1969: USAF RC-135E "Rivet Amber" was lost over the Bering Sea.
The following information is excerpted from a Report on the RC-135E "Rivet Amber" - submitted by Ron Strong.
The Rivet Amber had returned to Shemya AF Base, Alaska in June 1969 after an operational flight. After landing, inspection revealed extensive skin damage to the tail section - to include the vertical stabilizer. Despite objections by the maintenance crew, the aircrew were ordered to fly the aircraft to Eielson AF Base, Alaska for further inspection and any repairs.
On 5 June 1969, the Rivet Amber took off for Eielson AF Base and 45 minutes into the flight, declared a May Day, reporting severe vibration. They were descending to a lower altitude. A second call reported no other information than the aircraft's call sign. A third call indicated the crew was ordered to go to full oxygen. Tones from the HF transmitter continued to be detected for a period of time and then all contact was lost.
A massive search of the area by Air and Sea assets found no trace of the Rivet Amber.