Enhancing pilot ability to perform CDA with descriptive waypoints

Aircraft noise is a burden on people living around airports and is an impediment to the growth of air transportation. Continuous Descent Approach (CDA) is an approach that reduces noise impact on the ground by keeping the aircraft at a higher altitude longer than standard approaches and by keeping engines idle or near idle. However, CDA implementation requires controllers to add large separation buffers between aircraft because aircraft of different sizes and weights descend at different rates, consequently creating uncertainly in separation between aircraft. This paper proposes a viable near- term solution to allow pilots perform CDA more consistently through the use of Descriptive Waypoints (DWs), or checkpoints in terms of altitudes and speeds along the CDA path that provide the pilot targets and feedback along the CDA path. A human in the loop study was conducted to develop and determine the effectiveness of using DWs to improve flight performance during CDA procedures, and provide recommendations on DW design and integration into existing CDA procedures. Twelve instrument rated commercial pilots flew three different wind conditions using one, three, or five DWs. Dependent variables included: deviation from DW target altitude and Indicated Airspeed (IAS), average power usage, perceived workload, and pilot acceptance of DWs. Objective and subjective data were also collected to obtain pilot feedback on the design of DWs and their integration into CDA procedures, and determine pilot strategies while flying CDA with DWs. The results showed that as the number of DW increases, mean altitude deviations from the DW targets decreased from 922 feet to 196 feet and standard deviations from 571 feet to 239 feet with a slight increase in perceived workload and one percent increase in power usage and. The pilots commented that the DWs provide useful feedback to strategize how to make corrections to the altitude deviation in the vertical path, and that they would feel comfortable having the DW integrated in the flight chart or shown as a vertical view on a display. The pilots also provided a number of recommendations for integrating the DW into Jeppesen charts and roles for the pilot flying and the pilot not flying. These results imply that DWs can be used as an effective cuing system to enhance pilot ability to perform CDA, and that they are a potential choice for near to midterm implementation in improving the effectiveness of CDA procedures.