Avro Manchester
The Avro Manchester was a British twin-engined heavy bomber aircraft developed and primarily manufactured by A.V. Roe & Company (Avro) during the early stages of the Second World War, in response to Air Ministry Specification P.13/36 issued in 1936 for a new generation of medium-to-heavy bombers capable of carrying a 4,000 lb bomb load over 3,000 miles.[1][2] Powered by two unreliable Rolls-Royce Vulture engines, it featured a crew of six to seven, defensive armament of eight 0.303-inch machine guns, and a maximum bomb load of 10,350 lb, but suffered from chronic engine failures and stability issues that limited its effectiveness.[1][3] Only 202 examples were built between 1939 and 1941, marking it as a transitional design that directly influenced the highly successful Avro Lancaster through shared structural elements and lessons learned from its shortcomings.[2][1][4] Development of the Manchester began in April 1937 when Avro received an initial contract for two prototypes, with the first (serial L7246) making its maiden flight on 25 July 1939 from Ringway Aerodrome, just months before the outbreak of war.[3][2] The aircraft's design incorporated a deep fuselage for bomb stowage, a distinctive triple-finned tail on early Mk I variants (later simplified to twin fins on the Mk IA for better stability), and a wingspan expanded from 82 ft 2 in to 90 ft 1 in during testing to address handling problems.[1][3] Production totaled 157 by Avro and 43 by Metropolitan-Vickers, but the Vulture engines—each rated at 1,760 hp—proved prone to fires and power loss, contributing to at least 33 confirmed losses and rendering the type unsuitable for sustained operations.[2][3][4] By late 1941, Avro shifted focus to redesigning the Manchester into the four-engined Lancaster prototype (BT308, originally a Manchester Mk III), which first flew on 9 January 1941 and became one of the RAF's most iconic bombers.[1][3] In operational service, the Manchester entered RAF Bomber Command with No. 207 Squadron at Waddington on 6 November 1940, achieving its combat debut on the night of 24/25 February 1941 during a raid on German warships at Brest, France.[2][3][5] It was employed by eight bomber squadrons for night raids over Europe, accumulating 1,269 sorties by June 1942, but high attrition—121 aircraft lost, representing over 60% of the fleet—included 77 on operations, 20 in accidents, and 24 in training, with engine failures directly blamed for many incidents.[3][1] A notable highlight was the posthumous Victoria Cross awarded to Flying Officer Leslie Thomas Manser of No. 50 Squadron for his heroism during a raid on Dortmund on 30 May 1942, where he deliberately crashed his burning Manchester into the sea to save his crew.[2] The type was withdrawn from front-line bombing by 25 June 1942, though some lingered in training roles and with RAF Coastal Command until the war's end; no complete examples survive today, though relics and restorations exist in museums.[2][1]Design and Development
Background and Specification
In response to the escalating demands for modern strategic bombing capabilities in the mid-1930s, the British Air Ministry issued Specification P.13/36 in September 1936, seeking a twin-engined medium bomber capable of achieving a top speed of 275 mph at 15,000 ft, a range of 3,000 miles while carrying 4,000 lb of bombs, with a maximum bomb load of 8,000 lb to succeed existing medium bombers and support long-range operations.[6][2] Avro responded with its Type 679 proposal later that year, a monoplane design optimized for the specification's performance goals, which was selected alongside the rival Handley Page HP.56 as one of the leading contenders; the Fairey Night Bomber was also considered initially but did not progress to prototype stage.[2][7] The Air Ministry awarded Avro a contract for two prototypes in April 1937, valuing the Type 679's straightforward construction that facilitated potential mass production through modular assembly techniques suitable for wartime expansion.[2][8][3] Key initial design choices centered on powerplant selection to meet the speed requirements, with Avro opting for the advanced Rolls-Royce Vulture 24-cylinder X-block engines, each promising 1,760 hp output to enable the targeted 275 mph performance while maintaining the twin-engined configuration mandated by P.13/36.[4][2] This choice reflected confidence in the Vulture's innovative design, derived from coupling two Rolls-Royce Peregrine units, though it prioritized power density over proven reliability at the prototype stage. The Manchester's selection over alternatives like the HP.56 stemmed from its alignment with rapid manufacturability goals, leveraging Avro's experience in efficient production lines to support the RAF's rearmament needs.[2][9] The Manchester's foundational design later proved adaptable, forming the basis for the highly successful four-engined Avro Lancaster bomber.[2]Prototype Development
