Armstrong Whitworth A.W.15
| Company type | Company |
|---|---|
| Industry | Aerospace, Aircraft manufacturing |
| Founder | Sir W.G. Armstrong Whitworth |
| Headquarters | Coventry , United Kingdom |
Area served | United Kingdom, British Empire (Africa, India) |
Key people | John Lloyd (designer) |
| Products | Aircraft including Armstrong Whitworth AW.15 Atalanta |
The Armstrong Whitworth AW.15 Atalanta was a British four-engine airliner constructed by Sir W.G. Armstrong Whitworth Aircraft Limited at their facility in Coventry.
This aircraft was purpose-built to meet the requirements set by the British carrier Imperial Airways, which sought a new four-engine plane tailored for its African service routes. The design embraced a monoplane layout primarily because of its reduced drag, resulting in a configuration that significantly differed from the earlier Armstrong Whitworth Argosy airliner. After evaluating Armstrong Whitworth’s design, Imperial Airways committed to placing an order even before the prototype was completed or flown.
The prototype, registered G-ABPI, took to the skies for the first time on 6 June 1932 and was christened Atalanta, a name subsequently used for the entire series. Testing revealed only minor issues, which were swiftly addressed, allowing the aircraft to obtain its certificate of airworthiness within three months. The type entered commercial service on 26 September 1932 with Imperial Airways operating flights from Croydon to Brussels and Cologne. Primarily deployed on Imperial Airways’ Eastern routes as intended, the Atalanta remained in service for five years before being replaced; subsequently, various civil and military operators continued flying the model until its retirement during the Second World War.
Background
The inception of the AW.15 Atalanta largely stemmed from a specification issued by British airline Imperial Airways in 1930, which called for a four-engine airliner to operate on its African routes, particularly between Kisumu in Kenya and Cape Town, South Africa. Aviation historian Oliver Tapper notes that Imperial Airways recognised the necessity of using four engines—rather than three, as on the existing Armstrong Whitworth Argosy—to reduce the risk of forced landings caused by an engine failure during flight. Additional criteria included a minimum passenger capacity of nine, accommodation for a crew of three, freight and mail payload capability over distances up to 400 miles (640 km), and a cruising speed of approximately 115 mph (185 km/h) at an altitude of around 9,000 feet (2,740 m).
At Sir W.G. Armstrong Whitworth Aircraft Limited, designer John Lloyd analysed this brief and concluded that adopting a monoplane design would best satisfy these demands due to its superior aerodynamic efficiency compared to a biplane configuration. This concept marked a significant shift from the Argosy’s design, featuring engines mounted on the wings and a more streamlined fuselage shape. Internal assessments, including extensive wind tunnel testing, predicted that this new airliner would produce just 340 lb of parasitic drag—less than half that generated by the Argosy.
Into flight
Imperial Airways was sufficiently impressed by the design to place an order for production directly from the plans, bypassing the usual prototype evaluation stage. On 6 June 1932, the prototype, registered as G-ABPI, took to the skies for its inaugural flight under the command of pilot Alan Campbell-Orde. The aircraft was given the name Atalanta, a designation that later extended to the entire series. Its first public unveiling occurred on 27 June 1932 at the Society of British Aerospace Companies (SBAC) exhibition held at Hendon Aerodrome, where it received positive attention.
Following this, on 11 July 1932, the prototype was sent to RAF Martlesham Heath for formal testing and secured its certificate of airworthiness in August. Flight evaluations revealed the aircraft had minimal deficiencies; any initial issues were rapidly resolved. Pilots commented favorably on its handling characteristics and ease of control. However, engine-induced vibrations occasionally caused fuel tank ruptures and failures in bracing wires. To remedy this, rubber mounts were installed for oil tanks and steel tubing replaced the wires. A minor but noted drawback was occasional rudder over-correction and oscillation, which Armstrong Whitworth addressed by fitting what it claimed to be the world’s first spring tab servo device.
