The A300B11, a derivative of the A310, was designed upon the availability of "ten ton" thrust engines. Using four engines, it would seat between 180 and 200 passengers, and have a range of . It was deemed a replacement for the less-efficient Boeing 707s and Douglas DC-8s still in service. The A300B11 was joined by another design, the A300B9, which was a larger derivative of the A300. The B9 was developed by Airbus from the early 1970s at a slow pace until the early 1980s. It was essentially a stretched A300 with the same wing, coupled with the most powerful turbofan engine available at the time. It was targeted at the growing demand for high-capacity, medium-range, transcontinental trunk routes. The B9 offered the same range and payload as the McDonnell Douglas DC-10, but it used between 25% and 38% less fuel. The B9 was therefore considered a replacement for the DC-10 and the Lockheed L-1011 Tristar.
The A300B11, a derivative of the A310, was designed upon the availability of "ten ton" thrust engines. Using four engines, it would seat between 180 and 200 passengers, and have a range of . It was deemed a replacement for the less-efficient Boeing 707s and Douglas DC-8s still in service The A300B11 was joined by another design, the A300B9, which was a larger derivative of the A300. The B9 was developed by Airbus from the early 1970s at a slow pace until the early 1980s. It was essentially a stretched A300 with the same wing, coupled with the most powerful turbofan engine available at the time. It was targeted at the growing demand for high-capacity, medium-range, transcontinental trunk routes. The B9 offered the same range and payload as the McDonnell Douglas DC-10, but it used between 25% and 38% less fuel. The B9 was therefore considered a replacement for the DC-10 and the Lockheed L-1011 Tristar.