A good day, or a bad day at the office …
Depending on your perspective
Human Factors in Aviation
Design Delegation Holders, 20 October 2005
Dr Dougal Watson
Principal Medical Officer
Civil Aviation Authority
Lower Hutt New Zealand
A good day at the office!
Human Factors:
What’s it mean?
Human Factors in action: On the way to Auckland this morning.
Human Factors:
What’s it mean?
What is Human Factors
and what is it not?
Human Factors = Ergonomics
Human Factors:
Design engineering
Human Factors:
Definition 1
• Human Factors is the scientific discipline
concerned with the understanding of
interactions among humans and other
elements of a system, and the profession that
applies theory, principles, data and methods
to design in order to optimize human wellbeing and overall system performance.
International Ergonomics Association (http://www.iea.cc)
Human Factors:
Definition 2
• "Human Factors is about people: it is about people
in their working and living environments, and it is
about their relationship with equipment,
procedures, and the environment. Just as
importantly, it is about their relationships with
other people ... Its two objectives can be seen as
safety and efficiency.''
ICAO Circular 227
Not such a good day at the office!
Human Factors:
Definition 3
• Why do smart people do dangerous /
dumb things?
Human Factors:
Involves humans.
“Human beings by their very nature make
mistakes; therefore, it is unreasonable to expect
error-free human performance.” Shappell &
Wiegmann, 1997.
A bad day at the office!
Human Factors:
Why do smart people do dangerous / dumb things?
– Excessive Workload
• Physical and cognitive effort involved in task performance.
– Lack of Situation Awareness
• What’s going on?
• What’s likely to happen next?
• What will happen if I take a particular action?
– Excessive Stress, Fatigue, Uncertainty, etc.
• Impacts perceptual-motor performance, decision-making, etc.
– Diminished Attention
• Too much to attend to at once (overload)
• Too little to attend to for too long (underload)
– Poor Teamwork and Communication
• Often due to poor layout of work space and/or poor layout of command and
communication structure
– Quality engineering can help avoid virtually all of these problems
Human Factors:
Avoiding Errors.
• Plan, design, manufacture, and implement
systems that:
– Utilise human capabilities;
– Cater to human limitations:
• Redundancies;
• Layered defences;
• Fail-safe design etc etc etc
• Train & equip humans to:
– Utilise the system;
– Recognise and minimise their limitations;
– Learn from errors.
Not a good day at the office!
Human Factors:
Domains within Human Factors
• Physical
– anatomical, anthropometric, physiological and biomechanical
characteristics as they relate to physical activity
• Cognitive
– mental processes, such as perception, memory, reasoning, and
motor response, as they affect interactions among humans and
other elements of a system
• Organisational
– optimization of socio-technical systems, including their
organizational structures, policies, and processes
• Somewhat artificial delineation, in part reflecting the training
background of the practitioners
Human Factors:
Who does Human Factors?
• Multi-Disciplinary HF Specialists
• Some:
–
–
–
–
–
Psychologists
Engineers
Doctors
Kinesiologists
Retrained Subject Matter Experts … Yes, it is
possible to retrain engineers (pilots and
doctors)
– Scientists
Another bad day at the office!
Human Factors:
What is not Human Factors?
• “Just applied common sense”
• Training people to accommodate poor design
• Blaming the user
– “Pilot error”
• Designers projecting their skills onto users
– If it’s easy for the designer it must be easy for the end user
• Human Resources
• The Navy
Human Factors:
Why isn’t everyone doing it?
• “Voodoo Ergonomics”
• Everyone is an Operator … “It’s just common
sense!”
• While nobody intentionally designs systems to
interfere with human performance, they may resist
the up-front expense associated with “doing it
right.”
• HF folk have advertised & documented their
benefits poorly
Human Factors:
What about aviation?
• Over the past 40 years, over 80%
of accidents and incidents were
related to the human element and
were largely preventable through
the proper application of Human
Factors principles.
• If the accident or incident rate is
to be decreased, human factors
must be better understood and the
knowledge more broadly applied.
http://www.cami.jccbi.gov/AAM-600/610/600Air-HFB.html
A good day at the office!
Human Factors:
Some examples.
Human Factors in Everyday Life:
Medicine
Let he who is without sin …
•
•
•
•
•
•
•
Six accidents involving massive radiation overdose to
patients (1985 - 1987)
Therac-25 radiation treatment device
Controlled remotely
“Sloppy engineering” … “one of the most devastating
computer related disasters to date”
“A combination of technical failures (software and
possibly hardware) combined with human behaviour
resulting in catastrophic radiation overdoses”
‘Voluntary’ recall of equipment
Risk mitigation => hardware design, software design,
or training?
