search Skytamer.com

Avro 694 “Lincoln B.Mk.II”
British four-engine heavy-bomber


Archive Photos [1,2]


[Avro 694 “Lincoln B.Mk.II” (John Shupek 3-view drawing copyright © 2013 Skytamer Images) [1]]

[Airplane Card: Avro Lincoln, Wings, Topps Chewing Gum, 1952, USA, Card 4 of 200. (The Skytamer Archive copyright © 2013 Skytamer Images) [2]]

[Avro 694 “Lincoln B.Mk.II” (RF398) on display 9/12/2002 at the Royal Air Force Museum Cosford, Cosford, Shifnal, Shropshire, UK (John Shupek photos copyright © 2002 Skytamer Images) [3]]

Overview [4]


Avro 694 Lincoln

  • Role: Heavy bomber
  • Manufacturer: A.V. Roe (168), Metropolitan-Vickers (80) and Armstrong Whitworth (281)
  • First flight: 9 June 1944
  • Introduction: 1945
  • Retired: 1967 Argentine Air Force
  • Primary users: Royal Air Force; Argentine Air Force; Royal Australian Air Force
  • Number built: 604
  • Developed from: Avro Lancaster
  • Developed into: Avro Shackleton; Avro Tudor

The Avro Type 694, better known as the Avro Lincoln, was a British four-engine heavy bomber, which first flew on 9 June 1944. Developed from the Avro Lancaster, the first Lincoln variants were known initially as the Lancaster IV and V, but were renamed Lincoln I and II. It was the last piston-engine bomber used by the Royal Air Force.

The Lincoln became operational in August 1945. It had been assigned to units of Tiger Force, a British Commonwealth heavy bomber force, intended to take part in the Second World War Allied operations against the Japanese mainland, but the war ended before the Lincoln was operational. The Lincoln was used in action during the 1950s, by the RAF in the Mau Mau Uprising in Kenya, and with the RAF and RAAF during the Malayan Emergency.

In all 604 Lincolns were built. The type also saw significant service with the Royal Australian Air Force (RAAF) and Fuerza Aérea Argentina (Argentine Air Force), as well as some civil aviation usage.

Design and Development [4]


The Avro Lincoln was Roy Chadwick's development of the Lancaster, built to the Air Ministry Specification B.14/43, having stronger, longer span, higher aspect ratio (10.30 compared with 8.02) wings with two-stage supercharged Rolls-Royce Merlin 85 engines, and a bigger fuselage with increased fuel and bomb loads. As a result, the Lincoln had a higher operational ceiling and longer range than the Lancaster.

The prototype Lancaster IV (Lincoln I) was assembled by Avro's experimental flight department at Manchester's Ringway Airport and made its maiden flight from there on 9 June 1944. Main production was at Avro's Woodford, Cheshire and Chadderton, Lancashire factories. Additional aircraft were built by Armstrong Whitworth at Coventry. Production lines were also set up in Canada and Australia although with the end of the war production in Canada (at Victory Aircraft) was halted after one aircraft had been built. Production in Australia went ahead and Lincolns were subsequently manufactured there for the Royal Australian Air Force (RAAF).

One Lincoln B.Mk.XV pattern aircraft was also completed in Canada by Victory Aircraft with an order for six RCAF variants cancelled when hostilities ended. Along with two additional (Mk.I and Mk.II) aircraft on loan from the RAF, the type was briefly evaluated postwar by the RCAF.

The Lancaster V/Lincoln II differed mainly in that it was fitted with Merlin 68A engines.

Before the Lincoln was developed, the Australian government intended its Department of Aircraft Production (DAP), later known as the Government Aircraft Factory (GAF) would build the Lancaster Mk.III. Instead, a variant of the Lincoln I, renamed Mk.30 was built between 1946 and 1949, the largest aircraft ever built in Australia. Orders for 85 Mk.30 Lincolns were placed by the RAAF (which designated the type A-73), although only 73 were ever built.

The first five Australian examples (A73–1 to A73–5), were assembled from British-made components. A73-1 made its debut flight on 17 March 1946 and the first entirely Australian-built Lincoln, A73-6, was delivered in November 1946.

