TABLE OF CONTENTS There is no particular feeling of speed, except that the miles go faster. The sky is not dark and the horizon is not curved.
A. Turcat, Director of Concorde Flight Test, 1969
This chapter deals with atmospheric flight envelopes. The aircraft is to fly level in steady accelerated flight. We describe the shape/speed relationship, give various speed definitions, and the techniques required to measure them. Calculations of absolute ceiling and acceleration problems in supersonic regime are presented.
The flight corridor is the speed band at a given altitude where steady state flight is possible. The minimum level speed is called stalling speed; the maximum speed, if not called as such, is the dash speed of the aircraft. The aircraft can maintain a steady level flight at any speed within the flight corridor, by adjusting the throttle (engine thrust), attitude (angle of attack) and configuration (control surfaces). The boundaries of the flight corridor are controlled by the aerodynamic, propulsive and structural performance.
The set of all flight corridors from sea level to the absolute ceiling define the flight envelope. In other words, the flight envelope is the closed area in the U ? h diagram that includes all operating conditions for a particular aircraft at a given weight. The flight envelope depends on a large number of factors, including weight, aerodynamics, propulsion system, structural dynamics and atmospheric conditions.
The absolute ceiling is the maximum altitude at which an aircraft can keep...
