History of Flight
On April 9, 2018, at about 2048 mountain standard time, a Piper PA-24-260 airplane, registration N9456P, was destroyed when it impacted terrain shortly after takeoff from Scottsdale Airport (SDL), Scottsdale, Arizona. The airline transport pilot, the student pilot, and four passengers were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal cross-country flight destined for North Las Vegas Airport (VGT), Las Vegas, Nevada. Nighttime visual meteorological conditions prevailed, and no flight plan was filed.
The pilot had previously flown the airplane from VGT to SDL to pick up the others, landing at 2018. Surveillance video showed the student pilot in the front left seat and the airline transport pilot in the front right seat as they boarded about 2028. Video from a midfield camera captured the airplane's wings rocking during and shortly after rotation. The tower controller reported that as the airplane passed the tower, the wings appeared stable but the engine sounded underpowered. When asked if the airplane was experiencing difficulty, the pilot responded, "we're good. We're just in training mode." Radar data showed the airplane's last altitude about 200 ft above ground level during a left turn near the departure end of the runway. A traffic camera recorded the airplane in a left bank with increasing angle until its wings were nearly vertical, followed by impact with terrain and a fireball.
Estimated ground speed was 75 ± 4 knots shortly after takeoff, with a climb rate of 270 ft per minute. Twelve seconds later, as the airplane turned left, ground speed decayed to 50 ± 4 knots, and it began to descend. The airplane was airborne for about 70 seconds. Witnesses reported similar observations, including one who heard the controller's query and described an "early left crosswind turn" and engine sound lacking full power.
Personnel Information
The airline transport pilot held an ATP certificate with single-engine and multiengine land ratings, as well as a flight instructor certificate. He received a special issuance first-class medical certificate on February 7, 2018, with a limitation. He reported 5,200 hours total flight time, with 500 hours in the previous 6 months. His employer indicated that from August 24, 2017, to April 8, 2018, he flew 161 hours. He had about 2 hours in the accident airplane.
The student pilot had been receiving flight instruction from another instructor and did not possess a student pilot certificate or airman medical certificate. His total flight experience could not be determined.
Aircraft Information
The single-engine, retractable-gear airplane was manufactured in 1970 and powered by a 260-horsepower Lycoming IO-540-N1A5 engine with a two-blade constant-speed Hartzell propeller. It had six seats. The last annual inspection was on December 1, 2017, at 6,158 total airframe hours.
Weight and balance calculations based on estimated passenger weights, fuel load, and data from a flight software indicated a takeoff weight of about 3,335 pounds and a center of gravity (CG) of 95.22 inches aft of datum. The maximum allowable gross weight was 3,200 pounds, and the CG range was 80.5 to 93.0 inches. Thus, the airplane was 135 pounds overweight and its CG was 2.22 inches aft of the limit. Density altitude at the time was about 3,300 ft.
Meteorological Information
The 1953 SDL weather observation reported wind from 160° at 3 knots, visibility 10 miles, clear skies, temperature 28°C, dew point -5°C, and altimeter 29.94 inches of mercury, yielding a density altitude of about 3,300 ft.
Wreckage and Impact Information
The airplane came to rest in a golf course about 0.25-mile northwest of the end of runway 03 at an elevation of 1,484 ft. The debris field measured about 180 ft long by 40 ft wide. The right wing partially remained attached and had struck a tree; the left wing fragmented and separated. Both main landing gear detached. The empennage was intact but separated from the fuselage due to thermal damage. The stabilator trim drum indicated a slight nose-down trim setting.
Flight control continuity was established. The landing gear was retracted, and the flaps were in the retracted position at impact. The fuel selector was found in the left main tank position. The engine crankshaft rotated freely, compression was obtained on all cylinders, and the spark plug electrodes appeared normal. The propeller separated from the crankshaft flange; blades showed leading-edge gouging, torsional twisting, and chordwise striations consistent with rotation under power.
Examination revealed a broken No. 3 cylinder intake valve spring. Fractography showed fatigue cracks initiating at pits on the inside diameter, propagating through 40% to 50% of the diameter before final overstress fracture.
Medical and Pathological Examination
Autopsies performed by the Maricopa County Office of the Medical Examiner determined the cause of death for both pilots as blunt force injuries and thermal trauma. Toxicology testing for the pilot was negative for carbon monoxide, ethanol, and all drugs tested. For the student pilot, testing identified benzoylecgonine (a cocaine metabolite) in blood and urine, and MDMA (ecstasy) in urine. No carbon monoxide or ethanol was detected.