Trajectory-Based Operations (TBO) - Joint Planning and ...

Trajectory-Based Operations (TBO)
Study Team Report
departure. These were provided by the ANSP during flight planning. The planned profile is then
updated for weight and winds and provided back to the crew. Once received by the crew and entered
into the FMS, it is followed by an intent message from the aircraft to the ANSP verifying that the 4DT
is set. The 4DT includes a takeoff time that the flight crew will have to meet during the taxi portion of
the flight. The moving map actually displays required progression of time during taxi-out for takeoff.
When reaching the runway end for departure, the number of aircraft in the queue is low because taxiout
is managed from the gate. The ANSP clears Sunset 42 for takeoff. As the aircraft rolls down the
runway and lifts off, the surveillance system logs liftoff time from ADS-B. This information is sent to
the TBO strategic evaluation service to re-compute the 4DT and identifies any downstream strategic
changes that may be necessary. Takeoff time is also used in the TBO departure automation module to
calculate time performance for conformance monitoring.
Once a positive rate of climb is established, Sunset 42’s flight crew retracts the landing gear and
executes the prescribed sequence of climb speeds and flap retractions. Once established on the climb,
the FMS updates climb performance and refines the vertical profile. This new vertical profile is sent to
the ANSP via data link as part of an intent message. The ANSP can then update the vertical windows,
narrowing the amount of vertical airspace required to support the departure. Over time, the surveillance
capabilities of the ANSP have learned the bounds for this aircraft type; weight load and information
can then be used to reduce the required reservation of airspace due to shrinking the variability of
performance.
The flight crew monitors their in-trail spacing and relative altitude behind a heavy jet that took off just
prior to them (two-minute separation is not required due to crosswind) using their CDTI. Sunset 42
lifted off earlier on the runway than the heavy and immediately climbed above the heavy’s altitude
along the same flight track. The CDTI provides a history tail of the lead aircraft so that the crew can
plan wake vortex avoidance whether in visual or instrument flight rules by selecting data through the
CDTI.
As the aircraft climbs through 2,000 feet AGL, the tower transfers control of the aircraft within ANSP
automation to departure control. An unobtrusive tinkling chime reminds the flight crew that they are no
longer in contact with tower voice communications and can expect routine communications with ATC
through data link. A “channel open” light on the data link control panel indicates a data link
“handshake” has been made with the ANSP and a voice channel is available if needed.
Prior to 2,500 feet AGL, they engage lateral navigation (LNAV)/VNAV and begin the tailored OPC.
This sends an automatic message to ground automation to update the 4DT performance, so that
conformance monitoring automation can be updated. The aircraft climbs away from the airport along
an optimized vertical profile, exiting the high-density terminal airspace to the west with a climbing left
turn once above noise sensitive areas.
The heavy jet ahead of Sunset 42 is not a factor, as its departure speed is higher. Although not cleared
for any separation tasks, the flight crew monitors traffic on nearby dynamic RNAV/RNP OPDs from
southern California since they are passing relatively close below these arrival paths.
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