Why did the Avro Manchester fail?

Short answer

Because of its Rolls-Royce Vulture engines: they were insufficiently developed and turned out to lack power and reliability. The engine made the Manchester known mainly for its poor reliability, weak performance and unsuitability for its task. The type was grounded twice in 1941.

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

Lancaster B Mk I R5852 of No. 83 Squadron in flight over Lincolnshire, June 1942

Engines that were never reliable

Operated by the RAF and the Royal Canadian Air Force, the Manchester came to be regarded as a failure, mainly because of its Rolls-Royce Vulture engines, which were insufficiently developed and consequently lacked power and reliability. The engine made the Manchester notable chiefly for its lack of reliability, its poor performance and its general unsuitability for the task it was meant to perform. One account of those engines states that they never became reliable and did not deliver enough power: two extremely unreliable 1,750 hp Vultures had to drag a 50,000 lb aircraft. The same account describes having seen an aircraft undergoing an engine ground test with two pistons coming out through the side of the engine.

Groundings and firsthand accounts

On 13 April 1941 all Manchesters were temporarily grounded owing to a higher-than-expected number of engine bearing failures, and on 16 June 1941 a second grounding of the type was ordered. In a force of more than 400 bombers, only 15 were Manchesters.

The way out: four Merlins

The Manchester was redesigned as a four-engined heavy bomber, powered by the Rolls-Royce Merlin, and became known as the Lancaster. The Manchester Mk III, serial number BT308, first flew on 9 January 1941 and was essentially the first Lancaster, with a longer wing fitted with four Merlins. The Manchester, which had given trouble in service, was withdrawn in 1942.