Which Canadian mail plane ended up testing engines?

Short answer

From the Avro 627 Mailplane, which Avro developed in 1931 from the Antelope and which Roy Chadwick redesigned after interest from Canadian Airways, which had a possible mail plane requirement. Its only prototype, G-ABJM, travelled to Canada for trials, returned to England, and in 1933 became a test bed for the Armstrong Siddeley Tiger engine, renamed Avro 654.

Published: November 4, 2026 · Updated: November 4, 2026 · Edited by Above Ten Thousand · Editorial policy

Which Canadian mail plane ended up testing engines?

Avro 627 3 view NACA aircraft Circular No 150

A mail plane designed for Canada

The Avro 627 Mailplane was developed in 1931 at Avro from the Avro Antelope light bomber. Interest from Canadian Airways, which had a possible mail plane requirement, led Roy Chadwick to redesign the unfinished prototype once again until it became the Avro 627 Mailplane. The only prototype, registered G-ABJM, received its certification on 2 August 1931 and was shipped to Canada to carry out operational trials.

The trials and the return to England

Those trials proved satisfactory, but the Canadian government cut the civil aviation subsidy and Canadian Airways could not afford new aircraft, so the plane was returned to England. Once back, it entered the 1932 King's Cup Race, where it recorded the highest speed of the event, 176 mph (283 km/h).

Tiger test bed

In 1933 the Mailplane was converted into a high-speed test bed for the Armstrong Siddeley Tiger engine, and the modified aircraft became known as the Avro 654. After that conversion, its operational life was short: it was scrapped at Woodford airfield in 1934.