B Mk V Series 1 (Special) and Series 1a
The Halifax Mk V was virtually identical to the Mk II. The only difference was the use of the Dowty undercarriage in place of the Messier undercarriage used in the Mk II, which was in short supply. The Dowty undercarriage was used on the Avro Manchester and Lancaster bombers, but the version supplies for the Halifax used sub-standard castings, preventing the Mk V from being used with a full bomb load. This made the Mk V of limited use to Bomber Command, and so after it entered service in June 1943 most Mk Vs were transferred to other duties. In some ways the failure of the Mk V as a heavy bomber was fortunate. Many other RAF commands needed the capacity offered by the four engined heavies, but Bomber Command were very unwilling to release them for other duties.
GR Mk V Series 1A
Coastal Command benefited from the limits of the Mk V as a heavy bomber. The GR Mk V was used in greater numbers than any other maritime version. It was most often used in the anti-shipping role, but also served in the anti-submarine role.
Met Mk V
The Mk V was the first Halifax to be converted for meteorological duties. Three Coastal Command squadrons (Nos. 517, 518 and 520) used the aircraft to fly long range missions over the Atlantic from bases in Britain and Gibraltar. The Merlin engines used in the Mk V were not well suited to this duty which required very long range operation. Engine failures were relatively common, and delayed the entry of the type into regular meteorological service – with the heavy fuel load needed for these long range missions three engines could not keep the Halifax at altitude and the extended fuel tanks on the standard Mk V could not be jettisoned.
A Mk V Series 1 (Special) and Series 1A
The Mk V was also used heavily by the Airborne Forces. The A Mk V had the dorsal turret removed. Glider towing equipment was added to the rear of the fuselage. Internally the A Mk V was equipped to carry paratroops. The A Mk V Series 1A was in use at the time of D-Day.