Aerospace Medicine Technical Reports
FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute
Report No: DOT/FAA/AM-07/30
Title and Subtitle: Use of Traffic Displays for General Aviation Approach Spacing: A Human Factors Study
Report Date: December 2007
Authors: Nadler E, Yost A, Kendra A
Abstract: A flight experiment was conducted to assess human factors issues associated with pilot use of traffic displays for approach spacing. Sixteen multi-engine rated pilots participated. Eight flew approaches in a twin-engine Piper Aztec originating in Sanford, ME, and eight flew approaches in the same aircraft originating in Atlantic City, NJ.
The spacing target was a Cessna 206. The traffic display was either a Garmin International MX-20� (the �Basic� Cockpit Display of Traffic Information, or CDTI) or an MX-20� modified with features to help the pilot monitor the closing rate, the range and ground speed of the traffic-to-follow, and ownship ground speed (Range Monitor). Two other Equipment conditions were Baseline and Autopilot.
Pilots successfully used the displays to maintain the assigned spacing on visual and instrument approaches. The spacing deviations were significantly lower when using the displays during visual approaches than when attempting to maintain spacing without a traffic display. The mean spacing deviation during the IFR approaches was less than 0.10 NM for all three equipment conditions (Basic CDTI, Range Monitor, Autopilot), and these mean spacing deviations did not differ significantly. Range Monitor features appeared to particularly benefit the low-hour pilots.
While the traffic display reduced visual reacquisition times, this effect was only found with pilots whose displays showed additional traffic (not only the traffic-to-follow). In general, however, the additional traffic was associated with less time between fixations on the display and higher workload. Subjects appeared to have had difficulty identifying an optimal display range that would simultaneously provide traffic awareness and spacing task performance. The traffic display necessarily requires visual attention and reduces the attention available for scanning the instrument panel and on visual approaches, the outside world.
For this reason, even if pilots assume responsibility for spacing when they temporarily lose visual contact with the assigned traffic-to-follow, they should notify ATC of the loss of visual contact so that controllers can assume responsibility for separation from other aircraft.
Key Words: ADS-B Displays, CDTI Displays, Navigation Displays, Human Factors, Psychology, Applied Psychology
No. of Pages: 40
Civil Aerospace Medical Institute
Report No: DOT/FAA/AM-07/30
Title and Subtitle: Use of Traffic Displays for General Aviation Approach Spacing: A Human Factors Study
Report Date: December 2007
Authors: Nadler E, Yost A, Kendra A
Abstract: A flight experiment was conducted to assess human factors issues associated with pilot use of traffic displays for approach spacing. Sixteen multi-engine rated pilots participated. Eight flew approaches in a twin-engine Piper Aztec originating in Sanford, ME, and eight flew approaches in the same aircraft originating in Atlantic City, NJ.
The spacing target was a Cessna 206. The traffic display was either a Garmin International MX-20� (the �Basic� Cockpit Display of Traffic Information, or CDTI) or an MX-20� modified with features to help the pilot monitor the closing rate, the range and ground speed of the traffic-to-follow, and ownship ground speed (Range Monitor). Two other Equipment conditions were Baseline and Autopilot.
Pilots successfully used the displays to maintain the assigned spacing on visual and instrument approaches. The spacing deviations were significantly lower when using the displays during visual approaches than when attempting to maintain spacing without a traffic display. The mean spacing deviation during the IFR approaches was less than 0.10 NM for all three equipment conditions (Basic CDTI, Range Monitor, Autopilot), and these mean spacing deviations did not differ significantly. Range Monitor features appeared to particularly benefit the low-hour pilots.
While the traffic display reduced visual reacquisition times, this effect was only found with pilots whose displays showed additional traffic (not only the traffic-to-follow). In general, however, the additional traffic was associated with less time between fixations on the display and higher workload. Subjects appeared to have had difficulty identifying an optimal display range that would simultaneously provide traffic awareness and spacing task performance. The traffic display necessarily requires visual attention and reduces the attention available for scanning the instrument panel and on visual approaches, the outside world.
For this reason, even if pilots assume responsibility for spacing when they temporarily lose visual contact with the assigned traffic-to-follow, they should notify ATC of the loss of visual contact so that controllers can assume responsibility for separation from other aircraft.
Key Words: ADS-B Displays, CDTI Displays, Navigation Displays, Human Factors, Psychology, Applied Psychology
No. of Pages: 40
Last updated: Friday, June 1, 2012