The Halifax was the second of the four-engined heavy bombers to enter service with the Royal Air Force. The huge Stirling was already operational, but the prototype Lancaster had yet to fly in November 1940, when No. 35 squadron began operations with what became affectionately known as the “Halibag.”
Designer George Volkert’s design featured a 103 foot wingspan and was powered by four Rolls Royce Merlin engines, the same used by the Hawker Hurricane and Supermarine Spitfire. The first Halifax flew in October 1939.
However, all was not well with the design of the Halifax. A significant design modification was made after some inexplicable losses of fully loaded aircraft had shown that it was possible for the Halifax to enter an inverted and uncontrollable spin. A second major problem was a lack of engine power. In fact, most of the problems resulted from the Merlin engine, or more specifically, how they were installed. The propellers of the Halifax were placed too close to the leading edge of the wings. This disturbed the airflow over the wing, causing poor performance of the aircraft, compared to the Lancaster. Despite these problem, the Halifax was a sturdy and reliable aircraft and was generally well liked by its crews.
The problems were resolved with the Halifax Mk III which was powered by Bristol Hercules engines. These were placed correctly in relation to the wings, but most of all, were much more powerful than the Merlin engines. Although the Halifax’s performance now matched the Lancaster’s, Bomber Command’s head Arthur Harris retained a preference for the Lancaster.