Design of aircraft noise abatement approach procedures for near-term implementation

Abstract

Advanced aircraft noise abatement approach procedures -- characterized by decelerating, continuous descent approaches using idle thrust, and enabled by flight guidance technologies such as GPS and FMS -- have been shown to reduce operational aircraft noise on communities surrounding airports. However, implementation in the near future presents two challenges. The first is to mitigate the adverse effects on aircraft performance of uncertainties in pilot response, weather, and other system components. The second is to enhance the ability of air traffic controllers to separate aircraft that are decelerating at different rates. The work in this thesis primarily addresses the first challenge by developing, first, a methodology to determine the optimum design parameters for a continuous descent approach, and, second, a new pilot cueing system. The methodology involved: 1) conducting a simulator-based, human factors experiment to obtain models of pilot delay in extending flaps/gear in conditions with and without turbulence; 2) formulating the procedure's parameters as strategic and tactical control variables; 3) using the pilot delay models and the parameter formulation to perform a Monte Carlo Simulation to resolve the conflicting objectives of reducing noise and increasing probability of target achievement. Simulation results showed that the flap schedule has to be designed for a 50-ft- higher-than the target altitude without turbulence, and a 200-ft for turbulence; 4) determining the feasibility space of the parameters in different wind conditions. Results showed that when the wind uncertainty is large, accounting for the uncertainty in the procedure design significantly reduces the effectiveness of the procedure.

(cont.) A new pilot cueing system that does not require additional aircraft automation was developed to help pilots manage the deceleration of aircraft and achieve target conditions in a changing environment. The cueing system, consisting of gates (i.e., altitude/speed checkpoints) and a recommended flap schedule, was designed and evaluated in a second experiment using a desktop simulator which showed that gates reduce target error to within five knots and provide comparable performance to that of more automated systems without increasing pilot workload. Because the gates have the potential of enabling aircraft to fly consistent speed profiles, it is hypothesized that their implementation would address the second challenge by enhancing the controller's ability to predict aircraft trajectories and their future separation.