What happened
On June 7, 2014, an experimental, amateur-built Hermann Bjorn Lancair IV, registration N86NW, crashed into Lake Superior near Duluth, Minnesota. The aircraft departed Duluth International Airport (DLH) for a flight to Goose Bay, Newfoundland, Canada, under instrument flight rules (IFR).
Shortly after departure, the pilot failed to acknowledge air traffic control instructions to fly direct to Thunder Bay. Radar data showed the aircraft turning right and deviating from its assigned course. While the pilot did respond to a subsequent instruction to return to course, the aircraft eventually entered a steep, descending right turn. Despite air traffic control issuing a low altitude alert and instructing the pilot to climb immediately, the aircraft continued its descent and impacted the water approximately five minutes after departure. The pilot sustained 1 fatal injury.
The investigation
The investigation examined the wreckage, which was recovered from 137 feet of water. While the engine and propeller were examined in Prague, Czech Republic, the wings and much of the fuselage were not recovered, preventing verification of flight control continuity.
Data recovered from the aircraft's Chelton Integrated Display Units (IDUs) revealed significant discrepancies between the flight data recorded by the aircraft and the radar track data provided by air traffic control. The flight logs showed periods of straight and level flight, whereas radar indicated the aircraft was banking and changing heading. The logs also showed erratic wind direction changes, varying from 360 degrees to 203 degrees and back to 247 degrees in less than three minutes.
Additionally, the aircraft was found to be operating significantly over gross weight. The takeoff weight was estimated at 4,309 lbs, which was 509 lbs above the maximum allowable weight of 3,800 lbs. The center of gravity was also near the aft limit.