Pilot Support for Curved Decelerating Approaches in Actual Wind Conditions

Abstract

The most promising aircraft noise abatement approach procedures are those that combine flying longer at high altitude with continuous descents in a near-idle thrust setting. Although very effective at mitigating noise impact on the populated areas that surround airports, these procedures reduce runway capacity with respect to standard ILS approaches. Large uncertainties in descent trajectories force air traffic controllers to apply large separations in order to ensure safe operation. In this paper, a solution is presented that addresses the problems of variability in deceleration profiles and wind uncertainty. Spacing is done by providing pilots with a required time of arrival. A support system then helps the pilot in meeting this time goal. A wind prediction algorithm has been developed that creates a wind profile estimate along the intended three dimensional approach track, using filtered wind data observations broadcasted by preceding aircraft. By combining accurate wind estimates with a flap scheduling algorithm, accurate track prediction is available on-board. An interface has been designed that aids the pilot both in flying a controlled continuous descent approach and in meeting the time target set by air traffic control. To test the combined support system, a piloted simulator experiment was set up. The experiment was designed to place a continuous descent approach in realistic circumstances, including a curved trajectory to avoid noise sensitive areas, and varying airspeeds and wind conditions. Performance in terms of time goals is consistent under all tested conditions and significantly better in comparison with the non-supported condition. Also, workload is significantly lower with the display optimization present. Performance in terms of adherence to speed restrictions is unaffected. Providing the pilot with continuously updated time performance information based on actual meteorological circumstances is an important requirement for the implementation of CDAs in a time based spacing environment.