.
Increased terminal area throughput, due to more efficient arrival trajectories for appropriately equipped aircraft.
4.3.11 Terminal Arrival: Self-Spacing for Merging and In-Trail Separation
4.3.11.1 Problem
Excessive in-trail spacing buffers in arrival streams reduce runway throughput and airport capacity, especially in conditions of poor visibility and/or low ceilings.
In terminal area environments for which arrival demand approaches or exceeds capacity, aircraft landing rates are significantly lower under instrument meteorological conditions (IMC) than under visual meteorological conditions (VMC). In order to compensate for uncertainties in aircraft performance and position, the ATSP applies in-trail spacing buffers to arrival streams under IMC in order to ensure that minimum separation requirements between successive aircraft are met. The resulting generous arrival spacing reduces runway throughput below its capacity to accept aircraft.
4.3.11.2 Solution (Flight Deck focus)
Appropriately equipped aircraft are given clearance to merge with another arrival stream, and/or maintain in-trail separation relative to a leading aircraft.
In VMC, aircraft are often able to maintain closer spacing during the approach, thereby increasing the capacity of the terminal area and the runway acceptance rate. In the current system, the FD is often requested to accept responsibility for visual self-separation once they acknowledge they can see the leading aircraft. In this situation, the FD is responsible for determining and then maintaining a safe separation from other aircraft, and is therefore not subject to the ATSP’s minimum separation requirements.
Self spacing will enable the FD to autonomously merge with another arrival stream and/or maintain in-trail separation relative to another aircraft under IMC as they would under VMC, thus significantly increasing arrival throughput. Self spacing applies to aircraft that are subject to spacing requirements during arrival, from the feeder fix up to the final approach fix.
Anticipated procedures for self spacing involve the ATSP transferring responsibility for in-trail separation to properly equipped aircraft, while retaining responsibility for separating these aircraft from crossing traffic. Once the FD receives clearance to maintain spacing relative to a designated leading aircraft, the FD establishes and maintains a relative position with frequent monitoring and speed/course adjustments. Under some conditions, information such as required time of arrival (RTA) at the final approach fix may be provided by an appropriate ATSP-based DST, thereby enabling accurate inter-arrival spacing that accounts for differing final approach speeds or wake vortex avoidance. ATSP monitors all aircraft to ensure adequate separation. For cases where the flight crew fails to maintain adequate spacing, automated systems or the ATSP will provide a required correction.
Self spacing is expected to make use of datalink capabilities to provide position information and CDTI and/or advanced flight director/HUD guidance technology to provide spatial and temporal situation awareness to the flight crew. FD-based DSTs will provide information to enable manual station-keeping and/or monitoring of automatic 4D trajectory management.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：Concept Definition for Distributed Air/Ground Traffic Management (DAG-TM)(31)
