The most famous British bomber of the Second World War began life as one of its worst. Before the Avro Lancaster hauled bouncing bombs to the Ruhr dams and Tallboys onto the Tirpitz, there was the Avro Manchester — a twin-engine heavy so plagued by its own engines that crews learned to dread the sound of them.

Only about 200 were built. Dozens fell out of the sky not to enemy fire but to their own machinery. And yet, without that failure, there would have been no Lancaster at all. The Manchester is the rare case of a disaster that turned directly into a legend.

An engine with an X on its back

The Manchester's fate was sealed by its powerplant: the Rolls-Royce Vulture, a 24-cylinder monster made by stacking two Peregrine V-12 blocks into an "X." On paper it promised 1,760 horsepower. In reality it shed crankshafts, spun bearings and overheated so badly that Rolls-Royce had to throttle it back to around 1,500 hp just to keep it together.

That left the Manchester underpowered and dangerous. Lose one Vulture and the bomber could barely stay airborne on the other — one contemporary assessment reckoned a Manchester had roughly a three-in-four chance of crashing if an engine quit before it could get down.

The failed bomber that handed Britain the Lancaster.

The ground crews suffered too

The Vulture punished more than the men who flew behind it. Its X-layout made routine maintenance a nightmare: simply changing spark plugs meant pulling all four cowlings and stripping off the intake and exhaust manifolds. An engine that was hard to trust and hard to service is an engine on borrowed time.

By June 1942 the RAF had seen enough and withdrew the Manchester from operations after barely eighteen months. On its own record, it was a failure — short-lived, dangerous and disliked. But Avro's designers had already seen the way out.

Four Merlins and a legend

Rather than persevere with the Vulture, Roy Chadwick's team stretched the Manchester's wing and hung four reliable Rolls-Royce Merlins on it. The Air Ministry agreed it beat retooling the factories. The result was first called the Manchester Mark III, then given a new name: Lancaster.

That aircraft became everything the Manchester was not. More than 7,300 were built, and Bomber Command's chief regarded it as the war-winner the twin-engined version could never be.

The Lancaster at war — the bomber the Manchester made possible.

So the Manchester deserves better than to be remembered only as a lemon. It was the necessary mistake — the airframe that proved sound while its engines proved fatal, and the direct ancestor of the most celebrated bomber Britain ever built.

The story of Avro, the firm behind both the Manchester and the Lancaster.

Sources: Wikipedia (Avro Manchester, Rolls-Royce Vulture); Jon Lake; Vintage Aviation News.