When Things Go Wrong: Flight Crews and Emergencies Barbara Burian, Ph.D., FRAeS NASA Ames Research Center The Emergency and Abnormal Situations study was

When Things Go Wrong:When Things Go Wrong:

Flight Crews and EmergenciesFlight Crews and Emergencies

Barbara Burian, Ph.D., FRAeSNASA Ames Research Center

The Emergency and Abnormal Situations study was funded through NASA’s former

Aviation Safety and Security Program.Human SystemsIntegration Division

Emergency and Abnormal Checklists

NORMAL ITEMOVRD NOTES CHKL

OVRDCHKL

RESET

NORMAL MENU RESETS NON-NORMAL MENU

FIRE ENG R

Fire is detected in the right engine.

RIGHT AUTOTHROTTLE ARM SWITCH . . . . . . . . . . . OFF

RIGHT THRUST LEVER . . . . . . . . . . . . . . . . . . . . . .CLOSE

RIGHT FUEL CONTROL SWITCH . . . . . . . . . . . . .CUTOFF

RIGHT ENGINE FIRE SWITCH . . . . . . . . . . . . . . . . . . PULL

If FIRE ENG R message remains displayed:

3

2

1

RIGHT ENGINE FIRE SWITCH . . . . . . . . . . . . . ROTATERotate to the stop and hold for 1 second.

Boeing 777 ECL

Checklists and Procedures

Checklist Design Checklist Content

Human SystemsIntegration Division

Checklist Design Factors (Paper, Electronic, EFB)

Physical Properties and Interface - size, weight, materials, integration w/displays

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 and Workload - physical length, timing length, workload

Nomenclature & Abbreviations - terms, labels, abbreviations

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

Level of Detail - amount of information provided

Engineering Completeness - all necessary steps included

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

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

Progression & Checklist Navigation - movement within & between checklists/manuals

Access - finding correct checklist, prime real estate pgs.


Context



Pack Trip


•Master Caution Alert sounds

•Crew Identifies that Pack has tripped off

•Crew completes 4 step procedure

•Flight proceeds normally

ValueJet 592 - In-flight Fire Florida EvergladesMay 11, 1996

14:04:09 Takeoff

14:10:03 [chirping sound] “’bout to lose a bus”

14:10:15 “Got an electrical problem”

14:10:20 “We’re losing everything”

14:10:22 “We need to go back to Miami

14:10:25 “Fire, fire, fire, fire!” (from cabin)

14:10:32 “Uh, 592 needs immediate return to Miami” (to ATC)

14:13:43 CVR stops recording

14:14 ValuJet 592 disappears from radar

Requirements of the Emergency or Abnormal Situation

Checklists Procedures

ManualsLevel of time criticality

Degree of threat

Degree of novelty, ambiguity, complexity

Amount of increase in workload


Operational Requirements


Manuals

SOPs

Regulations

Different phases of flight

Weather, terrain, etc.



Aircraft and Systems


Manuals

Requirements of the specific malfunction

History of false warnings

Warning systems and alerts

Appropriate level of automation

Automated aircraft systems

Flight protection envelopes

Flight deck ergonomics




Philosophies and Economic Constraints


Manuals

Manufacturer philosophies

Company philosophies and policies

Types of checklists available (electronic, paper)

Philosophy of checklist use and functionality of electronic checklists

Cost-benefit tradeoffs, e.g., diversions

Updates and revisions

Human Performance Capabilities



Context




Human Performance Capabilities and Limitations under High Stress and

Workload


Philosophies and Economic Constraints


Manuals

Working, long term, and prospective memory

Mental computations

Judgment and decision making

Visual and auditory processing

Attention

Dealing with interruptions & distractions

Situational awareness

Ability to shift mental sets

Motor skills

Affective responses to stress

Human Performance under Stress


Well-learned motor skills• remain robust and relatively unaffected by stress

Our simulator training really paid off. This was my first engine shutdown in 20 years of flying and it felt like I had done it a thousand times before!

(ASRS Report, Accession #466167)



Tunneling• narrowing of human attention• restricts scanning of environmental cues• narrow focus on most salient or threatening cues• yields poor differential diagnosis of situation

Working Memory• capacity and length of time information can be held decreases• when exceeded – difficulty performing mental calculations,

problem solving, making sense of disparate pieces of information, shifting mental sets (concurrent task management)

Tendency to Rush



We did find communication difficult and the use of oxygen masks, intercom, trying to talk to ATC was a handful.

At night made it that much harder to read/accomplish checklist items. Turning cockpit lights on sooner would have helped.




Context

How Checklists are Used

Human Performance Capabilities

Example: Saudi Arabian Flight 163, August 19, 1980

Crew searched unsuccessfully for several minutes for a cargo fire checklist in the Abnormal section of the QRH.

The checklist they were looking for, but never found, was in the Emergency section of the QRH instead.


