Over the years manufacturers have looked at the requirements of commuter airlines with a view to producing new airliners to meet operator requirements.
The Douglas DC-2, which was a direct development of the sole DC-1 (X223Y), flew for the first time on 11 May 1934 powered by two Wright SGR-1820 engine of 537-kw (720-hp).
In the 1960s France and Germany worked together to jointly develop and produce an advance jet trainer, with a light attack variant, for service with their air forces and this involved the production of 200 aircraft for each service