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

Trajectory-Based Operations (TBO)
Study Team Report
Above 10,000 feet AGL, the crew reviews and briefly discusses updated timing constraints related to
the cruise portion of the flight, and whether a speed change will be needed to meet them. Since the
aircraft also has conformance monitoring capabilities through the FMS, the crew notices that they are
climbing slower than expected to meet top-of-climb and makes a vertical adjustment, trading optimum
climb to meet optimum time.
As Sunset 42 continues on its 4DT track, transfer of control and changes in frequency arrive on the
flight deck automatically, for both the data link and voice communications channels.
ANSP trial planning automation detects an upcoming conflict with WestAir 834 approaching from the
southwest at FL240. With projected loss of separation 12 minutes out, the strategic TBO evaluation
automation estimates that instructing WestAir to reduce its speed slightly will prevent the conflict from
developing. The strategic TBO evaluation automation calculates that this resolution will not interrupt
WestAir’s OPD timing, and will maintain Sunset 42’s schedule to meet en route timing constraints.
The strategic TBO evaluation automation prepares the 4DT modification for the tactical controller’s
review and acceptance, and then the controller sends it to WestAir. Sunset 42 is aware that WestAir is
to the southwest of their position, but the potential conflict and its resolution are transparent to them.
The FMS automatically generates and sends an intent report giving the aircraft’s status when the RNP
departure is complete. The ANSP monitors Sunset 42 as it exits its departure RNP path at the initial
cruise altitude. Since this is an intent message that is used for conformance monitoring, the message
also contains what the crew has set in the FMS for the next segment of the flight, projecting forward
the 4DT. Conformance monitoring on the ground is using surveillance information and clearance
information to track the aircraft’s compliance with the flight trajectory. Parameters in flight
performance are set by a combination of the clearance and the ANSP’s strategic controller. At initial
climb level off, the controller has set an RNP value of 2, a vertical tolerance of + 50 feet, and a time to
the next turn of - one minute and + three minutes as recommended by the TBO strategic evaluation
automation. This timing bound is set because of crossing traffic. The TBO strategic evaluation has also
set a five nm separation requirement for this airspace.
13.3 Phoenix to Miami Cruise Segment
During the cruise portion, Sunset 42 flies in TBO airspace along the U.S.-Mexico border before
proceeding over the Gulf of Mexico. While flying near the border, Sunset 42 encounters dynamic
special use airspace areas and Unmanned Aircraft Systems (UAS) operations. Once over the Gulf,
Sunset 42 transitions into self-separation airspace and encounters a large low-pressure system. It then
re-emerges into TBO managed airspace as it approaches the Florida coastline, prior to commencing its
descent—an OPD to MIA. 12
Other relevant aircraft in the cruise segment include Winds Air 134 and Westair 351. Winds Air 134
(Houston George Bush International Airport [IAH]-MIA) is a self-separating aircraft and Westair 351
(MSY-MIA) is a managed aircraft unequipped for self-separation. Both interact with Sunset 42 in selfseparation
airspace.
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The assumption is that in self-separation airspace, the aircraft is free to maneuver, and as such is on
an open trajectory, but not without conformance monitoring from the ground that is tracking progress.
The trajectory is closed before exiting self-separation airspace.
Joint Planning and Development Office
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