by both military and civil operators. At the time of its introduction, the type was considered to be unique in its class. Principally designed as a freighter, the aircraft could also be used for other tasks. The Argosy was offered in a convertible configuration for carrying both freight and passengers; the civil variant could accommodate a maximum of 80 passengers while providing comfort and speed conditions comparable to the contemporary Vickers Viscount airliners. In the cargo role, the Argosy was designed for rapid turnaround times of only 20 minutes without the use of lifting trucks or cranes, utilising pallets and rollers to eliminate packaging. In terms of its basic configuration, the Argosy's tailplane was mounted on twin booms that ran rearwards from the inner engine nacelles, leaving the cargo doors at the rear of the fuselage clear for straight-in loading. Sideways-opening doors were fitted at both ends of the fuselage and the flight deck was set above the freight hold. This configuration allowed for an unobstructed cargo space measuring with a sill height corresponding to that of a normal flatbed truck. It had a maximum weight of 88,000 lb (39,915 kg) and a payload of 28,000 lb (12,700 kg). When cruising at 276 mph (444 km/h), it had a range of 1,780 mi (2,865 km) and could seat a maximum of 89 passengers. The Argosy was powered by four Rolls-Royce Dart turboprop engines with Rotol-built four-blade propellers. The power rating of the engines depended on the aircraft variant. The sound produced by the Dart engines combined with its relatively unusual "pod and boom" basic configuration, which was similar to the earlier C-82 Packet and C-119 Flying Boxcar transport aircraft, has been attributed as the source of the type's nickname "The Whistling Wheelbarrow". Operational history Civil use The Argosy Series 100 first entered service with the American cargo airline Riddle Airlines. Early on, Riddle had expressed interest in the type, having ambitions to use the type to meet contracts to provide logistics support to the United States Air Force (USAF) within the domestic United States. During late 1960, Riddle purchased a batch of seven Argosies for this purpose. However, when Riddle lost the logistics contract during 1962, its Argosies were repossessed by Armstrong Whitworth and subsequently sold onto other airlines, some of which had taken over the contracts previously being served by Riddle. As a stopgap measure, BEA had ordered Armstrong