Factores Humanos Mantenimiento

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Human Factors

2 © Copyright 2014 Bell Helicopter Textron Inc., Fort Worth, Texas 76101 Export Classification C, ECCN No Technical Data

Objectives

• Define human factors • Show specific examples of human factors


What is Human Factors?

• Designing workplaces, tools, procedures, and policies so people can use them easily and safely

• Primary concern is for people in the organization • Combines elements from many disciplines • Critical to the overall flight safety and personal

safety The purpose of human factors training is to ensure safety and efficiency by drawing attention to issues that affect human performance.


• About 80 percent of maintenance mistakes involve human factors, according to the Federal Aviation Administration.

• “As aircraft became more reliable and less prone to mechanical failure, the percentage of accidents related to human factors (human causes) increased.”

Human Factors Other Factors

Human Factors


The Elements of Human Factors


Clinical psychology: • Relationships with other people • Stress management • Self image

Psychology

Experimental psychology: • Reinforcement of desired

behavior • Effects of stress on behavior • Effects of work policies and

procedures


Organizational psychology: • Rewards and compensation • Motivation • Work teams and groups • Equitable treatment

Psychology

Educational psychology: • Ways to help people to

remember • Design of instruction


• Study of human body part sizes

• Can the user reach controls?

• Ability to access aircraft parts and systems

• Designing for extremes, i.e., smallest female and largest male

• No such thing as the “average” person

Anthropometrics


Computer science: • Human-computer interaction • User interface design • Requirements analysis for software-

based tools and test equipment • Accommodation for range of

computer literacy

Science

Cognitive science: • Problem solving ability • Things that affect troubleshooting

performance • Effects of stress on mental

processing


Safety engineering: • Slips, trips, and falls • Materials handling, e.g., lifting • Toxic materials storage and use • Facility design and safety

Engineering

Industrial engineering: • Setting reasonable work standards • Making work tasks efficient • Efficient facility layout


• Skeletal and muscular structure

• Biomechanics • Physical structure of

perceptual elements, e.g., eyes

• Work physiology, e.g., heat generation and dissipation

• Fatigue effects

Medical Science


Inte

rnal

• Boring repetitive jobs

• Personal life problems

• Substance abuse

• Fatigue • Stress • Poor

communication • Unrealistic

deadlines

Exte

rnal

• Smelly fumes • Loud noises • Snow • Lack of spare

parts • Poor tool

control • Slippery floors • Lack of tools

and equipment • Bad lighting

Trai

ning

• Poorly designed testing for skill and knowledge

• Poor instruction • Incomplete or

incorrect documentation

• Poor training

Human Factors Related to Maintenance


The Dirty Dozen

• Lack of Communication • Complacency • Lack of Knowledge • Distraction • Lack of Teamwork • Fatigue • Lack of Resources • Pressure • Lack of Assertiveness • Stress • Lack of Awareness • Norm


• Lack of communication is a major cause of errors

• Verbal and non-verbal • Positive listening • Communication

protocols

Lack of Communication



When changing shifts, maintainers must communicate with one another, explaining what work has and has not been completed. • Affirm reception of

information (read back) • Never assume the information

transmitted is the same information received



Only 30% of verbal communication is received and understood. The safety nets: • Use logbooks, worksheets, etc. to communicate and

remove doubt • Discuss work to be done or what has been

completed • Never assume anything


Complacency

• Overconfident after becoming proficient in a certain task, which can mask the awareness of dangers.

• Self-satisfaction accompanied by a loss of awareness of the danger – "I've looked back there 1,000 times and never found

anything wrong."

The safety nets are:

• Train yourself to expect to find a fault • NEVER sign for anything you

didn't do


Lack of Knowledge

• Maintainers must remain up to date on current equipment and how to fix it.

• Aviation organizations have a regulatory responsibility to provide required training to their personnel.

