The Rolls-Royce RB.44 Tay was an enlarged version of the Nene. It saw no use by production aircraft in the UK but the design was licensed by Pratt & Whitney as the J48 and by Hispano-Suiza as the Verdon. Two early production examples of the Tay were evaluated during 1950 by the Royal Aircraft Establishment (RAE) at Farnborough Airfield Hampshire in a specially modified Vickers Viscount.