Any plane that you guys know about that was at first considered a failure but then became a sucess, or planes that almost miraculously became sucesses despite the odds, this is the place to mention 'em.
DH Mosquito Unwanted by the Air Ministry, so built as a private venture, then became one of the most successful aircraft of WW2
I don't now much about Mosquito's development (I am more inclined to Beaufighter) but just rembered a plane that may fit in this topic; The A-10. It was considered outdated ( jet close support plane with mostrous weapons but its speed doesn't exceed 690 km/h). However, in the Gulf War prooved itself to be formidable tank destroyer even at night.
For example: http://www.aviation-history.com/dehavil ... quito.html Amiens Raid Copenhagen Raid Oslo Raid Civilian Transport to Sweden First twin to land on a carrier http://freespace.virgin.net/pbratt.home ... %20BIV.htm
The Oslo Raid is hardly a success story as they missed the Gestapo HQ and hit a tram full of civilians instead.
P-39 Airacobra. Butchered by USAAF with removal of supercharger and mounting of additional armour. USAAF pilots hated it, Brits pushed them to Soviets after approx. 1 month but Soviets loved them. Some of most succesfull allied aces (Pokryshkin, Gulyayev, Ahmet-Khan Sultan, Guchek...) flew the Iron dog. Soviets considered it a very good fighter, heavly armed, adequatly armoured and very manourable. Brewster Buffalo Universaly hated by most pilots who flew it, but a sucess storey in Finland.
P39 Airacombra Eastern Front fighting rarely took place above 5000 meters. Below this altitude the P39 was quite succesfull as low-medium fighter. Brewster Buffalo Finland bought the export version(B-239 if i recall) of Buffalo which was better than USN and Commonwealth Buffalos. Also, this version was slightly better than the main soviet fighters of the period (I-16)- combine this with the very good training of Finnish pilots and you'll have the desired results. [/b]
Lockheed L-188 Electra....succes at first...failure thanks to bad publicity after a few crashes....succes as it became the basis of the P-3 Orion!