Armstrong Whitworth A.W.52

Armstrong Whitworth Aircraft

Industry	Aerospace
Founded	1912
Headquarters	Coventry , United Kingdom

Template:Infobox aircraft

The Armstrong Whitworth A.W.52 was a pioneering British flying wing aircraft developed and manufactured by Armstrong Whitworth Aircraft.

Originating from wartime investigations into the laminar flow airfoil, research suggested that pairing this with a flying wing design could significantly enhance aerodynamic efficiency compared to conventional aircraft. The project aimed to collect data and gain operational insight into the flying wing concept, supporting Armstrong Whitworth’s goal of creating a jet-powered flying wing airliner. Construction began in the late 1940s, resulting in three aircraft built for experimentation: one A.W.52G glider and two jet-driven prototypes.

The A.W.52 took to the skies for its inaugural flight on 13 November 1947. On 30 May 1949, during testing, the first prototype experienced intense pitch oscillations, prompting test pilot John Oliver Lancaster to eject—marking the first emergency ejection by a British aviator. Despite the pilot’s ejection, the aircraft stabilized and landed with minimal damage. Following this event, Armstrong Whitworth chose to discontinue further development, doubting the feasibility of the flying wing concept and the envisioned airliner it was meant to demonstrate. Nonetheless, the second prototype continued test flights under the Royal Aircraft Establishment until 1954.

Background

The concept of flying wing aircraft dates back to before the First World War, notably through the work of J. W. Dunne, which influenced designers like G. T. R. Hill to create experimental models such as the Westland-Hill Pterodactyl during the 1920s and early 1930s. Despite these early efforts, inherent challenges with the design led most projects to remain experimental without progressing further. In the mid-1940s, Armstrong Whitworth renewed interest by exploring how combining flying wing architecture with recent advances—the laminar flow airfoil and the turbojet engine—could yield performance improvements.

During the Second World War, John Lloyd of Armstrong Whitworth was commissioned by the Ministry of Supply to develop a full-scale wing for laminar flow drag measurements in a wind tunnel at the National Physical Laboratory. This led to practical trials involving a modified Hawker Hurricane fitted with an Armstrong Whitworth laminar flow wing, which demonstrated measurable performance benefits that diminished as surface contamination disrupted airflow. Lloyd calculated that employing a clean tailless design combined with a laminar flow wing could reduce aerodynamic drag to approximately one-third that of conventional aircraft, prompting him to design an airliner incorporating these features.

By 1943, an initial concept for this proposed jet-powered airliner had been formulated. It featured either four or six engines embedded within the wing structure to maintain smooth external surfaces and reduce drag. The design called for a considerably large wingspan—at least 160 ft—to provide adequate cabin space for passengers. The absence of a traditional fuselage and tail assembly allowed for a lighter overall structure despite its size. Comprehensive testing was required before proceeding further, including flight trials with scale models; this preliminary design was labelled as the A.W.50.

A.W.52G

To evaluate the low-speed flight behavior of the design, a wooden glider with a wingspan of 53 ft 10 in (16.41 m), called the A.W.52G, was developed. This glider measured approximately half the size of the powered A.W.52, which itself was about half the size of the intended airliner. It was understood that constructing a glider would be faster than building a powered version and would yield crucial aerodynamic insights to improve the subsequent powered aircraft, especially concerning control and stability. The A.W.52G primarily featured wooden construction and consisted of three main components: a central section housing a nacelle for two pilots, flanked by two outer wing panels. Control was managed through two wing-tip elevons, which combined the roles of conventional elevons and ailerons; additionally, a pair of Fowler flaps were fitted along the trailing edge.

Construction began in March 1943, with the decision to equip the glider with two anti-spin parachutes mounted at the wing tips to assist recovery should severe handling problems arise. Nearly two years later, on 2 March 1945, the glider completed its inaugural flight, being towed aloft by an Armstrong Whitworth Whitley bomber. Released from approximately 20,000 ft (6,100 m), it achieved flight durations near 30 minutes. Testing continued with generally positive outcomes until 1947. Afterward, it was exhibited statically outside Armstrong Whitworth's Baginton plant before being dismantled in the late 1950s.

Although the glider delivered important information regarding low-speed aerodynamics, it lacked the capability to reach high speeds necessary for comprehensive data gathering. To obtain this data, powered aircraft production was essential. By late 1944, the Ministry of Supply showed sufficient interest in Armstrong Whitworth's designs to award a contract for two A.W.52 prototypes intended for evaluation; these were nominally designated as mail carriers.

