Accession Number : AD0860596

Title :   A Search for the Minimum-Fuel Landing Trajectory of a Tilt-Wing VTOL Aircraft.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Brattland, Harold A.

Report Date : MAY 1969

Pagination or Media Count : 194

Abstract : Optimal control techniques are used to find the minimum-fuel landing trajectory of a tilt-wing VTOL aircraft. A fourth-order, nonlinear, mathematical model of the XC-142A was used, employing three controls: wing incidence, thrust and a limited authority pitch control. Optimization was accomplished by the conjugate gradient method using penalty functions to control terminal error and constrained variables. A control variable transformation was used to constrain the controls. To start the optimization algorithm, initial controls were computed to perform a landing trajectory with the model without exceeding the constraints. The increase in computing time due to the transformation was negligible. Convergence to terminal conditions was hindered by a wing lift anomaly. (Author)

Descriptors :   *FUEL CONSUMPTION), (*VERTICAL TAKEOFF AIRCRAFT, FLIGHT PATHS), (*TRANSPORT AIRCRAFT, FLIGHT PATHS), (*AIRCRAFT LANDINGS, OPTIMIZATION, COSTS, TILT WINGS, CONTROL, MATHEMATICAL MODELS, THESES, AVIATION FUELS.

Subject Categories : Transport Aircraft
      V/STOL

Distribution Statement : APPROVED FOR PUBLIC RELEASE