The aircraft was subsequently flown to Croydon Airport for acceptance trials with Imperial Airways, who reportedly expressed complete satisfaction with its performance. The Atalanta commenced commercial operations on 26 September 1932, servicing routes from Croydon to Brussels and Cologne. On 20 October 1932, during a test flight, the prototype sustained damage caused by fuel starvation linked to a faulty experimental vent on the fuel tank. Following this incident, Armstrong Whitworth reportedly sought to obscure the event by renaming the third production model (G-ABTI, Arethusa) as Atalanta.
Two further variants were proposed: the AW.25, powered by Armstrong Siddeley Jaguar engines, and the AW.26, equipped with Armstrong Siddeley Panther engines; however, neither design progressed beyond initial planning stages. According to Tapper, these variants failed to attract orders primarily due to unfortunate timing and the rapid introduction of larger aircraft from competitors.
Design
The Armstrong Whitworth Atalanta was a streamlined monoplane airliner with a high-wing configuration. Its fuselage had a square cross-section with smooth, rounded corners designed to minimize aerodynamic resistance. The aircraft's structure combined steel, plywood, and fabric materials. The fixed undercarriage was partially recessed into the fuselage and enclosed by aerodynamic fairings to reduce drag. Passengers enjoyed a cabin environment that was notably quiet and cool, furnished with comfortable, adjustable seating. For its time, the Atalanta's design was considered quite advanced; according to Century of Flight, it helped narrow the performance disparity between British and American airliners.
Propulsion came from four supercharged Armstrong Siddeley Serval III radial engines, each a ten-cylinder powerplant delivering up to 340 hp (250 kW). These engines were relatively new developments, essentially formed by combining two Armstrong Siddeley Mongoose units. Mounted on the wing's leading edge, the engines were faired smoothly into the wing contour to enhance aerodynamic efficiency. They were supported by a tubular frame attached to the wing’s forward spar and separated from the fuselage by a fire-resistant bulkhead to guard against engine fires. The aircraft housed two fuel tanks within the leading edge of the wing—one positioned between each engine pair—arranged to allow gravity-fed fuel delivery.
The Atalanta’s fuselage consisted of three distinct sections. Its construction incorporated innovative techniques for Armstrong Whitworth, such as using steel strips for the longerons and connecting struts. The cabin area was sheathed in plywood over lightweight stringers, while the rear fuselage was predominantly fabric-covered except for aluminium panels reinforcing the corners. The cantilever wings featured moderate tapering and were built in three parts around dual spars made from steel girders. Steel ribs supported the central wing section, whereas wooden ribs reinforced the outer panels, which were covered with plywood extending to the rear spar.
Inside, the Atalanta introduced several innovative elements. The cockpit, staffed by two pilots and a radio operator, was notably spacious; directly aft of this was a compartment designed to carry up to one tonne of air mail. Behind that space were a luggage hold and a galley. The main passenger cabin was adaptable, allowing operators to modify the balance between seating and cargo capacity. Initially, Imperial Airways configured it with nine seats arranged in alternating pairs and single seats, each equipped with tables. Special attention was given to air conditioning systems due to anticipated operation in warm climates. Subsequently, Imperial Airways reconfigured the cabin to an eleven-seat layout on its African routes to improve profitability.
