HANDLEY PAGE HALIFAX - The HANDLEY PAGE HP.57 HALIFAX heavy bomber was evolved by design team led by G R Volkert as final stage in process started in 1935 when a prototype of the twin-engined HP.55 had been ordered to Specification B.l/35 but superseded by two prototypes of the HP.56 to P.13/36, each powered by two Vultures. Substitution of four 1,145 hp Merlin Xs for the two Vultures, with increased dimensions and weights, resulted in HP.57, with design.arrmament of twin-gun nose and four-gun tail power-operated turrets (originally to be Frazer Nash, but finally standardised on Boulton Paul types), all with 0.303 in (7.7 mm) calibre guns and an 8,000 Ib (3,632 kg) bomb load. Unarmed first prototype flown at Bicester. on October 25, 1939, and second prototype with BP nose and tail turrets on August 17, 1940. Initial gross weight 47,000 Ib (21,338 kg), later 50,000 Ib (22,700 kg).
Handley Page Halifax I: Initial production variant (HP.57); 100 ordered to Specification 32/37 in January 1938 of which 84 delivered as Mk I, comprising 50 Mk I Series 1 with 55,000 Ib (24,970 kg) gross weight and 1,392 Imp gal (6,328 1) fuel in wing tanks, 25 Mk I Srs 2 with 60,000 Ib (27,240 kg) gross weight and pairs of Vickers 'K' guns firing through side hatches amidships, and nine Mk I Srs 3 with 1,636 Imp gal (7,437 1) fuel in wing tanks. All had provision to carry one, two or three 230 Imp gal (1,046 1) fuel tanks in bomb bay, in lieu of bombs, and extra bomb cells in the inner wing section. First production Mk I flown October 11, 1940; deliveries to No 35 Squadron began November 1940 and first operational sortie flown March 10/11, 1941. Max speed, 265 mph (426 km/h) at 17,500 ft (5,334 m). Initial rate of climb, 750 ft/min (3,81 m/sec). Service ceiling, 22,800ft (6,950 m). Range with bomb-bay fuel and 5,800 Ib (2,633 kg) bomb load, 1,860 mis (2,993 km). Empty weight, 33,860 Ib (15,372 kg). Gross weight, 55,000 Ib (24,970 kg). Span, 98 ft 10 in (30.21 m). Length, 70 ft 1 in (21.36 m). Wing area, 1,200 sqft (111.4 m2).
Handley Page Halifax B Mk II: Series production version (HP.59) similar to Mk I with 1,390 hp Merlin XX engines, larger oil coolers, wing fuel capacity of 1,882 Imp gal (8,556 1) and twin-gun BP dorsal turret in place of beam guns. Prototype (Mk I conversion) flown at Radlett July 3, 1941. Production shared between Handley Page (615), London Aircraft Production Group (450) at Leavesden, Rootes Securities (12) at Speke and English Electric (900) at Samlesbury. Initial production of Mk II Series I followed by Mk II Series I (Special) with interim nose fairing replacing nose turret, first flown August 15, 1942, and operated initially for SOE sorties by No 138 Sqn and later by bomber squadrons in 4 Group using kit-modified Series I aircraft. For SOE use, fitted with parachute exit cone in rear fuselage and retracting tailwheel; many such operated by No 148 Sqn from Brindisi to support Warsaw uprising July 1944. Later production version was Mk II Series 1A with more streamlined, largely transparent nose fairing replacing turret, and mounting one handheld 0.303 in (7.7 mm) Vickers 'K' gun, plus low-drag nacelles incorporating Morris radiators and - usually - BP four-gun dorsal turrets. Mk II production included 299 Series lAs, from end-1942 onwards. Later production Mk Us had 1,390 hp Merlin 22s, four-bladed propellers, gross weight of 65,000 Ib (29,510 kg) and D-type rectangular fins and/or H2S bombing aid with ventral radome. H2S first flown on Handley Page Halifax II on March 27, 1942. Some aircraft had modified bomb-doors to carry 8,000 Ib (3,632 kg) block-busters.
Handley Page Halifax B Mk III: Similar to B Mk II but with 1,615 hp Hercules VI radial engines and gross weight increased to 64,000 Ib (29,056 kg). Prototype converted from first B Mk II Srs 1 (Special), flown on October 12, 1942, and first production Mk III on August 29, 1943. Production Mk Ills (HP.61) had retractable tailwheel, D-type enlarged fins, Hercules VI or XVI engines, Srs 1A type nose with single gun plus four-gun dorsal and tail turrets and in some cases ventral fairing containing an 0.50 in (12.7 mm) gun in Preston-Green mount. Fuel capacity increased to 1,986 Imp gal (9,028 1) and all but first few had longer wing with span increased to 104 ft 2 in (31.75 m). Max bomb load, 10,000 Ib'(4,540 kg) in fuselage and 3,000 Ib (1,362 kg) in wings. Production totalled 326 by HP at Radlett, 900 by English Electric at Samlesbury, 260 by LAPG at Leavesden, 280 by Rootes Securities at Speke and 326 by Fairey Aviation at Stockport; first deliveries November 1943 to No 433 Sqn, RCAF and No 466 Sqn, RAAF, and used by 41 operational squadrons in 1944/45, principally in 4 and 6 Groups.