The safety nets offered are:

• Get training on type • Use up-to-date manuals • Ask a Tech. Rep. or someone

who knows


Distraction

Can cause us to think we are further ahead than we actually are. The safety nets for distractions are: • Always finish the job or unfasten the

connection. • Mark uncompleted work. • When returning to the job, always go

back three steps. • Use a detailed check sheet.


Lack of Teamwork

• A lack of teamwork can ultimately affect the safety of maintenance work.

• Not working together is tied in with lack of communication.

The safety nets for teamwork are:

• Discuss what, who, and how a job is to be done

• Be sure that everyone understands and agrees


Fatigue

Many human variables rise and fall daily due to natural circadian rhythm.


MARUFF, P., FALLETI, M. G., COLLIE, A., DARBY, D. and MCSTEPHEN, M. (2005), Fatigue‐related impairment in the speed, accuracy and variability of psychomotor performance: comparison with blood alcohol levels. Journal of Sleep Research, 14:21–27.

Fatigue can impair speed and accuracy of cognitive performance equal to or greater than blood alcohol concentrations (BAC).

Effects of Fatigue


Fatigue

Fatigued workers tend to underestimate the problem and overestimate the ability to cope with it.

The fatigue safety nets call for:

• Be aware of symptoms • Avoid complex tasks at the

bottom of circadian rhythm • Sleep and exercise regularly • Ask others to check work


• Allocate more critical tasks during day shifts when staff are likely to be more alert.

• Carry out appropriate checks after night shift work. • Break up lengthy repetitive tasks into smaller tasks,

with breaks in between.

Mitigate the Effects of Fatigue


Lack of Resources

• When there is a lack of resources available to properly fix something, cease maintenance until the proper parts are available.

• Lack of supply and support can interfere with one’s ability to complete a task.


• Check suspect areas at the beginning of the inspection and AOG the required parts.

• Order and stock anticipated parts before they are required.

• Know all available parts sources and arrange for pooling or loaning.

• Maintain a standard and if in doubt, ground the aircraft.


Pressure

• Pressure to get things repaired is always present in aviation.

• Do not let the pressures of time constraints get in the way with safely finishing a repair.

• Urgent demands can influence performance.

The safety nets to counteract this are:

• Be sure the pressure is not self-induced • Communicate concerns • Ask for extra help • Just say NO


Lack of Assertiveness

• Failing to alert others when something does not seem right can result in fatal accidents.

• Assertiveness is the ability to express feelings, opinions, beliefs, and needs in a positive, productive manner.

The counteracting safety nets are:

• If it is not critical, record it in the journey log book and only sign for what is serviceable.

• Refuse to compromise standards.


• Predictable, universal, human reaction to: – Fatigue – Time pressure – Difficult or unexpected situations – Personal problems

• Component of any human work • Stimulus that results in a change in arousal of the

nervous system and focuses our attention process • Stress hormones released, which changes heart rate • Subconscious response to the demands placed on a

person

Stress


• Acute Stress – Rapid build up – Shocks the nervous system – Easy to detect – heart rate, pulse, etc. – Can trigger “fight or flight” response – Body chemicals help cope

• Chronic Stress – Gradual build up over a long period of time – Difficult to detect – Does not trigger “fight or flight” response – Can lead to medical problems – ulcers, heart problems,

depression, etc. – Common in boring work, continuous low level of stress, etc.

Types of Stress


Stress Relievers


Stress

Stress safety nets call for: • Be aware of how stress can effect work • Stop and look rationally at the problem • Determine a rational course of action and follow it • Take time off or at least have a short break • Discuss it with someone • Ask fellow workers to monitor your work • Exercise your body


Lack of Awareness

• Failure to recognize all the consequences of an action, or lack of foresight


• Think of what may occur in the event of an accident. • Check to see if work will conflict with an existing

modification or repair. • Ask others if they can see any problem with the work

done.


Lack of Awareness


Norms

• The way things are normally done. • Unwritten rules followed or tolerated

by most of the organization. • Negative norms can detract from

established safety standard and cause an accident to occur.