The first prototype of the Avro Manchester, serial L7246, was constructed at Avro's Chadderton factory and completed in mid-1939 before being transferred to the experimental department at Manchester's Ringway Airport for final assembly.[10][4] It made its maiden flight on 25 July 1939 from Ringway, piloted by Avro's chief test pilot Captain H. A. Brown, in a brief 17-minute circuit that confirmed basic handling characteristics but highlighted areas for refinement.[11] Initial flight tests in late 1939 revealed significant stability issues, particularly poor directional control due to the original twin-finned tailplane design with inset vertical surfaces. To address this, Avro engineers added a third central fin and rudder to the rear fuselage by the end of 1939, improving yaw stability during subsequent evaluations at the Aeroplane and Armament Experimental Establishment (A&AEE) at Boscombe Down.[11][1] The second prototype, L7247, incorporated the revised tail configuration with the additional central fin from the outset and underwent construction at Ringway, achieving its first flight on 26 May 1940. This aircraft focused on armament integration trials, featuring Frazer-Nash hydraulic turrets in the nose, dorsal, and ventral positions armed with .303 Browning machine guns, which were tested for defensive capability during early sorties.[11][4] Parallel to airframe testing, the Rolls-Royce Vulture engines powering the prototypes encountered persistent development challenges from 1939 through 1940, including overheating in the complex X-24 cylinder arrangement and inconsistent power output below the targeted 1,760 horsepower, which compromised climb performance and reliability during ground runs and flight evaluations.[12][13] Despite these issues, following successful prototype evaluations, an initial production order for 200 aircraft was placed in September 1939.[11]Design Features
The Avro Manchester featured an all-metal monoplane construction, utilizing a high-aspect-ratio elliptical wing design with a span of 90 ft 1 in (27.46 m) to optimize lift and efficiency for its role as a heavy bomber.[1] The wings employed a two-spar aluminum alloy structure with self-sealing fuel tanks integrated within, contributing to the aircraft's overall robustness and protection against battle damage.[14] The fuselage was notably deep, providing space for a long, unobstructed internal bomb bay that could accommodate a maximum load of 10,350 lb (4,695 kg) of ordnance, including various bomb configurations or even two 18-inch torpedoes, while maintaining a smooth external profile through flush-riveted aluminum alloy skinning supported by longitudinal stringers.[14][4] This design emphasized ease of manufacture and repair, with the bomb bay doors operated hydraulically and equipped with safety interlocks to prevent accidental opening.[14] The powerplant comprised two Rolls-Royce Vulture 24-cylinder X-block engines, specifically the Mk II or XX variants, each delivering 1,760 hp for takeoff and driving de Havilland three-bladed variable-pitch Hydromatic propellers.[15][14] The Vulture engines were chosen for their compact size and high power density, derived from coupling two Rolls-Royce Peregrine V-12 units, though they proved problematic in service due to reliability issues.[12] The aircraft's retractable tricycle landing gear further supported its heavy load-carrying capability, with the main units housed in the deep fuselage to minimize drag. Defensive armament consisted of three hydraulically powered turrets: a nose turret mounting two .303 in (7.7 mm) Browning machine guns, a dorsal turret with four .303 in Brownings, and a tail turret with two .303 in Brownings, providing all-around coverage against interceptors.[1] The crew of seven included the pilot, co-pilot (often doubling as fighting controller), navigator, bombardier, and four dedicated gunners, with positions distributed to manage flight, bombing, and defense operations effectively.[1][16] Performance targets for the Manchester included a maximum speed of 282 mph (454 km/h) at 19,200 ft (5,852 m) and a service ceiling of 19,200 ft, reflecting the ambitious specifications for a twin-engined heavy bomber, though engine limitations resulted in actual figures closer to 265 mph at 17,000 ft and a ceiling of around 19,500 ft.[15][4]Production and Variants
Orders and Production
