Armstrong Whitworth AW.660 Argosy

The Armstrong Whitworth Argosy was a British post-war military transport/cargo aircraft and was the last aircraft produced by Armstrong Whitworth Aircraft. Although given different type numbers, the AW.650 civil and AW.660 military models were both called "Argosy" and for practical purposes are basically the same design.

Development and design
The Argosy came from the Air Ministry "Operational Requirement 323" (OR323) which resulted in a specification issued in 1955 for a medium-range freight aircraft capable of lifting 25,000 lb (11,340 kg) and that had a range of 2000 mi with 10000 lb. This led AW to develop a twin-engine design for the military, the AW.66. The potential for civil sales led to a civil design AW.65, which differed by having full section doors at each end of the fuselage to allow quick loading and unloading. A lack of funds led to abandonment of the military requirement, but Armstrong Whitworth had already decided to go ahead with the civil variant as a private venture, it being redesigned with four Rolls-Royce Darts as the AW.650.

The AW.650 was a high-wing four-engined general-purpose transport aircraft, powered by four Rolls-Royce Dart turboprop engines driving Rotol four-blade propellers. The tailplane was on twin booms from the inner engine nacelles, leaving the cargo doors at the rear of the fuselage clear for straight-in loading, while sideways-opening doors were fitted at both ends of the fuselage, with the flight deck high up in the nose. This gave an unobstructed cargo space measuring 10 x with a sill height corresponding to that of a normal flatbed truck. This unusual "pod and boom" structure would earn it the nickname "The Whistling Wheelbarrow". It had a maximum weight of 88,000 lb (39,915 kg) and a payload of 28,000 lb (12,700 kg). Cruising at 276 mph (444 km/h), it had a range of 1,780 mi (2,865 km) and could seat 89 passengers. The first Argosy made its maiden flight on 8 January 1959, receiving Federal Aviation Administration type certification on 2 December 1960. 10 of the initial civil version, the Series 100, were built.

While the RAF had lost interest in the original AW.66, it still needed to replace its obsolete piston engineed Vickers Valettas and Handley Page Hastings, and in 1959 the British Air Ministry drew up a specification for a military derivative of the AW.650 to serve as a medium-range transport, paratroop and supply aircraft. The resultant design, the AW.660, was significantly different from the AW.650. It had the nose door sealed to take a weather radar radome, the rear doors were changed to 'clam shell' style with an integral loading ramp, a stronger cargo floor was fitted. Two doors were fitted, one each on the starboard and port sides, to enable paratroopers to exit. The military Argosy had four Rolls-Royce Dart 101 turboprops and had twice the range of the civil Series 100. The new clamshell doors were tested on the second Argosy Series 100 from July 1960, while the first of the RAFs 56 Argosies flew on 4 March 1961.

British European Airways was interested in the Argosy as a replacement for its piston engined freighters, but the payload capacity of the Series 100 meant that it would not be profitable. In order to save money, the wing had been based on that of the Avro Shackleton, built by another part of the Hawker Siddeley Group, but to meet BEAs requirements, a new wing was designed, of the same aerodynamic design, but with a more modern "Fail safe" structure rather than the Safe-life design of the earlier wing. This produced a wing that was both stronger and lighter, while the new wing did not have a limited fatigue life. The revised version, the Series 200, also had larger cargo doors, integral wing fuel tanks and a modified landing gear.

The first Series 200 flew on 11 March 1964, being followed by six more Series 220s, with more powerful engines. A final Series 220 was not completed and was scrapped.

Civil use
The Argosy Series 100 entered service with the American cargo airline Riddle Airlines, who planned to use them to meet contracts to provide logistics support to the United States Air Force within the United States, at the end of 1960, Riddle purchasing seven Argosies. When Riddle lost the logistics contract in 1962, its Argosies were repossessed by Armstrong Whitworth and sold on to other airlines who had taken over the contracts from Riddle.

BEA ordered Armstrong Whitworth's three remaining Series 100s as a stopgap until it could receive its definitive Series 220s, for which it placed an order for five in 1964. It lost two Series 220s in crashes and purchased another to replace the lost aircraft. The small fleet of Argosies remained unprofitable, even when BEA received the more capable series 220s, and BEA withdrew its Argosy fleet in April 1970, replacing them with a freighter conversion of its Vickers Vanguards.

Two aircraft operated later by SAFE Air in New Zealand as the main link between the Chatham Islands and the mainland, were fitted with a pressurised "passenger capsule". One of these aircraft was damaged beyond repair in a landing accident in April 1990, and a third Argosy was leased by SAFE Air from Mayne Nickless of Australia for five months during 1990 as a replacement. The last flight by a New Zealand Argosy was made by operator SAFE Air in September 1990, that aircraft now being preserved at Woodbourne Airport, Blenheim, New Zealand.

The last Argosies, operated by American cargo airline Duncan Aviation, were withdrawn in 1991.

