There are always errors when measuring position and velocity of moving objects such as aircraft. Therefore, the information provided by global positioning systems is never totally exact. This paper studies the effects of these errors in the actual separation of aircraft in the context of statebased conflict detection and resolution. Assuming that the state information is uncertain but that boun...

Altimetry System Error (ASE) is a measure of the height-keeping performance of an aircraft. In airspace where the Reduced Vertical Separation Minimum (RVSM) is applied, the importance of accurate aircraft height-keeping is magnified. ASE is not detectible in routine operations; specialized measurement equipment is necessary to independently measure the errors. To be eligible for RVSM operations...

This paper provides a summary of conclusions from the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) Flight Experiment which NASA conducted to determine pilot acceptability of the HVO concept for normal conditions. The SATS HVO concept improves efficiency at non-towered, non-radar airports in Instrument Meteorological Conditions (IMC) while achieving a level of safet...

Wake vortices are a safety hazard to landing aircraft. A landing aircraft that encounters a wake may roll, resulting in a fatal crash if the roll is severe enough and/or if the aircraft is low enough to the ground. Therefore, aircraft are separated by a sufficient distance to ensure that wakes have time to decay in strength. However, because of the inherent variability in wake behavior and airc...

In this deliverable we study algorithms for mid-term aircraft conflict detection. A twoaircraft conflict occurs when some prescribed separation distance between two aircraft is violated. In a mid-term time scale, the contribution of the different sources of uncertainty affecting the aircraft motion cannot be neglected when predicting the aircraft future positions. Based on this consideration, w...

This paper describes the implementation of four different collision avoidance algorithms designed for multi-rotor aircraft. The primary contribution of this paper is the evaluation of each using a common set of assumptions, simulation capabilities, and metrics. The first algorithm is an extension of the next-generation manned aircraft algorithm that will soon be deployed worldwide; it poses the...

The use of a differential game and an optimal control theoretic approach for computing danger zones for this particular problem is new.The space outside thedangerzone is deemed provablysafe, implyingthatduringblunder situations, emergency evasivemaneuvers starting from outside the zone are guaranteed to be safe within limits on themaneuver severity of both the blundering and evading aircraft. I...

Aircraft collision avoidance maneuvers are important and complex applications. Curved flight exhibits nontrivial continuous behavior. In combination with the control choices during air traffic maneuvers, this yields hybrid systems with challenging interactions of discrete and continuous dynamics. As a case study illustrating the use of a new proof assistant for a logic for nonlinear hybrid syst...

A mixed integer linear program is presented for deterministically scheduling departure and arrival aircraft at airport runways. This method addresses different schemes of managing the departure queuing area by treating it as first-in-first-out queues or as a simple parking area where any available aircraft can take-off irrespective of its relative sequence with others. In addition, this method ...

For the last 10 years, airlines have widely supported research on the development of airspaces where aircraft would be free to decide their trajectory: these areas where called Free-flight airspaces. However, as soon as two aircraft are in the same area, their separation must be guaranteed. FACES is an autonomous and coordinated embarked (on board) conflict solver for Free Flight airspace. It s...