.
Reduced ATSP workload, due to transfer of separation responsibility to the flight crew of appropriately equipped aircraft.
4.3.12 Terminal Arrival: Trajectory Exchange for Merging and In-Trail Separation
4.3.12.1 Problem
Same as 4.3.11.1, but repeated here for completeness.
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.
4.3.12.2 Solution (ATSP focus)
Trajectory exchange between FD and ATSP to improve the accuracy of FD-based and ATSP-based DSTs for accurate merging and in-trail separation with minimal buffers.
FD will transmit relevant information on aircraft and trajectory parameters (e.g., aircraft weight, position, velocity components, estimated time of arrival at trajectory change points, planned final approach speed, local winds) via datalink to the ATSP. This information will allow the appropriate ATSP-based DST to accurately predict aircraft trajectories, thereby enabling it to plan conflict-free trajectories for accurate merging/spacing with minimal spacing buffers. The ATSP-computed trajectory will be transmitted via datalink to the FD for accurate execution by the FMS. The flight crew and ATSP monitor trajectory conformance. It is emphasized that the ATSP retains all responsibility for ensuring adequate spacing. An ATSP-based DST may provide speed advisories to the aircraft’s FMS in order to fine-tune the aircraft's trajectory; however, it is especially important to avoid a situation where the ATSP “remotely” flies the aircraft, and the flight crew is not effectively in the loop.
4.3.12.3 Potential Benefits
. Increased arrival capacity/throughput in IMC, due to a reduction in excessive spacing buffers resulting from the exchange of trajectory information between user and ATSP.
4.3.13 Terminal Approach: Airborne CD&R for Closely Spaced Approaches
4.3.13.1 Problem
During instrument meteorological conditions (IMC), independent approaches to closely spaced runways are not permitted under current procedures.
In the current ATM system, arrival capacity/throughput at airports with closely spaced runways is significantly reduced during IMC operations because independent approaches are not permitted for runways that are less than 4,300 ft apart (3,400 ft apart for airports equipped with a Precision Runway Monitor)
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本文链接地址：Concept Definition for Distributed Air/Ground Traffic Management (DAG-TM)(32)
