Results of a preliminary flight evaluation of the application of spoilers/dive brakes to a small, fixed-wing general aviation aircraft are presented. Steady state flight path angles up to 13 deg for a true airspeed of 85 mph were obtained with a spoiler/dive brake area of 5.7 sq ft. No change in trim airspeed was experienced for that configuration provided 15 deg of flaps were used. An 11.92 sq ft spoiler/dive brake configuration produced steady state flight path angles up to 18 deg at 90 mph true airspeed.
Preliminary evaluations conducted by two pilots indicated that the former configuration offered significant improvements in the vehicle's handling qualities during the total landing tasks, provided a suitable means of controlling the considerable performance of the spoilers/dive brakes was available. This was done by integrating their function with power changes such that the throttle became an authoritative and effective flight path angle control. Controlling the throttle and spoilers separately was acceptable provided the operation of the spoiler control handle was similar to the operation of the throttle, and both handles could be grasped in one hand simultaneously. A spoiler control handle which was physically separated from the throttle by a large distance was unacceptable and potentially dangerous.