1931 – Budd BB-1 Pioneer
U.S. railcar maker Budd built the BB-1 Pioneer experimental flying boat—based on the Italian Savoia-Marchetti S56—from corrosion-resistant stainless steel using newly developed spot welding. Budd tried again in 1943 with the RB-1 Conestoga cargo aircraft (pictured), but steel is heavy, and it did not catch on.
1940 – de Havilland Mosquito
With the wartime scarcity of aluminum, de Havilland built its Mosquito fighter-bomber (pictured) from wood—plywood facings bonded to a balsawood core and formed using molds to produce monocoque structures. This led to the development of metal-to-metal bonding, used in the de Havilland Comet jet airliner and by Fokker in the F27 and F28 airliners.
1952 – Douglas X-3 Stiletto
The first titanium aircraft was the Douglas X-3 Stiletto (pictured) flown in 1952. Designed to cruise at Mach 2, where skin friction required the heat resistance of titanium, the X-3 was underpowered and barely supersonic. Capable of Mach 3.2, Lockheed’s A-12 and SR-71 were also mainly titanium, and the material was to be used for Boeing’s canceled 2707 supersonic transport, designed to cruise at Mach 2.7.
1964 – Mikoyan-Gurevich MiG-25
Russian design bureau Mikoyan-Gurevich used welded nickel steel for the airframe of the Mach 2.8 MiG-25 fighter (pictured), first flown in 1964, because heat-resistant titanium was difficult to work with and hard to weld. The North American XB-70, designed to reach Mach 3.1, but canceled by the time it flew in 1964, used brazed stainless-steel honeycomb panels and titanium.