The Mk.30 initially featured four Merlin 85 engines, but was later equipped with a combination of two outboard Merlin 66s and two inboard Merlin 85s. The later Lincoln Mk.30A featured four Merlin 102s.

The RAAF heavily modified some Mk.30 aircraft for anti-submarine warfare during the 1950s, re-designating them GR.Mk.31. These examples had a 6 ft 6 in (1.98 m) longer nose to house acoustic submarine detection gear and its operators, larger fuel tanks to give 13 hours endurance, and a bomb bay modified to accept torpedoes. The Mk.31 was particularly difficult to land at night, as the bomber used a tailwheel and the long nose obstructed the pilot's view of the runway. 18 aircraft were remanufactured to this standard in 1952, gaining new serial numbers. Ten were subsequently upgraded to MR.Mk.31 standard, to include an updated radar. These Lincolns served with No. 10 Sqn RAAF at RAAF Townsville, until the discovery of corrosion in the wing spars forced the type's premature retirement in 1961.

The Avro Shackleton maritime patrol aircraft was derived from the Lincoln, as was the Tudor airliner, which used the wings of the Lincoln with a new pressurized fuselage.

Operational History [4]


Royal Air Force

The first RAF Lincolns joined No. 57 Squadron at East Kirby in 1945. No. 75 (New Zealand) Squadron RAF began re-equipping with Lincolns at RAF Spilsby during August 1945. However, 75 (NZ) Sqn received just three aircraft before VJ Day.

In the postwar Royal Air Force, the Lincoln equipped many bomber squadrons. Nearly 600 Lincolns were built to equip 29 RAF squadrons, mainly based in the United Kingdom. They were partially replaced by 88 Boeing Washingtons (B-29), on loan from the USAF, which had longer range and could reach targets inside the Iron Curtain. Small numbers remained in use with Nos 7, 83 and 97 Squadrons until the end of 1955 when they were replaced by the first of the V-bombers.

RAF Lincolns were used in combat during the 1950s, in Kenya against the Mau-Mau, operating from Eastleigh, and also served in Malaya during the Malayan Emergency, against insurgents aligned to the Malayan Communist Party. In Malaya, Lincolns operated from Changi and Tengah, More than 3,000 sorties were flown during their seven and a half year time in-theater, with half a million pounds of bombs dropped. This equated to 85% of the bomb tonnage dropped during the Malayan emergency.

On 12 March 1953, a RAF Lincoln (RF531 "C") of Central Gunnery School was shot down 20 mi (32 km) NE of Lüneburg, Germany by a Soviet MiG-15 as it flew to Berlin on a training flight, resulting in the deaths of the seven crew members.

In November 1955, four Lincolns of No. 7 Squadron RAF were detached for duties in British territories in the Middle East. In Bahrain, they carried out border patrols of the then Trucial States. When 7 Sqn was disbanded in December 1955, the four detached crews and aircraft became No. 1426 Flight RAF, officially a photographic reconnaissance unit. It was later sent to Aden, carrying out patrols in the lead up to the Aden Emergency.

As the RAF Lincolns became unserviceable due to wear and tear they were replaced by jet aircraft. The Lincolns of Bomber Command were phased out from the mid-1950s, and were completely replaced by jet bombers by 1963. The last Lincolns in RAF service were five operated by No. 151 Squadron, Signals Command, at RAF Watton, Norfolk, which were finally retired on 12 March 1963.

Royal Australian Air Force

From late 1946, Australian-built Lincolns were phased into No. 82 Wing RAAF at RAAF Amberley, replacing the Consolidated Liberators operated by 12, 21 and 23 Squadrons. In February 1948, these units were renumbered 1, 2 and 6 Squadrons respectively; a fourth RAAF Lincoln squadron, No. 10 was formed on 17 March 1949 at RAAF Townsville as a reconnaissance unit.

RAAF Lincolns took part in operations in Malaya in the 1950s, operating alongside RAF examples. The RAAF permanently based the B.Mk.30s of No.1 Squadron at Tengah for the duration of operations in Malaya.

The RAAF Lincolns were retired in 1961, with the MR.Mk.31's of No. 10 Squadron being the final variant to see service in Australia.

Argentine Air Force

The Lincoln served with the Fuerza Aerea Argentina from 1947: 30 aircraft were acquired (together with 15 Lancasters), giving Argentina the most powerful bombing force in South America. Eighteen of these were newly built, along with twelve ex-RAF aircraft.

