# Presentation: 037909

## A Cockpit Display Designed to Enable Limited Flight Deck Separation Responsibility 

- Walter W. Johnson & Vernol Battiste
*NASA Ames Research Center*
- Sheila Holland Bochow
*San Jose State University*

**Presented By: Vernol Battiste**

## Outline

- Goal of the display design
- Display and Functions
- Full mission simulation: display evaluation
- Crew perspective and comments
- Conclusions

## Goal

- A goal of the cockpit situation display (CSD) design is to present a combined cockpit display of traffic, conflict alerting, and flight path re-planning system which facilitates cockpit flight path re-planning and coordinating with ATC.

## CSD/NAV Display  B-747-400

**Display Features**:
- Position and intent of ownship and traffic
- Predictive Information
- Clutter management
- Color
- Selected route and ID

**CSD/NAV Display  B-747-400**

## CSD Depicting Three Alert Levels (SA)

**CSD Depicting Three Alert Levels (SA)**

**Situational awareness levels**:
- SA1 - Open yellow chevron
- SA2 - Filled yellow chevron
- SA3 - Filled yellow chevron with lines and circles indicating the point where separation will be lost. Flight ID is displayed for all SA levels.

## Static and Pulse Predictors

**Static and Pulse Predictors**

**Pulse**

**Static**

**Notes:**
Figure 5. Static predictors (top) are presented at a range of ten minutes.  The dashed portions of AAL85 and UAL75 represent the areas where these aircraft will be changing altitude.  Pulsed predictors (bottom) were similar to static, but they also included small bright bullets that were repetitively emitted from the individual aircraft.

## Advanced Route Assessment Tools

**Modification of current route profile at any waypoint**
**Heading**
**Speed**
**Altitude**
**Display synchronization to support intra-cockpit comm. **
**Route modifications sent to ATC for approval via FMS/FANS protocol**

## Predictor Tool

**Present future aircraft’s position in minutes ahead**
**Static**
**Pulse**
**Relative and absolute altitude tags**
**Aircraft Identification (full data blocks)**
**Smart Tags**
**Routes off**

## Example of altitude change resolution

**Example of altitude change resolution**

**Waypoint Names**
- Flight Plan
- ARAT

## Example of Lateral resolution maneuver

**Example of Lateral resolution maneuver**

## Simulation Study Objectives

**Simulation Study Objectives**

- To assess the value of 4/D intent information (flight plans) for flight crews performing  strategic self separation  during en route free flight operations.
- To obtain display usage measures for the various display tools.
- To obtain flight crew feedback on utility (effectiveness and workload) of specific display features and overall display design.
- *** To obtain measures of flight crew / ATC coordination
- *** To obtain measures of effectiveness of procedures emphasizing low and high ATC responsibility

## Approach

**Approach**

- 10 Boeing  747 flight crew flew 8 en route scenarios incorporating climbing, descending, and level encounter geometries.  The encounters reflected both “true” and “apparent” conflicts.
- The flights were conducted in an ATC super sector (FL350 and above covering two regular Oakland sectors) manned by an FPL controller from the areas of interest.
- The flight crew’s task was to maintain vertical (1000ft) and lateral separation, by re-planning their flight trajectory and submitting changes to ATC for approval.

## Procedures

**Procedures**

- All flight plan changes/maneuvers required coordination and concurrence with ATC via datalink and voice
- Flight crews attempted to optimize flight profiles based on their understanding of AOC and flight deck priorities
- ATC operated the sector based on current rules and practices

## Experimental Design

**ATC Role**

**Flight Deck **
**Intent **
**Information**

- Flight Plans

- No Flight
- Plans

- Strategic &
- Tactical

- Tactical

## Dependent Measures

**Dependent Measures**

**Separation violations **
**CPA**
**Number of changes initiated by crew, and number accepted by controller**
**Number of changes initiated by controller**
**Crew intervention time **
**Controller intervention time**

**Controller and crew assessment questionnaires **
**Subjective workload (crews and controllers)**
**ATC’s assessment of crew separation strategies (modify request) **
**Crew and controller acceptance**

## Results

- Post simulation, crews responded to a Likert scale format (1-7 scale) - generally 1 negative, and 7 positive, or preferences with either choice anchoring the scale (e.g.,1- static and 7 - pulse predictors)
- A neutral position of 4 was used as an anchor to evaluate ratings that were significantly (p<0.05) above or below the anchor, on a two tailed t-test.

