Texas Helicopter Co, which was acquired in 1985 by Aerodyne Systems Engineering Ltd, has developed a single-seat agricultural conversion of the Model 47, known as the M-74 "Wasp" and a tandem two-seater known as the M-79T "Hornet". The prototype of the latter (registered N1001X) received FAA certification on 25 April, 1985. This variant has also been proposed as an armed trainer for AH-64 "Apache" crews. In both "Wasp" and "Hornet", the fuselage had been redesigned and the Allison 250-C20B engine repositioned. Maximum take-off weight of the "Hornet" is 1440kg. In 1989, some thirty-five Wasps and Hornets were on the US civil register.

A.J.Pelletier "Bell Aircraft since 1935", 1992