Modification of safety level assessment methods in air traffic services using ADS-B

In the document of the Radio Technical Commission for Aeronautics (RTCA) [1], a methodology has been developed for the flight safety level assessment when using a promising automatic dependent surveillance system in broadcast mode (ADS-B) intended for certification of an air traffic control system. As the analysis presented in the article has shown, this technique is based on an erroneous hypothesis, the use of which leads to underestimated requirements for the ADS-B certified system. The example considered in the article shows that the rejection of this erroneous hypothesis can lead to tightening the requirements by an order of magnitude. To obtain correct results, the article proposes an easy-to-compute modification of the technique that is devoid of this, generally speaking, serious drawback. The use of the proposed technique is illustrated by an example.