Effect on Aeroplane

No effect on operational capabilities or safety

Slight reduction in functional capabilities or safety margins

Significant reduction in functional capabilities or safety margin

Large reduction in functional capabilities or safety margins

Normally with hull loss

Effect on occupants excluding flight crew

Inconvenience

Physical discomfort

Physical distress, possibly including injuries

Serious or fatal injury to a small number of passengers or cabin crew

Multiple fatalities

Effect on flight crew

No effect on flight crew

Slight increase in workload

Physical discomfort or a significant increase in workload

Physical distress or excessive workload impairs ability to perform tasks

Fatalities or incapacitation

Allowable qualitative probability

No Probability Requirement

<…Probable….>

<…Remote….>

Extremely < --------> Remote

Extremely Improbable

Allowable qualitative probability: Average probability per flight hour on the order of:

No Probability Requirement

<………>

<10⁻³

Note 1

<………>

<10⁻⁵

<………>

<10⁻⁷

<10⁻⁹

Classification of Failure Condition

No safety effect

<…Minor..>

<…Major….>

<…Hazardous….>

Catastrophic