The Aviation Traders ATL-98 Carvair is a retired large transport aircraft powered by four radial engines. It was a Douglas DC-4-based air ferry conversion developed by Freddie Laker's Aviation Traders (Engineering) Limited (ATL), with a capacity generally of 22 passengers in a rear cabin, and five cars loaded in at the front. Design and development Freddie Laker's idea to convert surplus examples of the Douglas DC-4 and its military counterpart the C-54 Skymaster to carry cars was a relatively inexpensive solution to develop a successor to the rapidly aging and increasingly inadequate Bristol 170 Freighter, the car ferry airlines' mainstay since the late 1940s. The Bristol Freighter's main drawback was its limited payload, in terms of the number of cars that fit into a single aircraft. Even the "long-nosed" Mark 32 was able to accommodate only three cars (in addition to 20 passengers). This made carrying cars by air a very tricky business. If a booked car failed to turn up, the flight instantly became unprofitable as a result of the one-third cut in payload. This situation was made worse by the increasing average length of British cars during the 1950s. The average UK car in 1959 was longer than in 1950. The extreme seasonality of the car ferry business furthermore resulted in poor aircraft utilization outside peak periods. Moreover, repeated takeoffs and landings on short cross-Channel flights, in turbulent air at lower altitudes with tight turnarounds of as little as 20 minutes, made the aircraft prone to structural fatigue problems. These necessitated rigorous and costly modification programmes, thereby further increasing the type's operating costs on what were essentially low-yield routes. When the major airlines replaced their obsolete piston airliners with new Boeing 707 and Douglas DC-8 jets on their prestige long-haul routes, the unit price of second-hand DC-4s dropped to as little as £50,000 (equivalent to £ million today). The conversion of each of these airframes into car-passenger carriers cost about £80,000 (£ million today). This was easily affordable by smaller airlines, such as the car ferry companies. Freddie Laker's cardboard model of a converted DC-4 featuring a door in the nose and a flight deck raised above the fuselage had shown that its payload was superior to the Bristol Freighter/Superfreighter. The aircraft was designed to accommodate five average-sized British cars plus 25 passengers as a result of the DC-4's longer and wider fuselage. British Air Ferries (BAF), for