What happened
On the afternoon of October 11, 1990, a Gulfstream Aerospace 690C Turbine Commander, registered as N45Q, vanished while conducting a wildlife survey mission. The aircraft was operating on behalf of the US Department of the Interior to track radio-collared polar bears. The flight, managed by Alaska Helicopters, Inc., departed from Deadhorse Airport at approximately 1429 Alaska daylight time under visual flight rules.
While the aircraft was performing maneuvers at an altitude of 22,000 feet MSL, approximately 200 miles north-northwest of Deadhorse, radar contact was lost. The flight plan had originally intended for a 5.5-hour duration, returning to the same airport, but the plane never reached its destination. Following the loss of signal, the FAA issued an alert notice later that evening.
An extensive search operation involving ground teams, surface vessels, and specialized radar-equipped aircraft was launched to locate the wreckage. However, despite these efforts, neither the aircraft nor its occupants were ever found. The search operations were eventually terminated on October 26, 1990.
Findings
It is presumed that the three occupants—consisting of the pilot and two passengers—sustained fatal injuries during the event. The aircraft, which was owned by Bowhead Equipment Company, is believed to have been destroyed upon impact with the Arctic Ocean.