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Human Error AnalysisAccident of flight HCY522 in the area of Grammatiko

33km NW of Athens International Airport14/8/2005

Loukia Loukopoulou, Ph.D.

Aviation PsychologistHuman Factors Researcher

Member of the Investigation Team of theHellenic Air Accident Investigation and

Aviation Safety Board

Analysis from a

Whole System Approach

Adapted from Edwards, 1988

CHECKLISTxxx xxxxx xxx xxxx ONxx xxxxxx SETxx xx xxxxx ARMED

SHEL model

Software

Hardware

Liveware

Environment

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Human Operator at the ♥ of the system

Safety does not reside in any one component, but in their interactions

Basic Concepts

Local rationality (Woods & Cook, 1999)

• Every person generally did what seemed rational to them at the time

Hindsight bias (Fischhoff, 2003)

• Easy to judge now –

• but, crew acted based on information and resources available at that time

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In reality…

Upper Management

Local Management

PreconditionsActivities

Active failures

Latent conditions

In reality, concerns the following questions:

Which factors would have led any pilot to make the same error under the same circumstances?

or

Which factors increase the probabilitiesthat another pilot will make the same error in the future?

The study of “pilot error”

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Human Errorin the accident of 14-08-2005

Findings from the Final Report

Meta-analysis

• Human Factors Analysis and Classification System

(Shappell & Wiegmann, 1997)

Note: 14 months in 15 minutes

(Shappell & Wiegmann, 1997)

1: Organization

2: Supervision

3: Preconditions

4: Acts

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Conclusions 3.1 Findings

• Flight Crew (20)• Cabin Crew (6)• Aircraft (13)• Manufacturer (6)• ATC (5)• ICAO, EASA, JAA (1)• Flight (7)• Operator (4)• Cyprus DCA (1)

3.2 Causes• Active (3)• Latent (4)• Contributing Factors (3)

Perceptual Errors

Decision Errors

Skill-based Errors

Errors

UNSAFE ACTS

ExceptionalRoutine

Violations

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FACTS

Pre-flight - Takeoff

Pressurization Mode Selector switch in the MAN(ual), instead of the ΑUTO position

• From engine-start to collision with ground

Aircraft pressurization system did not operate in the prescribed, automatic (AUTO) mode to pressurize aircraft during flight

CA FO

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Procedures

Preflight Procedure (FO)

Before Start Checklist (CA and FO)

After Takeoff Checklist (CA and FO)

Cabin pressurization panel ............................................................................ SetVerify that the AUTO FAIL light is extinguished.Verify that the OFF SCHED DESCENT light is extinguished.FLIGHT ALTITUDE indicator – Cruise altitudeLANDING ALTITUDE indicator – Destination field elevationCABIN Rate selector (as installed) – IndexCABIN ALTITUDE indicator (as installed) – 200 feet below destination field elevationFLT/GRD switch (as installed) – GRDPressurization mode selector – AUTO

[12 από 25] AIR COND & PRESS ………….. _PACK(S), BLEEDS ON, SET

[1 από 4] AIR COND & PRESS ………….. _ SET

#1

#2

#3

UNSAFE ACTS

Τhe flight crew did not recognize and correct the incorrect position of the pressurization mode selector (ΜΑΝ insead of AUTO).

Procedures: extended practice, repetition

• Complacency (automatization of actions)

• Expectations (looking without seeing)

“Loose” discipline of checklist performance (routine, exceptional?)

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Perceptual Errors

Decision Errors

Skill-based Errors

Erorrs

UNSAFE ACTS

ExceptionalRoutine

Violations

FACTS

Climb

Warning Horn

• 1. Cabin Altitude(insufficient pressurization)

• In the air (10,000 ft) – intermittent

• On the ground - #

• 2. Takeoff Configuration

• In the air - continuous

• On the ground - intermittent

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UNSAFE ACTS

The initial actions by the flight crew to disconnect the autopilot, to retard and then again advance the throttles, indicated that it interpreted the warning horn as a Takeoff Configuration Warning… the flight crew was not aware of the inadequate pressurization of the aircraft.

Automaticity in perceptual processes(warning horn on ground - intermittent)

Automaticity in reactions (motor memory)

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Perceptual Errors

Decision Errors

Skill-based Errors

Erorrs

UNSAFE ACTS

ExceptionalRoutine

Violations

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FACTS

Climb

Master Caution x2

• Equipment Cooling

• Oxygen Masks (passenger)

Contact Flight Dispatch

Mention only Equipment Cooling

Climb not suspended

Warning horn not silenced

CA FO

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UNSAFE ACTS

The flight crew possibly identified the reason for the Master Caution to be only the inadequate cooling of the Equipment … and did not identify the second reason for its activation, i.e.,passenger oxygen masks deployment,

Distraction / Preoccupation of Attention

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Perceptual Errors

Decision Errors

Skill-based Errors

Erorrs

UNSAFE ACTS

ExceptionalRoutine

Violations

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UNSAFE ACTS

Unscheduled Maintenance

After the pressurization test, the pressurization mode selector was not selected to AUTO.

Insufficient knowledge – Insufficient awareness

Complacency

The record of the maintenance actions in the Aircraft Technical Log was incomplete.

Routine Violation

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Perceptual Errors

Decision Errors

Skill-based Errors

Erorrs

UNSAFE ACTS

ExceptionalRoutine

Violations

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4: Acts

PRECONDITIONS FOR

UNSAFE ACTS

EnvironmentalFactors

Technological Environment

Physical Environment

Personal Readiness

CRM

Personnel FactorsCondition

of Operators

Adverse Physiological

States

Adverse Mental States

Physical/Mental Limitations

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PRECONDITIONS for unsafe acts

Τhe flight crew did not recognize and correct the incorrect position of the pressurization mode selector.

