9.8 Human Error

Question 1

what are the 4 different models and theories used to illustrate human error

Answer 1

‘SHELL model’
‘PEAR model’
‘error chain’
‘swiss cheese model’

Question 2

what does each letter on the ‘SHELL model’ represent

Answer 2

S - software
H - hardware
E - environment
L - live-ware (others)
L - live-ware (you)

Question 3

what does each letter of the ‘PEAR model’ represent

Answer 3

P - people
E - environment
A - actions
R - resources

Question 4

how can you identify a slips, lapses and mistake

Answer 4

by asking questions like:
were the actions directed by some prior intention
did the action proceed as planned
did they achieve their desired end

Question 5

what is a slip

Answer 5

actions which were not carried out as intended or planned

Question 6

what is a lapses

Answer 6

missed actions and omissions

Question 7

what are mistakes

Answer 7

a specific type of error caused by a faulty plan or intention

Question 8

what are some other types of errors

Answer 8

design versus operator induced errors
variable versus constant error
reversible versus irreversible error
skill based behaviours and associated errors

Question 9

what is a type 1 error

Answer 9

when a good item is incorrectly identified as faulty

Question 10

what is a type 2 error

Answer 10

when a fault is over looked

Question 11

in violations in aircraft maintenance, what does ROSE stand for

Answer 11

Routine
Optimising
Situational
Exceptional

Question 12

what is MORS

Answer 12

mandatory occurrence reporting system

Question 13

who must all incident be reported to

Answer 13

CAA

Question 14

what is CHIRP

Answer 14

Confidential Human Factors Incident Reporting Programme

Question 15

what are the aims of error management

Answer 15

to prevent errors from occurring
to eliminate or mitigate the impacts of errors

Question 16

who is ultimately responsible for taking utmost care of their work and keeping an eye out for error

Answer 16

the engineer

Question 17

when can environmental capture occur

Answer 17

when an engineer habitually performs a certain task in a specific location

Question 18

Why are most modern aviation accidents caused by human error rather than aircraft component failure?

A. Modern aircraft are unreliable
B. Maintenance practices have no impact
C. Modern aircraft are highly reliable and designed to fly safely if defects are detected and repaired
D. Pilots are not trained adequately

Answer 18

C. Modern aircraft are highly reliable and designed to fly safely if defects are detected and repaired

Question 19

Which of the following is NOT a type of error in aviation maintenance?

A. Slips
B. Lapses
C. Mistakes
D. Automation-induced failures

Answer 19

D. Automation-induced failures

Question 20

In the SHELL model, what does the “S” represent?

A. Supervisors
B. Software
C. Safety culture
D. Systems engineering

Answer 20

B. Software

Question 21

in the SHELL model, what does the term “Liveware” refer to?

A. The tools and equipment used by engineers
B. The physical environment
C. The person or people in the workplace, including engineers, supervisors, and managers
D. Software and manuals

Answer 21

C. The person or people in the workplace, including engineers, supervisors, and managers

Question 22

Which element of the PEAR model considers physical characteristics, skills, and human limitations?

A. People
B. Environment
C. Actions
D. Resources

Answer 22

A. People

Question 23

Which PEAR factor includes lighting, temperature, and noise levels in the workplace?

A. People
B. Environment
C. Actions
D. Resources

Answer 23

B. Environment

Question 24

What is the purpose of a Job Task Analysis (JTA) in aviation maintenance?

A. To identify salaries and work hours for engineers
B. To analyse all actions needed to complete a task efficiently and safely
C. To measure the reliability of aircraft components
D. To replace human judgment with automated systems

Answer 24

B. To analyse all actions needed to complete a task efficiently and safely

Question 25

In Reason’s Swiss Cheese Model, what do the “holes” in the slices of cheese represent? A. Opportunities for errors or failures in defences B. Equipment malfunctions C. Steps in maintenance procedures D. Untrained personnel

Answer 25

A. Opportunities for errors or failures in defences

Question 26

How does the Error Chain contribute to accidents in aviation maintenance? A. By showing that all errors are caused by software B. By illustrating how a series of human factor problems combine to create an incident C. By identifying the single person responsible for an accident D. By focusing only on pilot mistakes

Answer 26

B. By illustrating how a series of human factor problems combine to create an incident

Question 27

According to the SHELL model, human error is usually caused by: A. The individual alone B. Poorly designed interfaces between humans and software, hardware, and the environment C. Defective aircraft structure D. Random chance

Answer 27

B. Poorly designed interfaces between humans and software, hardware, and the environment

Question 28

Which question can help identify whether an error is a slip, lapse, or mistake? A. Was the action illegal? B. Did the action achieve the intended result? C. Was the tool defective? D. Was the weather suitable?

