Title: An update on Lessons Learned: Designing Human Factors Research Products that Customers Will Use (not just human factors)
1Managing Interruptions, Distractions and
Concurrent Task Demands
Key Dismukes Chief Scientist for Aerospace Human
Factors Human Factors Research and Technology
Division NASA-Ames Research Center ATA AQP Annual
Conference October 2003
2Our Research Team
- Immanuel Barshi
- LaQuisha Beckum
- Sean Belcher
- Rahul Dodhia
- Jon Holbrook
- Kim Jobe
- Tri Li
- Loukia Loukopoulos
- Jessica Lange Nowinski
- Mark Staal
3Consequences of Inadvertent Procedural Omissions
- LaGuardia (1994) MD-82 ran off runway end after
high-speed rejected take-off - NTSB Anomalous airspeed indications caused by
failure to turn on pitot heat - Detroit (1987) DC-9 crashed shortly after
take-off - NTSB Flaps/slats not set to take-off position
- Dallas (1988) B-727 crashed shortly after
take-off - NTSB Flaps/slats not set to take-off position
- Houston (1996) DC-9 landed gear-up
- NTSB Hydraulic pump not set to high position
-
4Were These Accidents Unique?
Not according to recent ASRS reports
- Rejected take-offs
- Anomalous airspeed indications (pitot heat not
on) - Configuration warning (flaps or trim not set)
- Other consequences of overlooked procedural steps
- Runway incursions
- Broken tow-bars
- Taxi into ditch
- Engine flame-out
- Overtemp engine
- Flew wrong departure route
- Go-around
- Unnecessary costs and delays
- But for luck any of these incidents might have
become accidents
- Departed with inadequate fuel
- APU left running during takeoff -- fire
- Packs failed in cruise
- Took off without PDC
- Deviated from speed or altitude restriction
- Nose gear failed to retract
- etc.
5Why?
- Why would experienced crews forget a procedural
step they normally perform day in and day out? - Why fail to catch omissions with checklists?
6An Ongoing NASA Research Project
- Carelessness not an adequate explanation
- Crews vulnerable to omissions when
- Interrupted or preoccupied with one of several
concurrent tasks (Young, Dismukes, Sumwalt,
1998). - Deferring tasks out of normal sequence
(Loukopoulos, Dismukes, Barshi, 2003). - Vulnerability to error among experienced pilots
largely driven by - Characteristics of tasks performed
- Demands tasks place on human cognitive processes
- Operating environment
- Norms for actual line operations
7Jumpseat Observation Study(Loukopoulos,
Dismukes, Barshi, 2003)
- Reviewed FOMs, observed line operations, analyzed
ASRS, NTSB reports - All phases of flight focus today on preflight
and taxi - Discovered disconnect between FOM/training and
actual line operations in depiction of task
management
8Preflight - In theory (FOM)
CAPTAIN
FIRST OFFICER
- Obtain ATIS
- Obtain clearance
- Review paperwork
- Prepare/review charts
- (Passenger count)
- (Load Sheet)
- Program FMC
- Begin checklist
- Review paperwork
- Sign flight release
- Prepare/review charts
- Review Load Schedule
- Review FMC
- Takeoff brief
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
9Depiction of Cockpit Task Management in
FOM/Training
- Tasks are serial and linear task A ? task B ?
task C in a fixed sequence.
10Preflight - In theory (FOM)
CAPTAIN
FIRST OFFICER
- Obtain ATIS
- Obtain clearance
- Review paperwork
- Prepare/review charts
- (Passenger count)
- (Load Sheet)
- Program FMC
- Begin checklist
- Review paperwork
- Sign flight release
- Prepare/review charts
- Review Load Schedule
- Review FMC
- Takeoff brief
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
11Depiction of Cockpit Task Management in
FOM/Training
- Linear task A ? task B ? task C in a fixed
sequence.
- Controllable tasks are initiated by crew at
their discretion. - Predictable
- Information available to crew when needed.
- Individuals can communicate as needed.
12Taxi-out - In theory (FOM)
CAPTAIN
FIRST OFFICER
- Captain
- Start taxiing
- Ask for checklist
- Receive takeoff clearance
- First Officer
-
- Receive taxi clearance
- Start checklist
- Checklist complete
- Receive takeoff clearance
MONITOR Ground Company/Dispatch
MONITOR Ground Company
Taxi Clearance
MONITOR Captain taxiing
Takeoff Clearance
TAKEOFF
13Depiction of Cockpit Task Management in
FOM/Training
- Linear task A ? task B ? task C in a fixed
sequence.
