HISTORY OF FLIGHT On August 23, 2009, about 1625 Pacific daylight time, a Piper PA-25 (tow airplane), N6353Z, sustained substantial damage following a loss of control and subsequent collision with terrain about 1/2-mile north of the departure end of runway 33 at Hobby Field Airport, Creswell, Oregon. Scotty Air of Creswell operated the tow airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot, the sole occupant of the airplane, was killed. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight that originated at Hobby Field Airport. The accident occurred shortly after takeoff from the uncontrolled airport with a glider in-tow. In a written report to the Safety Board, the student pilot of the glider in-tow reported that the takeoff roll, lift off, and climb to 200-feet was "normal." He stated that shortly after the glider reached 200-feet he heard a loud bang, and "glanced" over his right shoulder to find the rear door unlatched. As he looked back, he noted that the glider was "…above the normal tow position," and the tow plane was at his 11 o'clock position. The glider pilot stated that he "immediately" pushed the stick forward to maneuver the glider to the proper tow position. The glider pilot noted slack in the tow line, and stated the tow airplane descended below the glider to a point where he lost sight of it. He stated that the tow airplane did not seem to be in distress or out of control, and appeared to be in a 10 degree nose-down attitude prior to release. The glider pilot released from the tow airplane, turned 180 degrees back towards the airport, and landed without further incident. He stated the release felt normal; the glider did not pitch up or down, and no abnormal yaw was noted. The flight was the student pilot's second solo flight. Witnesses reported that the accident airplane departed runway 33 with N65974, a Schweizer glider, in tow. Shortly after takeoff, it appeared that the glider overtook the tow airplane. One witness stated it appeared that the glider moved ahead of the tow airplane as the tow airplane descended. The witness reported that the accident airplane appeared to be slow and, approximately 20 feet above the ground, abruptly nosed over and impacted terrain. PERSONNEL INFORMATION The pilot, age 41, held a commercial pilot certificate with airplane single-engine land privileges. His most recent second-class medical certificate was issued on September 25, 2008, and contained no limitations or waivers. The pilot's flight time logbook was reviewed. A review of the logbook revealed that the last flight time entry was dated August 17, 2009. The "Remarks Section" of the entry listed "Glider Tows" and 1 hour of flight time with three landings. The logbook indicated that the pilot's total flight time was approximately 511 hours. During the preceding 30 days, he had flown approximately 11 hours in the accident airplane with approximately 42 takeoffs. AIRCRAFT INFORMATION The single-seat, low-wing, Piper Pawnee was manufactured in 1961. The airplane was powered by a Lycoming O-320 engine, and equipped with a tow hook linked to a release handle located in the cockpit. A review of the maintenance logbooks revealed that the airframe and engine received an annual inspection on June 29, 2009, at a total airframe time of 2,955.7 hours. The engine's total time at inspection was 2,955.7 hours with 852.8 hours since major overhaul. WRECKAGE AND IMPACT INFORMATION According to local authorities and a Federal Aviation Administration (FAA) inspector who responded to the scene of the accident, the airplane came to rest in an open field north of the departure runway, and was completely consumed by post crash fire. The inspector reported that the tow hook remained attached to the airframe, and the hook was in the locked position, closed around the tow ring. The tow hook mounting plate was bent upward and the heads of two connecting bolts were in contact with the base of the rudder. The opposing end of the tow rope and ring that attaches to the glider was also present at the accident site. The FAA inspector reported that flight control system continuity was established at the accident site prior to the airplane being recovered. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on August 24, 2009, by the state medical examiner's office. The cause of death was reported as "blunt force injuries and fire inhalation." The FAA Civil Aeromedical Institute (CAMI) performed toxicological screenings on the pilot. The report contained the following positive results: Dextromethorphan detected in blood and urine Dextrorphan detected in blood and urine Diphenhydramine detected in blood and urine Doxylamine detected in blood and urine 0.0342 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Blood 0.0513 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Liver 0.4155 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Lung 0.0974 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Blood 0.1293 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Lung 0.3346 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Urine 1.3499 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Liver A review of the pilot’s FAA medical records, including his most recent FAA airman medical application, revealed no history of substance dependence or abuse. Refer to CAMI report # 200900204001 (contained in the public docket) for specific test parameters and results. TESTS AND RESEARCH Wreckage Examination The airplane was recovered from the accident site to a storage facility and later examined by a Safety Board investigator and a representative of the engine manufacturer. The engine was removed from the wreckage to facilitate the exam. Thermal and impact related damage was noted to the engine assembly. Valve train and accessory gear continuity was established by rotating the engine’s crankshaft by hand. All cylinders developed pressure when the crankshaft was manually rotated. Internal examination of the cylinders, utilizing a lighted bore scope, revealed no evidence of a mechanical malfunction. The magnetos sustained thermal damage, which precluded functional testing. The spark plugs were removed, and no abnormal wear patters were noted. The oil pickup screen was free of debris, and the oil sump contained oil. The carburetor was broken free at the flange. Both the mixture and throttle cables were still attached to their respective control arms. The carburetor was disassembled, and no anomalies or leakage was noted. The fuel inlet screen was free of contaminates. No engine anomalies were noted during the examination. The propeller remained attached to the crankshaft propeller flange. One blade was relatively straight and the other blade was bent aft. Both blades had chordwise scratches and polishing; one blade exhibited leading edge gouging. The tow airplane tail hook assembly and release mechanism was examined by a Safety Board investigator after the airplane was recovered from the accident site. The adapter mounting plate was bent upward. Both tail hooks (right and left) were intact and remained attached to the mounting plate. The right side hook was in use at the time of the accident. The hook was found in the locked position, closed around the tow ring. The release cable remained attached to the hook, and was continuous to the cockpit release handle. Functional testing of the tail hook assembly revealed no anomalies, and the assembly functioned appropriately.