flight, powered by a pair of British Rolls-Royce RA-26 Avon Mk.522, capable of providing of unitary thrust. For the maiden flight, which had a total duration of 41 minutes, the crew consisted of Pierre Nadot (first officer), André Moynot (second officer), Jean Avril (mechanic), André Préneron (radio operator) and Roger Beteille. Almost one year later, on 6 May 1956, the second prototype made its first flight. The first prototype had been fitted with a cargo door located on the lower left side of the fuselage, but this door was removed in the second prototype in favour of an all-seating arrangement. By October 1956, both prototypes had accumulated in excess of 1,000 flight hours. By the end of 1956, the two aircraft had visited various locations across Europe and North Africa; and trials were already underway for French carrier Air France. During 1957, the second prototype accumulated roughly 2,500 flight hours across various flights conducted throughout North America and South America. In 1956, the type received its first order from Air France; it was followed by Scandinavian Airlines System (SAS) in 1957. More orders followed, which had been partially driven by a campaign of direct presentations held at airshows and dedicated flight demonstrations using the two prototypes to potential customers. Also during 1956, SNCASE (Sud-Est – Southeast) had merged with SNCASO (Sud-Ouest – Southwest) and several other French aircraft manufacturers to become Sud Aviation; however, the original SE designation assigned to the airliner was retained. In May 1959, the Caravelle received its airworthiness certification, enabling the type to enter passenger service. On 26 April 1959, the Caravelle performed its first flight with paying passengers on board for Scandinavian operator SAS; shortly thereafter, the type commenced operations with Air France as well. Further development Within four years of entering airliner service, a total of 172 Caravelles had been sold to a range of operators. Aviation writer M.G. Douglas attributed the type's favourable early sales record to the effective marketing campaign of performing demonstrations to prospective customers using the two prototypes, as well to the Caravelle having effectively no jet-powered rivals, being the only short-haul jetliner for several years following its introduction. Several models of the Caravelle were developed and produced over the lifetime of the production run, often in response to the increasing power of the available engines, which allowed higher takeoff weights to be adopted. By 1963, there were a total