If you have flown before, the chances of you having been aboard an A320 family aircraft are pretty high. However, this doesn't apply to one particular variant of the A320 family - the Airbus A318 “baby jet”. 

The Ugly Duckling

While the A320 family of aircrafts has been regarded as a financial success, having sold 11,524 aircraft as of June 2024 (this includes all A318/A319/A320/A321 variants), Airbus has only managed to sell 80 A318 aircraft. The A318 is the smallest A320 family variant, with the aircraft being 6 meters shorter than the A320, and featuring approximately 50 fewer seats. The aircraft's range is also 200 miles shorter than an A320 at 3,600 miles due to smaller fuel tanks.

While a glance at the numbers may get one thinking that it is significantly cheaper to buy an A318, operating the type often costs the same as larger A320 variants such as the A320 or A321. Airbus originally planned to sell the A318 as a regional jet alternative with minimal training needed between its larger variants. The aerospace company was able to do this because the U.S. and EU classified the “baby jet” as being in the same category as its larger brothers. This significantly reduced the potential of the A318, thus buying an A320 with a little more funds made more sense to airlines. 

Another major issue with the A318 was with Unit Load Devices (ULD). These devices are the "containers" that are loaded onto the lower decks of passenger jets for secure cargo operations. ULDs are operable on all A319s, A320s and A321s, but are not operable on the A318. This makes cargo operations for the type inefficient, creating an issue for smooth operations at large, busy airports.