## Results: Display Clutter with and Without ARAT

- Neutral response with ARAT -M=4.13, without ARAT -M=4.5
- Flight crews reported that # of aircraft were the main cause of display clutter
- They suggested that the ability to remove aircraft that were flying away at a different altitude (assumed no longer a threat) could help solve this problem

## Results: Text Size and Readability

- Positive response
- Tail tags, M=5.69
- Aircraft ID blocks, M=6.0
- Flight plan waypoint names, M=5.78
- Neutral response
- ARAT waypoint names, M=4.44

**Notes:**
Dimming of waypoint names was a problem when discussing the change with ATC
Waypoint names overlapped with standard waypoint names

## Results: Aircraft Symbols

- Ownship and traffic (size, shape, altitude format, 1 minute predictor, & brightness), positive M=5.97
- Color coding of relative  altitudes (blue -above, green - below, and white -same altitude), Positive M=6.37
- Comment:
- The color coding allowed an instant recognition of the traffic situation.
- Brightness levels were not as effective.

## Results: Flight Plans

- Positive response to flight plans (symbol size, shape, waypoints, & altitude segment), M=5.75
- Positive response to the use of color in the flight plan, M=5.84
**Comment: Broken (dotted ) line was very effective**

## Results: Input Controls

- Predictor  panel mounted controls
- Ease of use, positive, M=5.61
- Desirability, positive, M=5.47
- ARAT panel mounted controls
- Ease of use, neutral, M=4.94
- Desirability, neutral, M=5.33
- Touch Pad predictor and ARAT
- Ease of use, neutral, M=4.69, & M=4.5
- Desirability, neutral, M=4.47, & M=4.18

**Notes:**
Precision on the touch pad was lower than  for the control panel

## Results: Aircraft ID Blocks

- 15 of 16 flight crew members reported that information in the flight ID block was necessary
- Comment: One addition to the current information set was suggested - final altitude for climbing and descending aircraft

## Results: Predictors

- Static, neutral M=4.44
- Pulse, very positive M=6.66
- Preference (1-static or 7-pulse), Positive M=6.03
- Input devices - controlling predictors
- Control panel, positive M=5.56
- Touch Pad, neutral M=4.22
- Preference (1 - control panel to 7 - touch pad), M=3.28

## Result: Alerts

- Alert Symbology
- Overall (shape, sound and function), positive M=5.63
- Effectiveness when ARAT engaged, positive M=5.82
- ARAT symbology (size, shape, waypoints, altitude segment, and waypoint table), positive M=5.50
- Alert Resolution
- Preference for vertical or lateral maneuver, Neutral M=4.47
- Location of initial maneuver (1 - near or 7 - away from ownship), neutral M=4.38
- Value of flight plan, positive M=5.47
- Alert timing
- Minimum time for alert level 3, M=5.63
- Placement of “Null” point, M=2.43 minutes ahead of ownship (current design is 1.50)

**Notes:**
All crews wanted to have flight plans for other traffic on the display

## Conclusions

- A goal of the CSD design and evaluation was to assess crew responses to 3-D and 4-D traffic information, display clutter, and flight re-planning tools.
- Positive response to 3-D flight plans
- Positive response to pulse predictor
- Positive response to altitude color coding (both flight plan & traffic)
- Neutral response to clutter management tools
- Ratings showed that crews had difficulty with the ARAT controls.
- Neutral ratings for panel and touch pad suggest that these input devices need work.
- Initial analysis of the performance data suggest that crews were successful at their primary task, of maintaining en route separation