Wainwright

The certificated airline transport pilot, with one non-revenue passenger, departed in the twin engine turboprop airplane from a rural airport on a CFR Part 135, VFR cargo flight over ocean waters. The flight did not reach its destination, and was reported overdue. Search personnel searched along the airplane's anticipated route of flight, over ocean waters. Shortly after initiation of the search, airborne search personnel reported sighting floating debris, consisting of what appeared to be aircraft seats, cardboard boxes, and small portions of aircraft wreckage, about 30.5 miles southwest of the flight's departure airport, and about 10 miles from shore. The airplane is presumed to have sunk in ocean waters estimated to be between 50 and 70 feet deep. Underwater search and recovery efforts were unsuccessful, and the airplane, pilot, and passenger remain missing. A review of archived radar data disclosed that as the accident airplane approached an area about 30.5 miles southwest of the departure airport, it descended to 500 feet msl, and then entered a right turn. As the turn progressed, the airplane continued to descend to 400 feet msl, with a radar-derived ground speed of 180 knots. The last radar return was recorded with the same radar-derived groundspeed, on an approximate heading of 200 degrees. A pilot who is familiar with geographical locations in the area reported that migrating whales are commonly sighted in the area where the radar depicted a descending right turn.

The pilot, who was also the station manager, arrived at the airport earlier than other company employees to prepare for a scheduled commuter flight, transporting seven passengers and cargo to another village during hours of arctic, predawn darkness. Heavy frost was described on vehicles and airplanes the morning of the accident, and the lineman who serviced the airplane described a thin glaze of ice on the upper surface of the left wing. The pilot was not observed deicing the airplane prior to flight, and was described by the other employees as in a hurry to depart on time. The pilot directed the lineman to place fuel in the left wing only, which resulted in a fuel imbalance between 450 and 991 pounds (left wing heavy). The first turn after takeoff was into the heavy left wing. The airplane was observed climbing past the end of the runway, and descending vertically into the water. No preimpact mechanical anomalies were found with the airplane or powerplant. The aileron trim indicator was found in the full right wing down position. Postaccident flight tests with left wing heavy lateral fuel imbalances, disclosed that approximately one-half of right wing down aileron control deflection was used to maintain level flight, thus leaving only one-half right wing down aileron control efficacy. Research has shown that frost on airfoils can result in reduced stall angles of attack (often below that required to activate stall warning devices), increases in stall speeds between 20% and 40%, asymmetric stalls resulting in large rolling moments, and differing stall angles of attack for wings with upward and downward deflected ailerons (as when recovering from turns).

The pilot had contacted the FSS 11 times on the day of the accident to obtain weather briefings. The conditions were below VFR minimums, which were required to conduct the passenger carrying commercial flight in a single-engine airplane. The conditions later improved and the pilot departed under a special VFR clearance. The pilot performed two approaches at the destination airport in IMC that were consistent with the two GPS approaches that were available there. Weather data and witnesses indicate that daylight conditions, low clouds and poor visibility prevailed, with cloud tops at 1,000 feet. After the second approach, the pilot radioed that he was heading back to the departure airport because he could not see the airport. No distress calls or unusual engine noises were heard. The airplane subsequently flew north of the airport and away from the departure airport at an altitude beneath the minimum radar coverage of 2,200 feet. It impacted the frozen Arctic Ocean in a right bank and at a 60-degree nose-down attitude about three miles away from the location of the pilot's last radio transmission. An examination of the airplane (before it sank through cracking ice) revealed no pre-impact mechanical malfunctions. An examination of the propeller revealed that it was under a power setting consistent with a maneuvering airspeed at the time of impact. An examination of the autopilot annunciator filament revealed that the autopilot was not engaged at impact. The airplane was nearly full of fuel and over its published maximum gross weight at impact. Small pieces of clear ice, about 1/4-inch thick, were found on portions of the tail surfaces. Interviews with operator employees and the pilot's wife revealed that the pilot may have felt pressure from himself and passengers to complete the flight.

The pilot Oskar Omdal was performing a local test flight on this aircraft named 'Elisabeth'. Shortly after takeoff from Wainwright, the aircraft stalled and crashed in a lagoon. While the pilot was uninjured, the aircraft was damaged beyond repair as a ski was torn off and went through the engine. The aircraft, owned by the Norwegian explorer Roald Amundsen, was performing some tests before an expedition to the Spitzberg archipelago.