Trajectory-Based Operations (TBO) - Joint Planning and ...
Trajectory-Based Operations (TBO) - Joint Planning and ...
Trajectory-Based Operations (TBO) - Joint Planning and ...
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<strong>Trajectory</strong>-<strong>Based</strong> <strong>Operations</strong> (<strong>TBO</strong>)<br />
Study Team Report<br />
may be brought in over the top of the weather <strong>and</strong> assigned a new arrival path segment. Weather<br />
avoidance may also include a flow corridor where aircraft are routed because of gaps in the convective<br />
weather, or because of areas reported or detected on radar as having passable conditions.<br />
The bottom line is to h<strong>and</strong>le weather strategically, based on airspace that is potentially constrained<br />
during the development <strong>and</strong> transport of the storm. This still leaves aircraft that are scheduled to depart<br />
or committed to l<strong>and</strong> during the window of worse weather.<br />
For runway changes, aircraft are held at the gate <strong>and</strong> given a start taxi time so they can load passengers<br />
accordingly. Once off the gate, they are sequenced to expedite their flow to the runway end, such that<br />
there are minimal or no queues that would either be trapped by the weather or require redirection<br />
during runway swaps. Aircraft with taxi-out times close to the change in runways would be directed to<br />
the new runway. The concept of managing departures off the gate is done using the functions of the<br />
ANSP’s surface movement management module. This module knows the taxi-out time by aircraft type,<br />
operator <strong>and</strong> gate, scheduling accordingly to avoid long queue formation during the worst part of the<br />
weather. This feature also deals with the deicing requirements for each aircraft type to get airborne<br />
within a specified interval.<br />
Aircraft on arrivals <strong>and</strong> in the weather are avoiding intense storm areas using voice requests, <strong>and</strong> are<br />
traveling in open trajectories under the direction of ATC through control by exception. The cockpit<br />
workload is too great to accept constant changes to the 4DT during this phase of flight, <strong>and</strong> turbulence<br />
may require speed <strong>and</strong> direction changes. Aircraft on RNAV/RNP arrivals can expect to fly the arrival,<br />
but then receive vectors to downwind as the runway directions change. Those that arrive at the height<br />
of the weather constraint may receive holding instructions as necessary to balance dem<strong>and</strong>. Coming<br />
out of holding, aircraft can expect a new 4DT provided by the <strong>TBO</strong> strategic evaluation service. The<br />
dem<strong>and</strong> cannot exceed what the controller can h<strong>and</strong>le in control by exception.<br />
Controllers are aided by automation to maintain a dem<strong>and</strong> that can support the higher volume of open<br />
trajectories that will be needed. Once the controller believes that the aircraft is capable of returning to<br />
4DT, a clearance is issued to close the trajectory, <strong>and</strong> automation resumes separation responsibilities.<br />
Deviations for weather are h<strong>and</strong>led first under <strong>TBO</strong> as a strategic change through issuance of a new<br />
4DT that considers weather, then as an open trajectory 4DT for maneuvering, then as an open<br />
trajectory, with vectors as control by exception. Once established on an approach path, the trajectory is<br />
again closed.<br />
16.2 Runway Closing<br />
A disabled aircraft on the runway creates this off-nominal event. The commuter aircraft had a right<br />
main gear collapse during l<strong>and</strong>ing rollout, <strong>and</strong> the aircraft veered off to the right <strong>and</strong> is sitting partially<br />
on the runway <strong>and</strong> partially on the grassy area. At the time of the event, two aircraft on final for the<br />
same runway were sent around <strong>and</strong> re-sequenced. A third was sequenced into a gap in the arrival<br />
stream for the parallel runway. L<strong>and</strong>ing operations were shifted to the parallel runway that was in the<br />
middle of a departure push <strong>and</strong> departures were held. Emergency vehicles are responding <strong>and</strong> those<br />
aircraft taxiing are told to hold their current position.<br />
<strong>Joint</strong> <strong>Planning</strong> <strong>and</strong> Development Office<br />
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