Ecological Interface Design in Aviation Domains: Improving Pilot Trust in Automated Collision Detection and Avoidance Presenter: Danny Ho Supervisor: Dr. Catherine M. Burns Advanced Interface Design Lab Systems Design Engineering University of Waterloo © 2003, Danny Ho

Establishing Perspective On July 1, 2002: Bakshirian Airlines Tupolov 154 collided with a DHL Cargo Boeing over Southern Germany Sequence of events as the two aircraft converged: 1)Onboard collision system told Boeing to climb 2)Onboard collision system told Tupolov to descend 3)Air traffic control (ATC) told Tupolov to climb 4)Boeing climbed 5)Tupolov climbed 6)Collision occurred at 35,000 feet. There were no survivors. The system FAILED! How?

Outline Defining the Problem and the Objective The Methodology Ecological Interface Design (EID) Abstraction Hierarchy (AH) The System Traffic Alerts and Collision Avoidance System (TCAS) Applying EID to TCAS Approach Implementation EID-Enhanced Displays Experimental Approach - Proposed Experimental Design Data Analysis Future Direction & Conclusions

Defining The Problem Possible Contributing Factors  Policies and procedures North American versus European policy  Human Factors Pilot execution Cognitive performance Interface inadequacies Trust in automation

Defining The Problem The pilot did not have the necessary information to perform effectively in the automated alerting situation The pilot didn’t know who to trust  TCAS or ATC?

Defining The Objective To propose display enhancements and evaluate their effects on pilot trust and decision making performance in automated air traffic alerting conditions It is hypothesized that:  An EID-enhanced display will increase decision making performance and accuracy  An EID-enhanced display will increase pilot trust in the TCAS automated alerts

The Methodology Ecological Interface Design (EID)  A framework for designing interfaces primarily for complex systems (Vicente, Rasmussen, 1992) Nuclear power plant control (Rasmussen, 1985) Aircraft engineering system (Dinadis & Vicente, 1999) Shipboard command and control (Burns et al., 2000)  Shown to improve operator task performance and conflict detection because it develops a contextual link between information to the trained operator  Uses Abstraction Hierarchy (AH) (Rasmussen 1985) as a design basis

The Methodology Abstraction Hierarchy (AH)  A 5-layered systems approach to component and interaction representation WHY? HOW?

The Methodology EID: “What data should be extracted, and how should it be presented to help the user understand the system?” UCD: “How do users perform, and what interface elements can be used to optimize their task performance?” The EID methodology should create displays that convince pilots to perform a task rather than command them to perform a task

The System - TCAS Traffic Alerts and Collision Avoidance System TCAS 2 – version 7.0  Internationally adopted and mandated by FAA for all North American aircraft with capacity exceeding 30  Operates independently of onboard systems/radar  TCAS 1 introduced in 1981  TCAS 1 provides only collision detection  TCAS 2 also calculates avoidance maneuver

TCAS - Flight Crew - ATC interaction

TCAS Overview 2 Levels of Alerts -TA : Traffic Advisory - ‘traffic, traffic’ - RA : Resolution Advisories - ‘climb’, ‘descend’, etc… Data Inputs - intruder range, altitude, bearing - ownship range, altitude, bearing Operational Parameters - protected volume varies with speed - threat based on time, not distance - pilot must inform ATC of RA maneuver - pilot must return to ATC course after RA - no RA’s under 1000 ft altitude - system accounts for slow convergences - if intruder doesn’t react to their RA, ownship RA can be recalculated

TCAS Aural and Visual Alerts

TCAS Display

TCAS in MS Flight Simulator 2002

Applying EID to TCAS This study introduces a novel approach to applying EID to collision detection and avoidance, dividing the problem into 3 entities (A)ircraft, (T)CAS, and (E)nvironment  A: One AH representing flight dynamics for each aircraft involved in the encounter  T: One AH of the TCAS system for each aircraft  E: One AH describes the airspace of the collision encounter

AH - Aircraft

AH - TCAS

AH - Environment

TCAS Implementation - unmodified Conforms to FAA specifications & algorithms - Written in Visual Basic - Uses FSUIPC 3 rd party module by Pete Dowson - Provides TCAS symbology - Provides aural announcements - Provides safe vertical speed ranges

EID-Enhanced TCAS Displays D1: unmodified TCAS symbology D2: circle around aircraft indicates protected volumes, red circle represents predicted collision area, time to loss of separation (LOS) is also indicated in seconds D3: TIME to LOS is used as radar scale instead of separation distance, LOS time shown, and ground speed velocity indicators for each aircraft

Experimental Design Participant background questionnaire TCAS, MSFS tutorial TCAS calculation proficiency exercise 3 sets of display condition trials (randomized)  Subjects press a button to show intent to maneuver  5 trials with colliding traffic, TCAS alerting on  8 trials with TCAS on/off, colliding/non-colliding traffic evenly permutated scenarios (randomized order)  NASA-TLX, self-confidence, and trust level surveys Overall display preference questionnaire

Data Analysis Within subjects design 1 factor (display condition: D1, D2, D3) repeated measures analysis of variance (ANOVA) Dependent variables  Colliding traffic and TCAS alerting on Reaction time after alert until intent to maneuver Conformance to TCAS calculated maneuver  Colliding traffic and TCAS alerting off Reaction time to sense a conflict with intent to maneuver Conformance to theoretical TCAS calculated maneuver Additional investigation of signal detection theory to determine effects across displays

Future Direction and Conclusions Experimental results will indicate if EID-enhanced displays improve pilot reaction time and conformance to TCAS alerts Results comparison between D2 and D3 will provide additional information on the effects of distance-scaled versus time-scaled displays on collision detection performance Qualitative interpretation shall illustrate the influence of EID-enhanced displays on pilot trust in automated displays

Acknowledgements Centre for Research in Earth & Space Technology (CRESTech) Microsoft, software and hardware sponsor Dr. Catherine M. Burns Members of AIDL Jin Qian, Dr. Jeanette O'Hara-Hines Department of Statistics & Actuarial Sciences Thesis readers  Dr. Carolyn G. MacGregor, SYDE  Dr. Hamid Tizhoosh, SYDE

Q & A Thank you!