Military use
The Argosy was used by the Royal Air Force for its capability to accommodate 69 troops, 48 stretcher cases or 29000 lb of freight. This meant it could carry military equipment such as the Saracen or Ferret armoured cars, or artillery such as the 105 mm (4.13 in) howitzer or Wombat. Design changes to the Saracen and the mainspar running through the top of the freight bay subsequently precluded the use of the Argosy as a Saracen transport.

The earliest deployments were in 1962 to 105 Squadron in the Middle East and 114 and 267 Squadrons at RAF Benson. The following year, 215 Squadron received its Argosies when based at RAF Changi, Singapore. The squadron was disbanded on New Year's Eve 1967, and the aircraft went to 70 Squadron at RAF Akrotiri, Cyprus. This was the last squadron to operate the aircraft in the transport role when it retired the last aircraft in February 1975, they had been replaced by Lockheed Hercules from December 1970. The E.1 version of the Argosy was with 115 Squadron from 1968 to 1978, most of the time based at RAF Cottesmore and used in the calibration role.

Armstrong Whitworth AW 650 Argosy (1959)
A total of 17 were built for civil operators Riddle Airlines (Series 101) and British European Airways (series 102 and 222).

10 Series 101 and 102 aircraft were built. Eight Series 200 aircraft were built, the series 200 had a larger freight hold and enlarged front and rear doors to enable it to carry standard size cargo pallets. The series 200 also had a lighter redesigned wing increasing the maximum range and Rolls-Royce Dart 532/1 turboprops.

Armstrong Whitworth AW 660 Argosy / Argosy C Mk 1
56 aircraft were produced for the RAF with the designation Argosy C Mk 1 (C.1) and served in six squadrons; three in the UK and one each in Aden, Cyprus, and the Far East. The Argosy was withdrawn from service in 1975 as an economic measure. Those aircraft not scrapped or retained were sold to commercial operators.

Hawker Siddeley Argosy E Mk 1
In 1963, Hawker Siddeley Group dropped the names of its component companies, rebranding its products under the Hawker Siddeley banner. To meet a requirement for a RAF flight inspection aircraft, nine Argosy C.1s were modified in 1971 as the Argosy E.1. These were a regular sight at British airfields operated by 115 Squadron until replaced by the Hawker Siddeley Andover in 1978.

Hawker Siddeley Argosy T Mk 2
After the removal of the Argosy C.1 from the cargo/transport role, it was decided to modify several aircraft as Navigation Trainers for the RAF Training Command. Two aircraft were modified as the Argosy T.2, but they were not successful and the programme was abandoned due to defence cuts. XP411 (see below) was one of these.

Military operators

 * Royal Air Force
 * No. 70 Squadron RAF (based in Cyprus)
 * No. 105 Squadron RAF (based in Middle East)
 * No. 114 Squadron RAF (based in United Kingdom)
 * No. 115 Squadron RAF (based in United Kingdom with the Argosy E.1)
 * No. 215 Squadron RAF (based in Singapore)
 * No. 267 Squadron RAF (based in United Kingdom)
 * No. 242 Operational Conversion Unit RAF
 * No. 6 Flying Training School RAF
 * No. 6 Flying Training School RAF

Civil operators

 * Brain and Brown Airfreighters
 * IPEC Aviation
 * Kris Air
 * Transair-Midwest
 * SOACO
 * Aer Turas
 * Nittler Air Transport
 * SAFE Air
 * $\phi$
 * Philippine Airlines
 * Air Bridge Carriers
 * British European Airways
 * Elan Parcel Service
 * Rolls-Royce
 * Sagittair
 * Capitol Air
 * Duncan Aviation
 * Riddle Airlines
 * Universal Airlines
 * Zantop Air Transport
 * Otrag Range Air Service
 * Sagittair
 * Capitol Air
 * Duncan Aviation
 * Riddle Airlines
 * Universal Airlines
 * Zantop Air Transport
 * Otrag Range Air Service
 * Otrag Range Air Service
 * Otrag Range Air Service

Survivors

 * ZK-SAE, Merchant Enterprise – Woodbourne Airport, Blenheim, New Zealand.
 * G-APRL – Midland Air Museum, Coventry, England.
 * G-BEOZ – Aeropark, East Midlands Airport, England.
 * XP447 – parked at General William J. Fox Airfield, Lancaster, California, USA.
 * XP411 – preserved at the Royal Air Force Museum Cosford, England.
 * The cockpit of XN819 – Newark Air Museum, Newark, England.
 * N896U – on display at Yankee Air Museum, Ypsilanti, Michigan, USA.
 * G-BFVT (Ex-RAF XR143) – parked at Sioux Gateway/Colonel Bud Day Field, Sioux City, Iowa, USA. Being refurbished to RAF appearance for display by the Warner Museum of Aviation and Transportation, Sioux City, IA.