refueling tankers, freighter models (new-build and conversions), combi aircraft, military airlifter, and VIP transport. Perhaps the most visually unique of the variants is the A300-600ST Beluga, an oversize cargo-carrying model operated by Airbus to carry aircraft sections between their manufacturing facilities. The A300 was the basis for, and retained a high level of commonality with, the second airliner produced by Airbus, the smaller Airbus A310. Operational history On 23 May 1974, the first A300 to enter service performed the first commercial flight of the type, flying from Paris to London, for Air France. Immediately after the launch, sales of the A300 were weak for some years, with most orders going to airlines that had an obligation to favor the domestically made product – notably Air France and Lufthansa, the first two airlines to place orders for the type. Following the appointment of Bernard Lathière as Henri Ziegler's replacement, an aggressive sales approach was adopted. Indian Airlines was the world's first domestic airline to purchase the A300, ordering three aircraft with three options. However, between December 1975 and May 1977, there were no sales for the type. During this period a number of "whitetail" A300s – completed but unsold aircraft – were completed and stored at Toulouse, and production fell to half an aircraft per month amid calls to pause production completely. During the flight testing of the A300B2, Airbus held a series of talks with Korean Air on the topic of developing a longer-range version of the A300, which would become the A300B4. In September 1974, Korean Air placed an order for 4 A300B4s with options for 2 further aircraft; this sale was viewed as significant as it was the first non-European international airline to order Airbus aircraft. Airbus had viewed South-East Asia as a vital market that was ready to be opened up and believed Korean Air to be the 'key'. Airlines operating the A300 on short haul routes were forced to reduce frequencies to try and fill the aircraft. As a result, they lost passengers to airlines operating more frequent narrow body flights. Eventually, Airbus had to build its own narrowbody aircraft (the A320) to compete with the Boeing 737 and McDonnell Douglas DC-9/MD-80. The savior of the A300 was the advent of ETOPS, a revised FAA rule which allows twin-engine jets to fly long-distance routes that were previously off-limits to them. This enabled Airbus to develop the