Avro Lancaster

Avro Lancaster Mk I PA474
Avro Lancaster Mk I - PA474
Design and Development

The origins of the Lancaster lie in a twin-engine bomber design submitted to meet Specification P.13/36, which was for a new generation of twin-engine medium bombers for "world-wide use", the engine specified as the Rolls-Royce Vulture. The resulting aircraft was the Avro Manchester, which, although a capable aircraft, was troubled by the unreliability of the Vulture. Only 200 Manchesters were built and they were withdrawn from service in 1942.

Avro's chief designer, Roy Chadwick, was already working on an improved Manchester design using four of the more reliable but less powerful Rolls-Royce Merlin engines on a larger wing. The aircraft was initially designated Avro Type 683 Manchester III, and later re-named the Lancaster. The prototype aircraft BT308 was assembled by Avro's experimental flight department at Manchester's Ringway Airport from where test pilot H.A. "Bill" Thorn took the controls for its first flight on Thursday, 9th January 1941. The aircraft proved to be a great improvement on its predecessor, being "one of the few warplanes in history to be 'right' from the start". Its initial three-finned tail layout, a result of the design being adapted from the Manchester I, was quickly changed on the second prototype DG595 and subsequent production aircraft to the familiar twin-finned specification also used on the later Manchester's.

Some of the later orders for Manchesters were changed in favour of Lancasters, the designs were very similar and both featured the same distinctive greenhouse cockpit, turret nose and twin tail. The Lancaster discarded the stubby central third tail fin of the early Manchesters and used the wider span tailplane and larger elliptical twin fins from the later Manchester IA.

The Lancaster is a mid-wing cantilever monoplane with an oval all-metal fuselage. The wing was constructed in five main sections, the fuselage in five sections. All wing and fuselage sections were built separately and fitted with all the required equipment before final assembly. The tail unit had twin oval fins and rudders.

The Lancaster was initially powered by four wing-mounted Rolls-Royce Merlin piston engines with three-bladed airscrews. It had retractable main landing gear and fixed tail-wheel, with the hydraulically operated main landing gear raised into the inner engine nacelles. The majority of Lancaster's built during the war years were manufactured by Avro at their factory at Chadderton near Manchester and test flown from Woodford Aerodrome in Cheshire.

Other Lancasters were built by Metropolitan-Vickers (1080, also tested at Woodford) and Armstrong Whitworth. The aircraft was also produced at the Austin Motor Company works in Longbridge, Birmingham later in the Second World War and postwar by Vickers-Armstrong at Chester. Only 300 of the Lancaster B II fitted with Bristol Hercules engines were constructed, this was a stopgap modification caused by a shortage of Merlin engines as fighter production was of higher priority. Many BII's were lost after running out of fuel. The Lancaster B III had Packard Merlin engines but was otherwise identical to contemporary B Is, with 3,030 B III's built, almost all at A.V. Roe's Newton Heath factory. The B I and B III were built concurrently, and minor modifications were made to both marks as new batches were ordered. Examples of these modifications were the relocation of the pilot head from the nose to the side of the cockpit, and the change from de Havilland "needle blade" propellers to Hamilton Standard or Nash Kelvinator made "paddle blade" propellers.

Of later variants, only the Canadian-built Lancaster B X manufactured by Victory Aircraft in Malton, Ontario was produced in significant numbers. A total of 430 of this type were built, earlier examples differing little from their British-built predecessors, except for using Packard-built Merlin engines and American-style instrumentation and electrics. Late-series models replaced the Frazer Nash mid-upper turret with a differently configured Martin turret, mounted slightly further forward for weight balance. A total of 7,377 Lancaster's of all marks were built throughout the duration of the war, each at a 1943 cost of £45-50,000 (approximately equivalent to £1.3-1.6 million in 2010 currency).

Test pilot Alex Henshaw is the only known pilot to have barrel rolled a Lancaster bomber, a feat considered almost impossible because of the slow speed of the aircraft.

