When Things Go Wrong: Flight Crews and Emergencies

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When Things Go WrongFlight Crews and
Emergencies

• Barbara Burian, Ph.D., FRAeS
• NASA Ames Research Center

The Emergency and Abnormal Situations study was
funded through NASAs former Aviation Safety and
Security Program.
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Emergency and Abnormal Checklists
Boeing 777 ECL
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Checklists and Procedures
Checklist Design
Checklist Content
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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.
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Checklists and Procedures
Checklist Design
Checklist Content
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Pack Trip

• Master Caution Alert sounds
• Crew Identifies that Pack has tripped off
• Crew completes 4 step procedure
• Flight proceeds normally

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ValueJet 592 - In-flight Fire Florida
Everglades May 11, 1996
140409 Takeoff 141003 chirping sound
bout to lose a bus 141015
Got an electrical problem 141020 Were
losing everything 141022 We need to go
back to Miami 141025
Fire, fire, fire, fire! (from
cabin) 141032 Uh, 592 needs immediate
return to Miami (to ATC) 141343
CVR stops recording 1414 ValuJet 592
disappears from radar
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Requirements of the Emergency or Abnormal
Situation
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Operational Requirements
Requirements of the Emergency or Abnormal
Situation
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Aircraft and Systems
Operational Requirements
Requirements of the Emergency or Abnormal
Situation
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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
Philosophies and Economic Constraints
Aircraft and Systems
Operational Requirements
Requirements of the Emergency or Abnormal
Situation
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Checklists and Procedures
Checklist Design
Checklist Content
Context
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Philosophies and Economic Constraints
Aircraft and Systems
Operational Requirements
Requirements of the Emergency or Abnormal
Situation
Human Performance Capabilities and Limitations
under High Stress and Workload
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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)
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Human Performance under Stress

• 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

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Human Performance under Stress
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.
(ASRS Report, Accession 472755)
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Checklists and Procedures
Checklist Design
Checklist Content
Context
Human Performance Capabilities
How Checklists are Used
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Checklists and Procedures Context and Human
Performance Considerations
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.
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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
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Checklists and Procedures Context and Human
Performance Considerations
Example Pilots routinely make errors in
correctly recalling memory items
Air Carrier/Manuf. N of CL with MI Total N 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
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Checklists and Procedures Context and Human
Performance Considerations
Example Applying multipliers to landing distances
1.7
1.55
1.8
1.35
1.15
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Checklists and Procedures Context and Human
Performance Considerations
Example Information missing from checklist
Valujet 558, Jan. 7, 1996
AOM
The missing information was included in the AOM
expanded checklists but was never transferred to
the QRH checklists.
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Checklists and Procedures Context and Human
Performance Considerations
Example Confusing and complex wording
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Checklists and Procedures Context and Human
Performance Considerations
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
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Example Complex Navigation
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Checklists and Procedures Context and Human
Performance Considerations
Example Checklist actions cause another abnormal
situation to occur
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.
(ASRS Report, Accession 473359)
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Checklists and Procedures Context and Human
Performance Considerations
Example Checklist actions not appropriate for
situation
Hydraulic caution light illuminated while
taxiingI completed the QRH checklistWe rolled
to a stop in the grassA very poorly written QRH
emergency checklist. CALLBACK The checklist is
for use in-flight, not on the ground.
(ASRS Report,
Accession 437817)
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Checklists and Procedures Context and Human
Performance Considerations
Example Swissair 111, Sept. 2, 1998
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Checklists and Procedures Context and Human
Performance Considerations
Example Swissair 111, September 2, 1998 -
continued
Time from first abnormal odor until Swissair 111
crashed in the ocean 20 minutes, 40 seconds
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Human Performance and Context in Emergency and
Abnormal Checklists
The Good News Emergency and Abnormal Checklists
and Procedures

• 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

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Addressing Context in Emergency and Abnormal
Checklists
To Ensure that Context is Addressed

• 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 MELed.
• 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.

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Addressing Human Performance under Stress in
Emergency and Abnormal Checklists
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

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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, dont go overboard with providing so
  much information that checklists take forever to
  go through/read

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Barbara Burian, Ph.D. bburian_at_mail.arc.nasa.gov E
mergency and Abnormal Situations
Study http//human-factors.arc.nasa.gov/eas
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The Context in Which Emergency and Abnormal
Situations Occur
Explosive Decompression
Aloha 243
JetBlue 292
Air Canada 797
Misaligned Nosegear
In-flight Fire
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In-flight Smoke, Fire, Fumes Integrated Checklist
Courtesy of United Airlines