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

Trajectory-Based Operations (TBO)
Study Team Report
It is important to emphasize that TBO is about choices. Once received, choices are negotiated,
accepted, and then executed with precision. As the airspace traffic density increases, there is greater
need for precision performance. But TBO can function at any level of precision. It is the execution of
the agreement that assures separation. Strategically, automation must provide choices to the
operator/user that resolve downstream conflicts and address flows. Weather is integrated into the
decisions that must be made both strategically and tactically. As the number of strategic decisions rise,
the number of tactical interventions will diminish, balancing workload both in the air and on the
ground. However, the amount of pre-planning for the flight will likely increase, and the interchange
between airline operations and the ANSP will rise as trajectories are used to strategically manage the
volume of traffic.
In communications, TBO is highly dependent on ground-ground connectivity for network-centric
operations and data link for negotiations, agreement, and validation of execution of any given 4DT.
But one data link pipe does not represent a single solution. Because TBO communications are mostly
in a strategic time frame, the urgency of connectivity is unnecessary for a majority of the transactions.
Multiple paths of communications can be used. The Study Team has made several recommendations
on developing the messaging content and requirements for TBO because of the urgency in getting to a
set of requirements. The requirements are more about the information flows between systems than
about the performance of the link. A total of 46 recommendations have been offered for further action,
ranging from better definitions of operational improvements to initiating the safety case for TBO.
With respect to aviation security, TBO represents one of the layers of adaptive security. Intent is a
powerful tool in monitoring conformance. Likewise, in flight planning there are opportunities to build
in authentication, from submittal of a plan to starting the aircraft. In-flight performance puts bounds
around the aircraft and deviations from these bounds have separation consequences that must be
addressed.
Environmentally, TBO provides an opportunity to meet improved noise performance by more closely
defining flight tracks. TBO offers savings in fuel burn, at the airport, during climb, through the use of
cruise climb, and the optimized arrivals to an airport. Noise, emissions, and fuel savings translate into
tangible environmental benefits and the procedures lead to saving cost of operations.
Finally, The TBO Study Team recognizes that this is the start of a greater debate on the details of
TBO. Our approach was to provide information on how TBO would work in the context of operational
scenarios. Much work must follow. Critical among this work is the beginning of a safety case and the
necessary analyses to reach decisions on fundamentally changing how aircraft are separated. This
safety case is followed by the functional requirements for TBO and a significant discussion on
definition of requirements for automation’s performance.
Joint Planning and Development Office
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