challenges in emergency and abnormal checklist design

Challenges in Emergency and Abnormal Checklist Design

Barbara Burian, Ph.D.San Jose State University Foundationat the NASA Ames Research Center

The Emergency and Abnormal Situations project is funded through the NASA Aviation Safety and Security Program.

Emergency and Abnormal Situations Project Industry Contacts and Consultants

Boeing, Bombardier, Airbus Industries, BAe Systems,

FAA, CAA (UK), JAA, ICAO,Eurocontrol, NavCanada

ALPA, APA, SWAPA, ATA, IATA, AFA, ADF

NTSB, TSB of Canada, ISASI

Airborne Express, Air Canada, Alaska, Aloha, American, Atlantic Southeast, Cathay Pacific, Continental, Delta, Fed Ex, Frontier, Hawaiian, Horizon, JetBlue, Southwest, United, UPS, US Airways, TWA (prior to merger)

Manufacturers:

Regulatory and Governmental Agencies:

Unions and Trade Groups:

Accident Investigation Bodies:

Airlines:

Emergency and Abnormal Situations Project

15 Different Categories of Issues – some are related to:

Emergency Equipment and Evacuation Issues

Automation and Automated Aircraft Systems

Training

Human Performance under Stress

Checklists and Procedures

Challenges in Emergency and Abnormal Checklist Design

Smoke, Fire, and Fumes

Checklists and Procedures

Smoke, Fire, and Fumes Checklists and Procedures

• Philosophies, company policies, and economic considerations

What Drives (or Should Drive*) the Design and Content?• Differences in aircraft and equipment design

• Type of operations – extended range, passenger vs. cargo

• History of the air carrier, History within the industry

• Assumptions about efficacy of crew response and expectations about amount of time available

• Human factors considerations, Understanding of human performancewhile under stress *

• Understanding of how different types of fires are ignited, fed, and spread

• Regulations, Advisory Circulars, etc.


Ambiguity of cues / level of certainty about situation

Conflicting warnings / cues

Smoke / Fumes of an unknown origin

Determining / Accessing the proper checklist

Length of time to complete procedures

Initiate descent / diversion and when

What type of descent profile

Checklist wording – how compulsory

Reduced visibility – font size, layout

What memory items

A Few of the Many Issues

Timing of source identification vs. smoke removal vs. descent initiation vs. fighting fire

High false smoke alarm rate

EROPS – nearest airport is far away

Ditching while on fire

How much troubleshooting

Fire in inaccessible places

Powering down electrical buses

Circuit breaker resetting

If / when to declare an emergency with ATC

Communicating / coordinating with Cabin crew


Methods for Accessing the Correct Checklist:

• Gateway Checklist

• Several Separate Checklists

• One Integrated Checklist

Accessing the Correct Checklist: Gateway Checklist

Accessing the Correct Checklist: Several Separate Checklists

Accessing the Correct Checklist: One Integrated Checklist

Courtesy of Captain Richard Gilbert, UAL

What Drives (or Should Drive) the Design and Content?


Determining / Accessing the Proper Checklist

• Differences in aircraft and equipment design




• Human factors considerations, Understanding of human performancewhile under stress





• Differences in aircraft and equipment design







Determining / Accessing the Proper Checklist


Emergency Descent and Diversion Guidance:

Where in the Checklist and

How Stated?

Swissair 111 - In-flight Fire Nova Scotia, Canada September 2, 1998

If smoke/fumes are not eliminated, land at nearest suitable airport

Swissair 111 - In-flight Fire Nova Scotia, Canada September 2, 1998

(7) Prepare to land immediately at nearest suitable airport

CRJ 900

A320

LDG ELV…………………10,000 FT/MEA

DESCENT (FL 100 OR MEA)….INITIATE

B767-400

If smoke or fumes are persistent:

Plan to land at the nearest suitable airport.


Emergency Descent and Diversion Guidance Summary: Air Conditioning Smoke

1

2

1

2

Number of Checklists*

If smoke or fumes are persistent: Plan to land at the nearest suitable airport.Next to the last itemB767-400

N/ANowhereA320

Prepare to land immediately at nearest suitable airport.

