A Maximum-Performance Take-Off System for a Critically-Loaded KC-135 Aircraft

The purpose of this study was to design and analyze an adaptive maximum-performance take-off system for use in any aircraft having critical take-off requirements. This was accomplished by using various combinations of available flight parameters as inputs to a flight director, analyzing each combination under conditions of normal and reduced aircraft thrust on an analog computer and selecting the combination giving the maximum take-off performance without any sacrifice of flight safety. This preliminary investigation revealed that a system holding a constant angle-of-attack until acceleration goes to zero, and then holding a constant velocity, produced maximum take-off performance. To insure its dynamic response the selected system was then analyzed for stability by the root-locus technique and then further sensitized on the analog computer. This analysis of the system indicated that the compensatory effects of ø and v were required to furnish the necessary lead to the system. The compensated system was then instrumented to drive a commercially available indicator and installed and flown in an Air Force T-37 flight simulator where the indicator take-off performance was compared with that of a normal take-off. The results indicated that a substantial increase in performance over the normal take-off techniques can be obtained for modern civilian and military aircraft having critical take-off requirements. Not only can the take-off performance obtained from these aircraft be improved, but safety can also be increased. The use of the flight director made complete pitch control possible with only one instruments.