History of Flight
On October 1, 2021, at approximately 0740 mountain standard time, a Piper PA-28-181 (N2868H) and a Robinson R22 (N412TL) were involved in a midair collision near Chandler, Arizona. The airplane, conducting a Part 91 instructional flight, sustained minor damage; the helicopter was destroyed. The flight instructor and student pilot aboard the airplane were not injured, while the helicopter's flight instructor and student pilot were fatally injured.
The airplane's flight instructor and student pilot had been performing touch-and-go landings on runway 4L, then switched to runway 4R at the tower controller's request. During one pattern, the controller asked them to extend their crosswind leg for helicopter traffic. On the accident approach, the airplane was cleared to land behind a twin-engine airplane. The instructor scanned for traffic and, abeam the runway numbers on downwind, reduced engine power to idle to simulate an engine failure. On final, he took control to demonstrate a slip and then heard and felt a loud bang. He declared an emergency, initially believing the airplane had struck birds. During landing flare, he noticed the left wing descending and used aileron inputs to keep it up. After touchdown, the airplane veered left and came to a stop between runways 04R and 04L. Both occupants exited safely.
Witnesses reported that an airplane on final approach descended on top of a helicopter and impacted the helicopter's main rotor blades. The helicopter descended, impacted terrain, and a post-impact fire ensued.
Review of air traffic control communications showed that at about 0732, the airplane was advised to extend its upwind leg for helicopters operating in the parallel taxiway pattern; one pilot acknowledged. At about 0737:06, the helicopter was cleared to land on the taxiway. At 0737:52, the controller cleared the airplane to land behind a twin-engine airplane, also noting a helicopter at low level ahead to the right, proceeding southbound. The airplane acknowledged. At 0740:41, the airplane instructor declared an emergency following the collision.
Recorded ADS-B data showed both aircraft on a base-to-final turn, with the airplane approaching runway 04R and the helicopter approaching taxiway C, a taxiway parallel and to the right of runway 04R. Their flight paths intersected at about 0740:15 at an altitude of about 1,400 feet msl.
Personnel Information
The airplane flight instructor had accumulated about 425 total hours of flight experience, with 32 hours as a flight instructor.
Wreckage and Impact Information
Examination of the airplane accident site revealed the airplane came to rest upright on the dirt field between runways 04R and 04L, on a heading of about 345° magnetic. The helicopter impacted terrain about 0.5 mile southwest of the approach end of runway 04R.
Postaccident examination of the airplane found no mechanical anomalies precluding normal operation. Flight control continuity was established from the cockpit to all primary flight controls. The airplane's nose landing gear and tire, as well as the left main landing gear, had separated and were located near the helicopter wreckage. Both tires were cut consistent with contact from the helicopter's main rotor blades. A piece of the helicopter's canopy was found lodged in the hat channel on the underside of the airplane.
The helicopter came to rest on its left side on a heading of about 053° magnetic, at an elevation of 1,236 feet msl. No visible ground scars were observed. All major structural components were within about 15 feet of the main wreckage. Postaccident examination of the helicopter was limited due to impact damage and post-crash fire.
Medical and Pathological Information
Autopsies performed by the Maricopa County Office of the Medical Examiner on the helicopter flight instructor and student pilot determined the cause of death as multiple blunt impact injuries. Toxicology testing of the helicopter flight instructor found no drugs of abuse. Toxicology testing of the helicopter student pilot detected amphetamine at 7 ng/ml in urine. Amphetamine is a Schedule II controlled substance available by prescription for attention deficit disorder and narcolepsy, with warnings about abuse potential, increased risk of sudden death, and potential mental health and behavioral changes. In some preparations, the prescription drug is metabolized to amphetamine; common brand names include Adderall, Dexedrine, and Vyvanse. After a single 30 mg oral dose, early blood levels averaged 0.111 µg/ml; average blood levels in adults using the long-acting prescription orally for a week were about 0.065 µg/ml.