Risk of Vertical Separation Loss at En-Route Phase of Airplane Flight

Safety of air transportation grounds on the exact following of preplanned trajectory by each airspace user. Different degradation factors actions on normal airplane operation lead to deviations out of cleared flight level that affect aviation safety level. In the paper we propose to use airplane trajectory data transferred by Automatic Dependent Surveillance-Broadcast equipment to estimate the risk of vertical separation loss. Risk is estimated as an area below the Probability Density Function of airplane deviation within altitude perils of cleared flight level. Data of barometrical altimeter measurements are used to fit double exponential and Triple Univariate Generalized Error Distribution probability density functions. A method of Maximum Posterior Probability is used to identify the flight phase with cleared flight level. Barometric altitude at the en-route phase of flight is only used. Proposed approach makes it possible to estimate risks by airplane type, airline, flight connection, pilot staff, flight route, or by part of airspace. As an example, a three months statistic of flight connection between Boryspil and Kharkiv airports is used to estimate the risk of vertical separation loss.