AVRO 683 LANCASTER
- Avro's design team under Roy Chadwick evolved a scheme for a Manchester
III pow-ered by four 1,145 hp Rolls-Royce Merlin Xs, to overcome difficulties
with the Vulture engine installation in the earlier twin-engined bomber.
With a new wider centre section and re-named Avro Lancaster, a proto-type
flew on January 9, 1941, at first with standard Manchester I triple-fin
tail unit and later with Manchester IA enlarged twin fins and wider tailplane.
Second prototype, with 1,280 hp Merlin XXs, flown May 13, 1941.
Avro Lancaster B Mk I: Production initiated 1941, replacing final
243 Manchesters on A V Roe contracts and 57 on Metropolitan-Vickers contracts,
and then continuing on major new contracts placed with Avro (Chadderton
and Yeadon), Vickers-Armstrong (Chester and Castle Bromwich), Armstrong
Whitworth (Baginton), Austin (Longbridge) and Metrovick (Manchester).
Initially with 1,280 hp Mejjlin XXs; Merlin 22s and Merlin 24s later,
With higher boost ratings. Armament comprised two 0.303-in (7.7-mm) Browning
guns each in nose and dorsal turrets, four in tail turret and provi-sion
for two in remotely-sighted ventral bar-bette, little used, especially
after ventral H2S radome fitted; turrets by Frazer Nash or Rose. Some
later Mk Is had a single 0.303-in (7.7-mm) or 0.50-in (12.7-mm) ventral
gun, manually operated, and a two-gun tail turret. Initial design bomb
load, 4,000 Ib (1,816 kg), later increased to 18,000 Ib (8,172 kg) without
special mods, including standard 8,000 Ib (3,632 kg) and 12,000 Ib (5,448
kg) bombs. Aircraft of Nos 9 and 617 Sqn modified in 1944 to carry 12,000-lb
(5,448-kg) 'Tallboy' bomb and used to attack and sink Tirpitz on November
12, 1944. Avro Lancaster entered ser-vice with No 44 (Rhodesia) Sqn, Waddington,
and used for first operational sortie on March 3, 1942. Total production,
3,434 (including special Mk I variants noted below).
Max speed, 275 mph (442 km/h) fully loaded at 15,000ft
(4,572 m). Service ceiling, 24,500 ft (7,468 m). Range, 1,660 mis (2,670
km) at 210 mph (338 km/h) with 14,000-lb (6,356-kg) bomb load. Gross weight,
initially, 60,000 Ib (27,240 kg); later 65,000 Ib (29,510 kg). Span, 102
ft 0 in (31.09m). Length, 68 ft 11 in (21.0m).
Avro Lancaster B Mk I (Special): 33 aircraft with Merlin 24s modified
1945 for 617 Sqn to carry 22,000-lb (9,988-kg) 'Grand Slam' bomb, with
no bomb-bay doors, and nose and dorsal turrets and H2S removed. First
operation.March 14, 1945, against Bielefeld Viaduct. Gross weight, 72,000
Ib (32,688 kg). o Avro Lancaster B Mk I (FE): Late produc-tion
aircraft for Tiger Force operation against Japanese targets in the Far
East, with modified radio, radar and navaids, and white top/black underside
finish. Two Avro Lancaster Is tested (by No 1577 SD Flight) in India and
Australia in 1945 with long range saddle tank in upper fuselage aft of
cockpit, for possible Tiger Force applica-tion. Two other Mk Is used by
No 1577 SD Flight to tow Horsa and Hamilcar gliders in trials for India-Burma
operations.
Avro Lancaster II: Similar to Mk I but with four 1,725 hp Hercules
VI or XVI radial air-cooled engines. Single prototype by Avro, first flown
on November 26, 1941, and 300 built by Armstrong Whitworth. Deliveries
starting October 1942. Performance, arma-ment and bomb load similar to
Mk I.
Avro Lancaster B Mk III: Similar to Mk I but with Packard-built
1,300 hp Merlin 28, 1,390 hp Merlin 38 or 1,620 hp Merlin 224 engines
supplied from USA. Armament and bomb load similar to Mk 1. Production
totalled 3,020 including 136 by Metrovick and 110 by Armstrong Whitworth,
the remainder by Avro. Twenty-three Mk Ills converted by Avro in 1943
to carry Vickers Type 464 spinning bomb for use by No 617 Sqn with front
and dorsal turret and bomb doors removed, small VSG hydraulic motor
in fuselage to spin weapon before release, and single 0.303-in (7.7-mm)
ventral gun fitted. First bomb drop on April 16, 1943, and used to attack
Mohne, Eder and Sorpe dams on May 111 18, 1943.
Max speed, 270 mph
(434 km/h) at 19,000ft (5,791 m). Cruising speed, 210 mph (338 km/h).
Initial rate of climb, about 600 ftlmin (3.05 ml sec). Time to 20,000
ft (6,100 m), 43.5 min. Service ceiling, 21,500ft (6,553 m). Range, 2,230
mis (3,588 km) with 7,000-lb (3,178 km) bomb load. Empty weight, 41,000
Ib (18,614km). Normal loaded weight, 53,000 Ib (24,062 kg). Maximum take-off
weight, 65,000 Ib (29,510 kg). Span, 102 ft 0 in (31.09 m). Length, 68
ft 11 in (21.02 m). Height, 19ft 6 in (5.95 m) . Wing area, 1,297 sqft
(120.5m2).
Avro Lancaster VI: Nine Avro Lancaster Ills fitted with 1,635 hp
Merlin 85 engines and four-blade propellers for general engine develop-ment
by Rolls-Royce (including other two-stage Merlin marks in due course)
and as potential successor to the Mks I and II. First conversion June/July
1943, service tri-als by Nos 7 and 635 Sqn (with nose and dorsal turrets
removed) until November 1944.
Avro Lancaster B Mk VII: Similar to B Mk III, with Packard Merlin
engines but with Martin 250 CE 23A dorsal turret mounting two 0.50-in
(12.7-mm) machine guns. 180 built by Austin, deliveries starting April
1945; some equipped for Tiger Force in Far East and designated Avro Lancaster
B Mk VII (FE).
Avro Lancaster B Mk X: Similar to B Mk III, built in Canada by
Victory Aircraft with Merlin 38 or 224, deepened bomb-bay and (later aircraft)
Martin dorsal turret. First flown on August 6, 1943; 430 built.
Avro Lancaster XPP: Two Avro Lancaster Xs con-verted by Victory
Aircraft as passenger and mail carriers (CF-CMT, CF-CMU), for TCA, with
fairings over nose and tail turret positions, no dorsal turret, extra
fuel in bomb bay and ten seats, following similar initial conversion of
one Mk I (CF-CMS).
