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 WatsonPrincipal Medical OfficerCivil 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 well-

being 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:

MedicineLet 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

Human Factors innovation• Mixed-case text, plus highlighting

of selected listing.• Saved 600ms in average call

operating time.• Translated to $2.94 million per

year.

• Small investment, small obvious improvement, good return at the bottom-line.

Mail Box Rentals 931 Roselle Rd SCHAUMBURG 60193 708 893-5705Mail Boxes etc

836 Arlington Heights Rd ELK GROVE VILLAGE 60007 708 956-11121749 W Golf Rd MOUNT PROSPECT 60056 708 640-7788

318 Hay Day Road BUFFALO GROVE 60069 708 123-4567830 W Main St LAKE ZURICH 60047 708 459-7060126 East Wing HOFFMAN ESTATES 60195 708 310-4402836 Arlington Heights Rd ELK GROVE VILLAGE 60007 708 956-11121749 W Golf Rd MOUNT PROSPECT 60056 708 640-7788318 Hay Day Road BUFFALO GROVE 60069 708 123-4567830 W Main St LAKE ZURICH 60047 708 459-7060126 East Wing HOFFMAN ESTATES 60195 708 310-4402 1749 W Golf Rd MOUNT PROSPECT 60056 708 640-7788318 Hay Day Road BUFFALO GROVE 60069 708 123-4567830 W Main St LAKE ZURICH 60047 708 459-7060126 East Wing HOFFMAN ESTATES 60195 708 310-4402

MAIL BOX RENTALS 931 ROSELLE RD SCHAUMBURG 60193 708 893-5705MAIL BOXES ETC

836 ARLINGTON HEIGHTS RD ELK GROVE VILLAGE 60007 708 956-11121749 W GOLF RD MOUNT PROSPECT 60056 708 640-7788318 HAY DAY ROAD BUFFALO GROVE 60069 708 123-4567830 W MAIN ST LAKE ZURICH 60047 708 459-7060126 EAST WING HOFFMAN ESTATES 60195 708 310-4402 836 ARLINGTON HEIGHTS RD ELK GROVE VILLAGE 60007 708 956-11121749 W GOLF RD MOUNT PROSPECT 60056 708 640-7788318 HAY DAY ROAD BUFFALO GROVE 60069 708 123-4567830 W MAIN ST LAKE ZURICH 60047 708 459-7060126 EAST WING HOFFMAN ESTATES 60195 708 310-4402 1749 W GOLF RD MOUNT PROSPECT 60056 708 640-7788318 HAY DAY ROAD BUFFALO GROVE 60069 708 123-4567830 W MAIN ST LAKE ZURICH 60047 708 459-7060126 EAST WING HOFFMAN ESTATES 60195 708 310-4402

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

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.

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.

Brk Isol 2

LG Ext 1

1 2

LG Ext Isol

Nose Deploy

1 2 3

1/2 1/2 FullBrakes

CDR PLTArm X XDpy X XJet X X

SSME Repo Fail

Main Deploy

NWS 1 NWS 2

Pyro 1

Pyro 2

LG Ext 2NWS S/V

BrkIso 1

BrkIso 3

BrkIso 2

FA3ManEPSFA2

ManEPSFA1ManEPS

FA1ManEPS FA2

Man EPS

EPSEPSEPS

NWS Fail

Landing Gear

Brakes Drag Chute

Hyd Landing MM 303 MET 10/10:45:35Hyd Landing MM 303 MET 10/10:45:35

L MG R MG

Hyd OB IB IB OB1- 3 XXXXS XXXXS XXXXS XXXXS2- 3 XXXXS XXXXS XXXXS XXXXS

L RBrake Press

L RNose XXXS XXXS XXXS XXXSMn IB XXXS XXXS XXXS XXXS

OB XXXS XXXS XXXS XXXS

Tire Press

Shuttle APU Display(off-nominal conditions)

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

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.

Nothing new under the sun

Not such a good day at the office!

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 StarlifterHuman 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?

Speedbird 245: You’re number two behind a Cessna. Beware wake

turbulence!

Speedbird 245: Caution, FOD hazard ahead!

It’s all a matter of perspective

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.