Middle of checklist (step 7)CRJ-900

If smoke/fumes not eliminated, land at nearest suitable airport

Last item, 2nd

checklistMD-11

WordingLocationAircraft Type

(A Somewhat Unfair Comparison)

* to get to descent / diversion guidance


Emergency Descent and Diversion Guidance Summary: Electrical Smoke / Fire

1

N/AThere is no electrical smoke or fire checklist

Prepare to land immediately at nearest suitable airport.

First third of checklist (step 6)

1CRJ-900

1

-

Number of Checklists*

If smoke or fumes or fire persists or source is unknown: Plan to land at the nearest suitable airport.

Last item on the checklist

B767-400

LAND ASAP

Avionics Smoke has items for electrical smoke – 1st item

A320

WordingLocationAircraft Type

* to get to descent / diversion guidance


In a study of 15 in-flight fires that occurred between January 1967 and September 1998, the TSB of Canada determined that the average amount of time between the detection of an on-board fire and when the aircraft ditched, conducted a forced landing, or crashed was 17 minutes.

Emergency Descent and Diversion


Cost of Diversions: fuel, passenger ill-will, operational considerations,aircraft and crew scheduling, possible evacuationinjuries, etc.

D. Blake, 2000

Verified Smoke Events Versus Smoke Alarms

020406080

100120140160180

False Cargo Smoke Alarms, 1974 -1999



Descent and Diversion Guidance – Location and Wording• Differences in aircraft and equipment design









Descent and Diversion Guidance – Location and Wording• Differences in aircraft and equipment design






• Regulations, Advisory Circulars, etc. (AC 120-80: “…flight crew members should begin planning for an emergency landing as soon as possible after the first indication of fire” pg 6.)

Immanuel Barshi, Ph.D.**Sean Belcher, M.A.**Ben Berman, A.B.**Barbara Burian, Ph.D.*Key Dismukes, Ph.D.**Richard Fariello, B.S.**

EAS Project Team

Colleen Geven, A.A.**Richard Geven, M.A.**Jon Holbrook, Ph.D.Jessica Lang Nowinski, Ph.D.Sharon Pickering, M.S.

* Certificated Pilot** ATP Certificate

Barbara Burian, Ph.D.

[email protected]

Emergency and Abnormal Situations Project

http://human-factors.arc.nasa.gov/eas

Other Issues in Emergency and Abnormal Checklist

Content and Design

Checklist Design Factors (Checklists, Procedures, Manuals)

Physical Properties and Interface - size, weight, materials, hold in one hand?

Typography and use of Symbology - font, font size, boldface, intuitive symbology

Layout, Format, Organization - visual look, arrangement, “white” space

Purpose - fix, troubleshoot, manage situation, guide CRM

Objective (of checklist item) - direct action, inform, assess, make decision

Length - physical length, timing length

Content - Nomenclature & Abbrev. - terms, labels, abbreviations

Content – Language, Grammar, & - English?, verb tense, reading difficulty, clarity, Wording orientation/perspective, directiveness

Content - Level of Detail - amount of information provided

Content - Engineering Correctness - all necessary steps included

Content - Engineering Coherence - order of steps/timing makes “sense” to aircraft

Content - Logical Coherence - order of actions makes sense to the pilot and make “sense” operationally

Progression - movement within & between checklists/manuals

Access - finding correct checklist, prime real estate pgs.

If Pack Fault due to low bleed air supply, thena bleed leak does not exist, and if WING ANTI-ICE is not required:

If Pack Fault due to low bleed air supply, and if a bleed leak does not exist, and if WING ANTI-ICE is not required:

Checklist Design Factors (Checklists, Procedures, Manuals)

Physical Properties and Interface - size, weight, materials, hold in one hand?

Typography and use of Symbology - font, font size, boldface, intuitive symbology

Layout, Format, Organization - visual look, arrangement, “white” space

Purpose - fix, troubleshoot, manage situation, guide CRM

Objective (of checklist item) - direct action, inform, assess, make decision

Length - physical length, timing length

Content - Nomenclature & Abbrev. - terms, labels, abbreviations

Content – Language, Grammar, & - English?, verb tense, reading difficulty, clarity, Wording orientation/perspective, directiveness

Content - Level of Detail - amount of information provided

Content - Engineering Correctness - all necessary steps included

Content - Engineering Coherence - order of steps/timing makes “sense” to aircraft

Content - Logical Coherence - order of actions makes sense to the pilot and make “sense” operationally

Progression - movement within & between checklists/manuals

Access - finding correct checklist, prime real estate pgs.

