During the design process , the A318 encountered several problems . The first one was the decline in demand for new aircraft following the September 11 attacks . Another was the new Pratt & Whitney turbofan engines , which burned more fuel than expected . By the time CFM International ( CFM ) had a more efficient engine ready for market , many A318 customers had already backed out , including Air China and British Airways . America West Airlines , which had selected the Pratt & Whitney engines , amended its A318 orders , opting instead for A319 or A320 aircraft . Trans World Airlines cancelled a significant order for fifty A318s after being acquired by American Airlines , which did not operate any A320 family aircraft at the time ( although neither did TWA when the order was originally placed ) . While Airbus was hoping to market the A318 as a regional jet alternative , laws in both the U.S. and Europe have kept it in the same class as larger aircraft for calculating charges such as landing fees , limiting the type 's market potential
September 11 attacks
September 11 attacks
Airbus A318