Armstrong Whitworth Atalanta
| Industry | Aerospace, Aircraft manufacturing |
|---|---|
| Headquarters | Coventry , United Kingdom |
| Products | Aircraft, including the Armstrong Whitworth AW.15 Atalanta |
The Armstrong Whitworth AW.15 Atalanta was a British four-engine airliner developed and manufactured by Sir W.G. Armstrong Whitworth Aircraft Limited at their facility in Coventry.
Designed specifically to meet the requirements of the British carrier Imperial Airways, the Atalanta was intended to operate on its African routes. The aircraft employed a monoplane design, chosen primarily for its reduced aerodynamic drag, marking a significant design shift from the earlier Armstrong Whitworth Argosy airliner. Even before a prototype had been constructed or flown, Imperial Airways committed to placing an order based on Armstrong Whitworth's proposal.
The prototype G-ABPI took to the skies for its inaugural flight on 6 June 1932; it carried the name Atalanta, which was subsequently applied to all aircraft of this model. Flight trials uncovered only minor issues, which were promptly addressed, allowing the aircraft to secure its airworthiness certification within three months. On 26 September 1932, Imperial Airways commenced commercial operations with the type on routes from Croydon to Brussels and Cologne. The Atalanta mainly operated on Imperial Airways' Eastern services for five years before being succeeded by newer models; in later years, both civilian and military operators continued using the aircraft until its retirement during the course of the Second World War.
Background
The inception of the AW.15 Atalanta is closely linked to a specification issued by British airline Imperial Airways in 1930, which called for a four-engine airliner tailored for 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 four engines—rather than three as on the existing Armstrong Whitworth Argosy—to ensure safe continuation of flights despite a single engine failure. The airline's criteria included accommodation for at least nine passengers, a crew of three, and sufficient capacity for freight and mail over distances up to 400 miles (640 km), with a cruising speed target of 115 mph (185 km/h) at an altitude of 9,000 ft (2,740 m).
At Sir W.G. Armstrong Whitworth Aircraft Limited, designer John Lloyd examined these requirements and concluded that adopting a monoplane layout would best satisfy them due to its superior aerodynamic efficiency compared to biplane designs. This concept represented a significant evolution from the Argosy, featuring engines mounted on the wings and a more streamlined fuselage profile. Internal analyses employing extensive wind tunnel testing indicated that the new airliner would produce approximately 340 pounds of parasitic drag—less than half that experienced by the Argosy model.
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 aircraft, registered as G-ABPI, completed its inaugural flight with Alan Campbell-Orde at the controls. This aircraft was christened Atalanta, a name that soon became associated with the entire model series. The Atalanta made its first public showing on 27 June 1932 during the Society of British Aerospace Companies (SBAC) exhibition held at Hendon Aerodrome, where it garnered positive attention.
Following this, on 11 July 1932, the prototype proceeded to RAF Martlesham Heath for official testing and secured its certificate of airworthiness within the next month. Flight evaluations revealed that the aircraft exhibited minimal defects, with initial issues being swiftly resolved. Pilots reported that it offered good handling characteristics and was straightforward to operate. Some vibration from the engines caused occasional failures such as fuel tank ruptures and broken bracing wires; these problems were mitigated by fitting rubber mounts to the oil tanks and substituting steel tubing for wire bracing. A minor concern involved rudder over-corrections leading to oscillations; this was addressed by incorporating what Armstrong Whitworth claimed was the first-ever spring tab servo control system.
The prototype was then transferred to Croydon Airport for acceptance trials conducted by Imperial Airways, who were reportedly fully satisfied with its capabilities. The aircraft entered commercial service on 26 September 1932, operating flights from Croydon to Brussels and Cologne. However, on 20 October 1932, during a test flight, the prototype sustained damage due to fuel starvation caused by a faulty experimental vent on the fuel tank. In response to this incident, Armstrong Whitworth reportedly renamed the third production example (G-ABTI, originally called Arethusa) as Atalanta, seemingly hoping the substitution would go unnoticed.
There were plans for two additional variants: the AW.25, powered by Armstrong Siddeley Jaguar engines, and the AW.26, equipped with Armstrong Siddeley Panther engines; neither progressed beyond design stages. According to Tapper, these variants failed to attract orders primarily due to unfortunate timing and the rapid introduction of larger airliners from rival manufacturers.