Following the successful evaluation of the prototypes, the Air Ministry placed a production contract with A.V. Roe and Company Limited (Avro) in 1937 for 200 Manchester aircraft under Specification P.13/36, with construction to commence at the company's Chadderton facility near Manchester.[9] The first production Manchester Mk I, serial L7276, was completed and delivered to RAF Boscombe Down for acceptance trials on 5 August 1940, with initial operational deliveries to squadrons beginning in November 1940.[9] In total, 209 Manchester aircraft were built, including the two prototypes (177 by Avro and 30 by Metropolitan-Vickers), with the majority assembled at Avro's Chadderton and Newton Heath factories in Greater Manchester.[9] Production reached a peak of approximately 32 aircraft per month by mid-1941, but output was severely limited by persistent shortages of Rolls-Royce Vulture engines and ongoing quality control problems with the powerplants, which frequently failed during testing and early service.[1] To enhance wartime manufacturing efficiency and mitigate risks from potential bombing, Avro adapted its processes by subcontracting component production and partial assembly to Metropolitan-Vickers at their Mosley Road works in Manchester, as well as utilizing dispersed shadow factories allocated by the Ministry of Aircraft Production; of a 100-aircraft order placed with Metropolitan-Vickers in 1939, 30 were completed as Manchesters before the line shifted.[9] Additional contracts for up to 400 more aircraft were awarded to firms including Armstrong Whitworth and Fairey Aviation, but these shadow factory allocations emphasized modular construction techniques to accelerate output amid labor and material constraints. By late 1941, escalating engine reliability issues and disappointing operational performance led to the cancellation of all outstanding Manchester orders after 207 production examples had been built, with uncompleted airframes and resources redirected toward the more promising four-engined Avro Lancaster derivative.[9] This decision effectively ended Manchester production in November 1941, averting a larger commitment of over 700 aircraft that had been initially envisaged.[9]Variant Descriptions
The Manchester Mk I served as the initial production version of the twin-engined heavy bomber, powered by two Rolls-Royce Vulture Mk II engines and featuring early tail turrets for defensive armament.[4] A total of 20 aircraft of this mark were constructed, representing the baseline configuration before subsequent refinements.[9] The Manchester Mk IA represented an improved iteration introduced from April 1941, incorporating Rolls-Royce Vulture Mk XX engines for enhanced reliability, bulged bomb doors to accommodate larger ordnance such as the 4,000 lb bomb, and revised radio equipment for better crew communication.[17] This variant addressed some handling issues of the Mk I through modifications to the tail assembly, including larger fins, and upgraded the rear turret to a four-gun Frazer-Nash model; 187 were built.[2] Several minor variants were proposed but not pursued to production. The Mk IB was envisioned with Bristol Hercules radial engines to mitigate Vulture unreliability, though none were constructed.[9] Similarly, the Mk IC emerged as a proposal for a dedicated night fighter adaptation, while the Mk II was an advanced design with twin Bristol Centaurus engines; this and the four-engined Mk III ultimately informed the Lancaster's development rather than entering service as Manchesters.[18] In addition to standard marks, one Manchester aircraft (BT308) underwent special conversion in 1941 to serve as the prototype for the four-engined Type 683 Lancaster, involving the addition of two outboard Rolls-Royce Merlin engines, an extended wingspan, and revised tail configuration to validate the airframe's potential for heavier payloads and improved performance. These adaptations confirmed the viability of evolving the Manchester design into a more successful platform.[1]Operational History
Service Entry and Early Operations
