China
Africa
Explore chapters and articles related to this topic
ATC/ATM (Air Traffic Control/Management)
Published in Milan Janić, System Analysis and Modelling in Air Transport, 2021
For the purpose of modelling capacity, an air route network, established in the airspace between two continents, i.e., over the ocean, is considered as the system. The airspace is assumed to be without ground-based navigational facilities and equipment, including radar coverage, thus preventing provision of the direct ATC monitoring and control of air traffic flows there. Under such conditions, the aircraft has to perform RNAV by using the traditional compass and/or the satellite navigation systems, such as GPS (Global Position System) (USDD, 2008). During that phase of flight, the aircraft follow the routes called the “tracks”, defined by the series of WPs (Way Point(s))4 indicating locations along the tracks where the course, speed, and/or altitude can change. In most cases, these routes/tracks coincide with the great-circles, i.e., the shortest distances between any two points on the globe, implying orthodrome-based navigation. In addition, before entering and after leaving these routes/tracks, the aircraft can also use the ground-based navigational facilities and equipment such as VOR and DME on the range of about 240 Nm (440 km). Also, the radar coverage, and consequently the radar monitoring, can also be provided during the phases of flights over the continental parts of the flights. Figure 4.8(a, b) shows an example of such traffic patterns (Dhief, 2018; ICAO, 2017; NATS, 2015; https://www.fiightradar24.com/).
Airspace Systems Technologies
Published in Emily S. Nelson, Dhanireddy R. Reddy, Green Aviation: Reduction of Environmental Impact Through Aircraft Technology and Alternative Fuels, 2018
Area Navigation (RNAV) is a method of navigation that enables an aircraft to fly along a desired flight path within the coverage of the navigational aids or within the limits of the aircraft, or a combination of both. The safety along an RNAV route is ensured through a combination of aircraft navigation accuracy, route separation, and ATC radar monitoring and communications. Required Navigation Performance (RNP) is RNAV operations with aircraft onboard equipment for performance monitoring and alerting. The PBN concept assumes that the navigation specification will be met through a combination of ground-based, satellite-based, and aircraft-based hardware and software. RNAV- and RNP-equipped aircraft can fly direct trajectories between points in the airspace, and RNAV and RNP specify the cross-track accuracy between the desired and actual trajectory of the aircraft. As shown in Figure\\ 7.7, an aircraft with RNP 2 capability will be able to follow the desired trajectory with a cross-track accuracy of 2 nautical miles (3.7 km) 95% of the time and within a lateral containment region of 4 nautical miles (7.4 km) all (99.999%) the time. PBN varies from RNP 10 to the 0.1-nautical-mile precision and the curved paths of the RNP 0.1 Authorization Required approaches. Table\\ 7.1 shows some of the commonly used performance and the functional requirements during the different phases of flight of an aircraft today.
Area navigation
Published in Mike Tooley, David Wyatt, Aircraft Communications and Navigation Systems, 2017
These features lead to a reduction of operating costs achieved by saving time and/or fuel. RNAV- equipped aircraft are able to operate in flexible scenarios that are not possible with conventional airway routes; this leads to higher utilisation of the aircraft. VOR–DME-defined airways were supplemented in the 1970s with RNAV routes, but this scheme has now been superseded (see Figure 16.7 Features and benefits of RNAV ‘Required navigation performance’ at the end of distance, bearing and time to the active this chapter). waypoint.
Design Factors of Guiding Aircraft Through Continuous Descent Operations: Pilot and Controller Perspectives
Published in The International Journal of Aerospace Psychology, 2019
Lateral path designs are the routes that guide aircraft during CDO procedures. Davison Reynolds, Reynolds, and Hansman (2005) classified prevailing CDA procedures into two types: basic CDAs and area navigation (RNAV) CDAs. Basic CDAs retain the lateral control flexibility associated with using heading vectors. Controllers, unlike in step-down approaches, must estimate the track distance to be flown by an aircraft. Pilots use the track distance estimates to determine the appropriate descent rate and speed. RNAV CDAs predefine the lateral trajectory in terms of waypoints with altitude and speed targets. The aircraft equipped with RNAV, such as the flight management system (FMS), follows a narrow navigation path until final approach clearances. Anderson and Warren (2002) presented the capabilities of the FMS to allow idle thrust descent from about 8,000 to 2,000 ft based on a simulation for a 737–700 aircraft. Flight management techniques could tailor the final descent paths for aircraft conducting CDAs. Communication and coordination between flight crews and ATC controllers were also highlighted by this study. However, Weitz, Hurtado, Barmore, and Krishnamurthy (2005) evaluated airborne precision spacing techniques to merge and space the aircraft flying CDA arrival routes. The results revealed that the benefits retained from both techniques might be unachievable because of sensitivities to spacing errors.