The Handley Page Halifax is a British Royal Air Force (RAF) four-engined heavy bomber of the Second World War. It was developed by Handley Page to the same specification as the contemporary twin-engine Avro Manchester. The Halifax has its origins in the twin-engine HP56 proposal of the late 1930s, produced in response to the British Air Ministry's Specification P.13/36 for a capable medium bomber for "world-wide use." The HP56 was ordered as a backup to the Avro 679, both aircraft being designed to use the underperforming Rolls-Royce Vulture engine. The Handley Page design was altered at the Ministry to a four-engine arrangement powered by the Rolls-Royce Merlin engine; the rival Avro 679 was produced as the twin-engine Avro Manchester which, while regarded as unsuccessful mainly due to the Vulture engine, was a direct predecessor of the famed Avro Lancaster. Both the Lancaster and the Halifax would emerge as capable four-engined strategic bombers, thousands of which would be built and operated by the RAF and several other services during the War. The Handley Page Halifax was a mostly orthodox design, a mid-wing monoplane with a tail unit featuring twin fins and rudders. The Halifax featured all-metal construction with a smooth, stressed skin covering the majority of the exterior surfaces; the flight control surfaces were an exception, being fabric-covered instead. The slab-sided fuselage contained a 22-foot bomb bay, which contained the majority of the Halifax's payload, while the cockpit was flush with the upper fuselage. The Halifax was powered by four engines, two spaced evenly on each wing. Early production Halifax bombers were powered by models of the Rolls-Royce Merlin engine; later aircraft were commonly powered by the larger Bristol Hercules radial engine. To contain and attach the engines to the airframe, Handley Page developed their own design for the power egg instead of using the typical, slimmer Rolls-Royce counterpart; despite generating increased drag, this in-house design was readily adaptable to the alternative Hercules engine on later aircraft. A total of 6,176 Halifax's and 2 prototypes were built. The Halifax served with 460,462 and 466 squadrons, RAAF. For more information on the development, design, operational history and variants, click here.
