Accession Number:

ADA055381

Title:

Optimal Flare with Wind Disturbances.

Descriptive Note:

Final rept. Jan 75-Jun 76,

Corporate Author:

AIR FORCE FLIGHT DYNAMICS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1977-04-01

Pagination or Media Count:

63.0

Abstract:

A linear optimal control law is developed to flare an aircraft, in constant wind and wind shear conditions, with minimal touchdown longitudinal range and sink rate dispersions. Range is included as a state variable in order to specify a touchdown point. Control variables are control column and throttle movement. In-flight constraints are placed on pitch rate, normal airspeed, longitudinal airspeed, and elevator angle this permits a smooth profile with a gradual speed bleed. Terminal constraints are placed on pitch rate, longitudinal airspeed, thrust, range, sink rate, and altitude this yields minimal range and sink rate dispersions with acceptable aircraft states at touchdown. Optimal time varying feedback gains are obtained for a no-wind condition they are good for any initial conditions. Since flare time changes in wind conditions, the no wind gains are scheduled as a function of range. Wind and ground effect are considered to be disturbances.

Subject Categories:

  • Aerodynamics
  • Military Aircraft Operations

Distribution Statement:

APPROVED FOR PUBLIC RELEASE