De Havilland BC DH.91 Albatross

The De Havilland BC DH.91 Albatross was a four-engined long-distance airliner for 28 passengers built by De Havilland British Columbia in 1938 based on the DH.91 Albatross transatlantic mailplane of DHBC's parent company, De Havilland Aircraft of the United Kingdom.

Although ultimately unsuccessful, the DH.91 was a milestone for British Columbia's aviation industry in that it was the first attempt at local manufacture of a long-range, land-based airliner.

Design & development
The British DH.91 was designed in 1936 by A. E. Hagg to Air Ministry specification 36/35 for a transatlantic mail plane. Two were built to the original design, after which a version to carry 22 passengers was developed, the main differences being extra windows and the replacement of split flaps with slotted flaps; five examples formed the production order delivered in 1938/1939. All seven were delivered to Imperial Airways, which later became BOAC.

Intrigued by the design from the outset, British Columbia's Inter-Dominion Air Lines asked DHBC to create a version for 28 to 30 passengers. Designated DH.91B Albatross, the biggest difference between the BC and British versions was the use of four HIV-12A Harrier engines from Hoffar Aero Engines, each producing 475 hp, instead of the de Havilland Gipsy Twelve V-12 engines used on the British variant, which produced only 415 hp each. The fuselage remained nearly identical to the British version, which meant that the 28 passengers had somewhat less space on the Inter-Dominion aircraft than did those travelling on the 22-passenger Imperial Airways plane. Completed in September and October 1938, three were delivered to Inter-Dominion in May of 1939 for in-service evaluation; if successful, orders for a further nine were foreseen.

Operational history
With its 925 nautical mile range, the DH.91B could fly from Vancouver to Toronto, Ontario, Canada needing only a single stop in Brandon, Manitoba. The DH.91B was slightly faster than the DH.91, cruising at 182 knots at 15,000 feet as compared to 174 knots (maximum speed 200 knots vs 196 knots), meaning the trip from Vancouver to Toronto could be made in about thirteen hours. Despite the speed, they were unpopular with passengers due to the restricted space and noise. Inter-Dominion asked DHBC to redesign the interior for 24 passengers and better soundproofing, but the outbreak of the Second World War in September of 1939 led to the cancellation of the project.

The three aircraft were converted for mail and cargo use, and during the war they were used regularly to transport Soviet pilots from Anadyr in the Soviet Far East to BC to take delivery of the Skemcis fighters manufactured for the Soviet air force by Supermarine British Columbia. Inter-Dominion sold all three in 1947 to the air force of the Republic of China; one was destroyed on the ground at Nanjing during the civil war, but the other two survived and were operated until 1952 by the air force of the People's Republic of China. Neither is believed to survive.