Accident Overview
On August 12, 2010, about 1500 Alaska daylight time, a Piper PA-18-150 airplane, registration N2413H, sustained substantial damage following a loss of control and impact with terrain near McGrath, Alaska. The aircraft was operating as a visual flight rules (VFR) personal cross-country flight under 14 CFR Part 91. Instrument meteorological conditions were reported in the area at the time. No flight plan had been filed. The flight originated from Tanana, Alaska, and was en route to McGrath.
Flight History
The accident airplane was the lead aircraft in a flight of two. The pilot of the second airplane reported that as they approached McGrath, weather deteriorated. The lead airplane continued toward mountainous terrain with worsening conditions. After crossing the first ridge, the weather became turbulent, dark, and rainy, forcing both aircraft to descend to remain clear of clouds. The lead pilot radioed, “Buddy are you still with me?” The second pilot responded, “barely,” then lost sight of the lead airplane and turned back. About three minutes later, he heard a short burst of noise on the radio resembling an open microphone. Repeated attempts to contact the lead pilot were unsuccessful. The wreckage was located the next day in a box canyon at the end of rising terrain.
Pilot Information
The pilot, aged 79, held a commercial pilot certificate with single-engine land and sea ratings and a third-class FAA medical certificate dated June 5, 2009, with a restriction for hearing amplification. Insurance records from March 2010 indicated 19,500 hours total flight time, with 7,000 hours in the PA-18 and 300 hours in the previous 12 months.
Aircraft Information
The airplane was powered by a Lycoming O-320 engine rated at 150 horsepower. No aircraft or engine logs were available for review.
Wreckage Examination
On August 13, an NTSB investigator-in-chief and an FAA inspector examined the wreckage. The airplane came to rest upright, nose down on an estimated heading of 130 degrees. Impact signatures indicated a left-wing and nose-low attitude. The left wing was displaced aft with extensive leading edge crushing and upward bending from mid-span outboard. The right wing showed leading edge damage and forward displacement. The fuselage had extensive frame buckling. The empennage was canted left about 10 degrees, with relatively undamaged stabilizers. The propeller had separated from the crankshaft; both blades had chord-wise scratches and broken tips. The engine remained attached but with broken top mounts and impact damage to the crankcase. No mechanical anomalies were found that would have prevented normal operation. The cockpit was extensively damaged; the aircraft was not equipped with shoulder harnesses, and neither occupant was wearing a lap belt. The emergency locator transmitter was found in the OFF position.
Medical Findings
A postmortem examination attributed the pilot's cause of death to multiple blunt force trauma. Toxicological tests detected diphenhydramine in urine and blood (0.007 ug/ml). Diphenhydramine is a sedating antihistamine used for allergies, cold symptoms, and as a sleep aid.
Additional Information
A Garmin GPSMAP 396 portable GPS receiver was recovered from the wreckage. The NTSB extracted route-of-flight data including time, latitude, longitude, and GPS altitude. The data corroborated the second pilot's account.