WPR20LA270

The pilot’s decision to conduct a steep departure at a high-density altitude and the exceedance of the airplane’s critical angle of attack during a climb, which resulted in an accelerated stall and subsequent loss of control. Contributing to the accident was the installation of a high pitch angle propeller that was not designed for the installed engine which likely degraded the airplane’s performance.

The accident airplane’s takeoff run from a dirt runway was not observed. However, while taxiing his airplane toward the airport’s only asphalt runway, a friend of the accident pilot and pilot-rated passenger observed the accident airplane in a steep left turn about 350 ft above the runway. The airplane then transitioned into a nose-down dive, consistent with a loss of control following an accelerated stall, which resulted in impact with terrain. Examination of the wreckage revealed no preimpact mechanical anomalies with the engine or airframe that could have precluded normal operation. An experimental propeller that was designed for a more powerful engine was attached to the engine at the time of the accident. The propeller’s blade angle was excessive for the engine-propeller configuration, which would have slowed the propeller. This, in turn, would have led to an overall decrease in performance, further degrading the airplane’s ability to climb as the density altitude was nearly double the field elevation of the departure airport when the accident occurred. Additionally, the airplane may have been over its gross weight; however, this could not be determined as the fuel quantities at the time of departure were unknown. The airplane had vortex generators installed, which may have slightly reduced the airplane’s stall speed, but this performance improvement was not guaranteed as stated by the manufacturer. The investigation was unable to determine whether the pilot performed any preflight performance computations, which would have showed that the airplane required 3,750 ft of runway surface to clear a 50 ft obstacle given the temperature and density altitude. Although there was no need to clear a 50 ft obstacle that day, and this performance information was for a lower performance engine than the one he had installed, a conscientious pilot would have exercised caution during the takeoff attempt after reviewing this performance data. However, the witness observation of the airplane altitude is consistent with the pilot performing a high rate of climb departure after takeoff. The pilot’s toxicology testing demonstrated previous use of cocaine, but no active cocaine in his system at the time of the event. The investigation was unable to determine if he had any impairment from cocaine withdrawal at or near the time of the accident and whether his cocaine use contributed to the accident circumstances due to a lack of available evidence.

