Cockpit Traffic Displays Using Varying Levels of
Intruder Intent Information
R. John Hansman (rjhans@mit.edu),
Amy R. Pritchett (amyruth@mit.edu)
Motivation
Advancements in datalink systems will allow more transfer of traffic
information between aircraft. Available information will likely
include aircraft intent, which may improve traffic conflict
alerting systems. The FAA's plan to transition toward a more unstructured
Air Traffic Management System, such as Free Flight will likely place more
responsibility on pilots to anticipate traffic conflicts and develop
maneuver strategies.
Research Objectives and Approach
The primary research objective is to assess the benefit of different levels
of aircraft intent information in recognizing and resolving traffic conflicts.
This may be done by breaking down intent information into four major categories.
1. Current TCAS with Aircraft ID: Current cockpit traffic display which
shows an intruder aircraft's position and altitude relative to the
ownship. The intruder's company and flight number are also shown
next to the aircraft symbol.
2. Rate Enhanced TCAS: Estimation of future aircraft position is based on
an intruder's current state (heading, airspeed, and vertical speed).
3. Rate Enhanced TCAS with Aircraft Commanded State: Estimation of future
aircraft position is based on an intruder's current and commanded states.
A commanded state could include a heading or altitude being captured by the
autopilot.
4. Intent: Future aircraft position is based on an intruder's programmed FMS
flight plan: includes waypoints, altitudes, and the tops and bottoms
of climbs and descents.
The following figure illustrates the four levels of intent.
Relative altitudes are shown in hundreds of feet. Velocity vectors are
shown as solid lines and commanded vectors are drawn as dashed lines.
Waypoints are indicated by stars.
Displays
A cockpit display of traffic information (CDTI) will be developed for
each of the four levels of intent information. A sample display for
each level is shown in the following figures.
Click on any image to see a larger version.
TCAS Display
This is the current traffic display used in commercial airplanes. The
intruder
(UA 385) is 2000 feet above the ownship, and is approaching from
the northeast.
Rate Enhanced TCAS Display
The intruder's absolute heading is shown by the white arrow.
Rate Enhanced TCAS Display with Aircraft Commanded State
The white arrow shows the intruder's current absolute heading. The
intruder is turning left to a heading of south. This new, commanded
heading, is shown by the dashed magenta arrow.
Intent Display
The white arrow shows the intruder's current absolute heading. The intruder
is flying a programmed FMS flight plan. The track to the next waypoint is
shown by the solid magenta line.
Experiment
An experiment will be designed to test the benefit of adding additional
intent information to a cockpit traffic display. The experiment will be
conducted on the part task B-747 flight simulator at the MIT Aeronautical
Systems Lab. Commercial airline pilots will be used as subjects, and will
be presented with a series of traffic scenarios using each of the four
displays. Pilots will be tested for their ability to identify
traffic conflicts, assess their hazard level, and make an appropriate
avoidance maneuver, if necessary. Similarities in the type of maneuver
(lateral, vertical, or speed change) in addition to subjective pilot comments
will be noted for each display.
Current Activities
Current work is focusing on refining the four traffic displays.
Considerations are being given to the presentation of vertical information
and the development of hazard criteria for displaying multiple aircraft
conflicts. Common scenarios are being developed to simulate
many types of traffic conflicts, including: lateral only, vertical only,
lateral and vertical, and maneuvering intruder aircraft.
