History of Flight
On June 24, 2018, at approximately 1040 Alaska daylight time, a Piper PA-18 airplane, registration N8664Y, sustained substantial damage after impacting terrain about 26 miles southwest of Delta Junction, Alaska. The commercial pilot and a passenger were fatally injured. The airplane was operated by the pilot under Title 14 Code of Federal Regulations Part 91 as a visual flight rules personal flight. No flight plan was filed. The flight departed Sewell Strip, Salcha, Alaska, about 1022 and was destined for a homestead about 8 miles west of McCarthy, Alaska.
Family members reported the airplane overdue on June 25. An alert notice was issued at 1139, initiating a search involving the Alaska Air National Guard, Alaska Army National Guard, US Marine Corps, Civil Air Patrol, Alaska State Troopers, and volunteers. The wreckage was located on June 27 by an Alaska Army National Guard aircrew.
Review of archived FAA radar data indicated the airplane departed Sewell Strip about 1022, with the last radar return at about 1037. The accident site was approximately 9 miles south of that last return.
Personnel Information
The pilot, aged 63, held a commercial pilot certificate with an airplane single-engine land rating. He was issued an FAA third-class airman medical certificate on May 9, 2018, with no limitations. On the application, he reported 9,600 total flight hours.
Aircraft Information
The two-seat, high-wing Piper PA-18 was manufactured in 1970. It was powered by a Lycoming O-320 series engine. The engine's last annual inspection was on June 11, 2018, at which time it had accumulated 3,452 total hours, with 1,449 hours since major overhaul.
The airplane was equipped with a legacy 121.5-MHz emergency locator transmitter (ELT). As of February 1, 2009, search and rescue satellites stopped monitoring 121.5-MHz signals. Installation of digital 406-MHz ELTs is voluntary. The ELT was not a 406-MHz model.
Meteorological Information
The nearest official weather reporting station was Allen Army Airfield (PABI), about 22 miles northeast of the accident site. A METAR at 0953 reported wind from 260° at 8 knots, visibility 10 statute miles, light rain, ceiling 6,000 ft broken, 10,000 ft overcast, temperature 55°F, dewpoint 48°F, altimeter 29.96 inHg. Archived weather data for the area between 1000 and 1130 indicated a ceiling between 5,000 and 6,000 ft above ground level with forward visibility between 6 and 10 statute miles.
Wreckage and Impact Information
The accident site was on a knoll with sparse spruce trees and muskeg, at an elevation of about 2,550 ft mean sea level and a heading of about 265°. An initial ground scar was marked by disturbed vegetation and small wreckage fragments, including a right navigation light lens. The main wreckage came to rest about 100 ft from the initial scar.
Both wings sustained substantial damage; the fuselage showed extensive crushing and impact damage. Flight control continuity was established for elevator and rudder cables to a point under the cabin floorboard where damage prevented further movement. Aileron control continuity was established from the surface to the fuselage. The right wing's upper cable bell crank was fractured, consistent with impact. All other cables remained attached.
The propeller separated from the engine at the hub and was found about 20 ft before the main wreckage. Both blades exhibited torsional twisting and S-bending, consistent with engine power at impact.
The ELT was secure in its cradle with the antenna attached. The switch was in the "OFF" position. When moved to "ON," a signal on 121.5 MHz was heard; moving back to "OFF" stopped it. The switch was then set to "ARM" and G-force activation tested, producing a signal. A placard showed the battery was manufactured in April 2017, with an expiration date of June 2019.
On August 6, a follow-up examination of the engine and fuel system revealed no anomalies, contamination, or evidence of malfunction. Spark plugs and rocker arm covers were removed; spark plugs showed normal operational signatures. The crankshaft rotated freely with thumb compression and suction on all cylinders. Continuity was established throughout the engine and valvetrain. Both magnetos produced spark at all ignition wires when the crankshaft was rotated.
Postaccident examination found no evidence of preimpact mechanical failures or malfunctions that would have precluded normal operation.
Medical and Pathological Information
An autopsy performed by the State of Alaska Medical Examiner's Office determined the pilot's cause of death as multiple blunt force injuries. Toxicology testing by the FAA Forensic Sciences Laboratory was negative for drugs, ethanol, and carbon monoxide.