The pilot’s flight logbook was not recovered, but according to a friend, the pilot had likely accrued about 200 hours in the accident airplane make and model at the time of the accident. The passenger was a certified flight instructor with most of her flight experience having been accumulated in Cessna 172 airplanes and rotorcraft. Her flight time in the accident airplane was unknown, but according to friends, her time may have been limited as the accident pilot preferred to fly the airplane. According to the friend who witnessed the accident, he did not observe any unusual behavior by the pilot or passenger on the day of the accident. An autopsy on the pilot and passenger were completed by the Washoe County Regional Medical Examiner’s Office, Reno, Nevada on August 17, 2020. The autopsy reported listed the pilot’s weight as 220 lbs and the passenger’s weight as 158 lbs and attributed the cause of death to “multiple blunt force injuries.” The FAA’s Forensic Sciences Laboratory performed toxicology testing on the pilot’s tissue samples, which identified benzoylecgonine, a metabolite of cocaine, in his cavity blood and urine; and ecgonine methyl ester, another metabolite of cocaine, was detected at trace levels in both his blood and urine. FAA toxicology testing on the pilot-rated passenger identified cocaine, cocaethylene (a cocaine metabolite only formed when alcohol and cocaine are used simultaneously), benzoylecgonine, ecgonine methyl ester, phentermine (a sympathomimetic used to treat obesity, but also available as a street drug), diazepam (a sedating benzodiazepine), its metabolite nordiazepam, and two active metabolites, oxazepam, and temazepam, in her urine. Benzoylecgonine, ecgonine methyl ester, diazepam, nordiazepam, and phentermine were found in the passenger’s cavity blood. Cocaine is a strong central nervous system stimulant. Initial effects include: euphoria, excitation, general arousal, dizziness, increased focus and alertness. At higher doses, effects may include psychosis, confusion, delusions, hallucinations, fear, antisocial behavior, and aggressiveness. Late effects, beginning within 1 to 2 hours after use, include: dysphoria, depression, agitation, nervousness, drug craving, general central nervous system depression, fatigue, and insomnia.  Additional performance effects are expected after higher doses, with chronic ingestion, and during drug withdrawal including agitation, anxiety, distress, inability to focus on divided attention tasks, inability to follow directions, confusion, hostility, time distortion, and poor balance and coordination. Withdrawal symptoms may be significant when no cocaine is identifiable in the person’s system. According to the accident pilot’s airframe and powerplant mechanic, the pilot frequently “tinkered” with the airplane. The mechanic stated that he provided owner-assisted inspections to the accident pilot, during which time the pilot would typically perform the maintenance himself and the mechanic would subsequently inspect his work and make a logbook endorsement. According to the mechanic, the pilot had sometimes performed maintenance on his airplane without an endorsement from a mechanic. The accident pilot was not a certificated airframe and powerplant mechanic nor was he employed as an aircraft technician. According to a friend, after the engine was overhauled and installed on the airplane, the accident pilot found that it would reach 3,000 rpm at full throttle, when the engine was rated at 2,700 rpm. To reduce the rpm and noise at takeoff, the pilot installed a new propeller, but the friend could not recall who completed the installation. It is unknown if he consulted a mechanic about the excessively high engine rpm or the propeller installation. The engine total time and time since overhaul could not be determined from the maintenance records. The fixed-pitch, experimental category propeller was manufactured by Catto Propellers and was constructed of glass and carbon composite. According to the manufacturer’s data plate on the propeller hub, the propeller diameter was 84 inches, and the pitch was 42.5° for a “Cub Type.” In the third line, the data plate stated “Engn: ECI-340 170+hp Design RPM 2750.” According to the propeller manufacturer, this Catto propeller was designed for an experimental Titan 340, 170 hp engine rated at 2,750 rpm. The accident airplane was equipped with a Lycoming Engines O-320-A2B “C” series, 150 hp engine rated at 2,700 rpm. Airworthiness records showed that a McCauley 1A175-GM824 fixed pitch propeller was installed on July 17, 2014, and logbook records did not indicate that another propeller had been installed after the 2014 installation. According to the pilots’ friends, they believe the pilot had borrowed the Catto propeller from another local aircraft owner sometime after the engine overhaul. The investigation could not determine who installed the propeller or how many times the pilot had flown the accident airplane after the propeller was installed. Federal Aviation Administration Aviation Maintenance Technician Handbook - Powerplant Volume 2 (FAA-H-8083-32A), Chapter 7, Propellers states: For any single revolution of the propeller, the amount of air displaced (moved) depends on the blade angle, which determines the quantity or amount of mass of air the propeller moves…If the blade angle is increased, more load is placed on the engine, tending to slow it down unless more power is applied.” Fixed-pitch and ground-adjustable propellers are designed for best efficiency at one rotation and forward speed…they are designed to fit a given airplane and engine combination. A propeller may be used that provides the maximum propeller efficiency or takeoff, climb, cruising, or high speeds. Any change in these conditions results lowering the efficiency of both the propeller and the engine. Takeoff Performance Information The excerpt below from the owner’s operating manual show the procedures for TAKE-OFF, CLIMB, AND STALLS. The stabilizer adjustment should be set approximately at the neutral position for take-off, depending on loading of the aircraft. Fuel selector should be on left tank, flaps down one-third or two-thirds if desired. After climbing airspeed has been reached, flaps should be retracted to achieve maximum rate of climb. According to the fixed based operator attendant who refueled the accident airplane, he deposited 25 gallons of 100 low lead aviation grade gasoline in the left tank and no fuel in the right tank as instructed by the pilot. The wreckage came to rest in dirt about 50 ft southwest of runway 11/29 on an eastern heading. All major structural surfaces were accounted for at the accident site. The initial impact point was marked by left wing navigation light fragments that were in a small dirt impression a few feet north of the main wreckage. The nose and cabin were crushed aft, and the propeller blades had separated from the propeller hub. Both wings were deformed but remained attached to the fuselage. The left wing displayed an upward bend about midspan, and the right wing displayed a slight upward bend at the wing root. Hydraulic deformation was noted on the leading edge of both wings, in the area of the fuel tanks. The tail section remained attached to the airplane and was unremarkable. + Figure 1: Diagram of departure runway and main wreckage location on airport Postaccident examination of the airframe and engine revealed no preimpact anomalies. On August 15, 2020, about 1340 Pacific daylight time, a Piper PA-14 airplane, N91449, was substantially damaged when it was involved in an accident at Susanville Municipal Airport (SVE), Susanville, California. The pilot and pilot-rated passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to a friend of the pilot who also witnessed the acci