Handley Page Halifax A Mk III: Thirty Rootes-built B Mk Ills converted to serve as interim Airborne Forces glider tug and paratroop transport pending production of A Mk VII. Used to tow Horsa and Hamilcar gliders in airborne assaults on European targets after D-Day.
Handley Page Halifax IV: Projected development of Mk II with 1,280 hp Merlin 60s (HP.60A), with long-tailed inner nacelles and totally-enclosed wheel bays, enlarged fins and rudders, enlarged bomb-doors for 8,000 Ib (3,632 kg) block-busters and extended span. One Mk II tested with Merlin XXs in Merlin 60 powerplants as Mk II Srs 2 in March 1943, later used as test-bed for Merlin 61s and 65s, with long-tailed inner nacelles but original fins and rudders and short span wing.
Handley Page Halifax B Mk V: Same as B Mk II but with Dowty main undercarriage and retraction system replacing Messier system. Prototype (Mk II converted) flown October 1941 and production (HP.63) totalled 658 by Rootes Securities and 246 by Fairey Aviation at Stockport. Series I, Series 1 (Special) and Series 1A variants as for B Mk II. B Mk Vs used primarily by squadrons of No 6 (RCAF) Group; others converted to GR Mk V and Met Mk V for Coastal Command. Mk Vs also modified as first Handley Page Halifaxes to serve with Airborne Forces as tugs for Horsa and Hamilcar, and to carry paratroops. First three modified Mk Vs to 38 Group in October 1942 for first British glider-borne operation ('Freshman'), two Horsas towed by Handley Page Halifax Vs with troops to attack Norak Hydro Plant making heavy water in Norway. First 38 Group squadron equipped with Handley Page Halifax Vs, No 295, in February 1943.
Handley Page Halifax GR Mk II _and GR Mk V: Conversion of B Mk A and B Mk V for Coastal Command, by Cunliffe-Owen, mostly of Rootes-built aircraft. Fitted with F.N.64 two-gun ventral turret and 690 Imp gal (3,137 1) extra fuel in three bomb-bay tanks; single 0.50 in (12.7 mm) Browning on Preston-Green mount later replaced the-ventral F.N.64. Primarily Mk II Srs 1A standard, used by four squadrons on antisubmarine and shipping patrols, from late-1942 onwards.

Handley Page Halifax B Mk VI: Similar to B Mk III powered by 1,675 kp Hercules 100s with revised fuel system for tropical operations and 2,190 Imp gal (9,956 1) basic capacity plus three-tank 690 Imp gal (3,137 1) bomb-bay option. Extended wing-tips, Series 1A nose, rectangular fins and rudders as standard. Prototype flown December 19, 1943; production first flight October 10, 1944; production totals 132 by HP and 325 by English Electric. Equipped several bomber squadrons and for radar counter-measures.

Max speed, 312 mph (502 km/h) at 22,000ft (6,706m) and 290 mph (497 km/h) at 10,500ft (3,200 m). Cruising speed, 218-260 mph (351-418 km/h) at 20,000ft (6,100 m). Time to 20,000Jft (6,100 m) at max weight, 50 min. Service ceiling at max weight, 24,000 ft (7,315 m). Range, 1,260 mis (2,027 km) with max bombs, 2,400 mis (3,867 km) with max fuel. Tare weight, 39,000 Ib (17,706 kg). Gross weight, 68,000 Ib (30,872 kg). Span, 104 ft 2 in (31.75 m). Length, 70 ft 5 in (21.46 m). Wing area, 1,275 sq ft (118.4 mf).
Handley Page Halifax Met Mk II, Met Mk III, Met Mk V, Met Mk VI: Conversion of bomber variants for use by squadrons of Coastal Command on meteorological reconnaissance duties.
Handley Page Halifax B Mk VII: As B Mk VI but with 1,615 hp Hercules XVIs, as airframe production outpaced engine availability. Fifteen built by HP, 12 by English Electric, 90 by Fairey. Used primarily by squadrons of No 6 (RCAF) Group.
Handley Page Halifax A Mk VII: Variant of B Mk VII produced for 38 Group Airborne Forces as glider tug and paratrooper, with ventral dropping hatch provided. Production totalled 120 by Rootes, 69 by Fairey, 49 by HP and eight by English Electric. Operational in UK, Middle East and Far East to August 1945 and beyond.
Handley Page Halifax C Mk VIII: Unarmed passenger, freight or casualty transport version of Handley Page Halifax B Mk VI, able to carry 10 stretchers, 11 passengers or paratroops (with ventral exit cone) plus 8,000 Ib (3,632 kg) capacity detachable freight pannier in bomb-bay. Crew of five and dual controls; Hercules 100 engines. 100 ordered as HP.70, plus 304 panniers; first flown June 1945 and served post-war with five squadrons.
Handley Page Halifax C Mk II, C Mk VI, C Mk VII:
Bomber variants converted to carry freight, eight passengers or nine stretchers, plus six passengers in crew rest bunks. All guns, dorsal turret, H2S scanner and radome and some radio removed. One C Mk III and C Mk VIIs could carry freight pannier as C Mk VIII.
Handley Page Halifax A Mk IX, A Mk X: Post-war versions (Mk X not built) with Hercules XVI and Hercules 100 respectively, derived from A Mk VII.