Description of the Derivation of the Collision Risk Model Used in the Vertical Separation Simulation Risk Model

摘要

This report presents a brief description of the derivation of the collision risk equations for the use on the vertical separation Midair Collision Simulation Risk Model. It also describes the estimation of the Collision Risk Model parameters for the current 2000-foot standard and the proposed 1000-foot planned vertical separation standard. The model itself consists of specialized computer programs and systematic procedures that realistically and economically simulate aircraft flight-planned movements in the National Airspace System (NAS). These aircraft movements are based on flight plans and tracking data transmitted to Central Flow Control Facility (CFCF) from all the 20 centers that make up the NAS. The task is to find the frequency, Na, with which a pair of aircraft flying at and above flight level (FL)290 would, by flight-planned intent, be proximate (near each other) in the NAS. The purpose of this mathematical model is to make a quantitative judgement about the safety of the proposed 1000-foot vertical separation, and provide an estimate of the risk of midair collision due to the loss of 1000-foot planned vertical separation. As the result of this first phase of the study, it is recommended that the model be enhanced to do the following: 1) step climbing, and 2) point-to-point navigation. Keywords: Tracking system; Proximity shell; Separation vectors; Collision slab; Central flow.