Etude de casRéaction aux alarmes TCAS « AVS »

Symposium DSAC

TCAS : Trafic Collision Avoidance System Détecte les trajectoires de collision potentielle Alerte l’équipage: Trafic Alert (‘’TA’’) Indique la maneuvre à effectuer pour garantir la

séparation verticale : Resolution Advisory (‘’RA’’)

Alarme vocale+

Indication d’assiette

Vitesse verticale demandée

San Diego - 1978 - B727Approche – 2600 ft

Los Angeles-1986- DC9Approche – 6000ft

1000 ft

10 20 30 40 50 600 sec

Réel

Idéal

Surveillance et prévention des

réactions excessives

Réactions inverses à RA TCAS ‘’AVS’’

Publication de l’événementRéception de deux autres rapports similairesMise en place d’une détection systématique

Alarme sur trajectoire et séparation initiale nominale

Premières actionsDétection et suivi des réactions inverses

Correct Reaction92.6%

Opposite Reaction7.4%

Réactions conformes93%

Réactions Inverses7%

Réactions pilote auxRA TCAS ‘’AVS’’

3 sec pitch order opposite to RA

RA

t sec7 Consecutive sec

Premières actionsPartage d’information, premières analyses

Bulletin TCASEurocontrol

Premières analysesPrincipaux facteurs contributifs ‘’Adjust’’ n’indique pas le sens de correction Aiguille de vitesse verticale rouge sur fond rouge Guidage en Vitesse verticale et non en Assiette Simulateurs non adaptés aux TCAS « AVS »

Présentation des événements et partage avec l’ensemble des compagnies de l’algorithme

d’analyse des vols pour la détection des cas de réaction inverse.

Safety Conference Airbus

Monitoring TCAS Crew Responses

Barcelona - October 2003

Evolution du TCAS

TCAS 7.0 TCAS 7.1

‘’Level Off’’

Reduction du risque

Procedures ATC Design Training Design

Reduction of Number of TCAS Ras ‘‘AVS‘‘

Reduction of Misinterpretation

Measures for Risk Reduction

A380, A350, etc …

Mais

Airbus

Boeing

+ FMGSAltitude capture software

Quelques leçonsSur le retour d’expérience Retour d’expérience actif Canaux de retour complémentaires Risques partagés >> Traitement partagé (collision en vol)

Sur la gestion de risque Gestion de la sécurité = > Surveillance et gestion des

défenses/barrière ou principe de sécurité Nécessité d’un modèle partagé

Having a well recognized safety model in mind, referring to a limited number of well identified accident families will :

tell us what and where we should look for

give sense to the safety data we collect

orient the design of new safety data software tool

clarify priorities and support prevention strategies

encourage a more systematic, proactive and efficient management of safety functions : “control”, “recovery” and “mitigation”

Airline Safety ManagementImportance of having a shared “safety model”

AccidentsOperations Loss of control CFIT Mid air collision Runway collision Runway excursion Other damages/injuries (Flight)

Other damages/injuries (Ground)

Accident and Defenses

Undesired EventControl

Recovery

Mitigation

Operations

Airline Safety ManagementImportance of having a shared “safety model”

Safety PrinciplesAny action contributing to prevent or recover a “loss of control” or minimizing damage

Safety ModelAccident = “loss of control”

Undesirable events (UE) Points where the “control of the situation is lost”

Three key safety functions Control Recovery Mitigation

Airline Safety ManagementInfluence of actors: Unsafe Conditions

Flight ops, ground ops, maintenance, cargo and other actorsare supporting or affecting the control, recovery or mitigation function separately, or collectively by interacting with each other

When the result of an action or inaction affects one of the « Safety Principles » , it is referred to an «Unsafe Condition» or ‘’UC’’

EXTERNAL (ATC, Reg Oversight, etc.)

FLIGHT OPS MAINTENANCE GROUND OPS

When the result of an action or inaction from stakholders affects one of the « Safety Principles » it is referred to an «Unsafe Condition»

FLIGHT OPS

Unsafe conditions related to flight ops

MAINTENANCE

Unsafe conditions related to aircraft maintenance release

EXTERNAL (ATC, Reg Oversight, etc.)

Unsafe conditions related to external actors

GROUND OPS

Unsafe conditions related to aircraft ground handling

Severity of accident

Corporate MatrixP

robability of accident scenario

1 2 53 4

1

2

3

4

5

Mitigation impact

2111132111432115432155432

Never

Unlikely

Often

Seldom

Alw

ays

Undesired event leads to accident

Frequent

Occasional

Remote

Improbable

Highly improbable

Probability of

Undesired event

Recovery Matrix

1

2

3

4

5

1 2 53 4

2111132111432115432155432

Never

Unlikely

Often

Seldom

Alw

ays

Unsafe Condition leads to Undesired event

Frequent

Occasional

Remote

Improbable

Highly improbable

Unsafe

Condition is

Control Matrix

1

2

3

4

5

1 2 53 4

Canaux de retour complémentaires

Surveys

FDM (FOQA)

Space of precursors

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Air Safety Reports