- Controllable tasks are initiated by crew at
their discretion. - Predictable
- Information available to crew when needed.
- Individuals can communicate as needed.
- Overall picture flight operations are pilot-
driven and under moment-to-moment control of crew.
14- Review paperwork
- Sign flight release
- Prepare/review charts
- Review Load Schedule
- Review FMC
Preflight - the reality
CAPTAIN
FIRST OFFICER
-
- Obtain ATIS
- Obtain clearance
- Review paperwork
- Prepare/review charts
-
- (Passenger count)
- (Load Sheet)
- Program FMC
- Begin checklist
Ground/ Company/ Dispatch Frequencies
Interphone
Cabin Attendant
procedure
Gate Agent
ACARs / OPC
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
15- Review paperwork
- Sign flight release
- Prepare/review charts
- Review Load Schedule
- Review FMC
Preflight - the reality
CAPTAIN
FIRST OFFICER
-
- Obtain ATIS
- Obtain clearance
- Review paperwork
- Prepare/review charts
-
- (Passenger count)
- (Load Sheet)
- Program FMC
- Begin checklist
Ground/ Company/ Dispatch Frequencies
Interphone
Cabin Attendant
procedure
Gate Agent
ACARs / OPC
procedure
procedure
checklist
CLEARANCE
checklist
ENGINE START PUSHBACK
16Line Observations Reveal a Different Story
- Normal line operations are quite dynamic
- Each pilot must juggle several tasks
concurrently. - Crews are frequently interrupted.
- External demands arrive at unpredictable moments.
- Conditions sometimes force task elements to be
performed out of normal sequence.
17Line Observations Reveal a Different Story
- Each pilot must juggle several tasks
concurrently. - Crews are frequently interrupted.
- External demands arrive at unpredictable moments.
- Conditions sometimes force task elements to be
performed out of normal sequence.
- Normal line operations are quite dynamic
- Crews must at times struggle to maintain control
of the timing and sequence of their work tasks.
18Conflict Between Theory and Reality
- FOM is a powerful tool for safety by providing
- Operational reality disrupts ideal execution of
procedures
- Explicit description of how each task is to
be performed - Standardization across crews
- Checklists and checking procedures
19So What?
- Pilots become accustomed to concurrent task
demands, interruptions, distractions and
disruptions. - However these situations substantially increase
vulnerability to error, especially omission of
critical procedural steps.
20ERRORS attributed to concurrent task demands,
interruptions, and disruptions (ASRS reports)
Forgot logbook at ramp - kept deferring to check
it distractions busy with preflight -
discovered en route
Skipped over checklist item - fuel pumps deferred
during preflight because refueling - engine
starvation in flight
Omitted review of charts - distractions - speed
violation on departure
Entered wrong weight in FMS - tail strike at
takeoff
Improper setting of pressurization during
preflight flow - interruptions - cabin altitude
warning light in cruise
Omitted flow and checklist items - interruptions
delay change in departure runway - discover
insufficient fuel at 12000 ft
Read but not verify checklist item - distractions
- pushback with throttles open, damage to aircraft
Started taxi without clearance - crew discussing
taxi instructions - struck pushback tug
Neglected to set flaps -preoccupied with new
departure clearance and packs-off operation -
aborted takeoff
FO failed to monitor CA busy with flow night
taxi taxi in wrong direction
FO failed to monitor CA -runway change busy
reprogramming FMC - taxied past intended taxiway
Omitted setting flap - busy with delayed engine
start rushed to accept takeoff clearance -
aborted takeoff
Failed to verify new clearance - monitoring
convective activity on radar - flew wrong heading
PREFLIGHT gt PUSHBACK gt TAXI gt TAEKOFF gt CLIMB gt
CRUISE gt DESCEND gt LAND
Omitted climb checklist - busy copying hold
instructions - missed setting altimeter and
overshot altitude
Failed to reset bleeds on - complex departure
multiple ATC calls traffic - altitude warning
and 02 mask deployment
Did not notice wind - preoccupied with
annunciator light handling radios - track
deviation
Forgot to reset altimeters - distracted by FA in
cockpit - TCAS RA and overshot arrival fix
Failed to monitor PF - busy reprogramming FMS
weather changes - go around
Failed to verify FMC settings - PNF giving IOE to
PF multiple ATC calls hold instruction - flew
pattern in wrong direction
ATC instructions too close to turn fix - busy
slowing aircraft approach checklist radios -
failed to make published turn
Vectored too close - busy catching up with
glideslope not instructed to switch to Tower -
landed without clearance
Forgot to switch to Tower at FAF - last minute
runway change busy reconfiguring aircraft -
landed without clearance
Unstabilized approach - accepted runway change
right before FAF did not review charts or make
callouts - tailstrike
Did not complete checklist - TCAS alerts
parallel runways in use GPWS alert - did not
extend gear for landing
Did not extend gear checklist interrupted TCAS
alerts parallel runways in use GPWS alert -
struck ground on go-around
21Why So Vulnerable to These Errors?
