Orbiter Approach and Landing Tests- Correlation of Flight and Predicted Performance Data

Abstract

The development of modern, conventional aircraft includes an extensive flight test program to verify the predicted flight characteristics and design capabilities. Such flight test programs exercise the aircraft through the full range of its capabilities over a lengthy time span. This paper presents the results of a program in which a flight test vehicle was flown for a limited number of flights. The vehicle was the NASA Space Shuttle Oribiter. The vehicle was configured with a tailcone both on and off during the flight test program; however, the data presented in this paper represents the tailcone-off flights. The total free-flight time for the entire flight test program was less than one-half hour. The flight regime tested represented only the approach and landing phase of the vehicle's planned flight capability. The Space Shuttle Orbiter program relied heavily on an extensive windtunnel test program to predict the aerodynamic performance data over the complete flight range, as well as to predict data tolerances. During the flight test program short maneuvers were performed to provide flight motion data. A data extraction program was developed to produce flight-derived aerodynamic performance data in coefficient form from the motion data. The resultant flight test data were correlated with the predicted data and fell within the predicted data tolerances for all phases of the subsonic flight test regime, including ground effects.