Revisiting the 1% Rule
10.46246/KJAsEM.250033
- Author:
JoungSoon JANG
- Publication Type:Review Article
- From:Korean Journal of Aerospace and Environmental Medicine
2026;36(1):4-8
- CountryRepublic of Korea
- Language:English
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Abstract:
The 1% rule has been introduced as a practical model for aeromedical risk acceptance to airworthiness risk. It has been incorporated into European Joint Aviation Authorities’ guidance, then endorsed by International Civil Aviation Organization as threshold of decision. Although it has served as an important benchmark in aeromedical judgment, the underlying assumptions for initial setting have changed, making it necessary to revise the 1% rule. Specifically, the risk of heart disease has been excessively emphasized, which could lead to unintended losses of experienced older pilots. On the other hand, as pilots are now working to older ages, issues such as brain diseases are becoming more relevant, making additional tests for asymptomatic cerebral infarctions necessary. Maintaining strict standards alone does not necessarily contribute to aviation safety. More flexible criteria are needed depending on the working environment in aviation, and for example, standards such as the 2% or 5% rule could be introduced.
