In the late 1970s, Dornier GmbH developed a new kind of wing, the TNT ("Tragflügel neuer Technologie" – Aerofoil new technology), subsidized by the German Government. Dornier tested it on a modified Do 28D-2 "Skyservant" and with Pratt & Whitney Canada PT6A-110 turboprop engines. Finally, Dornier changed the engine and tested the new aircraft, which was named Dornier 128 with two Garrett AiResearch TPE-331-5 engines. The company developed a new fuselage for the TNT and TPE 331–5 in two variants (15- and 19-passenger) and named both project-aircraft E-1 (later Dornier 228-100) and E-2 (later Dornier 228-200). At the ILA Berlin Air Show in 1980, Dornier presented the new aircraft to the public. Both of the prototypes were flown on 28 March 1981 and 9 May 1981 for the first time.