THE CHALLENGE OF

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THE CHALLENGE OF ROUTINE FLIGHT
OPERATIONS Loukia D. Loukopoulos R. Key
Dismukes Immanuel Barshi NASA Ames Research
Center Moffett Field, CA U.S.A.
22nd European Annual Conference on Human Decision
Making and Control 2-4 June, 2003 Linköping
University, Sweden
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MOTIVATION

• Complex operating environment (cockpit)
• pilots
• number of tasks
• timing of tasks

• INTERACTIONS among tasks and operators

• Characterize nature of interaction
• Characterize demand such interaction places on
  cognition
• Errors?
• Solutions?

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METHODS

• Comprehensive approach
• Cockpit jumpseat observation of routine flights
  (100 hours)
• Boeing 737 2 air carriers 1- 4 hours per leg
  U.S.-wide
• notes informal interviews
• Training (initial, transition/upgrade)
• Written materials (manufacturer and carrier FOMs)
• Incident reports (ASRS, NTSB)
• Qualitative analysis applies to all phases of
  flight use Preflight
  for illustration (Taxi Out in paper)

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PERSPECTIVES - layering

• Ideal
• manufacturer perspective (manuals)

Assumed carrier perspective (FOMs, training)
Real observer perspective (jumpseating)
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Manufacturers representation? (ideal)
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PHASE OF FLIGHT - ideal (manufacturer)

• Goals
• Prepare aircraft for next phase of flight
• Considerations
• Safety
• Design specifications
• Perspective
• Detached from operational reality

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Preflight - ideal (manufacturer)
CAPTAIN
FIRST OFFICER
Begin checklist Checklist
complete Begin checklist Checklist complete
Ask for checklist Ask
for checklist
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
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Carriers representation? (assumed)
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PHASE OF FLIGHT - assumed (carrier)

• Goals
• Prepare aircraft for next phase of flight
• Considerations
• Safety
• Design specifications

• Additional constraints
• Priorities (fuel, time, passenger comfort)
• Type of operations (short/long-haul,
  turn-arounds, regions/airports, fleet)
• Philosophy (safety, efficiency)
• New technologies (ACARS, on-board performance
  computer)
• Coordination with agents (dispatch, maintenance,
  company)

• Perspective
• Suggestive of operational reality

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Preflight - assumed (carrier)
CAPTAIN
FIRST OFFICER
Obtain ATIS Obtain clearance Review
paperwork Prepare/review charts (Passenger
count) (Load Sheet) Program FMC Begin
checklist Checklist complete Begin
checklist Checklist complete
Review paperwork Sign flight release Prepare/revi
ew charts Review Load Schedule Review
FMC Takeoff brief Ask for checklist Ask
for checklist
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
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PHASE OF FLIGHT - assumed (carrier)
x
CAPTAIN
FIRST OFFICER
monitor
A B C D
1 2 3 4
- y
INFORMATION
if z then C
EVENT

• Activities are
• Linear task B always follows task A,
  in this sequence

• Controllable tasks initiated by pilot,
  independently

• Predictable information available when
  needed
• communication possible when necessary

• PILOT-driven operation

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COGNITIVE ASPECTS - (carrier perspective)

• Activities are
• Linear, Controllable, Predictable

• Training and repeated Practice on the line build
• Automaticity (reduced cognitive requirements)
• Habit (speed, accuracy)
• Reliance on triggers (memory aid)
• (task 2 triggers task 3)
• (Captains request for the checklist cues FO to
  begin checklist)

Are these good outcomes? v Standardization
(between pilots/crews) v Accurate, efficient,
safe performance
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and so it should all work as expected
or maybe not?!
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PREFLIGHT Captains ASRS Report (edited)

• At this point the scheduled flight is about 1.5
  hours behind schedule. Prior to our arrival we
  experienced some problems with the autopilot
  system and had to call maintenance for approval
  to continue operations in accordance with the
  MEL. I discussed this with FO who contacted
  company, and called for fuel. I went inside the
  terminal to call Maintenance.

I headed back to the aircraft the passengers
were boarding and the FO was at the back of the
aircraft. As we both got into the cockpit, the
FO started the Load Manifest and I completed the
write-up in the logbook. I then started the
Before Start checks but was distracted by the
events of a final baggage and passenger count.
There were other flights on the ground and I had
seen the fuel truck moving about.
With the passengers and bags onboard and the
doors closed, the engines were started and a call
for taxi made. The main runway has been closed
for construction and we were given a shorter
runway. After a look at the takeoff data, winds,
and weights, we advised Tower we needed a
different runway. When cleared for takeoff we
had not completed the checklist so we advised
Tower we needed some more time. Once completed,
we departed with a climb in VFR conditions.
After climbing through 12000 ft I was scanning
the instruments and noticed the fuel quantity
only showed 980 lbs.
The series of events from the first landing until
takeoff was about 15 minutes. I feel there were
many distractions that interrupted the flows on
the preflight check and items were skipped.
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PREFLIGHT errors attributed to distractions
(incident reports)
CAPTAIN
FIRST OFFICER
Obtain ATIS Obtain clearance Review
paperwork Prepare/review charts (Passenger
count) (Load Sheet) Program FMC Begin
checklist Checklist complete Begin
checklist Checklist complete
Review paperwork Sign flight release Prepare/revi
ew charts Review Load Schedule Review
FMC Takeoff brief Ask for checklist Ask
for checklist
CLEARANCE
ENGINE START PUSHBACK
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ERRORS

• Wide range of outcomes
• Large number of omissions not caught by later
  checklist
• Consequences spill into all phases

WHY?