The Avro Manchester entered service with No. 207 Squadron of RAF Bomber Command at RAF Waddington in November 1940, when the first production aircraft, serial number L7279, was delivered from the manufacturer following trials at Boscombe Down.[5] Conversion training for the squadron's crews began shortly thereafter, revealing some handling quirks such as sensitivity to crosswinds and the need for precise trim adjustments due to the central fin configuration, though the aircraft's bombing accuracy and load-carrying capacity proved adequate during practice sorties.[19] The Manchester's operational debut occurred during a night raid on the German naval base at Brest on 24–25 February 1941, with six aircraft from No. 207 Squadron participating in the attack on docked warships including the battleships Scharnhorst and Gneisenau.[4] Early operations through 1941 emphasized night bombing missions against strategic targets such as ports, industrial factories, and urban centers in occupied France and Germany, with the type contributing to raids on Brest and other naval facilities housing surface raiders. A significant early mission took place on 24 July 1941, when Manchesters from No. 207 Squadron joined attacks on the Gneisenau at Brest as part of Operation Sunrise, employing 1,000 lb bombs to target the battleship during its repair period.[20] By mid-1942, approximately 1,200 sorties had been flown by the 193 operational Manchesters, primarily in night operations that delivered over 1,600 tons of bombs on enemy infrastructure.[17] The aircraft participated in night raids on Berlin, including the significant operation on 7 November 1941, forming part of a force of over 160 bombers dispatched to strike the German capital in retaliation for Luftwaffe attacks on British cities. Initial loss rates in these early operations averaged around 10 percent, mainly due to anti-aircraft flak and encounters with night fighters, with 78 aircraft ultimately lost in combat over the type's service life.[2]Engine Issues and Groundings
The Rolls-Royce Vulture engines powering the Avro Manchester were plagued by reliability issues stemming from their complex X-24 configuration, including frequent overheating, big-end bearing failures, and in-flight fires that compromised operational safety. These flaws arose primarily from inadequate cooling in the densely packed cylinder arrangement and weaknesses in the connecting rod design, resulting in an average time between major overhauls or failures of approximately 76 flying hours during early service.[12] The severity of these problems became evident shortly after the Manchester entered squadron service, culminating in the first fleet-wide grounding on 13 April 1941, when all operational aircraft were stood down following a series of engine fires traced to bearing seizures during flights. This incident affected the 40 Manchesters then in service, prompting intensive inspections, partial engine redesigns to address lubrication and cooling deficiencies, and temporary restrictions on engine power output to 1,760 horsepower. Operations resumed on 25 April 1941 after these interim fixes, but the underlying vulnerabilities persisted.[21] A second grounding occurred on 16 June 1941, triggered by multiple crashes linked to propeller malfunctions exacerbated by engine torque irregularities and vibration issues, further highlighting the Vulture's instability under load. In response, Rolls-Royce implemented additional modifications, such as reinforced crankshaft components and enhanced oil systems, while Avro introduced the Manchester Mk IA variant starting in late 1941, featuring strengthened engine mountings, fireproof bulkheads between the engines and fuselage to contain potential fires, and revised cooling intakes to mitigate overheating. Despite these efforts, engine-related unreliability continued to hamper the type, with Vulture failures contributing to around 30 non-combat losses out of approximately 123 total aircraft attrition, accounting for roughly 20% of all Manchester write-offs.[21][1][4] The recurrent engine crises severely delayed the formation and effectiveness of Manchester-equipped squadrons, often leaving units with serviceability rates below 50% and forcing reliance on alternative bombers for missions. Detailed post-incident analyses by the Royal Air Force, including accident investigation reports from 1941, identified common failure modes such as crankshaft fractures and coolant cavitation, which underscored the Vulture's developmental shortcomings and accelerated the program's abandonment in favor of four-engined designs.[4][2]Withdrawal and Legacy