Design
The Armstrong Whitworth Atalanta was designed as a streamlined high-wing monoplane airliner. Its fuselage featured a square cross-section with smooth, rounded edges to minimize aerodynamic resistance. Constructed using a combination of steel, plywood, and fabric, the airframe reflected a composite approach to materials. The fixed undercarriage was partially recessed into the fuselage and fitted with streamlined fairings to reduce drag effectively. Passengers enjoyed a cabin environment that was relatively quiet and cool, outfitted with adjustable seating for enhanced comfort. The Atalanta’s design was considered advanced for its time; according to Century of Flight, it helped narrow the performance disparity between British and American commercial aircraft.
Propulsion came from four supercharged Armstrong Siddeley Serval III ten-cylinder radial engines, each delivering up to 340 hp (250 kW). These engines represented a recent innovation, essentially combining two Armstrong Siddeley Mongoose units into one powerplant. Mounted on the wing’s leading edge, the engines were faired seamlessly into the wing profile to optimize aerodynamic efficiency. They were attached via a tubular framework connected to the wing’s forward spar and safeguarded from potential fire hazards by a fire-resistant bulkhead. Both fuel tanks were integrated within the leading edge of the wing—one located between each engine pair—allowing fuel to be gravity-fed directly.
The Atalanta’s fuselage consisted of three distinct sections and incorporated novel construction techniques for Armstrong Whitworth, including the use of steel strips for forming the longerons and interconnecting struts. The passenger cabin area was sheathed in plywood over lightweight stringers, while the rear fuselage was predominantly covered with fabric except for aluminium panels reinforcing the corners. The moderately tapered cantilever wings were also assembled in three parts around two steel girder spars. Steel ribs supported the wing’s center section, whereas wooden ribs were used in the outer sections, which were covered with plywood extending up to the rear spar.
Inside, the Atalanta introduced several innovative features. The cockpit was notably spacious, accommodating two pilots and a radio operator. Immediately aft of the cockpit was a compartment designed to hold up to one tonne of air mail, followed by a luggage compartment and a galley. The main passenger cabin was versatile, allowing operators to adjust the balance between seating and freight capacity as needed. Initially, Imperial Airways configured the aircraft with nine seats arranged in alternating pairs and singles, each accompanied by tables. Given its anticipated operation in warmer regions, particular emphasis was placed on effective air conditioning. Subsequently, Imperial Airways modified the layout to an eleven-seat arrangement for its African routes to enhance profitability.
Operational history
Imperial Airways placed an order for eight units, all of which were delivered by 1933.[1] The inaugural flight occurred on 26 September 1932, connecting Croydon Airport to Brussels and subsequently Cologne. On 5 January 1933, the prototype G-ABPI embarked from Croydon Airport on a test journey to Cape Town, South Africa.[2] Three additional aircraft joined the prototype in South Africa to operate the route between Cape Town and Kisumu. Due to high passenger demand, the Atalanta’s capacity was insufficient, leading to its replacement by the de Havilland Hercules.[3]
The first direct air mail service between London and Karachi was operated by an Atalanta on 1 July 1933.[4] Four aircraft—two registered in India and two in Britain—served the Karachi-Calcutta route, which was later extended to Rangoon and Singapore. On 29 May 1933, G-ABTL conducted a route survey flight to Melbourne, Australia, arriving on 30 June.[5] The through service to Australia began in December 1934. Over the following years, Imperial Airways explored additional potential routes for this model, including destinations in China.[6]
In 1937, Imperial Airways decided to withdraw the Atalanta from its African operations. Soon after, two aircraft were leased to Wilson Airways for service in Kenya until July 1938. Subsequently, the African-based Atalantas were reassigned to India.[7] Before the onset of the Second World War, three of these aircraft had been lost.[8]
Following the outbreak of war, BOAC took control of the remaining five Atalantas.[9] In March 1941, they were requisitioned by the Royal Air Force (RAF) in India, where they transported troops to Iraq during the Rashid Ali uprising.[7]
After Japan entered the war in December 1941, these aircraft were transferred to the Indian Air Force for coastal reconnaissance missions. They were equipped with a single .303 in (7.7 mm) machine gun, operated by the navigator.[10] The last patrol using this type took place on 30 August 1942. The two surviving aircraft were reassigned to transport roles and remained operational until June 1944.[11][12][13]
Operators
Civil operators
- Indian Trans-Continental Airways
Military operators
Aircraft names and registrations
- Atalanta (c/n 740; G-ABPI, later renamed Arethusa; subsequently VT-AEF, DG453)
- Andromeda (c/n 741; G-ABTH)
- Arethusa (c/n 742; 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 the collection of Captain RP Mollard who operated mail flights to Darwin in 1934