EVALUATION OF THE GRUMMAN AG-CAT AGRICULTURAL AIRCRAFT.

Abstract : The aircraft was evaluated in three configurations: (1) clean or basic aircraft, (2) aircraft with spray dispersal equipment attached, and (3) aircraft with solid material distributor attached. Level flight, power required tests, and climb performance tests indicate that the dispersal systems greatly reduce the economy and safety of the aircraft in agricultural operations. The results indicate that the efficiency of the dispersal systems must be increased before improvement in the aerodynamic design of the basic aircraft will significantly increase the economy and safety of operation. A qualitative assessment of the stability and control characteristics of the Grumman Ag-Cat revealed that the dynamic longitudinal stability appeared to be excellent in all test configurations. The lateral-directional characteristics appeared adequate, and the control forces were nominal in normal maneuvers. In high rate of roll maneuvers, the aileron forces were slightly high. The aerodynamic stall warning was considered adequate in all configurations except at maximum gross weight in accelerated maneuvers. Numerous aerodynamic measurements were made to determine the chordwise wing pressure distributions, the spanwise wing loading, the profile wing drag, the skin-friction drag, the wing stall patterns, and the nature of the wing-tip vortex field behind the aircraft. Chemical distribution tests were run to determine the distribution characteristics of the solid material distributor. (Author)