The 578DX was a 20,000 lb thrust, gearbox driven, counter rotating propfan technology demonstrator built by Allison, Pratt & Whitney, Hamilton Standard, and Rohr Industries in the 1980's. It flew successfully on the port pylon of an MD80 aircraft from April 13, 1989 to May 20, 1989. The NASA Lewis Research Center and the NASA/Industry Advanced Turboprop Team, which included Pratt & Whitney Allison, won the Collier Trophy in 1987 for "The development of advanced turboprop propulsion concepts for single rotation, gearless counter rotation, and geared counter rotation unducted fan systems." Credit to the RollsRoyce Heritage Trust Allison Branch archives, Indianapolis, Indiana, USA.