• Potential for accidents
• time, fuel, ramp mishaps, taxiway/runway
  incursions, rejected takeoffs

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Line representation (real)
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Preflight - real (compiled observations)
CAPTAIN
FIRST OFFICER
Obtain ATIS Obtain clearance Review
paperwork Prepare/review charts (Passenger
count) (Load Sheet) Program FMC Begin
checklist Checklist complete Begin
checklist Checklist complete
Review paperwork Sign flight release Prepare/revi
ew charts Review Load Schedule Review
FMC Takeoff brief Ask for checklist Ask
for checklist
Ground/ Company/ Dispatch Frequencies
Interphone
Cabin Attendant
procedure
Gate Agent
ACARs / OPC
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
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PHASE OF FLIGHT - real
z1 z2 z3 z4 z5
CAPTAIN
FIRST OFFICER
x
y
monitor z
A B C D
1 2 3 4
z
Wait
CLEARANCE
Activities are Linear
Predictable
Controllable
PILOT-driven
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Results

• Multiple interactions among operators and tasks
• (within, outside cockpit)
• Pervasive and unnoticed most often dealt with
  successfully
• Training
• does not adequately reflect reality
• does not adequately prepare pilots for line
  flying (learn on the job)
• Interactions are not well characterized
• Effects (challenges) are underestimated
• Vulnerability to errors are not appreciated
• Neither is the potential for such errors to lead
  to accidents

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So what are these Interactions?

• Characterize nature of interaction
• Characterize demand such interaction places on
  cognition

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Interactions 1

• Pilots are constantly being interrupted
• Interruptions demand attention (to note and
  assess)
• and action (to resolve)

• Observations from the jumpseat
• The first officer monitored the Ground frequency
  throughout the preflight preparations. A call
  with departure information interrupted her as she
  was setting the pressurization panel (a
  prescribed step in the procedure). She continued
  dialing the destination altitude before
  interrupting the procedure to acknowledge the
  call from Ground. She then copied the memorized
  information on the load sheet before resuming the
  interrupted procedure.

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Interactions 2

• Pilots must often perform gt1 tasks concurrently
• Some combinations are often practiced together
• Others combinations are new must be carried out
  on the spot

• From the jumpseat
• The captain monitored the cockpit interphone
  while performing his preflight duties and
  expecting to be contacted by the push back crew.
  A flight attendant notified him of a potential
  issue with a passenger. He relied on the cabin
  crew to resolve it with the help of the Gate
  Agent and continued with the preflight procedure.
  At the same time, he continued to monitor the
  conversation taking place right outside the
  cockpit door, intending to intervene if necessary.

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Interactions 3

• Pilots do not/cannot always initiate actions
• Circumstances may not be right for an action
• Information/tool/agent may not be available

• From the jumpseat
• CA reached the point on his preflight procedure
  calling for verification of sufficient fuel on
  board. He looked around for a fuel slip but
  quickly realized that it had not yet been brought
  to the cockpit - that implied that refueling was
  still underway. He formed the intention to
  return to the fuel quantity action item later and
  proceeded on with the remaining procedural steps.
  

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Challenge 1

• In order to respond to the multiple, complex, and
  unpredictable interactions, a pilot must
• Suspend/Defer activities
• i.e., must resume the suspended task or
• start the deferred task at a later
  time

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Challenge 2

• In order to respond to the multiple, complex, and
  unpredictable interactions, a pilot must
• Interleave activities
• i.e., combine habitual or novel activities
• in previously-encountered or new ways

• requires
• shift attention between activities
• remembering the activities
• remembering to check on the progress of each
  activity
• deciding when/how often to check progress

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Research Implications
Pilots are vulnerable to errors under such
circumstances because

• Events in the environment continue to flow in
  habitual sequence and with their usual timing
• Triggers for sequence of activities are
  disrupted or even lost altogether

• Memory
• esp. Prospective Memory (for intentions)
• Attention
• continuous sampling of environmental stimuli
  monitoring (essentially a continuous PM demand)

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Practical Implications (carriers)

• Acknowledge pilot fallibility
• Examine procedures and checklists, incident
  (ASAP) reports
• Blank-slate approach
• source
• nature
• timing of challenges in everyday operations
• Design robust procedures
• warning signs (red flags)
• triggers for items at risk (tie critical
  functions to fixed reference points)
• traps (strict decision criteria not to cross
  unless all expected activities fulfilled)
• Develop (better) guidance for Monitoring

