Cognitive Engineering Perspective of ASAS

Amy Pritchett

Cognitive Engineering Center

School of Aerospace Engineering

Georgia Tech

Atlanta, GA

Our View of ‘the System’

human

& physical environment

& procedural environment

& social/organization environment

Behaviours of Interest

Alerting Component Command Component

Comprehension of Occurrence Comprehension of Directions of Alert Given By Command

Base Reaction Time Ability to Follow Command

Perception of Alert Correctness Perception of Command Correctness

Willingness to Act Upon Alert Willingness to Follow Command

Propensity to Follow Alert Propensity to Follow CommandIn Operational Context In Operational Context

Impact on Monitoring Impact on Decision Making Behaviour Behaviour

Impact of False Alarms Impact of Erroneous Commandson Pilot Behaviour on Pilot Behaviour

Impact of False Alarms Impact of Erroneous Commandson System Performance on System Performance

Op

erat

ion

al I

mp

act

Con

trol

lab

ility

Du

rin

g T

esti

ng

Simultaneous, Closely Spaced Parallel Runway Operations

Motivation: The Ability to Land Aircraft Simultaneously on Closely-Spaced Runways During Instrument Meteorological Conditions Could Substantially Reduce Flight Delays

Problem: Aircraft are Closer Together Than During Any Other Phase of Flight

Parallel Runway Operations Experiment -

Effects of Displays on Performance

0%

10%

20%

30%

Baseline PFD EHSI Combo

Ap

proa

ches

% Under 500'% Under 1000'

Display

Parallel Runway Operations Experiment -

Non-Conformance Rate By Displays

0%

10%

20%

30%

40%

50%

BaselineEHSI

EnhancedEHSI

PFD &Baseline

EHSI

PFD &Enhanced

EHSI

Parallel Runway Operations Experiment -

Effects of Non-Conformance

Matches DisplayedManeuver

Does Not Match

Matches DisplayedManeuver

Does Not Match

No Alert or Maneuver Shown Alert & Maneuver Is Shown

0%

10%

20%

30%

40%

% o

f Ap

proa

ches

Under 500' Under 1000'

Comparing Experiment Results

0

2

4

6

8

10

12

14

16

18

NTZ Alert MIT Alert No Alert NTZ Alert MIT Alert No Alert NTZ Alert MIT Alert

Best Reaction Time Experiment Best Judgement Experiment

Basic Display NTZ Display MIT Display

Similar Differences Found Between Operational Studies!

Implications for Situation Awareness

Situation awareness OF WHAT? Good traffic information

and hope they will arrive at the same conclusions as the ASAS?

Would like to communicate the alerting/maneuver logic Requires it to be

COMMUNICABLE

Achieved Separation Distance

7.2

7.4

7.6

7.8

8.0

8.2

8.4

8.6

8.8

Baseline Display Display withSpeed

Display withSpeed andAutopilotTargets

Baseline STAR

STAR with Speed

STAR with Speed andMerging Path

•Significant display/procedure interactions (F=2.91, p<.04)

0%

5%

10%

15%

20%

25%

Baseline Display Display withSpeed

Display withSpeed and

Autopilot Targets

Per

cen

tag

e o

f T

ota

l S

pee

d C

han

ges

Mad

e w

ith

in 8

Sec

on

ds

of

ST

AR

Ch

art

Ref

eren

ce

Baseline STAR

STAR with Speed

STAR with Speed andMerging Path

Percentage of Total Speed Changes Made Within 8 Seconds of STAR Chart Reference

•Marginal effects due to displays (F=3.06, p<.06)

•Marginal effects due to procedures (F=2.83, p<.07)

0

0.5

1

1.5

2

2.5

3

3.5

4

Baseline Display Display with Speed Display with Speedand Autopilot Targets

Sep

arat

ion

(n

m)

•Marginally significant display effects (F=3.05, p=.10)

(Error Bars Represent )

Deviant Scenario Average Separation Values

Implications for Procedures

Procedures can be as rigorously designed as technology Includes procedures for using the system, for

crew interaction, and for ATC/ATM Procedures provide a baseline for behavior

And as such are often the basis for:• Expectation• Monitoring • Planning• etc

Modeling the Role of Alerting Systems

Do machine-driven definitions of role define everyway that pilots will use alerting systems? They direct attention to signals or hazards and that’s it?

NO! Pilot-determined roles?

How alerting system is used, and what it is useful for, is:• Context sensitive• Opportunistic by the pilot• Idiosyncratic

Attention Director

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

X

Look!

Task Management Aid

Environment

Displays Controls

ComputerHuman

NominalTask 1 Nominal

Task 2

Trusted Monitor

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

X

Look!

Nuisance

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

Overload

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

Final Authority of Problem

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

It’s OK, blame it on me

Resolution Assessor

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

Desired Cue

Environment

Displays Controls

ComputerHuman

NominalTask

Initiator of Procedures

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

Command Device

Environment

Displays Controls

ComputerHuman

NominalTask Alerted

Task

Take-Aways

How ASAS will be used, and how well, needs to consider behavior in context Understanding of the logic relative to the needs

of the situation Operating procedures ‘Roles’ of the ASAS

Difficult to predict – but it can be done!

Thank You!

Questions?