Risk and Safety

Accidents and incidents happen with all parachute systems. These are called mishaps. Some mishaps are minor. Some can be fatal or cause total system loss.

Everyone involved with parachute systems should be familiar with

• identifying hazards
• assigning risk levels to the hazard
• assigning risk criteria and
• identifying preventive measures or recommendations to reduce or eliminate a hazard.

Definitions

Mishap:

An unplanned event or series of events that results in death, injury, occupational illness or damage to or loss of equipment or property.

Hazard:

A condition that is a prerequisite for a mishap.

Risk:

An expression of the possibility of a mishap in terms of hazard severity and hazard probability.

Safety:

Freedom from those conditions that can cause death, injury, occupational illness, or damage to or loss of property.

Hazard Severity:

Description	Category	Mishap Definition
Catastrophic	1	Death or system loss.
Critical	2	Severe injury, severe occupational illness, or major system damage.
Marginal	3	Minor injury, minor occupational illness, or minor system damage.
Negligible	4	Less than minor injury, occupational illness, or system damage.

Hazard Probability:

Description	Level	Specific Individual Item	Fleet or Inventory
Frequent	A	Likely to occur.	Continuously experienced.
Probable	B	Will occur several times in life of an item.	Will occur frequently.
Occasional	C	Likely to occur sometime in life of an item.	Will occur several times.
Remote	D	Unlikely but possible to occur in life of an item.	Unlikely but can reasonably be expected to occur.
Improbable	E	So unlikely, it can be assumed occurrence may not be experienced.	Unlikely to occur, but possible.

Risk Assessment

Many hazards can be identified for any system. Each hazard has a severity and probability of occurrence.

If a hazard has several levels of severity, then the most severe one is assigned to the hazard.

If a hazard has several levels of probability of occurrence, then the most frequent level is assigned to the hazard.

The risk level of each hazard puts the hazard someplace in the Risk Assessment Matrix. A criterion is assigned to each risk level in the matrix.

Below are two sample Hazard Risk Assessment Matrices. A level of acceptance is associated with each risk level. Safety enters in the assigning risk criteria. One person may assign 'undesirable' to Occasional-Marginal Risks. Another person may call the same risk 'acceptable with review'.

Example

Loss of altitude awareness is a common hazard in skydiving. Loss of altitude awareness can lead to a fatal mishap. The severity of loss of altitude awareness is Catastrophic, or Category 1. The probability of occurrence can be Frequent, or Level A.

Overall, the hazard of loss of altitude awareness is Catastrophic-Frequent. This is called 1A in the first Risk Matrix and is called 1 in the second Risk Matrix.

The hazard is definitely is the undesirable risk level.

Now, the question is how is the risk of this hazard reduced. We need to identify ways we can change the system to reduce the risk level.

Changing either the severity or probability of occurrence or both can reduce the risk.

One way to reduce the severity is to add an automatic activation device (AAD) to the jumper. A reliable AAD will save the jumper from certain death in the event the jumper looses altitude awareness. With an AAD this hazard has Marginal severity. The AAD may fire when the jumper is not in a good position for deployment. There is some possibility that the parachute may experience damage during deployment or inflation.

There are several ways to reduce the probability of occurrence. The jumper can use a visual altimeter, audible altimeter, look at the ground every few seconds or pay attention to other jumpers' opening.

If all of these measures are used the probability of occurrence is reduced to Remote.

The hazard of loss of altitude awareness for a jumper using an AAD, visual altimeter, audible altimeter, looking at the ground every few seconds and paying attention to other jumpers' opening is Marginal-Remote. This is 3D in the first Risk Matrix and 14 in the second Risk Matrix. These have an 'acceptable with review' risk criterion. This means that the jumper needs to be aware that the devices do not guarantee loss of altitude awareness will not happen. The devices allow the jumper to become aware of his loss of altitude awareness in time to pull.

There are some other considerations. The introduction of these devices may raise or lower the risk criterion of other hazards. The extra devices also make for a more complex system with higher maintenance requirements and more failure modes.

Failure mode analysis is another aspect of system performance.

Summary

Hazards may be identified for any system. The risk level with and without controls may also be determined. Each person can make an educated assessment on what risk levels are acceptable and what risk levels are unacceptable.