Canadair DC-4M Argonaut

The DC-4M was a license built version of the Douglas DC-4, with four Rolls-Royce Merlin engines built by Canadair. This variant used a pressurized fuselage based on the construction methods used for the DC-6, but with the shorter length of the DC-4.

The aircraft was known as the Argonaught when in service with British Overseas Airways Corporation BOAC, and as the North Star to the Canadians.

Visually its recognition features were the Merlin engines and square cabin windows (the DC-4 had round cabin windows)

It used the Rolls Royce engines and in consequence reduced the US dollar content of the aircraft, which was important in Britain immediately after the Second World War