Human Factors in Everyday Life:
Footpaths
Things that get in your way.
• People usually follow footpaths when
they’re convenient.
• Many people take the path of least
resistance.
• Take a hint from people's behaviour.
• What does the savvy civil engineer or
builder do?
Human Factors in Everyday Life:
Centre High-Mounted Stop Lights
Human Factors innovation
•
•
•
•
NTSB estimates $910 million savings
pa just in property damage.
Also many millions in medical costs
saved.
$5 million spent in developmental
research and regulatory programs.
What CFO wouldn’t see the
attractiveness of over $1 billion annual
return on a $5 million one-off
investment?
A great day at the office!
Human Factors in Everyday Life:
Mop Sink
Things that don’t work the
way you expect
• Men’s washroom in restaurant.
• No urinal.
• Sign over the mop-sink.
– The mop sink looks enough like
a urinal for it to be used as one.
• When simple things have signs,
especially homemade signs, it is
usually a signal that they aren't
well-designed.
Human Factors in Everyday Life:
Call Centre CRT Display
MAIL BOX RENTALS 931 ROSELLE RD
MAIL BOXES ETC
836 ARLINGTON HEIGHTS RD
1749 W GOLF RD
318 HAY DAY ROAD
830 W MAIN ST
126 EAST WING
836 ARLINGTON HEIGHTS RD
1749 W GOLF RD
318 HAY DAY ROAD
830 W MAIN ST
126 EAST WING
1749 W GOLF RD
318 HAY DAY ROAD
830 W MAIN ST
126 EAST WING
SCHAUMBURG 60193
708 893-5705
ELK GROVE VILLAGE 60007
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
ELK GROVE VILLAGE 60007
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
708 956-1112
708 640-7788
708 123-4567
708 459-7060
708 310-4402
708 956-1112
708 640-7788
708 123-4567
708 459-7060
708 310-4402
708 640-7788
708 123-4567
708 459-7060
708 310-4402
Mail Box Rentals
931 Roselle Rd
Mail Boxes etc
836 Arlington Heights Rd
1749 W Golf Rd

318 Hay Day Road
830 W Main St
126 East Wing
836 Arlington Heights Rd
1749 W Golf Rd
318 Hay Day Road
830 W Main St
126 East Wing
1749 W Golf Rd
318 Hay Day Road
830 W Main St
126 East Wing
SCHAUMBURG 60193
708 893-5705
• Mixed-case text, plus highlighting
of selected listing.
• Saved 600ms in average call
operating time.
• Translated to $2.94 million per
year.
ELK GROVE VILLAGE 60007
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
ELK GROVE VILLAGE 60007
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
MOUNT PROSPECT 60056
BUFFALO GROVE 60069
LAKE ZURICH 60047
HOFFMAN ESTATES 60195
708 956-1112
708 640-7788
708 123-4567
708 459-7060
708 310-4402
708 956-1112
708 640-7788
708 123-4567
708 459-7060
708 310-4402
708 640-7788
708 123-4567
708 459-7060
708 310-4402
• Small investment, small obvious
improvement, good return at the
bottom-line.
Human Factors innovation
Human Factors in Everyday Life:
Car Seat Adjustment
Controls with unexpected function.
• Want to slide the seat back? Reach down
and pull the lever.
• Lever quickly detaches the whole seat.
• No-one likely to want to detach a seat while
sitting in it. Move the control to somewhere
it can’t be reached while sitting.
Human Factors in (not exactly) everyday life:
Shuttle Cockpit
Shuttle APU Display
(off-nominal conditions)
MM 303
Hyd Landing
MET 10/10:45:35
Landing Gear
1
2
EPS FA1
Man
LG Ext Isol
FA2 EPS
Man
EPS
LG Ext 1
EPS
LG Ext 2
Nose Deploy
NWS 1 NWS 2
NWS Fail
NWS S/V
Pyro 1
Main Deploy
L MG
R MG
Pyro 2
EPS
Brakes
1
Brk
Iso 1
EPS
1/2
Hyd
1- 3
2- 3
2
FA1
Man
Drag Chute
Brk
Iso 2
EPS
1/2
Brakes
Brk Isol 2
3
FA2
Man
Full
Brk
Iso 3
EPS
FA3
Man
Arm
Dpy
Jet
CDR PLT
X
X
X X
X X
SSME Repo
Fail
Brake Press
Tire Press
L
R
L
R
OB
IB
IB
OB
Nose
XXXS XXXS XXXS XXXS
XXXXS XXXXS XXXXS XXXXS Mn IB XXXS XXXS XXXS XXXS
XXXXS XXXXS XXXXS XXXXS
OB XXXS XXXS XXXS XXXS
Benefits:
• The sub-systems are
separated (e.g., landing gear,
brakes, drag chute).