Answer 28

B. Did the action achieve the intended result?

Question 29

What is a slip in aviation maintenance? A. A deliberate violation of procedures B. An action not carried out as intended or planned C. A failure due to a faulty plan D. Forgetting to perform a task

Answer 29

B. An action not carried out as intended or planned

Question 30

What is a lapse? A. Missing or forgetting an action due to memory or attention failure B. Choosing the wrong procedure deliberately C. A mechanical failure D. A decision made with incomplete knowledge

Answer 30

A. Missing or forgetting an action due to memory or attention failure

Question 31

Mistakes occur at which stage of an action? A. Execution B. Storage (memory) C. Planning D. Post-inspection

Answer 31

C. Planning

Question 32

Which of the following is an example of a violation? A. Accidentally installing the wrong rivet B. Forgetting to remove a protective cap C. Deliberately ignoring the maintenance manual to save time D. Mixing up two parts during assembly

Answer 32

C. Deliberately ignoring the maintenance manual to save time

Question 33

Design-induced errors differ from operator-induced errors because: A. They are always reversible B. They occur before the aircraft leaves the ground due to design flaws C. Operators cannot detect them D. They are caused by fatigue

Answer 33

B. They occur before the aircraft leaves the ground due to design flaws

Question 34

Variable errors are: A. Random and difficult to predict B. Systematic and predictable C. Always reversible D. Caused by violations

Answer 34

A. Random and difficult to predict

Question 35

Constant errors are: A. Random mistakes that occur sporadically B. Consistent, systematic errors that can be anticipated and controlled C. Deliberate violations D. Errors due to lack of training

Answer 35

. Consistent, systematic errors that can be anticipated and controlled

Question 36

Which of the following is an example of a reversible error? A. Over-pressurizing a fuselage B. Installing a wrong rivet that can be replaced C. Ignoring a fuel leak D. Forgetting to tighten a torque tube permanently

Answer 36

B. Installing a wrong rivet that can be replaced

Question 37

Skill-based behaviour errors include: A. Action slips, environmental capture, and reversion B. Knowledge-based misjudgments C. Deliberate violations D. Faulty rule selection

Answer 37

A. Action slips, environmental capture, and reversion

Question 38

A rule-based error occurs when: A. An engineer executes a routine procedure incorrectly B. A new task is attempted without prior knowledge C. A conscious violation is committed D. A mechanical component fails

Answer 38

A. An engineer executes a routine procedure incorrectly

Question 39

Knowledge-based errors occur when: A. An engineer relies on established procedures B. An engineer evaluates information and applies incomplete or incorrect knowledge C. The tools are faulty D. A colleague distracts the engineer

Answer 39

B. An engineer evaluates information and applies incomplete or incorrect knowledge

Question 40

Type 2 errors in visual inspection are: A. Incorrectly identifying a good item as faulty B. Failing to detect a real fault C. Errors in tool selection D. Deliberate violations

Answer 40

B. Failing to detect a real fault

Question 41

Which type of violation involves breaking rules to save time or make tasks easier, but becomes routine for a workgroup? A. Routine violation B. Optimising violation C. Situational violation D. Exceptional violation

Answer 41

A. Routine violation

Question 42

Which violation occurs in rare or emergency situations, where breaking rules is inevitable to prevent harm? A. Routine B. Optimising C. Situational D. Exceptional

Answer 42

D. Exceptional

Question 43

Most human errors in aviation maintenance: A. Directly cause accidents every time B. Lie “beneath the surface” and often do not result in accidents C. Are always visible and easy to detect D. Are usually intentional violations

Answer 43

B. Lie “beneath the surface” and often do not result in accidents

Question 44

The primary purpose of Mandatory Occurrence Reporting Systems (MORS) is to: A. Punish engineers for mistakes B. Collect information on actual or potential safety hazards and deficiencies C. Replace maintenance manuals D. Train pilots in emergency procedures

Answer 44

B. Collect information on actual or potential safety hazards and deficiencies

Question 45

According to EU Regulation 376/2014, occurrences must be reported if: A. They could endanger aircraft safety if not corrected B. They involve minor inconveniences only C. They are already well-known issues D. They are purely voluntary and optional

Answer 45

A. They could endanger aircraft safety if not corrected

Question 46

The CHIRP programme in the UK is designed to: A. Punish engineers for unsafe practices B. Allow confidential reporting of human factors and safety incidents C. Replace the CAA MORS reporting system D. Automate aircraft maintenance tasks

Answer 46

B. Allow confidential reporting of human factors and safety incidents

Question 47

In a “just culture,” when an error occurs: A. Engineers are automatically blamed and reprimanded B. Errors are ignored to avoid conflict C. Errors are investigated objectively to address contributing factors and system issues D. Only management is held responsible

Answer 47

C. Errors are investigated objectively to address contributing factors and system issues

Question 48

The primary goal of error management in aircraft maintenance is to: A. Eliminate all errors completely B. Prevent errors and mitigate their impacts C. Assign blame to individual engineers D. Increase the workload of maintenance staff

Answer 48

B. Prevent errors and mitigate their impacts

Question 49

According to Prof. Reason, the two main components of error management are: A. Error prediction and error reporting B. Error containment and error reduction C. Error training and error documentation D. Error supervision and error mitigation

Answer 49

B. Error containment and error reduction

Question 50

Safety Management Systems (SMS) in maintenance organisations are used to: A. Replace engineers with automated systems B. Collate data on errors, incidents, and accidents to identify weak spots C. Assign penalties to engineers who make mistakes D. Monitor pilots’ in-flight performance exclusively

Answer 50

B. Collate data on errors, incidents, and accidents to identify weak spots

Question 51

A key strategy to prevent errors is to ensure engineers follow procedures by: A. Making procedures difficult to access so they are memorable B. Presenting procedures in a user-friendly way and encouraging compliance C. Allowing engineers to cut corners if they are experienced D. Relying only on engineers’ memory rather than written procedures

Answer 51

B. Presenting procedures in a user-friendly way and encouraging compliance

Question 52

Organisations must balance error management with profitability because: A. All preventative measures are cost-free B. Some measures are costly, but neglecting them increases the risk of errors C. Error management is more important than safety D. Engineers are solely responsible for preventing errors, so organisations need not invest in defences

Answer 52

B. Some measures are costly, but neglecting them increases the risk of errors