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

Trajectory-Based Operations (TBO)
Study Team Report
at 8,000 feet (2,500 feet AGL). She lowers the landing gear and continues slowly while crossing
CYOTE at 8,000 feet. The virtual tower controller advises N72MD that the Moon Air aircraft ahead
has reported deteriorating visibility at the runway.
When aircraft N43P is five nm east of the LIVINGSTON feeder fix, a data link message is received
from the BZN virtual tower sequencing N43P to conduct the RNAV (RNP) RWY 30 Approach with
five nm spacing behind aircraft N72MD. The pilot of N43P pushes a virtual button on his glass cockpit
display to accept the clearance (WILCO). He sees on the CDTI display that aircraft N72MD has
already started to RF leg from CYOTE to WOLFE. N43P’s onboard spacing tool determines a relative
4DT for the approach to maintain adequate spacing behind the slower aircraft throughout the approach
and landing. Upon reaching the EAGLE IAF, the pilot of N43P is instructed to contact the virtual
tower via voice radio. The virtual tower ANSP clears N43P by voice for the approach and landing with
delegated separation authority to conduct spacing behind N72MD. The pilot accepts the clearance via
voice. This represents the first voice communication the pilot has had with a controller since leaving
Cincinnati airspace. The assigned clearance means the controller intervenes by exception and only
does so by voice when data communications are inadequate or the aircraft is not suitably equipped.
N43P continues the approach, with onboard spacing tools continuously monitoring the progress of
N72MD ahead and periodically updating the speed guidance for spacing.
The pilot of N72MD begins to roll out of the RF turn to the final approach with situational awareness
of the surrounding terrain and flight path via the SVS terrain and Highway-In-The-Sky (HITS)
displays. Pathway deviation indicators provide the guidance necessary to accomplish the RF turn and
the RNP 0.1 approach. The pathway deviation indicators compensate adequately for the winds, and the
pilot is able to maintain the course within RNP 0.1.
The navigation display shows WOLFE (FAF) at rollout of the turn four nm from the RWY 30
threshold with an altitude of 6,700 feet mean sea level (MSL). Upon reaching WOLFE, the virtual
tower ANSP gives N72MD landing clearance via voice and instructs the pilot to report clear of the
runway. Due to the high winds, the pilot will maintain an approach speed of Vref+20 until
approximately one half mile from the runway threshold then slow to Vref+10 for landing. The aircraft
is established on the straight-in segment of the final approach course at three nm from the runway.
At approximately one mile from the runway, the snow increases in intensity. The virtual tower ANSP
reports that the visibility is now down to less than a quarter mile in blowing snow. The pilot is able to
use the SVS to maintain runway alignment and vertical profile, but has not visually acquired the
runway before reaching decision height, and is forced to conduct a missed approach. The virtual tower
ANSP provides vectors for N72MD to leave the BZN vicinity with a left turn to cross over SLOAN at
10,000 feet. While in the turn, N72MD advises that she will proceed to her alternate and receives
another vector from the ADS-B surveillance on course to successfully land at an alternate airport with
better current weather. At handoff from the virtual tower to the en route tactical controller, a new 4DT
to the alternate has been determined, and will be provided to the pilot to go from an open to a closed
trajectory in TBO.
Aircraft N43P also encounters the higher intensity snow at one mile from the runway. However, N43P
is equipped with an EVS in addition to its SVS. The N43P EVS provides the pilot with current runway
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