The Lincolns entered service with I Grupo de Bombardeo of V Brigada Aérea in 1947. Eleven remained in use at the beginning of 1965, but most were retired during the next year. The last examples were retired in 1967.

The Argentine aircraft were used in bombing missions against rebels during the attempted military coup of September 1951 and by both the government and rebel forces during the 1955 Revolución Libertadora coup that deposed Juan Perón. Lincolns were also used to drop supplies in support of Argentine operations in the Antarctic. One of the bombers was returned to Avro in the United Kingdom in 1948 for modification to allow it to operate Antarctic support flights, including the addition of a Lancastrian nose and tail cone, removal of armament and additional fuel tanks. The aircraft was civilian registered and named Cruz del Sur; it undertook its first airdrop supply flight to the Antarctic San Martín Base in December 1951.

Use in Aero-engine Research

Lincolns were frequently employed as test-beds in new jet engine development. RF403, RE339/G and SX972 flew with a pair of Armstrong Siddeley Python turboprops outboard in place of the Merlins, and was used for the ballistic casing drop-test program for the Blue Danube atomic weapon. SX972 was further modified to fly with a pair of Bristol Proteus turboprops. RA716/G had a similarly placed pair of Bristol Theseus turboprops and later also flew with Rolls-Royce Avon turbojets replacing the pair of turboprops. Lincoln Test Bed RF533 kept its Merlins but had a Napier Naiad turboprop in the nose. It later flew, bearing the civilian "Class B" test registration G-37-1, with a similarly placed Rolls-Royce Tyne which it displayed at the 1956 Society of British Aircraft Constructors (SBAC) show, making a low level flypast on just the nose Tyne, the four Merlins being shut down and propellers feathered. SX973 had a Napier Nomad diesel turbo-compound installed in a similar nose-mounted installation. RA643 flew with a Bristol Phoebus turbojet in the bomb bay, and SX971 had an afterburning Rolls-Royce Derwent mounted ventrally.

Commercial Service

Two Lincoln IIs were operated by D. Napier & Son Ltd. for icing research from 1948 to 1962. A transport conversion of the Lincoln II, using the streamlined nose and tail cones of the Lancastrian and a ventral cargo pannier, was known as the Avro 695 Lincolnian.

One Lincoln Freighter converted by Airflight Ltd. was used on the Berlin Air Lift by Surrey Flying Services Ltd.

One Argentine example was converted to a Lincolnian by Avro at Langar. Four Lincolnian conversions by Field Aircraft Services for use as meat haulers in Paraguay were not delivered and subsequently scrapped.

Variants [4]


  • Avro Type 694: Prototypes to Air Ministry Specification 14/43, three-built.
  • Lincoln I: Long-range bomber version for the RAF. Powered by four 1,750 hp (1,305 kW) Rolls-Royce Merlin 85 inline piston engines.
  • Lincoln II: Long-range bomber version for the RAF. Powered by four Rolls-Royce Merlin 66, 68A and 300 inline piston engines. Built by Avro, Armstrong-Whitworth and Vickers-Metropolitan.
  • Lincoln III: The Lincoln III was intended to be a maritime reconnaissance, anti-submarine warfare aircraft. The aircraft later became the Avro Shackleton.
  • Lincoln IV: Lincoln II converted to Merlin 85 power.
  • Lincoln Mk.15 (B.Mk.XV): This designation was given to one aircraft, built by Victory Aircraft in Canada.
  • Lincoln Mk.30: Long-range bomber version for the RAAF.
  • Lincoln Mk.30A: Long-range bomber version for the RAAF, fitted with a longer nose and Merlin 102s.
  • Lincoln Mk.31: Anti-submarine/maritime reconnaissance version for the RAAF.
  • Avro 695 Lincolnian: Transport derivative similar to the Avro Lancastrian.
  • Lincoln ASR.3: Initial designation of the Avro Shackleton, which was based on the Lincoln.

