1951 Canadian Pacific Air Lines Douglas DC-4 disappearance
|Missing Aircraft summary|
|Date||21 July 1951|
|Site||probably Alaska, United States|
|Aircraft type||Douglas DC-4 (former C-54A/R5D-1)|
|Operator||Canadian Pacific Air Lines|
|Flight origin||Vancouver International Airport, British Columbia, Canada|
|Stopover||Elmendorf Air Force Base, Alaska, United States|
|Destination||Haneda Army Air Base, Tokyo, Japan|
The 1951 Canadian Pacific Douglas DC-4 disappearance occurred on 21 July when a Douglas DC-4 four-engined piston airliner registered CF-CPC of Canadian Pacific Air Lines disappeared on a scheduled flight for the United Nations from Vancouver, Canada, to Tokyo, Japan. Neither the aircraft nor the 31 passengers and six crew have been found.
At 18:35 the DC-4 departed Vancouver International Airport, Canada on a scheduled flight to Tokyo; it was due to stop over at Anchorage Airport in Alaska. The flight was on schedule and reported at the Cape Spencer intersection in British Columbia 90 minutes out from Anchorage; it gave an estimate of 24:00 for Yakutat in Alaska. The weather in the area was heavy rain and icing conditions with a visibility of 500 feet. Nothing further was heard from the aircraft, and at 00:44 an emergency warning was issued when the aircraft was overdue to report. The United States Air Force and Royal Canadian Air Force carried out an extensive search but failed to find any trace of the aircraft or its 37 occupants. The search was finally called off on 31 October 1951.
The aircraft, a Douglas DC-4 four-engined piston airliner had been built in 1944 for the United States Army Air Forces as a Douglas C-54A Skymaster but on delivery in June 1944 it was diverted to the United States Navy with the designation R5D-1. In 1946 it was converted to a civil Douglas DC-4 standard for Pan American Airlines as Clipper Winged Racer. It was sold to Canadian Pacific Airlines in 1950.
Passengers and crew
All the six crew were Canadian and the passengers were 28 serving and civilian members of the United States armed forces and three United Nations officials.
According to the July 21, 1951, edition of the New York Times, however, first reports listed three of the passengers as United Nations officials, but United Nations headquarters in New York reported later that no members of its Secretariat or other officials were aboard the craft.
The probable cause was reported as "As no traces of the aircraft or its occupants has been found to date the cause of the disappearance has not been determined." 
- Civil Aviation Authority 1974, p. 12/51
- "Canadian Airliner Missing 38 Persons On Board". News. The Times (52060). London. 23 July 1951. col E, p. 7.
- Eastwood 1991, p. 123
- World Accident Summary. Civil Aviation Authority (United Kingdom). 1974. ISBN 0-903083-44-2.
- Eastwood, Tony; John Roach (1991). Piston Engine Airliner Production List. The Aviation Hobby Shop. ISBN 0-907178-37-5.
- Jackson, A.J. (1973). British Civil Aircraft since 1919 Volume 1. London: Putnam. ISBN 0-370-10006-9.