Category Archives: Cargo

Cargo

Armstrong-Whitworth A.W.52 (A+V Models, Resin)

TYPE: Flying Wing, Fast Transport, Bomber Project

ACCOMMODATION: Crew of two (Pilot and navigator/flight test observer

POWER PLANT: Two Rolls-Royce Nene centrifugal-flow turbojets, rated at 2.240 kp thrust each

PERFORMANCE: 500 mph at sea level

COMMENT: The Armstrong Whitworth A.W.52 was a British flying wing aircraft design of the late 1940s for research into a proposed flying wing bomber and/or jet liner. Three aircraft, the A.W.52G glider and two turbojet-powered research aircraft, were built for the programme. The airliner was cancelled but research flying continued until 1954.
Armstrong-Witworth Aircraft proposed a turbojet-powered six or four-engine flying wing bomber/airliner design, using a laminar flow wing, during the Second World War. This had to be a large aircraft in order to provide bomb bay resp. passenger head-room within the wing. The low-speed characteristics of the design were tested on a 16.41 m span wooden glider known as the A.W. 52G; the glider was designed to be roughly half the size of the powered A.W.52, which in turn would be about half the size of the airliner. Construction of the AW.52G began in March 1943, with the glider making its maiden flight, towed by an Armstrong Whitworth Whitley bomber, on 2 March 1945. Flight testing, with tug releases from 20,000 ft giving flights of around 30 min continued, mostly satisfactorily until 1947. In 1944, Armstrong Whitworth received a contract that would allow them to produce two A.W.52 prototypes for evaluation, nominally asmail carrying aircraft.
The A.W.52 was intended for high speeds and was an all-metal turbojet-powered aircraft, with a retractable undercarriage; aerodynamically it had much in common with the glider. Both aircraft were moderately-swept flying wings with a centre section having a straight trailing edge. The wing tips carried small (not full chord) end-plate fin and rudders, which operated differentially, with a greater angle on the outer one. Roll and pitch were controlled with evelons that extended inward from the wing tips over most (in the case of the A.W.52 about three-quarters) of the outer, swept part of the trailing edge. The elevons moved together as elevators and differentially as ailerons. They were quite complicated surfaces – which included trim tabs – and hinged not from the wing but from “correctors”, which were wing-mounted; the correctors provided pitch trim. To delay tip stall, air was sucked out of a slot just in front of the elevons, by pumps powered by undercarriage-mounted fans on the glider and directly from the engine in the A.W.52. The inner centre section wing carried Fowler flaps and the upper surface of the outer section carried spoilers.
Maintenance of laminar flow over the wings was vital to the design and so they were built with great attention to surface flatness. Rather than the usual approach, where skinning is added to a structure defined by ribs, the A.W.52’s wings were built in two halves (upper and lower) from the outside in, starting from pre-formed surfaces, adding stringers and ribs then joining the two halves together. The result was a surface smooth to better than 2/1000 of an inch.
The crew sat in tandem in a nacelle so that the pilot was just forward of the wing leading edge, providing a better view than in the glider. The pressurised cockpit was slightly off-set to port. The engines were mounted in the wing centre section, close to the centre line and so not disturbing the upper wing surface.
The first prototype flew on 13 November 1947 powered by two Rolls-Royce Nene turbojet engines of 2.240 kp thrust each. This was followed by the second prototype on 1 September 1948 with the lower-powered  Rolls-Royce Dervent engines, rated at 1.580 kp each. Trials were disappointing: laminar flow could not be maintained, so maximum speeds, though respectable, were less than expected. As in any tail-less aircraft, take-off and landing runs were longer than for a conventional aircraft (at similar wing loadings) because at high angles of attack, downward elevon forces were much greater than those of elevators with their large moment.
The first prototype crashed without loss of life on 30 May 1949, making it the first occasion of an emergency ejection by a British pilot. Despite the termination of development, the second prototype remained flying with the Royal Aircraft Establishment until 1954 (Ref.: 27).

Bristol “Buckingham” B 1 (Valom)

TYPE: Medium bomber

ACCOMMODATION: Crew of two

POWER PLANT: Two Bristol “Centaurus” IX radial engines, rated at 2,520 hp each

PERFORMANCE: 336 mph at 12,000 ft

COMMENT : In early 1939 Bristol suggested a bomber variant of the “Beaufighter” with their Bristol “Hercules” engines. British policy at the time was an expectation for medium bombers to be provided from the US allowing British industry to concentrate on heavy bomber designs but a design was requested preferably based on an existing design which meant working with the Bristol “Beaufort” or “Beaufighter”.
Air Ministry specification B.7/40 called for a medium bomber to replace the Bristol “Blenheim”. The specification stipulated a speed of at least 300 mph at 5,000 ft, a normal load of 500 kg of bombs and a center turret armed with at least two 12.7 mm machine guns. Only Armstrong Whitworth Company tendered a full design but it did not meet with approval. So when Bristol brought their Type 162 (tentatively named “Beaumont”), which was fortunately well matched to B.7/40 specification, to the Air Staff, this led to a request to complete a mockup in 1940 and then a confirmed contract for three prototypes in February 1941. The “Beaumont” was based on the rear fuselage and tail of a “Beaufighter”, with a new center and front fuselage. The armament was a mid-upper turret with four machine guns, four more machine guns firing forward and two firing to the rear.
Construction began in late 1940, with a new Air Ministry Specification B.2/41 to be written around it. Changes in the requirements, removing dive bombing and ground attack support which incoming US bombers were expected to be capable of and increasing the performance to allow for the future, meant the “Beaumont” would no longer suffice. The changes in performance, requiring a bomb load of 4,000 lb, a speed of 360 mph and a range of 1,600 miles meant a redesign by Bristol to use the Bristol “Centaurus” engine.
The Bristol redesign with a larger wing and the more powerful engines was the Bristol ”Buckingham”. It had gun installations in the nose, dorsal and ventral turrets. Generally conventional in appearance, one unusual feature was that the bomb-aimer/navigator was housed in a mid-fuselage ventral gondola, resembling those on the earlier German Heinkel He 111H and American Boeing B-17C and -D in appearance. This was part of an attempt to give all the crew positions unobstructed views and access to each other’s positions. The bomb bay could hold up to 2,000 kg bombs. The rear of the gondola had a hydraulically powered turret with two Browning machine guns. The Bristol-designed dorsal turret carried four Brownings. A further four fixed, forward-firing Brownings were controlled by the pilot. Following more changes, specification B.2/41 was replaced by B.P/41. An order for 400, at an initial rate of 25 per month, was made with deliveries expected in March 1943. The first flight took place on 4 February 1943. During testing, the “Buckingham” exhibited poor stability which led to the enlargement of the twin fins, along with other modifications. The Bristol “Buckingham B1” was first flown 12 February 1944 with “Centarus” VI or XI engines, 400 ordered but reduced first to 300 then to 119, with only 54 built as bombers. Overtaken by events, it was mainly used primarily for transport and liaison duties (Ref.: 24).