Checklists and Procedures: Context and Human Performance Considerations

Example: Six Different Checklist Titles for the Same Condition – B737 no flap, no slat

All Flaps Up Landing

Flaps – All Flap and LED Up Landing

No Flap/No Slat Landing

Symmetrical Non-Normal Trailing Edge Flaps or No Flaps

No Trailing Edge Flaps

Alternate Flaps Operation



Example: Pilots routinely make errors in correctly recalling “memory items”

Air Carrier/Manuf.

N of CL with MI

TotalN of MI

Action Item MI

Conditional MI

Note MI

Other MI

A Classic 23 120 93 21 3 3

B Classic 4 15 13 1 0 1

C Classic 16 112 73 16 21 2

D Classic 5 17 15 2 0 0

Boeing Classic 16 113 73 16 22 2

E NG 9 20 17 3 0 0

F NG 3 11 10 1 0 0

G NG 12 45 37 5 2 1

H NG 10 44 35 5 2 2

Boeing NG 18 129 83 19 24 3

Boe. NG – Rev. 13 77 52 10 14 1



Example: Applying multipliers to landing distances

1.7

1.55

1.8

1.35

1.15


Example: Information missing from checklist – Valujet 558, Jan. 7, 1996

The missing information was included in the AOM expanded checklists but was never transferred to the QRH checklists.

Pull cbs

Reset cbs

AOM



Example: Confusing and complex wording

If Pack Fault due to low bleed air supply, then a 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:



Example: Crew confusion – FedEx 1406, September 5, 1996

FE was confused by step 5 and did not complete steps 6 and 7

Items Pertaining to Adjusting Cabin Altitude or Flight Level


Start

Example: Complex Navigation


Accomplishing the [immediate action] item for cockpit/cabin smoke on the ground in the XXX aircraft induces the abnormal procedure of equipment overheat due to the step of the turning off left and right recirculation fans, the left recirculation fan being the primary equipment cooling on the ground.



Example: Checklist actions cause another abnormal situation to occur


Hydraulic caution light illuminated while taxiing…I completed the QRH checklist…We rolled to a stop in the grass…A very poorly written QRH emergency checklist. CALLBACK: …The checklist is for use in-flight, not on the ground.



Example: Checklist actions not appropriate for situation


Example: Swissair 111, Sept. 2, 1998


http://www.bst.gc.ca/en/reports/air/1998/a98h0003/01report/visual_library/flightprofile.asp


Example: Swissair 111, September 2, 1998 - continued

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

Time needed for completion of the two checklists:

Approximately 30 minutes

Time from first abnormal odor until Swissair 111 crashed in the ocean:

20 minutes, 40 seconds


Human Performance and Context in Emergency and Abnormal Checklists


• can be written to address the multiple contexts in which emergency and abnormal situations occur

• can be designed to accommodate many human performance limitations that occur under high stress and high workload

The Good News: Emergency and Abnormal Checklists and Procedures


To Ensure that Context is Addressed:

Addressing Context inEmergency and Abnormal Checklists

• Make sure checklists are designed for full range of the scenarios for which they will be used (e.g., pressurization: slow leak – to – explosive/rapid decompression)

• Make sure checklists are appropriate for all phases of flight and aircraft configurations for which they may be used (e.g., on ground, in-flight, throttles at idle)

• Make sure checklists address relevant environmental conditions (e.g., icing) and loss of pertinent equipment that has been MEL’ed.

• Conduct a realistic timing assessment of crucial checklists and procedures (length of completion).

• Conduct a realistic workload assessment of checklists and procedures, especially when conducted during various phases of flight.


To Ensure that Tunneling is Addressed:

• Draw crew attention to environmental or situational cues that support diagnosis

• Draw crew attention to environmental or situational cues that contraindicate diagnosis

• Cues specified must be ones that flight crews are able to assess

Addressing Human Performance under Stress in Emergency and Abnormal Checklists

To Ensure that Working Memory Limitations are Addressed:

• Provide information or resources (e.g., EFB) to diminish/eliminate memory load and need to perform mental calculations

• Place remaining “memory items” on quick reference cards/QRH cover (paper and unannunciated electronic checklists)

• Integrate all needed information (tables, normal checklists) with emergency and abnormal checklists – “get in, stay in”

• Make sure all checklists are complete and ramification of crucial steps is provided (before the step is to be carried out)

• Provide “purpose of item” and “purpose of checklist” statements

• Provide information describing aircraft performance limitations

• Provide information describing remaining aircraft capabilities

• However, don’t go overboard with providing so much information that checklists take forever to go through/read

Addressing Human Performance under Stress in Emergency and Abnormal Checklists

Barbara Burian, Ph.D.

[email protected]

Emergency and Abnormal Situations Study

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


The Context in Which Emergency and Abnormal Situations Occur

JetBlue 292

Aloha 243

Air Canada 797

Explosive Decompression

Misaligned Nosegear

In-flight Fire

In-flight Smoke, Fire, Fumes Integrated Checklist

Courtesy of United Airlines

Documents

When Things Go Wrong: Flight Crews and Emergencies Barbara Burian, Ph.D., FRAeS NASA Ames Research Center The Emergency and Abnormal Situations study was