11, 2002, at a total time of 3,282 hours. The engine was a Textron Lycoming O-320-E2G, serial number L-43385-27A. Time on the engine since a field overhaul was 636 hours as of the annual inspection. WRECKAGE AND IMPACT INFORMATION The airplane came to rest with the fuselage between two mobile homes. Fire consumed a majority of the cabin structure and skins. MEDICAL AND PATHOLOGICAL INFORMATION The Maricopa County Coroner completed an autopsy. The FAA Toxicology and Accident Research Laboratory performed toxicological testing of specimens of the pilot. The report contained the following findings for tested drugs: dextromethorphan detected in urine; dextrorphan detected in urine; 0.042 (ug/ml, ug/g) doxylamine detected in blood, doxylamine present in urine; phenylpropanolamine detected in urine; pseudoephedrine detected in blood; pseudoephedrine present in urine; and 10.99 (ug/ml, ug/g) acetaminophen detected in urine. The report contained no findings for carbon monoxide or cyanide detected in blood, and no ethanol detected in urine. TESTS AND RESEARCH Investigators from the National Transportation Safety Board, the FAA, and Textron Lycoming examined the wreckage. They removed the engine from the wreckage and slung it from a hoist. Fire consumed the carburetor. The throttle and mixture controls remained securely attached at their respective control arms. The fuel pump remained attached to the engine at the mounting pad. Fire consumed most of the fuel pump. Investigators removed the top and bottom spark plugs. The electrodes were circular, not mechanically damaged, and the gaps were similar. The electrodes were gray in color, which corresponded to normal operation according to the Champion AV-27 Check-a-Plug chart. Fire destroyed the ignition harness. The magnetos were secure on their mounts, but both magnetos sustained thermal damage to their housings. Investigators could not functionally test either magneto, and they could not determine magneto to engine timing. Fire consumed the aluminum oil sump. However, investigators recovered the steel quick drain. It was at maximum extension (closed), and the o-ring was in place. Safety wire was secure on the nut and formed a loop at the opposite end. The oil sump screen was clean, but there was melted metal at the end of the screen. All oil lines were accounted for, including the pressure line to the gauge, but all lines sustained thermal damage. All oil line B-nuts on the accessory housing were secure. Fire consumed the oil cooler. The oil pump had metal material burnished and extruded at the drive gear thrust surface. There was no scoring on the internal housing, the gears were undamaged, and the pump drive meshed with the crankshaft interface. The main oil pressure screen was clean. Investigators removed the cylinders. Cylinders No. 1 and No. 3 sustained significant thermal damage resulting from the post impact ground fire. None of the combustion chambers, valves, or pistons exhibited mechanical damage. Investigators disassembled the crankcase. The camshaft was intact, and each of the camlobes appeared similar in shape. The crankshaft remained intact. The main bearings' tangs were undamaged, and the bearings were on their respective dowels. There was no discoloration, fretting, or mechanical damage to the bearing surface. However, all of the bearings had melted metal on the forward edge of the bearing, but none on the aft edge. The amount of melted material decreased progressively from bearing 1 to 4 (front to aft). The melted material was at the 7-o'clock position on the crankshaft. At the accident site, the engine was pointing nose down, and canted about 30 degrees counterclockwise (left side down). All four connecting rods remained secure at each of their respective crankshaft journals. All connecting rods rotated freely on the crankshaft, but all had fore and aft movement as well as lateral play. All four journals exhibited discoloration. All connecting rod bearings exhibited some extrusion and metal transfer from the bearing to the journal. Cylinder No. 1 connecting rod bearing extruded the most; it had the most metal transfer. Cylinder No. 3 bearing sustained the next worse damage. Cylinders No. 1 and 4 were the least damaged. Investigators found no obvious obstructions or preimpact contaminates in the oil passages of the engine. Investigators visually established mechanical continuity of the rotating group and internal mechanisms during the disassembly and examination of the engine. ADDITIONAL INFORMATION The IIC released the wreckage to the owner's representative.
failure of the lubricating system resulting in a total loss of engine power and an off airport forced landing.
Source: NTSB Aviation Accident Database
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