Click to edit Master title style

• Click to edit Master text styles• Second level• Third level• Fourth level• Fifth level

1

The Limits of Expertise:The Misunderstood Role of

Pilot Error in Airline Accidents

Key DismukesNASA Ames Research Center

Ben Berman and Loukia LoukopoulosSan Jose State University Foundation at

NASA Ames Research Center

ALPA Air Safety Week19 August 2004



2

Approach

• Reviewed NTSB reports of the 19 U.S. airline accidents between 1990-2000 attributed primarily to crew error.

• Asked: Why might any airline crew in situation of accident crew be vulnerable to the same error?



3

Hindsight Bias

• Knowing the outcome of an accident flight reveals what crew should have done differently.

• Accident crew does not know the outcome.– They respond to situation as they perceive it at the

moment.



4

Immediate demands of situation & tasks

being performed

Training, experience,& personal goals

Social/OrganizationalInfluences- Formal procedures &

policies- Explicit goals & rewards- Implicit goals & rewards

Actual “norms” for line operations

Human cognitioncharacteristics &

limitations

Crew responses to situation



5

A Truism

• No one thing “causes” accidents.

• Confluence of multiple events, actions taken or not taken, and environmental factors.



6

Confluence of Factors in a CFIT Accident

Non-precision approach ≥ 250 foot

terrain clearance

Are most pilots aware of this?

Weather conditions

Airline’s use of QFE altimetry

Strong crosswind

Autopilot would not hold

PF selected Heading Select

Additional workload

Increased vulnerabilityto error

Crew error (70 feet) in altimeter setting

Altimeter updatenot available

170 foot error in altimeter reading

Tower closed

Tower windowbroke

Rapid change in barometric pressure

Approach controllerfailed to updatealtimeter setting

Altitude Hold may allow altitudesag 130 feet in

turbulence

PF used Altitude Hold to capture MDA

PM used non-standard callouts to alert PF

Training & Standardization issues?

Aircraft struck trees310 feet below MDA

?

?



7

Chance Combination of Contributing Factors

• Airline accidents are extremely rare in modern operations– Countermeasures in place for single-point failures of equipment

or human performance

• Occasionally accidents slip through multiple defenses because of chance combination of multiple factors– Number of possible combinations/permutations of factors is vast– Difficult to devise countermeasures

• Vague advice to pilots to “break the accident chain” is not helpful



8

Six Overlapping Clusters of Error Patterns

1) Inadvertent slips and oversights while performing highly practiced tasks under normal conditions

2) Inadvertent slips and oversights while performing highly practiced tasks under challenging conditions

3) Inadequate execution of non-normal procedures under challenging conditions

4) Inadequate response to rare situations for which pilots are not trained

5) Judgment in ambiguous situations

6) Deviation from explicit guidance or SOP



9

1) Inadvertent Slips/Oversights in Practiced Tasks under Normal Conditions

• Examples: – Omitting procedural step or checklist item– Remembering altimeter setting incorrectly– Misjudging landing flare

• Identical to errors pilots frequently report to ASRS and ASAP and errors observed in LOSA

• Commonplace error had to combine with multiple other factors to result in accident



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2) Inadvertent Slips/Oversights in Practiced Tasks under Challenging Conditions

• Probability of commonplace errors goes up with workload, time pressure, fatigue and stress

• Snowball effects: events/decisions/actions increase workload, time pressure, and stress downstream, increasing chance of more problems and errors



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3) Inadequate Execution of Non-normal Procedures under Challenging Conditions

• Failure to recover from spiral dive, stall, or windshear

• Veridian study suggests existing training not sufficient

• Surprise, confusion, and stress may impede correct diagnosis of upset and timely execution of appropriate procedure



12

4) Inadequate Response to Rare Situations for which Pilots are not Trained

• Examples: – False stickshaker activation just after rotation– Oversensitive autopilot drove aircraft down at Decision

Height– Anomalous airspeed indications past rotation speed– Uncommanded autothrottle disconnect with non-salient

annunciation

• Surprise, confusion, stress, and time pressure play a role

• No data on what percentage of airline pilots would respond adequately in these situations



13

5) Judgment and Decision-making in Ambiguous Situations

• Examples:– Continuing approach in vicinity of thunderstorms– Not de-icing or not repeating de-icing

• No algorithm to calculate when to break off approach; company guidance usually generic

• Crew must integrate incomplete and fragmentary information and make best judgment

– If guess wrong, crew error is found to be “cause”

• Accident crew judgment & decision-making may not differ from non-accident crews in similar situations:

– Lincoln Lab study: Penetration of storm cells on approach not uncommon– Other flights may have landed or taken off without difficulty a minute or two

before accident flight

• Questions:– What are actual industry norms for these operations?– Sufficient guidance for crews to balance competing goals?– Implicitly tolerate/encourage less conservative behavior as long as crews

get by with it?