Operational history
Imperial Airways placed an order for eight aircraft, all of which were delivered by 1933.[1] The inaugural flight took place on 26 September 1932, traveling from Croydon Airport to Brussels and then onward to Cologne. The prototype, G-ABPI, embarked on a test flight from Croydon to Cape Town, South Africa, on 5 January 1933.[2] Subsequently, three additional aircraft joined the initial one in South Africa to operate the route between Cape Town and Kisumu. Due to high passenger demand, the Atalanta's capacity proved inadequate, leading to its replacement by the de Havilland Hercules.[3]
On 1 July 1933, an Atalanta conducted the first nonstop air mail service connecting London and Karachi.[4] The fleet included two aircraft registered in India and two registered in Britain, servicing a Karachi-Calcutta route that was eventually extended to include Rangoon and Singapore. On 29 May 1933, G-ABTL completed a route survey flight reaching Melbourne, Australia by 30 June.[5] By December 1934, through services to Australia were officially launched. In the following years, Imperial Airways evaluated several other potential destinations for the Atalanta, including routes to China.[6]
In 1937, Imperial Airways decided to retire the Atalanta from its African operations. Shortly after this decision, two aircraft were leased by Wilson Airways for Kenyan routes until July 1938. Subsequently, the Atalantas previously operating in Africa were relocated to India.[7] Prior to the onset of the Second World War, three of these aircraft had been lost.[8]
Following the outbreak of war, the remaining five Atalantas were initially absorbed into British Overseas Airways Corporation (BOAC) operations.[9] In March 1941, they were requisitioned by the Royal Air Force (RAF) in India, where they played a role in transporting troops to Iraq during the Rashid Ali uprising.[7]
After Japan entered the war in December 1941, control of the fleet was transferred to the Indian Air Force, which employed them for coastal reconnaissance missions armed with a single .303 in (7.7 mm) machine gun operated by the navigator.[10] The last patrol mission occurred on 30 August 1942; thereafter, the two surviving aircraft were reassigned to transport roles and remained active until June 1944.[11][12][13]
Operators
Civil operators
- Indian Trans-Continental Airways
Military operators
Aircraft names and registrations
- Atalanta (c/n 740; initially G-ABPI, later renamed Arethusa; subsequently VT-AEF, DG453)
- Andromeda (c/n 741; G-ABTH)
- Arethusa (c/n 742; originally G-ABTI, later renamed Atalanta; subsequently DG451)
- Artemis (c/n 743; G-ABTJ; later DG452)
- Athena (c/n 744; G-ABTK)
- Astraea (c/n 784; G-ABTL; later DG450)
- Amalthea (c/n 785; G-ABTG)
- Aurora (c/n 786; G-ABTM, later VT-AEG, DG454)
Specifications
See also
Notes
Citations
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedTapper p227 - ↑ Tapper 1988, pp. 227-228.
- ↑ Tapper 1988, p. 228.
- ↑ Tapper 1988, p. 230.
- ↑ Tapper 1988, pp. 229-230.
- ↑ Tapper 1988, p. 231.
- ↑ 7.0 7.1 Williams Aeroplane Monthly November 1980, p. 568.
- ↑ Tapper 1988, pp. 231-232.
- ↑ Tapper 1988, p. 232.
- ↑ Tapper 1988, p. 234.
- ↑ "Airlines and Airliners: Armstrong Whitworth Atalanta." century-of-flight.net. Retrieved: 2 July 2010.
- ↑ Williams Aeroplane Monthly November 1980, pp. 568, 570.
- ↑ Warne 1985, p. 5.
Bibliography
- "The A.W. X.V Monoplane." Flight, Vol. XXIV, No. 28, 8 July 1932, pp. 619–623. Accessed 7 November 2021.
- "The A.W. X.V Monoplane" (continued). Flight, Vol. XXIV, No. 29, 15 July 1932, pp. 661–665. Accessed 7 November 2021.
- The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). London: Orbis Publishing, 1985.
- Jackson, A.J. British Civil Aircraft Since 1919, Volume 1. London: Putnam, 1974. ISBN 0-370-10006-9.
- Stroud, John. "Wings of Peace". Aeroplane Monthly, June 1986, Vol. 14 No. 6, pp. 320–326. Template:ISSN.
- Tapper, Oliver. Armstrong Whitworth Aircraft since 1913. London: Putnam, 1988. ISBN 0-85177-826-7.
- Warne, D. W. "In Defence of India". Air Enthusiast, No. 28, July–October 1985, pp. 1–7. ISSN 0143-5450.
- Williams, Ray. "Atalanta - Part 1". Aeroplane Monthly, October 1980, Vol. 8 No. 10, pp. 506–511. ISSN 0143-7240.
- Williams, Ray. "Atalanta - Part 2". Aeroplane Monthly, November 1980, Vol. 8 No. 11, pp. 564–570. ISSN 0143-7240.
External links
- [1] Image of 'Aurora' from Captain RP Mollard's collection; he piloted mail flights to Darwin in 1934.