Peoria, AZ, USA
N4602Y
Piper PA-25-235
The tow plane stalled and impacted terrain following a nose high pitch excursion during a tow operation. The glider pilot, who was being towed at the time, reported experiencing a normal takeoff until about 100-150 feet above the ground. The tow plane then began to out climb the glider and slack developed in the tow line. The glider pilot released from the tow when she realized that while trying to chase the tow plane, the glider was nearing a stall speed. Witnesses to the accident observed the tow plane pitch nose high twice before it stalled and spun to the right. One of the witnesses was another pilot who flew the accident airplane on 12 previous flights that day. He reported observing no problems with the airplane during his flights that would have prevented its normal operation. Additional witnesses reported hearing a normal engine noise throughout the event. Post accident examination of the airplane revealed no anomalies that would have affected its flying abilities. Toxicological tests of samples from the pilot revealed the presence of phentermine, ephedrine, and pseudoephedrine. Phentermine is a prescription stimulant drug; ephedrine and pseudoephedrine are components of over the counter compounds and have stimulant properties.
HISTORY OF FLIGHT On June 13, 2004, at 1504 mountain standard time, a Piper PA-25-235 (Piper Pawnee) airplane, N4602Y, impacted terrain after takeoff from the Pleasant Valley Airport, Peoria, Arizona. The commercial pilot, who was the sole occupant, sustained fatal injuries; the airplane was substantially damaged. Turf Soaring School was operating the airplane as a glider towing flight under the provisions of 14 CFR Part 91. Visual meteorological conditions prevailed, and a flight plan had not been filed. The local flight was departing at the time of the accident. The glider pilot, who was being towed by the accident airplane, reported that they became airborne and both the tow plane and glider exhibited "typical attitudes and speeds until approximately 100 [to] 150 feet above the ground." She reported that a "small amount of slack developed in the tow rope as the [tow plane] began to out climb the glider." She adjusted the glider's pitch attitude in an attempt to match that of the tow plane. As the glider lost airspeed due to the high pitch attitude, more slack developed in the tow rope. She became concerned with the possibility of stalling and elected to release from the tow plane and recover glider speed. The glider pitched nose down and performed a 210-degree turn to the right back toward the airport. The glider landed across the runways and impacted cactus and shrub before coming to rest upright with minimal damage. A number of glider rated pilots, who witnessed the accident, reported that the tow plane took off with the glider in tow and initially appeared "normal." One witness, who operated the accident airplane during the 12 previous flights, observed the Piper Pawnee pitch up, accelerating its rate of climb. The tow rope went slack between the tow plane and the glider. The Pawnee nosed over, leveled off, and the tow rope tightened. The Pawnee then pitched nose up, higher than the previous excursion, resulting in the tow rope slacking again. At this point the glider pilot released the tow rope and maneuvered the glider to the right. The Pawnee continued with a nose high pitch attitude and "wallowed around" until suddenly it "spun to the right real fast." The airplane rotated around its longitudinal axis two or three times prior to impacting the ground. Some of the witnesses mentioned that there was no change in engine noise throughout the entire event. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with glider, single engine, multiengine, and instrument airplane ratings. The pilot also held a rating for single engine sea airplanes. He held a flight instructor certificate for gliders and single engine, multiengine and instrument airplanes. His last medical certificate (first-class) was issued on August 16, 2001, with no limitations. According to the operator, the pilot accumulated a total of 1,774 hours of flight time, of which 300 hours were accumulated in tail wheel equipped airplanes. It is uncertain how many hours the pilot accumulated in the accident airplane make and model or in glider towing operations. AIRCRAFT INFORMATION The 1967-model airplane (serial number 25-4294) was of steel-tube-truss design with fabric covering. It was powered by a 235-horsepower Lycoming O-540-B2B5 engine (serial number L-9402-40). On January 12, 2004, at an airplane total time of 12,866.3 hours, the airplane underwent its last annual inspection. On April 7, 2004, 61 hours prior to the 100-hour, the "outer elevator hinge bolts and bushings were changed." The airplane underwent its last 100-hour inspection between April and May 2004 (the exact date was not in the maintenance record endorsement). At the time of that inspection, the airframe accumulated a total time of 13,058.4 hours, and the engine accumulated a total of 992 hours since its last major overhaul. The pilot that flew the 12 flights in the accident airplane prior to the accident reported noting no anomalies with the airplane. He mentioned that their was a small oil leak from one of the engine's rocker arm covers, but he noticed the pilot check the rocker arm cover prior to the accident flight. The airplane was equipped with a manual elevator trim system that when adjusted, would preset the elevator position in the desired up position via spring tension. The airplane incorporated a glider release in the event that the tow pilot needed to release the glider during towing operations. METEOROLOGICAL INFORMATION At 1453, the weather observation facility at the Phoenix Deer Valley Airport (10 miles southeast of the accident site) reported the wind from 200 degrees at 7 knots; visibility 10 statute miles; sky clear; temperature 38 degrees Celsius; dew point -04 degrees Celsius; and altimeter setting 29.88 inches of mercury. The glider pilot, who was being towed during the accident flight, reported that there were no wind gusts or dust devils in the area at the time of the accident. WRECKAGE AND IMPACT INFORMATION According to witnesses, the airplane came to rest in the same place of impact. The tail of the airplane was jutting up in the air and was lowered during rescue attempts. The Federal Aviation Administration inspector examined the airplane at the accident site and was able to verify flight control continuity from the flight control surfaces to the cockpit area. The control yoke broke and was deflected to the right. The 200-foot tow rope came to rest adjacent to the airplane, and the tow ring was lying on the ground next to the tail wheel. The elevator was deflected in the full up position at the accident site. The elevator trim cable was taught due to the deformation of the empennage. A definite preimpact elevator trim position could not be determined. PATHOLOGICAL INFORMATION An autopsy on the pilot was performed by the Maricopa County Medical Examiner's Office. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed a toxicology test for carbon monoxide, cyanide, ethanol, and drugs. The following are the results of the toxicology test: - Tetrahydrocannabinol Carboxylic Acid (marijuana) detected in blood - 0.0117 ug/ml Tetrahydrocannabinol Carboxylic Acid (marijuana) detected in urine - 0.048 ug/ml Phentermine detected in blood - Phentermine present in urine - Ephedrine present in urine - Pseudoephedrine present in urine - Tetrahydrocannabinol (marijuana) NOT detected in blood - Ephedrine NOT detected in blood - Pseudoephedrine NOT detected in blood ADDITIONAL INFORMATION The wreckage was released to the owner's representative on November 17, 2004.
the pilot's failure to maintain a proper pitch attitude during tow operations and his failure to maintain an adequate airspeed, which resulted in an inadvertent stall/spin.
Source: NTSB Aviation Accident Database
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