The Avro Manchester was withdrawn from frontline operational service with RAF Bomber Command following its final sorties on the night of 25/26 June 1942, targeting Bremen as part of the third 1,000-bomber raid.[22] By early July 1942, all Manchester-equipped squadrons had transitioned to more reliable four-engined heavy bombers, primarily the Avro Lancaster, though some received Handley Page Halifaxes or Short Stirlings.[23] The remaining airframes were repurposed for training roles within conversion units and heavy conversion units, continuing in this capacity until mid-1943 when they were fully phased out due to ongoing maintenance challenges. After withdrawal from bombing, some Manchesters were transferred to RAF Coastal Command for maritime reconnaissance and anti-submarine duties, serving in this role until 1945.[22][1] Over its brief combat career, 193 operational Manchesters completed 1,269 sorties, dropping approximately 1,826 tons of bombs on German targets.[22] The type suffered heavy losses, with 78 aircraft destroyed in combat and 45 more lost in non-operational incidents, including 30 attributed to engine failure.[22] These figures underscored the Manchester's vulnerability, exacerbated by the Rolls-Royce Vulture engines' chronic unreliability—such as propensity for fires and power loss—which contrasted sharply with the superior performance of emerging alternatives like the Lancaster, hastening the decision to retire the type from bombing operations.[4] Despite its operational shortcomings, the Manchester served as the direct precursor to the highly successful Avro Lancaster, with key design elements including the large, unobstructed bomb bay and elliptical wing planform carried over almost unchanged to the new four-engined bomber.[24] The experience with the Vulture's failures also reinforced lessons in engine selection and reliability testing, influencing subsequent RAF procurement policies to prioritize proven powerplants like the Rolls-Royce Merlin.[21] Post-war, no complete Manchester airframes survived; the handful of stored examples were scrapped during the 1940s and 1950s, with the last known remains recovered from a flooded quarry and dismantled by a U.S. military unit in the mid-1950s.[25] The aircraft's historical significance endures as a critical stepping stone in the evolution of RAF Bomber Command's night offensive strategy, bridging early heavy bomber efforts to the Lancaster's pivotal role in the Allied strategic bombing campaign.[22]Operators and Specifications
Military Operators
The Avro Manchester was primarily operated by the Royal Air Force (RAF) Bomber Command during its short service life from 1941 to 1942. The first squadron to equip with the type was No. 207 Squadron, which began receiving aircraft at RAF Waddington in November 1940 and used them for operational bombing missions.[2] Subsequent squadrons included Nos. 97, 83, 106, 49, 50, 61, 57, 44, and 144, with the latter operating only a single flight of Manchesters; these units were based at various airfields such as Coningsby, Scampton, Skellingthorpe, and Oakington, primarily for night bombing roles until transitioning to the Avro Lancaster due to the Manchester's engine reliability issues. No. 207 Squadron later formed part of the Pathfinder Force, though by then it had converted to Lancasters.[26] Although no Royal Canadian Air Force (RCAF) squadrons were formally equipped with the Manchester on strength, Canadian aircrew served extensively in RAF Bomber Command units operating the type, contributing to its sorties as part of the integrated Allied effort.[23] In addition to operational squadrons, the Manchester was employed by training units for heavy bomber crew conversion. No. 1654 Heavy Conversion Unit (HCU), initially at RAF Waddington and later relocating to RAF Wigsley, utilized Manchesters from July 1942 until their phased withdrawal around 1943 in favor of more reliable four-engined types.[27] No. 9 Squadron also employed the aircraft briefly for training purposes only. A small number of Manchesters were also operated by RAF Coastal Command for training and anti-submarine duties until the end of the war.[1] The Manchester saw no combat use by foreign operators, though limited evaluation flights were conducted by other Allied forces to assess its design potential before production ceased.[1]Technical Specifications (Manchester Mk I)
The Avro Manchester Mk I was a twin-engine heavy bomber with specifications reflecting its design for medium-range operations in the early stages of World War II.General characteristics
- Crew: 7[4]
- Length: 68 ft 10 in (20.98 m)[9]
- Wingspan: 90 ft 1 in (27.46 m)[4]
- Height: 19 ft 6 in (5.94 m)[9]
- Wing area: 1,131 sq ft (105.1 m²)[9]
- Empty weight: 29,430 lb (13,350 kg)[28]
- Max takeoff weight: 50,000 lb (22,680 kg)[4]
Powerplant
- Engines: 2 × Rolls-Royce Vulture 24-cylinder X-24, liquid-cooled piston engines, 1,760 hp (1,310 kW) each at 3,000 rpm[4]
Performance
- Maximum speed: 265 mph (426 km/h, 230 kn) at 17,000 ft (5,180 m)[28]
- Cruise speed: 185 mph (298 km/h, 161 kn) at 15,000 ft (4,570 m)[28]
- Range: 1,200 mi (1,930 km, 1,040 nmi) with 10,350 lb (4,699 kg) bomb load[28]
- Service ceiling: 19,200 ft (5,856 m)[28]
- Rate of climb: 640 ft/min (3.3 m/s)[29]