22Why So Vulnerable to These Errors?
- Brain has two ways of processing information to
perform tasks - Cockpit tasks vary from requiring mainly
controlled processing to being largely automatic.
- 1) Controlled processing
- Corresponds to conscious attention
- Slow, serial, and effortful low capacity
- Required for tasks with novel aspects
-
- 2) Automatic processing
- Fast, minimal effort, high capacity
- Develops with extensive practice of habitual
procedure - Requires minimal conscious supervision
23Automatic processing has enormous advantages but
also has serious vulnerabilities
24Aft Overhead
Aft Overhead
PREFLIGHT Flow (B73-300 - as trained) (checklist
items are marked )
Forward Overhead
Forward Overhead
Mode Control Panel
Mode Control Panel
First Officer Instrument
Captain Instrument
Center Instrument
Center Instrument
Captain Instrument
First Officer Instrument
Forward Electronic
Forward Electronic
Control Stand
Control Stand
Aft Electronic
Aft Electronic
Logbook/Gear Pins
Logbook/Gear Pins
25Vulnerabilities of Automatic Processing
- If procedural flow is interrupted, chain is
broken. - Pause prevents one step from triggering the next.
- Initiation of automatic process depends on
receiving signal or noticing a cue in the cockpit
environment. - If signal does not occur, individual is not
prompted to initiate procedure.
26Vulnerabilities of Automatic Processing
- If procedural flow is interrupted, chain is
broken. - Pause prevents one step from triggering the next.
- Initiation of automatic process depends on
receiving signal or noticing a cue in the cockpit
environment. - If signal does not occur, individual is not
prompted to initiate procedure. - Highly practiced procedures and checklists tend
to develop look without seeing automatic
responses. - High workload and/or rushing prevent conscious
supervision of automatic processes--exacerbates
vulnerability
27Vulnerability to Errors of Omission Can Be
Reduced
- 1) Actions airline operations and training
departments can take - 2) Actions individual pilots can take
28Ways Airlines Can Reduce Vulnerabilities
- Analyze actual line ops write procedures to
minimize opportunities for disruptions.
- Avoid floating procedural items allowed to be
performed at varying times. - Anchor critical items (e.g., setting takeoff
flaps) to distinct step that cannot be forgotten
(e.g., before start of taxi).
29Ways Airlines Can Reduce Vulnerabilities
- Analyze actual line ops write procedures to
minimize opportunities for disruptions.
- Avoid floating procedural items allowed to be
performed at varying times. - Anchor critical items (e.g., setting takeoff
flaps) to distinct step that cannot be forgotten
(e.g., before start of taxi).
- Analyze actual fleet norms for how checklists
are executed and bottom-lines observed. - LOSA
- Train with realistic concurrent task demands.
30Ways Pilots Can Reduce Vulnerability
- Being aware of vulnerability reduces threat.
- Especially vulnerable when head-down,
communicating, searching for traffic, or managing
abnormals.
- When interrupted or deferring a task
- Pause to encode intention to resume
- Create conspicuous cue as reminder (e.g.
checklist in throttle quadrant) - Develop habit of deliberate execution of
procedures and checklists to allow controlled
supervision of habitual responses. - Avoid rushing.
31Ways Pilots Can Reduce Vulnerability
- Being aware of vulnerability reduces threat.
- Especially vulnerable when head-down,
communicating, searching for traffic, or managing
abnormals.
- When interrupted or deferring a task
- Pause to encode intention to resume
- Create conspicuous cue as reminder (e.g.
checklist in throttle quadrant) - Develop habit of deliberate execution of
procedures and checklists to allow controlled
supervision of habitual responses. - Avoid rushing.
- Pause at critical junctures to review.
- Schedule/reschedule activities to minimize
concurrent task demands (e.g., brief before TOD). - Treat monitoring as essential task (Sumwalt).
32- For further information
- http//human-factors.arc.nasa.gov/ihs/flightcognit
ion/ - This work is supported by NASAs Airspace
Systems Program and by the FAA (AFS-230), Dr.
Eleana Edens, program manager.