Aircraft wake vortices can pose a threat, especially in the terminal environment where aircraft operate in close proximity. Vortex separation standards preclude hazardous encounters, but are oftentimes very conservative. A key to increasing airport capacity is to know when vortices are not a hazard so that aircraft can land and take off with closer intervals. A conference was held in London to ...

Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. Regulators will establish minimum operating standards for DAA effectiveness, but different combinations of algor...

The present article considers the application of robust H∞ filters for nonlinear aircraft models in cruise flight conditions. The achieved performance of various design scenarios are first compared with the best achievable lower bound, calculated using frequency-gridding method. The synthesis problem is than validated on the linear uncertain aircraft model, later on the nonlinear, high-fidelity...

Stage separation is a critical technical issue for developing two-stage-to-orbit (TSTO) launch systems with widebody carrier aircraft that use air-breathing propulsion and launch vehicle stages that use rocket propulsion. During conceptual design phases, this issue can be addressed with a combination of engineering methods, computational fluid dynamics simulations, and trajectory analysis of th...

An emerging Next Generation Air Transportation System concept Equivalent Visual Operations (EVO) can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced f...

This paper describes human-in-the-loop research at NASA Ames Research Center on service provider-based automated separation assurance for the Next Generation Air Transportation System (NextGen). Key human/automation integration aspects such as levels of automation and roles and responsibilities of automated separation management are investigated in the Airspace Operations Laboratory. A trilogy ...

The concept of distributed air-to-air separation assurance envisions aircraft detecting and resolving conflicts autonomously without the need for a ground based air traffic service provider. Current automated conflict resolution algorithms that assume instantaneous heading changes without consideration of turn dynamics can result in unintentional loss of separation. A simulation of distributed ...

Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport c...