14

6) Deviation from Explicit Guidance or SOP

• Example: Attempting to land fromunstabilized approach resulting from slam-dunk approach

• Simple willful violation or more complex issue?– Are stabilized approach criteria published/trained as

guidance or absolute bottom lines?– What are norms in company and the industry?

• Pilots may not realize that struggling to stabilize approach before touchdown imposes such workload that they cannot evaluate whether landing will work out



15

Cross-Cutting Factors Contributing to Crew Errors



16

Situations Requiring Rapid Response

• Nearly 2/3 of 19 accidents• Examples: upset attitudes, false stickshaker

activation after rotation, anomalous airspeed indications at rotation, pilot-induced oscillation during flare, autopilot induced oscillation at Decision Height

• Very rare occurrences, but high risk• Surprise is a factor• Inadequate time to think though situation

– automatic response required



17

Challenges of Managing Concurrent Tasks

• A factor in great majority of accidents

• Workload quite high in some accidents but in most time was available to perform all tasks

• Especially vulnerable to error when switching attention among tasks, interrupted, distracted, or forced to defer tasks out of normal sequence

• Vulnerability inherent in basic cognitive processes:– Can attend to only one distinct task at a given instant– Once attention is diverted from a task do not always remember

to resume task if not prompted

• Better monitoring can help prevent/catch errors– But monitoring is itself a concurrent task and vulnerable to the

same factors that produce errors



18

Equipment Failures and Design Flaws

• Occurred in 2/3 of these accidents

• Some equipment failures/design flaws precipitated chain of eventsExample: false stickshaker after rotation

• Some equipment failures/design flaws undermined efforts of crew to respondExample: stickshaker failed to activate when aircraft

approached stall



19

Stress

• Hard to evaluate extent, but stress is normal physiological/behavioral response to threat

• Acute stress hampers performance– Narrows attention (“tunneling”)– Reduces working memory capacity

• Combination of surprise, stress, time pressure, and concurrent task demands can be lethal setup

• Beginning NASA research project on effects of stress on crew performance



20

Shortcomings in Training and/or Guidance

• >1/3 of accidents

• Inadequate guidance to pilots about known problems (e.g. high sensitivity of wings without leading edge devices to minute amounts of frost)

• Upset attitude recovery training

• How to deal with fact that not possible to train for every possible situation?



21

Plan Continuation Bias

• Unconscious cognitive bias to continue original plan in spite of changing conditions

• Appears stronger as one nears completion of activity (e.g., approach to landing)

• Bias may prevent noticing subtle cues indicating original conditions have changed

• May combine with other cognitive biases:– frequency sampling bias (“It’s always worked before”)– reactive responding is easier than proactive thinking



22

Social/Organizational Issues

• Actual norms may deviate from Flight Operating Manual – Little data available on extent to which accident

crews actions are typical/atypical

• Little study or acknowledgment of competing pressures– e.g., on-time performance vs. conservative

response to ambiguous situations– Pilots may not be consciously aware of influence

of internalized competing goals



23

Countermeasures? No Easy Solutions• Recognize that most accidents are systems accidents

– Identify hidden vulnerabilities of systems– Pilots, managers, designers of equipment & procedures should be well

educated about human cognitive characteristics & limitations– Review procedures to insure they do not contribute to inherent cognitive

vulnerabilities– Insist on conservative hard-bottom lines in critical situations

• Need better info on how airspace system typically operates and how crews respond– LOSA and FOQA

• Beef up training– upset attitude recovery and other rapid response situations– monitoring

• Acknowledge inherent trade-offs between safety and system efficiency– Include all parties in analysis of trade-offs– Make policy decisions explicit



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More information on NASA Human Factors Research:

http://human-factors.arc.nasa.gov/ihs/flightcognition/

challenges in emergency and abnormal checklist design

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