Static and dynamic angles of repose in loose granular materials under reduced gravity

Granular materials avalanche when a static angle of repose is exceeded and freeze at a dynamic angle of repose. Such avalanches occur subaerially on steep hillslopes and wind dunes and subaqueously at the lee side of deltas. Until now it has been assumed that the angles of repose are independent of gravitational acceleration. The objective of...

Real-time Wind Profile Estimation using Airborne Sensors

Wind is one of the major contributors to uncertainty in continuous descent approach operations. Especially when aircraft that are flying low or idle thrust approaches are issued a required time of arrival over the runway threshold, as is foreseen in some of the future ATC scenarios, the on-board availability of both dependable and accurate wind...

A Time-Space Diagram as Controller Support Tool for Closed Path Continuous Descent Operations

Tactical control during a closed-path Continuous Descent Operation stops the aircraft from following its optimized descent. To mitigate tactical control, air traffic controllers apply arbitrary large spacing buffers to account for the unpredictability of the aircraft trajectory from the controller’s point of view. A controller support tool is...

Control Space Analysis of Three-Degree Decelerating Approaches at Amsterdam Airport Schiphol

Amsterdam Schiphol Airport currently uses a Continuous Descent Approach during night time operations only, due to reduced runway capacity caused by unpredictable individual aircraft behavior. The Three-Degree Decelerating Approach (TDDA) has been developed to increase predictability and runway capacity by switching the sepa- ration task from Air...