Management of continuous descent approach during interval management operation

Abstract

This paper reports on the performance and workload of pilots participating in a human-in-theloop simulation of interval management operations during a continuous descent approach (CDA) into Louisville International Airport (SDF).The experiment examined variations in pilot roles and responsibilities in an implementation of interval management automation.The roles and responsibility manipulation showed that whether pilots were instructed to follow speed guidance strictly, or to exercise their own judgment, had no effect on workload and only a small effect on interval management performance. However, requiring the pilots to manually enter speeds into the autopilot, rather than having the automation automatically update the autopilot, frequently led to poorer energy management, and higher spacing interval errors at the final approach fix, even in the conditions where pilots were instructed to strictly follow speed guidance. This finding was traced to poorer compliance with the automated speed guidance, lack of awareness of this poor compliance, and insufficient awareness of the energy state of the aircraft. These results suggest that some form of energy guidance may be needed to augment interval management. To do this, recommendations were made for integrating the spacing interval management automation with near-term or far-term energy management systems.Workload measurement showed that, when pilots were required to maneuver to avoid en route weather, the manual conditions resulted in an increase in workload, although the overall level would still be considered low under normal circumstances.

Pilot response to off-nominal conditions in merging and spacing operation

“…The Pilot Instruction manipulation determined whether the pilot was told to faithfully follow automated speed commands (Follow Speed Command); or was given the latitude to overrule/augment this automated guidance with his or her own judgment (Pilot Discretion). For the purpose of this paper, these two manipulations were not considered because they did not yield any statistically significant results in the en route segment; however, they affected the CDA segment of the operation and are discussed in the companion paper [14]. The focus of this paper is the weather manipulation, which represents the offnominal conditions occurred in en route segment.…”

“…The automated spacing tool is based on the ASTAR algorithm developed at NASA Langley. The reader is referred to [14] for a more complete description of the simulation environment and tools used in this HITL study.…”

“…Time interval between aircraft at the merge point 5. Amount of path stretch in different weather conditions Additional data concerning the management of the CDAs were obtained and presented in the companion paper [14].…”

“…The first aspect of the study is presented in a companion paper [14], which examines how well pilots could manage CDAs and interval management while using ASTAR automation. The results, reported for the CDA segment (after the top of descent) of the operation, showed that requiring the pilots to manually enter speeds into the autopilot, rather than having the automation automatically update the autopilot, frequently led to poorer energy management and higher spacing interval errors at the final approach fix.…”

Arrival Time Control during Continuous Descent and Its Application to Air Traffic Control

“…[9][10][11][12][13][14] Although these concepts differ in detail, their basic strategies can be summarized as follows: an aircraft descends from the top of descent (TOD) to reach the merging point at a required time, and maintains an appropriate interval with the preceding aircraft by airborne separation as shown in Fig. 1.…”