Lack of international uniformity in assessing color vision deficiency in professional pilots.

INTRODUCTION: Color is an important characteristic of the aviation environment. Pilots must rapidly and accurately differentiate and identify colors. The medical standards published by the International Civil Aviation Organization (ICAO) require that pilots have "the ability to perceive readily those colors the perception of which is necessary for the safe performance of duties." The general wording of that color vision (CV) standard, coupled with the associated flexibility provisions, allows for different approaches to the assessment of color vision deficient (CVD) pilots. METHODS: Data was gathered and analyzed regarding medical assessment practices applied by different countries to CVD pilots. RESULTS: Data was obtained from 78 countries, representing 78% of the population and 92% of the aviation activity of the world. That data indicates wide variation in the medical assessment of CVD pilots. Countries use different tools and procedures for the testing of pilots, and also apply different result criteria to those tests. At one extreme an applicant making one error upon Ishihara 24-plate pseudoisochromatic plate (PIP) testing is declined a class 1 medical assessment, while at another extreme an applicant failing every color vision test required by the regulatory authority may be issued a medical assessment allowing commercial and airline copilot privileges. CONCLUSIONS: The medical assessment of CVD applicants is not performed consistently across the world. Factors that favor uniformity have been inadequate to encourage countries toward consistent medical assessment outcomes. This data is not consistent with the highest practicable degree of uniformity in medical assessment outcomes, and encourages aeromedical tourism.

Safety management as a foundation for evidence-based aeromedical standards and reporting of medical events.

The different interpretations by States (countries) of the aeromedical standards established by the International Civil Aviation Organization has resulted in a variety of approaches to the development of national aeromedical policy, and consequently a relative lack of harmonization. However, in many areas of aviation, safety management systems have been recently introduced and may represent a way forward. A safety management system can be defined as "A systematic approach to managing safety, including the necessary organizational structures, accountabilities, policies, and procedures" (1). There are four main areas where, by applying safety management principles, it may be possible to better use aeromedical data to enhance flight safety. These are: 1) adjustment of the periodicity and content of routine medical examinations to more accurately reflect aeromedical risk; 2) improvement in reporting and analysis of routine medical examination data; 3) improvement in reporting and analysis of in-flight medical events; and 4) support for improved reporting of relevant aeromedical events through the promotion of an appropriate culture by companies and regulatory authorities. This paper explores how the principles of safety management may be applied to aeromedical systems to improve their contribution to safety.

Aeromedical decision-making: an evidence-based risk management paradigm.

Aeromedical decisions take many forms and are made by different groups and individuals. Because of the ubiquity of aviation in the world today, it is important that aeromedical decisions are of the highest quality that can be reasonably achieved. A paradigm of evidence-based aeromedical risk management is reported on here. It combines the concept of evidence-based medicine with structured risk management methodologies to produce a methodology capable of delivering the highest quality of aeromedical decisions. While neither of these concepts is new, practitioners do need to ensure that they have the skills and knowledge to maximize the quality of their aeromedical decisions.

Effect of hypobaric hypoxia on auditory sensitivity.

INTRODUCTION: Previous studies on the effect of hypobaric hypoxia on auditory sensitivity are not readily interpretable, in most cases because the potential effect of ambient pressure on stimulus level was not considered. In this study, auditory sensitivity to 1, 8, 12, and 16 kHz tones was compared between conditions of hypoxia and normoxia at the same simulated altitude (3700 m). METHOD: In the hypoxic condition, the partial pressure of oxygen in the inspired air was allowed to decrease with increasing altitude. In the normoxic condition, the partial pressure of oxygen was maintained at a level equivalent to that experienced at mean sea level (MSL). This comparison also controlled for any effect resulting from physiological consequences of hypobaria other than hypoxia (such as a change in middle-ear impedance). RESULTS: A small (2.57 dB) reduction in sensitivity across the frequency range tested was observed. CONCLUSION: A reduction in sensitivity of this magnitude would not be expected to have a large impact on the effectiveness of information transfer via the auditory modality.