• Illumination Conditions?

PRECONDITIONS for unsafe acts

Τhe flight crew did not recognize and correct the incorrect position of the pressurization mode selector.

• Illumination conditions

• Inadequate Procedures

Before Start Checklist (CA and FO)

[12 από 25] AIR COND & PRESS ………….. _PACK(S), BLEEDS ON, SET

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PRECONDITIONS for unsafe acts

Incorrect interpretation of Warning Horn

Non-recognition of oxygen mask deployment

• Warning horn design (2 in 1)

• Stress (unexpected situation, noise)

• Hypoxia

• Inadequate CRM

PRECONDITIONS for unsafe acts

After the pressurization test, the pressurization mode selector was not selected to AUTO.

• Unclear Procedure

“Put the airplane back to its initial condition”

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3: Preconditions

Inadequate Supervision

Planned Inappropriate Operations

Failed to Correct Problem

Supervisory Violations

UNSAFESUPERVISON

2

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UNSAFE SUPERVISION

Τhe flight crew did not recognize and correct the incorrect position of the pressurization mode selector.• “Loose” discipline of procedure/checklist

performance?

The record of the maintenance actions in the Aircraft Technical Log was incomplete.• Routine Violation?

UNSAFE SUPERVISION

Numerous remarks in the last five years by training and check pilots on file referring to checklist discipline and procedural (SOP) difficulties.

• Inadequate supervision

• Failure to correct known problem

• Supervisory violations

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UNSAFE SUPERVISION

Absence of applied hypoxia training for airline transport pilots

• Planned inappropriate operations

UNSAFE SUPERVISION

Large number of incidents in the past

• Confusion re: significance of warning horn

• Cabin altitude or Takeoff configuration?

• Pressurization problems

• Pilot error (omission, oversight)

Failure to correct known problems @ international level

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UNSAFE SUPERVISION

Audits of Regulatory Authority (DCA) by international organizations

• Identification of deficiencies

• Plans for corrective actions

• Non-enforcement of implementation of action plans so that the State fullfil its international obligations

Supervisory Violations?

2: Supervision

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Resource Management

Organizational Climate

Operational Process

ORGANIZATIONAL INFLUENCES

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ORGANIZATIONAL INFLUENCES

Accidents in the past

• Resource Management (compromises)

Non-enforcement of implementation of action plans so that the State fullfil its international obligations

• Operational Process

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ORGANIZATIONAL INFLUENCES Organizational deficiencies at the Operator level, e.g.,

• Inadequate Quality system• Insufficient updating of manuals, oeprators’ qualifications,

certificates, training records.• Inadequate organization, management, staffing, and

operational supervision • Insufficient corrective actions in response to series of audit

findings• Ineffective flight safety culture

Organizational deficiencies at the Regulatory Authority level, e.g.,

• Lack of funds and staff, adequate training, expertise/skills• Over-reliance on another DCA• Insufficient structure to support safety oversight• Lack of Risk Management program• Lack of effective implementation of corrective actions

Resource Management

Organizational Climate

Operational Process

ORGANIZATIONAL INFLUENCES

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1: Organization

1 Organization

2 Supervision

3 Preconditions

4 Acts

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3.1 Findings

• Flight Crew (20)

• Cabin Crew (6)

• Aircraft (13)

• Manufacturer (6)

• ATC (5)

• ICAO, EASA, JAA (1)

• Flight (7)

• Operator (4)

• Cyprus DCA (1)

3.2 Causes

• Active (3)

• Latent (4) + Contributing Factors (3)

CONCLUSIONS – Final Report

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Ευχαριστώ – Thank you!

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CAUSESDirect Causes 1. Non-recognition that the cabin pressurization mode

selector was in the MAN (manual) position during the performance of the:

• a) Preflight procedure;• b) Before Start checklist; and• c) After Takeoff checklist.

2. Non-identification of the warnings and the reasons for the activation of the warnings (cabin altitude warning horn, passenger oxygen masks deployment indication, Master Caution), and continuation of the climb.

3. Incapacitation of the flight crew due to hypoxia, resulting in continuation of the flight via the flight management computer and the autopilot, depletion of the fuel and engine flameout, and impact of the aircraft with the ground.

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CAUSESLatent Causes 1. The Operator’s deficiencies in organization, quality

management and safety culture, documented diachronically as findings in numerous audits.

2. The Regulatory Authority’s diachronic inadequate execution of its oversight responsibilities to ensure the safety of operations of the airlines under its supervision and its inadequate responses to findings of deficiencies documented in numerous audits.

3. Inadequate application of Crew Resource Management (CRM) principles by the flight crew.

4. Ineffectiveness and inadequacy of measures taken by the manufacturer in response to previous pressurization incidents in the particular type of aircraft, both with regard to modifications to aircraft systems as well as to guidance to the crews

CAUSES

Contributing Factors

1. Omission of returning the pressurization mode selector to AUTO after unscheduled maintenance on the aircraft.

2. Lack of specific procedures (on an international basis) for cabin crew procedures to address the situation of loss of pressurization, passenger oxygen masks deployment, and continuation of the aircraft ascent (climb).

3. Ineffectiveness of international aviation authorities to enforce implementation of corrective action plans after relevant audits.