N310PDGrumman American Avn. AA-5B

On November 22, 2019, about 1838 mountain standard time, a Grumman AA-5B airplane, N310PD, was destroyed when it was involved in an accident near Jackpot, Nevada. The noninstrument-rated pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot and his wife were departing from Jackpot Airport (06U) on a cross-country flight to their home airport. A witness near the airport stated that he saw the airplane depart from runway 15 and subsequently turn left. In the witness’ experience watching airplanes depart from this airport, the airplane was at an unusually low altitude when it began the left turn. The witness then looked away while the airplane was turning and immediately heard a loud explosion. He then looked back in the direction of the airport and observed a fire.

GPS data showed that the airplane begin its takeoff roll from the departure runway about 1837:07 and lifted off the ground into a climb about midfield. The data track ceased at 1837:54, at which time the airplane was about 250 ft above ground level at a groundspeed of 95 kts while maintaining the runway heading. The GPS also contained data from previous flights, including three prior departures from 06U to the southeast, similar to the accident flight, the most recent of which was about 1 week before the accident. During each flight, the airplane lifted off the ground about midfield, began an immediate left turn, and transitioned to an easterly heading by the time the airplane reached the departure end of runway 15.

Figure 1: Comparison of pilot’s previous departures from 06U

The pilot’s logbooks could not be located. At the time of the pilot’s most recent Federal Aviation Administration (FAA) airman medical examination, which took place in 2013, he reported 2,700 total hours of flight experience.

Family and friends of the pilot reported that he did not fly at night. According to a friend, the pilot flew to 06U once every 2 to 3 months, mostly in daytime conditions, but had recently told his wife that he wanted to become more proficient in night flying. A family member reported that the pilot flew about once a week, mostly in daytime conditions. The family member flew with the pilot numerous times and occasionally accompanied him to 06U. Before departure, which was always in daytime conditions, the pilot would routinely review the surrounding hazards with the family member, which included the pilot’s concern about a 200-ft tall plateau beyond the departure end of runway 15. This terrain feature was not visible at night. The family member theorized that the pilot was likely concerned about the location of the plateau due to the accident airplane’s poor climb rate. When departing runway 15, the airplane would lift off the ground about midfield and the pilot would almost immediately begin a left turn on every departure.

The pilot’s previous two departures from 06U (in October and November) took place in nighttime conditions, at 1949 and 2040, respectively. A review of lunar data showed that the moon was in the first quarter phase with 44.2% illumination during the pilot’s October flight and in the waning gibbous phase with 86.4% illumination during a flight that took place 1 week before the accident. During both flights, the moon was visible along the horizon. On the day of the accident, the moon was in the waning crescent phase with 16.1% illumination and was not visible above the horizon.

According to a witness, the wind at the time of the accident was calm.

The airplane came to rest inverted in a level hay field about 1/4 nautical mile east of the departure end of runway 15 at 06U on a heading of about 095° magnetic. All major components were found at the accident site. The initial impact point was marked by an 18-inch-long by 36-inch-wide ground scar at the beginning of the debris path, which was 276 ft long and oriented on a heading of 212° magnetic. The wreckage was fragmented, and numerous components were distributed along the wreckage path; the main wreckage was consumed by postcrash fire.

Airframe Examination

The wreckage was fragmented and mostly consumed by postcrash fire. Elevator and elevator trim continuity were established from the elevators to the base of the control yoke quadrant. The rudder control was continuous from the rudder to the rudder pedals. Both ailerons had separated from their respective wing attachments along with their control cable attachment ends and were not located among the recovered wreckage. The vacuum pump rotors and vanes were intact and unremarkable.

Photographs of the elevator trim jackscrew and flap drive jackscrew were shown to a mechanic familiar with the accident airplane make and model. After testing the range of the wing flap and elevator trim on an exemplar airplane, he reported that the elevator trim jackscrew position was consistent with a full nose-down position and the flap jackscrew was in the full retracted position, consistent with the flaps being retracted.

Two mechanics familiar with the accident airplane make and model reported that a full nose-down elevator trim position would have created hard resistance for the pilot after takeoff. One of the mechanics reported that the airplane’s trim indicator was equipped with a marking that represents the appropriate position for takeoff. The “BEFORE TAKEOFF” checklist as noted in the pilot’s operating handbook lists the task item: “Trim Tab – SET.”

Engine Examination

Mechanical continuity was established throughout the valve train to the accessory section as the crankshaft was manually rotated with a drive tool. During rotation, thumb compression in the proper firing order of all four cylinders was achieved and each rocker displayed normal lift. Examination of interior components revealed no indications of catastrophic engine failure. Cylinder No. 2 was replaced with an overhauled cylinder about 2 weeks before the accident. The cylinder’s piston face displayed a swirl pattern, consistent with normal operation for new cylinders.

The left and right magnetos remained securely attached at their respective mounting pads. The ignition harness was secure at each magneto. Magneto timing could not be determined due to the destruction of the flywheel; however, the drives of each magneto remained intact and undamaged. An examination of the top spark plugs revealed signatures consistent with normal wear.

Both propeller blades remained attached to the propeller hub, which had separated from the engine. The blades exhibited spanwise gouging, leading edge scuffing and torsional twisting along with separations at each blade tip, consistent with the absorption of rotational forces at the time of impact.

Spatial Disorientation

According to the Federal Aviation Administration (FAA) Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25B):

Spatial disorientation specifically refers to the lack of orientation with regard to the position, attitude, or movement of the airplane in space.

Under normal flight conditions, when there is a visual reference to the horizon and ground, the sensory system in the inner ear helps to identify the pitch, roll, and yaw movements of the aircraft. When visual contact with the horizon is lost, the vestibular system [the part of the body responsible for a person’s sense of position and balance] becomes unreliable. Without visual references outside the aircraft, there are many situations in which combinations of normal motions and forces create convincing illusions that are difficult to overcome.

Unless a pilot has many hours of training in instrument flight, flight should be avoided in reduced visibility or at night when the horizon is not visible. A pilot can reduce susceptibility to disorienting illusions through training and awareness and learning to rely totally on flight instruments.

The pilot’s most recent medical certificate was issued in January 2013. He had not completed the requirements for BasicMed.

The Washoe County Regional Medical Examiner’s Office, Reno, Nevada performed an autopsy of the pilot, which showed that he had a right coronary artery stent placement and severe atherosclerosis in his left anterior descending coronary artery. Medical records obtained from the pilot’s primary care provider showed that, during a visit with his physician on November 9, 2018, the pilot had reported a stroke that occurred in 2017, gastric reflux disease, and high cholesterol. A physical examination during this time, which included an electrocardiogram, revealed atrial fibrillation. At this time the pilot was advised to “avoid flying until evaluated by cardiology.” A subsequent nuclear stress test performed on November 27, 2018, discovered an area of infarct and ischemia around the right coronary artery.