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Cognitive Performance in Aviation Training and
Operations http//human-factors.arc.nasa.gov/fligh
tcognition/
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Backup slides from here on...
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Preflight B737 Ops Manual
FLIGHT ALTITUDE indicator --- cruise
altitude LANDING ALTITUDE indicator ---
destination field elevation Pressurization mode
selector --- AUTO AUTOMATIC FAIL light
--- Extinguished
PANEL OFF light --- Extinguished Set
panel --- As desired WARNING Do not
key HF radio while airplane is
being fueled. Injury to
personnel or fire may result
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TAXI - ideal (manufacturer)

• Goals
• bring aircraft to departure runway
• configure it for takeoff (next phase of flight)
• Considerations
• safe operation
• within performance limitations and design
  specifications

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Taxi B737 Ops Manual
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Taxi - ideal (manufacturer)
CAPTAIN
FIRST OFFICER
Receive taxi clearance Start
checklist Checklist complete Receive takeoff
clearance Start checklist Checklist
complete
Receive taxi clearance Start taxiing Ask
for checklist Receive takeoff
clearance Ask for checklist Line up
with runway
TAKEOFF
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PHASE OF FLIGHT - ideal (manufacturer)
CAPTAIN
FIRST OFFICER
A B C D
1 2 3 4

• Controllable tasks initiated by pilot,
  independently

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TAXI - assumed (carrier)

• Goals
• bring aircraft to departure runway
• configure it for takeoff (next phase of flight)
• Considerations
• Safe operation
• Within performance limitations and design
  specifications

• Carrier (additional) considerations
• Priorities (fuel, time, passenger comfort)
• Type of operations (short/long-haul,
  turn-arounds, regions/airports, fleet)
• Philosophy (safety, efficiency)
• Technologies on-board (ACARS, laptop)
• Coordination with agents (Ground, Tower,
  dispatch, other aircraft)

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Taxi - assumed (carrier)
CAPTAIN
FIRST OFFICER
Start taxiing Ask for checklist Recei
ve takeoff clearance Ask for
checklist Line up with runway
Receive taxi clearance Start
checklist Checklist complete Receive takeoff
clearance Start checklist Checklist complete
MONITOR Ground Company/Dispatch
MONITOR Ground Company
Taxi Clearance
MONITOR Captain taxiing
Takeoff Clearance
TAKEOFF
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TAXI-OUT -real Captains ASRS Report 425357
(edited)

• The aircraft we had for this flight had an
  inoperative fuel gauge, and an inoperative APU
  DFW was in the midst of a departure rush. Since
  we had to do a crossbleed start, we did not do
  the After Start checklist immediately...

We got clearance to taxi and requested a spot to
do the start. We stopped ... as instructed and
completed the start. As we were finishing, ground
control was giving instructions to aircraft
taxiing mentioning us in reference. We heard
this, completed the after start checklist, and
told ground we were ready to taxi.
We were given instructions to hold short of
taxiway WJ, give way to opposite direction
traffic, then proceed N to taxiway Z to taxiway
HY to taxiway Y across the bridge to taxiway J to
taxiway EF for takeoff on runway 17R, follow an
ACR aircraft. With all the above, taxiing to a
new and unfamiliar runway (for this crew) in the
dark, we didn't complete the before takeoff
checklist. As we were cleared for takeoff and
applied power, the takeoff warning horn sounded
and we immediately realized that the flaps had
not been extended for takeoff.
There were many distractions leading up to this
incident which should have been warning
signals. There was a time pressure element, we
were running late and knew we had an airplane
change in a short ground time in Denver before
our next flight. The APU and the necessity for
the crossbleed start precluded the normal flow of
calling for flaps and the before takeoff
checklist as we taxi from the gate. I was
distracted by calling for taxi, so ground control
knew we were ready to move. Immediately after
that call we were given a complicated taxi route
with hold short and follow instructions and we
were concentrating on finding the taxiways in the
dark
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TAXI-OUT errors attributed to distractions
(ASRS incidents)
Start taxiing Ask for checklist Recei
ve takeoff clearance Ask for
checklist Line up with runway
CAPTAIN
FIRST OFFICER
Receive taxi clearance Start
checklist Checklist complete Receive takeoff
clearance Start checklist Checklist complete
TAKEOFF
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Taxi-out - real (compiled observations)
Start taxiing Ask for checklist Recei
ve takeoff clearance Ask for
checklist Line up with runway
CAPTAIN
FIRST OFFICER
Receive taxi clearance Start
checklist Checklist complete Receive takeoff
clearance Start checklist Checklist complete
MONITOR Ground//Dispatch
MONITOR Ground/Company
Taxi Clearance
MONITOR Captain taxiing
Takeoff Clearance
TAKEOFF
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MOTIVATION study complex operating environment
as an entity

• operator(s)
• external agents
• tasks
• hardware/software

• Characterize nature of interactions
• Characterize their effects on the (routine
  flight) operation
• Develop or help guide development of
  tools/solutions to mitigate errors