• Important information
(landing gear) is displayed at
the top.
• Color-coding separates
different components such as
labels and data.
• Off-nominal elements are
color-coded.
This display is a work-in-progress which needs to undergo testing and evaluation. Even after revisions, it might not be implemented on the shuttle because of budget constraints or other factors.
Human Factors in (not exactly) everyday life:
Challenges on ISS for Emergency Escape
• Problem – Disorientation & lack of ISS architectural awareness
–
–
–
–
Disorientation reported on ISS in Node 1, as well as Mir
On-orbit is the first experience with the entire lay-out of ISS
Visiting Crews will not have time to learn the ISS layout
Disorientation can increase translation time and impact efficiency & safety
Solution: Phosphorescent Emergency Egress Path
Placards
 Icons & Arrows
 Indicate distinct multiple egress
paths to the specific vehicles
 Icons & text provide redundant
cueing
 Adaptable to location within ISS
 Russian Text for the Soyuz when
used in the FGB and SM
 Phosphorescent
 Self-illuminated relative to
surroundings
 Facilitate identification in reduced
visibility conditions
 Change out every 2 years
СОЮЗ
CRV
Shuttle
Human Factors in Aviation:
C150
‘Human Factors’ not
always right.
• Human Factors expert
analysis.
• Inconsistent design wrt
throttle and carbie heat
controls.
How Cessna 150s
are made
Human Factors in Aviation:
Light aircraft emergency fuel management
• Checking or changing fuel supply in an emergency?
Human Factors in Aviation:
S35 & V35 Bonanzas
Change fuel tank in an
emergency.
• Fuel control handle under the front
of the pilot seat, on the left beside
cabin wall
• Seat often needs to be slid back to
access control
– Especially for a short-ass pilot
like me
• Sliding seat back can make full
control input impossible.
Otherwise a great aeroplane.
Not such a good day at the office!
Nothing new under the sun
Human Factors in Aviation:
Cali Air Disaster
AA965 B757 21DEC95
• Classic case of “human error”
complicated by sleep
deprivation.
• Programmed autopilot to lock
on to “Romeo” beacon instead
of “Rozo.”
– Caused slow turn into a
mountain.
– 150 killed.
• Cockpit voice recorder
captured crew complaints of
excessive fatigue, yawning,
etc.
• 1997 Pulitzer Prize
Human Factors in Aviation:
C-141 Starlifter
Human Factors in design
• 40 years ago. Multi-role aircraft concept
employing roll-on / roll-off alternative
mission kits.
• Kits heavy and complex and required lots
of time and effort to install.
• HF analysis of mission profiles and
equipment needs lead to complete
restructuring of equipment deployment.
• $500k investment lead to $5M initial
savings.
• What would your CFO think?
It’s all a matter of perspective
Speedbird 245: Caution, FOD
Speedbird 245: You’re number two
behind a Cessna. Beware wake
turbulence!
hazard ahead!
Human Factors in Aviation:
British Midlands Air Disaster (Kegworth)
B737-400 08JAN89
• Fan blade in left engine detached during climb
=> compressor stall.
• Crew throttled back right engine & shuddering
stopped. Right engine shutdown.
• Almost normal emergency approach for some
time then increased vibration again from left
engine and then abrupt loss of power.
• Couldn’t restart right engine.
• Aircraft struck a field adjacent to M1 motorway.
47 dead, 74 seriously injured.
• A problem of perceptual sets where pax and
cabin crew had noted smoke from the left engine
but the information was inadequately
communicated to the flight deck.
There must be a human factors message in this … somewhere
Please!!!
Human Factors, aviation, and you.
- A plea to the engineers involved in aviation
- Good human factors in the design, development,
manufacture, and maintenance of aircraft and aviation
systems will reduce safety failures … big time!
- Good human factors will also financially benefit your
employer
- Good ergonomics is good economics (google-it!)
Human Factors Resources
• Internet
• Books, Reports, & Magazines
• Massey, Auckland, & Otago Universities
• RNZAF (Not the Navy though)
• Colleagues, Clubs, & Societies
• Private Companies
• Formal training of our people
Whenever we talk about a pilot who has been killed in
a flying accident, we should all keep one thing in mind.
They made a judgment. They believed in it so strongly
that they knowingly bet their life on it. That their
judgment was faulty is a tragedy,…
Every engineer, instructor, supervisor, doctor, and
contemporary who ever spoke to them had the
opportunity to influence their judgment, so a little bit
of all of us goes with every pilot we lose.