Avro Lancaster Mk I Avro Lancaster Mk I Avro Lancaster Mk I
Operational History

Lancasters flew 156,000 sorties and dropped 608,612 tons of bombs between 1942 and 1945. Just 35 Lancasters completed more than 100 successful operations each, and 3,249 were lost in action. The most successful survivor completed 139 operations, and was scrapped in 1947. A famous Lancaster bombing raid was the 1943 mission, codenamed Operation Chastise, to destroy the dams of the Ruhr Valley. The mission was carried out by No.617 Squadron in modified Mk III's carrying special drum shaped bouncing bombs designed by Barnes Wallis. The story of the mission was later made into a film, The Dam Busters. Also famous was a series of Lancaster attacks using Tallboy bombs against the German battleship Tirpitz, which first disabled and later sank the ship.

Lancasters from Bomber Command were to have formed the main strength of Tiger Force, the Commonwealth bomber contingent scheduled to take part in Operation Downfall, the codename for the planned invasion of Japan in late 1945, from bases on Okinawa. RAF Lancasters dropped food into the Holland region of the occupied Netherlands, with the acquiescence of the occupying German forces, to feed people who were in danger of starvation. Named after the food Manna which miraculously appeared for the Israelites in the book of Exodus, the aircraft involved were from No.1, No.3 and No.8 Groups, and consisted of 145 Mosquitoes and 3,156 Lancasters, flying between them a total of 3,298 sorties. The first of the two RAF Lancasters chosen for the test flight was nicknamed "Bad Penny" from the old expression: "a bad penny always turns up". This bomber, with a crew of seven men (five Canadians including pilot Robert Upcott, took off in bad weather on the morning of 29th April 1945 without a cease fire agreement from the German forces, and successfully dropped her cargo.

A development of the Lancaster was the Avro Lincoln bomber, initially known as the Lancaster IV and Lancaster V. These two marks became the Lincoln B.1 and B.2 respectively. There was also a civilian airliner based on the Lancaster, the Lancastrian. Other developments were the York, a square-bodied transport and, via the Lincoln, the Shackleton which continued in airborne early warning service up to 1992.

In 1946, four Lancasters were converted by Avro at Bracebridge Heath, Lincolnshire as freighters for use by British South American Airways, but proved to be uneconomical and were withdrawn after a year in service.

Four Lancaster III's were converted by Flight Refuelling Limited as two pairs of tanker and receiver aircraft for development of in-flight refuelling. In 1947, one aircraft was flown non-stop 3,355 miles from London to Bermuda. Later the two tanker aircraft were joined by another converted Lancaster and were used in the Berlin Airlift, achieving 757 tanker sorties. During its Argentine service, Lancaster's were used in several military coups.

Today there are only two airworthy Lancasters remaining in the world. One currently operating in Canada, the other in the UK at RAF Coningsby. One other example still survives in ground taxing condition at East Kirkby Heritage Centre, and is regularly seen stretching her legs around the former WWII airfield.

Production Summary
Mk I3434
B.Mk I Special33 ( All Mk I conversions)
B.Mk I (FE)Unknown
B.Mk 10
Mk II301
B.Mk IIUnknown
Mk III3039
B.Mk 30
B.Mk III (FE)Unknown
B.Mk VI7
B.Mk VII180
B.Mk X430
Specifications(Lancaster B.Mk I)
Length:69.49ft (21.18m)
Width:102.00ft (31.09m)
Height:20.01ft (6.10m)
Empty Weight:36,901lbs (16,738kg)
MTOW:69,999lbs (31,751kg)
Max Speed:287mph (462kmh; 249kts)
Max Range:2,529miles (4,070km)
Service Ceiling:24,508ft (7,470m; 4.6miles)
Engine:4 x Rolls-Royce Merlin XXIV V-12 water-cooled piston engines generating 1,640hp each
Armament Standard:2 x 7.7mm machine guns in nose
2 x 7.7mm machine guns in dorsal turret
4 x 7.7mm machine guns in tail turret
Armament Optional:18,000 lbs of internal ordnance