R.C.J. Ruigrok

CONCEPTUAL DESIGN OF FREE FLIGHT WITH AIRBORNE SEPARATION ASSURANCE

The study described in this paper originally only aimed at studying the human factors problems of airborne separation hi a Free Flight environment. However to define the Free Flight environment with sufficient detail, a concept was designed at NLR. This conceptual design includes rules-of-the-sky, a conflict resolution algorithm, conflict detection, cockpit display recommendations, system description as well as operational implications. The feasibility of the design has been evaluated in three sub-studies: (i) off-line traffic simulations with very high traffic densities and a total of up to 300 aircraft, (ii) a safety analysis comparing the resolution method with current day ATC and (iii) a man-in-the-loop simulator experiment hi traffic densities up to three times the average WestEuropean traffic density with eight air line crews. None of these studies could refute the feasibility of the Free Flight conceptual design.

GRACE - a Versatile Simulator Architecture Making Simulation of Multiple Complex Aircraft Simple

Versatility is an essential asset of any research flight simulator but at the same time a high level of realism is needed to create the right experimental environment. How can a research flight simulator combine both efficiently and become the ultimate research platform? The answer to this question lies in the design of the architecture of the research flight simulator and the software techniques used to enhance its versatility. Each research project poses its specific requirements on the research flight simulator. Different projects require different aircraft types to address specific operational issues. To cope with these ever changing requirements a research flight simulator must be modular not only in software but also in hardware. Flight training simulators need a high level of realism because its essential for the quality of flight training to create a cockpit environment that closely matches the real live cockpit. For a research flight simulator the focus of attention is aimed at the research objective and the changes it brings to the flight deck. In order to produce a high level of realism for a number of aircraft types, as in the case of a research flight simulator, the simulator must be reconfigurable to represent these aircraft types. A cost-efficient solution is one cockpit which can be reconfigured to represent different aircraft types by exchanging hardware components. To combine both versatility and a high level of realism in a research flight simulator a special versatile modular architecture is needed that facilitates both. The National Aerospace Laboratory (NLR) has developed such an architecture and has implemented this architecture with the construction of its new research flight simulator called Generic Research Aircraft Cockpit Environment (GRACE). Both the hardware and the software used for GRACE are constructed to fit in this versatile modular structure. To make it easy to exchange components of the simulator the interfaces between the components must be designed to be generic. Generic in this sense means that the interfaces can support the superset of signals that any module may use. Special attention is needed to control the configuration of the simulator. Flexible configuration of the communication interfaces is the key to easy introduction of new and research specific modules to the architecture. Another technique applied to increase versatility is the use of adaptive software modules. The described versatile modular architecture and all the applied techniques to enhance this architecture are successfully demonstrated for the first time ever in the GRACE research flight simulator. In the most recent research projects GRACE was operated in four different aircraft configurations consisting of Fokker F100, Boeing B747400, Airbus A320 and A330. A lot of research specific software and hardware was integrated into GRACE with low effort and in a short time span. Its unique architecture has made GRACE the most versatile research flight simulator in the world today.

Combining 4D and ASAS for Efficient TMA Operations

*† Time-based trajectory-based (4D) operations in the Terminal Area (TMA) around airports have shown to provide good results in terms of efficiency and environment, for one aircraft in isolation. Airborne Separation Assurance System (ASAS) operations have shown to provide the capability to maintain spacing with other aircraft, given that the initial spacing is reasonably well established. In summary, 4D misses the option to control separation / spacing with many aircraft in an area. ASAS on its own misses the possibility to set the initial separation / spacing adequate. This paper describes results of separate 4D and ASAS trials, together with an elaboration of the optimum combination of 4D and ASAS for efficient and environmentally friendly TMA operations.

Research flight simulation of future autonomous aircraft operations

A key element in the development and innovation of future aviation concepts and systems is research flight simulation. Research flight simulation is applied when the performance and perception of human pilots is a key measure of the overall assessment. This paper gives an overview of the research simulation set-up of the National Aerospace Laboratory (NLR), Amsterdam, the Netherlands, which is used for the human-in-the-loop evaluation of future operational concepts. Special attention is given to the research topic of airborne separation assurance; often referred to as free flight. The presented set-up has proven to be a flexible evaluation tool for assessing human-in-the-loop performance when operating in a simulated future autonomous aircraft environment.

The Transition Towards Free Flight: A Human Factors Evaluation of Mixed Equipage, Integrated Air-Ground, Free Flight ATM Scenarios

This paper describes the initial results of a simulation experiment in which the human factors implications of three Mixed Equipage, Integrated Air-Ground, Free Flight Air Traffic Management (ATM) scenarios were investigated. The experiment primarily addressed how to accommodate a fleet of mixed equipped aircraft, with and without Airborne Separation Assurance System (ASAS), in a transitional free flight era in which both air and ground players have defined responsibilities. All three transitional ATM operational concepts evaluated, were designed with the idea that equipping aircraft should be immediately beneficial to the airlines.

Curved approaches and airborne spacing for efficient closely spaced parallel runway operations in IMC

In this contribution the existing RPAT concept for simultaneous approaches to closely spaced parallel runways is further elaborated to be implemented in low visibility. Besides RNP capabilities this concept uses as well ASAS spacing capabilities. The basic procedure design aspects and the required airborne functions are described. The airborne spacing will first be initiated by a 4D approach in which the trajectory of the target aircraft is being predicted based on position information provided by ADS-B or TIS-B. The ASPA function itself is then used to adjust the spacing such that after the S-curve the RPAT aircraft is parallel or slightly behind the target aircraft. Further on, results from simulations trails and initial flight trials will be presented. It is foreseen to fully flight test this concept in fall/winter 2010 at Braunschweig airport.

Man-in-the-loop part of a study looking at a free flight concept

The paper describes the man-in-the-loop part of a study looking at a free flight concept with detection and resolution of conflicts during cruise flight by means of airborne systems. The overall study included fast-time simulations to define a base-line concept, a safety analysis, and a man-in-the-loop simulator experiment to investigate human factors issues. Part of the human factors study was the integration of traffic information, conflict detection and conflict resolution advisories in the displays. Based on the results of the three sub-studies, the feasibility of the free flight concept as defined in this study, could not be refuted.

Flight Testing the Airborne Separation Assistance System

The Mediterranean Free Flight (MFF) project aimed at validating the Airborne Separation Assistance System (ASAS) applications. For this purpose, the project has defined three ASAS operational concepts to be tested during flight trials: ASAS Spacing, ASAS Separation and ASAS Self-Separation, also known as Free Flight. The flight trials objectives were to complement the results provided by simulations on workload, acceptability, suitability of tools and quality of service of the overall architecture.