Mustang and StearmanThe North American Mustang and Boeing Steerman from Vintage Wings of Canada.
The Mustang IV (named P-51 in the USA) is arguably the finest fighter aircraft design of all time let alone the Second World War. The first prototype of the P-51 was originally designed and built by North American Aviation not for the United States Army Air Force (USAAF), but in response to an RAF requirement. Most of the following production aircraft were powered by Packard-built Rolls-Royce Merlin engines that were capable of superb performance at high altitude.
The Boeing Stearman was manufactured as an initial training aeroplane by Boeing Aircraft Company (Witchita Division), which eventually constructed at least 8500 Stearmans, or more than 10,300 if one includes spare parts. No other biplane was ever built in this quantity. Beginning in 1934, the Americans sold the Stearman for export as the 'Kaydet.'