The safety nets offered are:

• Always work as per the instructions or have the instructions changed

• Be aware that "norms" don't make it right


Issue Helicopter meets hangar Technician meets

rotating shaft

Reason Pilot lacks awareness of

surroundings Technician lacks

awareness of surroundings

Field Issues


Tell Tales Aircraft destroyed Hairy shaft

Cause

Lack of awareness Complacency Fatigue

Field Issues


206B Case Study


206B Case Study

Sequence of events: Owner contracted for maintenance work.

Owner hired commercial pilot to oversee the work.

25 April – Work began as per contract and to correct

discrepancies.

Apprentice mechanic removed, stripped, and primed droop restrainers and mast nut.


206B Case Study

• 26 April – Mechanic A directed parts to be stripped again and he would prime them the evening of 27 April.

Parts remained on work bench.

• 27April – No work scheduled on helicopter.

Apprentice mechanic working on adjacent aircraft. Mechanic B doing paperwork.

Pilot arrived at 0930 and requested Mechanic B to work on the helicopter.

Mechanic B agreed to devote the remainder of day to servicing helicopter.


206B Case Study

Pilot assisted Mechanic B with roof water leak – moved helicopter out/in hangar.

Pushed helicopter out onto ramp at 1500.

Pilot with Mechanic B aboard started engine, brought helicopter to a hover, and then landed to talk to Mechanic A.

Pilot and Mechanic B took off to perform flight checks.

When returning to field, helicopter crashed.


206B Case Study

Safety Board Investigation determined:

• Flap restraint and mast nut

not installed

• At 500 ft above ground level, the entire main rotor separated

• Extensive discussion concerning:

– Lack of logbook entries

– Absence of an adequate

Preflight Check


206B Case Study

Human Factors involved:

• Complacency with logs/record keeping

• Failure in communications

• Assumptions:

– Apprentice assumed mast nut reinstalled

– Pilot assumed aircraft OK

Expectations:

• Pilot expected aircraft OK if Mechanic aboard

• Mechanic expected Pilot to ensure aircraft OK


Human Error

Count the number of “f”s in the following sentence.


Human Error

Finished files are the result of years

of scientific study combined with the

experience of years.


Human Error

Did you count 3? Did you count 4?


Human Error

The answer “6” Finished files are the result of years

of scientific study combined with the

experience of years.


The Odds are Against Doing it Right!

Human Error

• Only one way to disassemble

• 40,000+ ways to incorrectly reassemble!


Cost:

• Loss of money • Personal injuries • Loss of life

Consequences vary:

• Major errors do not always lead to major accidents • Minor errors can lead to major accidents

Costs and Consequences


Traditional ways of addressing human error:

• Selection of personnel • Procedures/standardization • Technology/automation • Redundancy • Training • Motivation

Addressing Human Error


Conduct maintenance in a way that enables the aircraft to be released to service in a safe condition.

Approach to Human Factors & Safety


Question

A. True B. False

TrueFa

lse

0%0%

Do you have a Safety Management System at your workplace?

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A. 1 – 3 years B. 4 – 6 years C. 7 or more years D. Never trained at Bell

Training Academy

1 – 3 years

4 – 6 years

7 or more ye

ars

Never t

rained at Bell T

r...

0% 0%0%0%

Question

How long has it been since you last trained at the Bell Training Academy?

10


A. Pilot Initial B. Pilot Refresher C. Field Maintenance D. Electrical/Avionics E. Other F. Never trained at Bell

Training Academy

Pilot In

itial

Pilot R

efresh

er

Field M

aintenance

Electrica

l/Avio

nicsOther

Never t

rained at Bell T

r...

0% 0% 0%0%0%0%

Question

What type of course did you take at the Bell Training Academy?

10


Thank you for your participation!

Questions

Factores Humanos Mantenimiento

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Transcript of Factores Humanos Mantenimiento