Week 7

Question 1

Why are accidents important ?

Answer 1

Legal duty - international civil aviation (ICAO) member states provide air traffic services to ensure safety of aircraft, passengers and others affected by aircraft
Public perception of safety

Question 2

What is the reactive approach?

Answer 2

Identifying and fixing problems after they occur
Historically safety critical industries such as aviation, chemical, oil and energy took reactive approaches rapidly

Question 3

Why is the reactive approach not enough ?

Answer 3

It assumes accidents inevitable (waiting)
Unreliable solution compared to proactive

Question 4

What is the proactive approach?

Answer 4

Considering incidents lead to accidents so intervening at this level.
Incidents have less severe outcome
Makes use of safety triangle principle - reducing incidents reduces accidents

Question 5

What is the ICAO incident definition?

Answer 5

An occurrence other than accident associated with the operation of an aircraft which affects or could affect safety of operation

Question 6

What are the features of the ICAO incident definition?

Answer 6

Ambiguous
Expected and unforeseen like accidents
Different outcome
In incident safety of operations affected but no damages

Question 7

What does the proactive approach entail ?

Answer 7

Report of incidents
Collection and analysis of info
Effective incident reporting system so all less safe incidents considered in identification of safety problems

Question 8

What is needed for proactivity ?

Answer 8

A just culture with focus on learning from mistakes without being blamed.

Question 9

What does reliability of reported info rely on?

Answer 9

How orgs handle blame and punishment
How orgs encourage individuals to provide safety info in an atmosphere of trust

Question 10

What is identified in analysis of incident reports ?

Answer 10

Hazards
Variations
Disruptions
Degradations
Of systems itherwise undetected as they wouldn’t lead to consequences otherwise
And defences against safety problems

Question 11

What is the predictive approach?

Answer 11

Identifying all system deficiencies before they lead to occurrences such as incidents
Observing normal operation and efficiency of safety barriers

Question 12

What data is needed for predictive approach?

Answer 12

Accident data
Incident data
Hazards

Question 13

What is the definition of a system hazard ?

Answer 13

An uncommon or unwanted system state during which operative conditions of system affected.
Can jeopardise safety and contribute to development of incident

Question 14

A hazard may be identified as a precursor to an incident but may not always cause a safety occurrence. True or false?

Answer 14

True

Question 15

What is the difference between safety methodology development for proactive approaches and predictive?

Answer 15

More well developed and implemented for proactive approach
Fewer methodologies can predict risk

Question 16

What do industries agree about the definition of an accident ?

Answer 16

Emphasise damaging and observable outcome
Ignore occurrences related to security

Question 17

What does the ICAO define an accident as ?

Answer 17

An accident which occurs between boarding and all disembarking where one is seriously or fatally injured, aircraft substantially damaged, or aircraft missing

Question 18

How does the MAIB definition of accident differ from ICAO?

Answer 18

Mention of pollution or potential of pollution due to vessel damage

Question 19

What other accidents are included in MAIB definition as well as :
Death or serious injury of individual
Loss of individual from ship
Loss of vessel
Material damage of vessel?

Answer 19

Stranding or disabling vessel
Vessel collision
Damage by vessel to external marine infrastructure endangering vessel safety

Question 20

What are the accident and incident relationship features ?

Answer 20

1. Common cause - similar underlying causes of incidents and accidents
2. Identification of varying severity levels

Question 21

What did Heinrich study in 1931 Industrial Accident Prevention : A Scientific Approach ?

Answer 21

Workplace injuries and accident data collected by the insurance company he worked at over 30 yrs

Question 22

What causal factors of industrial accidents did he identify ?

Answer 22

Unsafe acts of people
Unsafe mechanical or physical conditions

Question 23

What did the Heinrich Pyramid find ?

Answer 23

For every 300 unsafe acts there are 29 accidents with minor injury and one with major injury

Question 24

What is Heinrich’s theory of accident causation ?

Answer 24

Unsafe acts lead to minor injuries and over time major injury (his pyramid aims to illustrate this )

Question 25

Why did Manuele (2001) think Heinrich’s ratio was misleading ?

Answer 25

Impossible that 10/11 incidents reported in 1926 no-injury cases due to nature of reporting at this time

Question 26

How is the adapted Heinrich pyramid derived from the standard one ?

Answer 26

1 major injury - accidents
29 minor injuries - serious incidents
300 unsafe acts - innocuous incidents

Question 27

What are the implications of Heinrich pyramid ?

Answer 27

Same common causes at work throughout triangle
Link of accidents with serious incidents and less severe safety occurrences by assuming statistical relation

Question 28

What’s the evidence challenging the constant ratio ?

Answer 28

Little evidence of a stable ratio found in multiple studies
In some sectors there’s a negative correlation between number of incidents recorded and fatality

Question 29

What is one explanation for a negative correlation between recorded and fatal accidents ? (Few recorded lots of fatal accidents )

Answer 29

Under reporting due to incidents being hidden
Can be due to blame culture, lack of resources to report experience and corporate zero accident targets

Question 30

What is another explanation ? (Lots recorded, few accidents ?

Answer 30

Non fatal incidents allow staff to learn how system reacts in abnormal conditions, provides training in bringing system back to control and prevents risk complacency

Question 31

Is there a Heinrich Ratio in air traffic management ?

Answer 31

Ratio between incidents and accidents undefined
Uncertain to identify due to unreported incidents ratio

Question 32

Accidents in complex ultra safe sociotechnical systems are characterised by many rare and nonlinear combinations of factors which aren’t evidenced in routine incidents often. True or false ?

Answer 32

True