Accident Details
On April 27, 2012, at approximately 1620 Alaska daylight time, a ski-equipped Piper PA-18-150 airplane, registration N7059, sustained substantial damage when the right main landing gear collapsed while landing on a frozen, snow-covered lake about 28 miles west of Paxon, Alaska. The aircraft was operated by the State of Alaska Department of Public Safety, Alaska State Troopers, under visual flight rules (VFR) as a public use flight in accordance with 14 CFR Part 91. The solo pilot was not injured. Company flight following procedures were in effect. The flight had departed Anchorage, Alaska, about 1400 the same day.
Aircraft Information
The accident aircraft was a Piper PA-18-150 equipped with skis and a Burl’s Aircraft LLC Alpha Omega Suspension System (AOSS), installed under supplemental type certificate (STC) SA02214AK. The pilot reported that the airplane was on a routine law enforcement flight.
Pilot Report
In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge dated April 30, the pilot stated that upon landing on the flat, smooth snow-covered ice, the airplane pitched forward violently, then to the right, and then back to the left. A postaccident examination by the pilot revealed that the right main landing gear had collapsed and subsequently folded under the airplane. The wings and fuselage sustained substantial damage.
Landing Gear Examination
A postaccident examination of the right main landing gear found a fractured suspension strut. The fracture occurred laterally across a bored and threaded suspension tube. The tube exhibited a slight bend with tearing along the fracture line on the inside of the bend. The pilot reported that other than the fractured main landing suspension strut, there were no preaccident mechanical anomalies with the airplane.