A.W.52

Designed for high-speed experimentation, the A.W.52 was an all-metal turbojet-powered aircraft featuring retractable landing gear. Its aerodynamic layout shared many traits with the glider, both being moderately swept flying wings with a central section characterized by a straight trailing edge. Small end-plate fins and rudders were positioned at the wing tips (not extending full chord), operating differentially with greater deflection on the outer rudder. Elevons controlled roll and pitch; they extended inward from the wing tips along roughly three-quarters of the swept trailing edge on the A.W.52. These elevons functioned collectively as elevators and differentially as ailerons. The control surfaces were complex—including trim tabs—and hinged not directly on the wing but on "correctors" mounted on it; these correctors provided pitch trim adjustments. To prevent tip stall, air was extracted from a slot just ahead of the elevons by pumps: undercarriage-driven fans on the glider and engine-driven pumps on the A.W.52. The inner center wing section incorporated Fowler flaps while spoilers were installed on the upper surface of the outer wing sections.

Model of the A.W.52 displayed at the Midland Air Museum, Coventry

Preserving laminar flow across the wings was critical to performance; thus, manufacturing emphasized extreme surface smoothness. Instead of adding skin over a rib-defined frame (the usual method), each wing half (upper and lower) was constructed from pre-shaped surfaces outward-inward—adding stringers and ribs before joining them—resulting in surface smoothness better than 0.002 inches (50 μm). The crew sat in tandem within a nacelle positioned so that the pilot was just ahead of the wing’s leading edge, offering superior visibility compared to the glider’s cockpit. This pressurized cockpit was located near the aircraft’s centerline but slightly offset to port. Engines were embedded within the wing’s center section close to its midline to avoid disturbing upper wing surfaces. To reduce tip stall risk, a boundary layer control system powered by engine compressors was integrated.

The first prototype took flight on 13 November 1947, powered by two Rolls-Royce Nene engines each delivering up to 5,000 lbf (22 kN) thrust. The second prototype followed nearly a year later on 1 September 1948, equipped instead with two less powerful Rolls-Royce Derwent engines rated at 3,500 lbf (16 kN) each. Testing results from both prototypes were largely unsatisfactory: laminar flow could not be sustained as anticipated, limiting maximum speeds despite respectable performance. It was ultimately determined that maintaining laminar flow on a flying wing design was unfeasible as hoped. Like other tailless aircraft, takeoff and landing distances were longer than comparable conventional designs due to greater downward forces generated by elevons at high angles of attack compared to traditional elevators.

Incident and project cessation

On 30 May 1949, during a dive at approximately 320 mph (510 km/h) in the initial prototype, test pilot John Oliver Lancaster experienced a pitch oscillation suspected to originate from elevon flutter. Beginning at around two cycles per second, the oscillation quickly escalated to a level that rendered control impossible. With the risk of structural failure imminent, Lancaster made the decision to eject using the aircraft’s Martin-Baker Pre-Mk.1 ejection seat, becoming the first British aviator to employ this system during an actual emergency. It was fortunate that Lancaster was alone in the cockpit, as the second crew member did not have access to an ejection seat.

After Lancaster ejected, the oscillations ceased, and the aircraft proceeded to glide down, landing with minimal damage in an open field north of Southam in Warwickshire. In light of this event and the underwhelming progress achieved up to that point, Armstrong Whitworth's leadership resolved to discontinue further development of the flying wing design. Instead, they redirected their focus and resources toward the Armstrong Whitworth Apollo, a turboprop passenger aircraft featuring a more traditional layout.

Following Armstrong Whitworth's exit from the project, the second A.W.52 was transferred to the Royal Aircraft Establishment and relocated to RAE Farnborough, where it served as a platform for experimental flights over several years. The aircraft was ultimately dismantled in June 1954.

Operators

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• Royal Aircraft Establishment

Specifications (TS 363, Nene powered)

Armstrong Whitworth AW-52 three-view illustration from Les Ailes, 18 January 1947

See also

Bibliography

• Buttler, Tony and Jean-Louis Delezenne. X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974. Manchester, UK: Hikoki Publications, 2015. ISBN 978-1-902-10921-3
• Mettam, H.A. (26 March 1970), "The Pterodactyl Story", Flight International, 97 (3185): 514–518
• Pelletier, Alain J. "Towards the Ideal Aircraft: The Life and Times of the Flying Wing, Part Two". Air Enthusiast, No. 65, September–October 1996, pp. 8–19. Template:ISSN.
• Sturtivant, R. (1990). British Research and Development Aircraft. G.T. Foulis. p. 45. ISBN 0854296972.
• Tapper, Oliver (1988). Armstrong Whitworth Aircraft since 1913. London: Putnam. ISBN 0-85177-826-7.
• Williams, Roy (December 1981 – March 1982). "Armstrong Whitworth's Flying Wings... A Tale of No Tails". Air Enthusiast. No. 17. pp. 1–12. ISSN 0143-5450.

External links

• "On the Wing" Flight 15 January 1948
• "The Airborne Wing" Flight 25 December 1947
• Jets 45 Histories
• British Flying Wings at century-of-flight.net
• Video on Youtube