Operators [4]


  • Argentina:
    • Argentine Air Force I Grupo de Bombardeo of V Brigada Aerea.
    • Fuerza Aerea de Tareas Antarticas (FATA)
  • Australia: Royal Australian Air Force - 54 Avro Lincolns were in service with the RAAF from 1946 to 1961.
    • No. 1 Squadron RAAF
    • No. 2 Squadron RAAF
    • No. 6 Squadron RAAF
    • No. 10 Squadron RAAF
    • No. 12 Squadron RAAF (redesignated No. 1 Squadron in 1948)
    • Heavy Bomber Crew Conversion Unit RAAF
    • Lincoln Conversion Flight RAAF
  • Canada: Royal Canadian Air Force Three Avro Lincolns were in service with the RCAF from 1946 to 1948.
  • United Kingdom: Royal Air Force
    • No. 7 Squadron RAF
    • No. 9 Squadron RAF
    • No. 12 Squadron RAF
    • No. 15 Squadron RAF
    • No. 35 Squadron RAF
    • No. 44 Squadron RAF
    • No. 49 Squadron RAF
    • No. 50 Squadron RAF
    • No. 57 Squadron RAF
    • No. 58 Squadron RAF
    • No. 61 Squadron RAF
    • No. 75 (New Zealand) Squadron RAF
    • No. 83 Squadron RAF
    • No. 90 Squadron RAF
    • No. 97 Squadron RAF
    • No. 100 Squadron RAF
    • No. 101 Squadron RAF
    • No. 115 Squadron RAF
    • No. 116 Squadron RAF
    • No. 138 Squadron RAF
    • No. 148 Squadron RAF
    • No. 149 Squadron RAF
    • No. 151 Squadron RAF
    • No. 192 Squadron RAF
    • No. 199 Squadron RAF
    • No. 207 Squadron RAF
    • No. 214 Squadron RAF
    • No. 230 Operational Conversion Unit RAF
    • No. 527 Squadron RAF
    • No. 617 Squadron RAF
    • No. 1426 Flight RAF
    • Bomber Command Bombing School (BCBS)
    • Flight Refuelling Ltd (FRL) - used some converted as tankers for flight refueling

Survivors [4]


Four aircraft have survived:

  1. Lincoln II B-004: On display as B-010 at the National Museum of Aeronautics, Buenos Aires, Argentina.
  2. Lincoln II B-016A: Gate guardian at the Villa Reynolds airbase, San Luis Province, Argentina
  3. Lincoln II RF342: In storage for future restoration at the Australian National Aviation Museum, Melbourne, Australia.
  4. Lincoln II RF398: On display at the Royal Air Force Museum Cosford, United Kingdom.

Avro Lincoln B.Mk.II Specifications [5]


Type:

  • Four-engine heavy-bomber

Wings

  • All-metal cantilever mid-wing monoplane.
  • Airfoil section NACA 23000 Series.
  • Wing built in five main sections; center section integral with fuselage and bearing inner engine nacelles and undercarriage attachments; two intermediate sections bearing outer nacelles; and two outer wings.
  • Trading-edge of intermediate sections built separately.
  • Detachable tips.
  • Two-spar structure.
  • Center-section spars of extruded square-section booms bolted to plate webs with vertical top-hat section stabilizers.
  • Outer spars have extruded spindled booms of U-section tapering to angle-section towards tips, and play plate webs.
  • Ribs of pressed diaphragm type, with heavy engine ribs and joint ribs of N-girder construction.
  • Light alloy top-hat section spanwise stringers in leading and trailing-edge sections and between spars of center-section over fuel tanks.
  • Stressed light alloy skin.
  • Mean aerodynamic dihedral 4 degrees.
  • Gross wing area 1,421 ft²
  • All-metal ailerons in two sections; metal covering.
  • Auto servo-tab and hand trim-tabs.
  • Hydraulically-operated split trailing-edge flaps in two sections between ailerons and fuselage with stiffening of light alloy castellated reinforcement.

Fuselage:

  • All-metal semi-monocoque structure built in five main sections bolted together; nose section, with front gun-turret; cabin section; center-section; aft section bearing dorsal turret; and tail-section bearing tail-unit rear turret.
  • Channel-section frames and continuous angle-section longitudinal stringers.
  • Stress skin of longitudinal light alloy panels.
  • Main bomb floor of two cast C-beams with two cast C-intercoastals to carry main bomb suspension, bounded by extruded members of flanged channel-section.

Tail Unit:

  • All-metal cantilever structure, standard Lancaster unit except for slight increase of rudder area.
  • Low-mounted two-spar tailplane carrying twin elliptical fins and rudders at extremities.
  • Sheet metal covering on all surfaces.
  • Inset trim-tabs in all movable surfaces; automatic balance-tabs in elevators.
  • Mass balances.
  • Tailplane span 33 ft 9 in.

Landing Gear:

  • Retractable two-wheel type.
  • Each main wheel carried between two Dowty shock-absorber legs attached to girder casting below front spar and retracting Backwards into inner nacelles.
  • Hydraulic operation, with emergency-lowering compressed-air system.
  • Track 23 ft 9 in.
  • Non-retractable tailwheel.

Power Plant:

  • Four 1,635-hp Rolls-Royce Merlin 85 or Packard-Merlin 68 twelve-cylinder Vee liquid-cooled engines mounted as power-eggs on welded steel-two bearers, and enclosed in cylindrical cowlings.
  • Rotol or de Havilland four-blade constant-speed full-feathering airscrews, 13 ft 0 in diameter.
  • Six main fuel tanks; one light alloy tank in each center-section and two Marston, flexible tanks in each intermediate wing panel.
  • Total fuel capacity 3,580 Imp. gallons.
  • Oil capacity 150 Imp. gallons.

Accommodation:

  • Crew of seven; front gunner/bomb-aimer; pilot; flight engineer/co-pilot; navigator; wireless-operator; dorsal gunner and rear gunner.
  • Pilot's seat on port with armored Back-plate.
  • Nose-window of welded steel-tube framework with toughened glass and Perspex panels.

Armament:

  • Twin 0.5 in. Browning machine-guns in Boulton Paul Type F nose-turret remotely-controlled from bomb-aimer's seat, with Mk.IIIM periscope sight.
  • Two 20 mm Hispano Mk.IV or Mk.V cannon in Bristol B-17 Mk.I dorsal turret.
  • Twin 0.5 in. Browning machine-guns in Boulton Paul Type D rear turret with radar sight.
  • Maximum bomb-load 22,000 lbs.

Equipment:

  • 24-volt electric system.
  • Full radar and radio gear.
  • Inflatable dinghy in tale of fuselage.
  • F-24 camera.

Dimensions:

  • Span: 120 ft.
  • Length: 78 ft. 3½ in.
  • Height (tail down, over rudders): 17 ft. 3½ in.
  • Will track: 23 ft. 9 in.
  • Tailplane span: 33 ft. 9 in.
  • Gross wing area 1,421 ft²

Weights and Loadings:

  • Weight empty (equipped): 44,188 lbs.
  • Weight loaded: 82,000 lbs.
  • Wing loading: 52.77 lbs/ft²
  • Power loading: 12.2 lbs/hp
  • Span loading: 5.7 lbs/ft²

Performance:

  • Maximum speed (18,300 ft): 310 mph
  • Stalling speed (flaps in undercarriage down): 75 mph
  • Maximum range (82,000 lbs., still air at 215 mph, at 20,000 feet): 4,000 miles
  • Range (260 mph with 14,000 lbs bomb-load): 3,250 miles
  • Range (260 mph with 22,000 lbs bomb-load): 1,150 miles

References


  1. Shupek, John. “Avro: Avro 694 Lincoln B.Mk.II”, The Skytamer Archive (3-view drawing by John Shupek copyright © 2013 Skytamer Images. ALL RIGHTS RESERVED)
  2. Topps Chewing Gum, “Wings”, Airplane Trade Cards, 1952, R707-4, USA
  3. Shupek, John. “Avro: Avro 694 Lincoln B.Mk.II”, The Skytamer Archive (Photos by John Shupek copyright © 2002 Skytamer Images. ALL RIGHTS RESERVED)
  4. Wikipedia, Avro Lincoln
  5. Bridgman, Leonard, “Avro: The Avro 694 Lincoln.” Jane's All The World's Aircraft 1948. Sampson Low, Marston & Company Limited, London, 1948. pp. 34c-35c

Copyright © 1998-2018 (Our 20th Year) Skytamer Images, Whittier, California
ALL RIGHTS RESERVED