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Calculation of Fligh T Deck Interval Mana Gement Assigned Spacing Goals Subjec T to Multiple Schedu Ling Constraints
| Content Provider | Semantic Scholar |
|---|---|
| Author | Robinson, J. Elliott Field, Moffett |
| Copyright Year | 2014 |
| Abstract | The Federal Aviation Administration’s Next Generation Air Transportation System will combine advanced air traffic management technologies, performance-based procedures, and state-of-the-art avionics to maintain efficient operations throughout the entire arrival phase of flight. Flight deck Interval Management (FIM) operations are expected to use sophisticated airborne spacing capabilities to meet precise in-trail spacing from top-of-descent to touchdown. Recent human-in-the-loop simulations by the National Aeronautics and Space Administration have found that selection of the assigned spacing goal using the runway schedule can lead to premature interruptions of the FIM operation during periods of high traffic demand. This study compares three methods for calculating the assigned spacing goal for a FIM operation that is also subject to time-based metering constraints. The particular paradigms investigated include: one based upon the desired runway spacing interval, one based upon the desired meter fix spacing interval, and a composite method that combines both intervals. These three paradigms are evaluated for the primary arrival procedures to Phoenix Sky Harbor International Airport using the entire set of Rapid Update Cycle wind forecasts from 2011. For typical meter fix and runway spacing intervals, the runwayand meter fix-based paradigms exhibit moderate FIM interruption rates due to their inability to consider multiple metering constraints. The addition of larger separation buffers decreases the FIM interruption rate but also significantly reduces the achievable runway throughput. The composite paradigm causes no FIM interruptions, and maintains higher runway throughput more often than the other paradigms. A key implication of the results with respect to time-based metering is that FIM operations using a single assigned spacing goal will not allow reduction of the arrival schedule’s excess spacing buffer. Alternative solutions for conducting the FIM operation in a manner more compatible with the arrival schedule are discussed in detail. Introduction The Federal Aviation Administration (FAA) is developing the Next Generation Air Transportation System (NextGen) which envisions advanced air traffic management technologies and procedures to accommodate safely, efficiently, and reliably the forecasted increase in traffic demand [1]. As a result of high fuel costs and a desire to leverage existing advanced aircraft equipage, a primary focus of NextGen is the use of fuel-efficient performancebased navigation (PBN) procedures in the already dense terminal area, such as Area Navigation (RNAV) and Required Navigational Performance (RNP) Optimized Profile Descents (OPDs). In order to achieve consistent use of these advanced procedures during periods of traffic congestion, timebased scheduling will be combined with advanced ground-based and airborne spacing technologies. Time-based arrival scheduling will progressively meter the traffic flows in order to smoothly merge aircraft arriving from different directions and to avoid downstream congestion that would otherwise prevent aircraft from flying the efficient flight paths. Orderly traffic flows enable aircraft to maintain the fuelefficient PBN procedures by sustaining the use of speed adjustments to control aircraft along their routes and reducing the need to use vectoring to absorb additional delay due to excess demand or to avoid separation violations. In NextGen, air traffic controllers will use ground-based scheduling and spacing tools to accurately meet an efficient arrival schedule during periods of low, medium, and high traffic demand. Meanwhile, the best-equipped aircraft will use onboard capabilities to achieve and maintain the desired inter-arrival spacing without speed instructions from the air traffic controller. The National Aeronautics and Space Administration (NASA) has developed its Air Traffic Management Technology Demonstration #1 (ATD-1) concept as part of its air traffic management research [2]. ATD-1 integrates time-based scheduling throughout the entire arrival phase of flight with ground-based Controller-Managed Spacing (CMS) tools and airborne Flight deck Interval Management (FIM) capabilities. The time-based scheduling capabilities extend the FAA’s Time-Based Flow Management (TBFM) system to include detailed modeling and scheduling of the terminal portions of the PBN arrival procedures. The CMS tools, a product of NASA’s air traffic management research in the congested terminal area, provide textual and graphical representations of the arrival schedule as well as speed advisories to meet that schedule. Use of these tools enables controllers to accurately and efficiently maintain the integrity of the time-based schedule and adhere to the PBN arrival procedures. The FIM capability is an Automatic Dependent Surveillance – Broadcast (ADS-B) airborne spacing application called Airborne Spacing for Terminal Arrival Routes (ASTAR) [3]. This application provides speed commands to the flight crew in lieu of speed instructions from the air traffic controller. These speed commands enable the flight crew to maintain the schedule’s arrival sequence and desired in-trail spacing while adhering to the PBN arrival procedure. Airborne spacing has been proposed as a means to achieve additional spacing precision not expected by ground-based spacing tools [4]. The eventual outcomes of ATD-1 will be the development of mature operational prototypes for both the ground and airborne systems, a series of flight trials to demonstrate the viability of the operational concept, and the transfer of the technologies to the FAA and aviation industry stakeholders. The remainder of the paper is organized as follows. The relationship of time-based arrival scheduling and the FIM operation is explained. A simple analytical model is used to show that normal operations will routinely encounter conditions where a single spacing goal cannot satisfy the desired separation requirements. A framework is established to estimate the number of FIM interruptions that will occur for different methods for calculating a spacing goal appropriate for a time-based metering environment subject to multiple scheduling constraints. Results are presented using the primary arrival procedures to Phoenix Sky Harbor International Airport and one year of wind conditions for its terminal area. The paper concludes with recommendations for improving the compatibility of time-based metering and FIM operations with changes to both the ATD-1 operational concept and the calculation of the spacing goal. Background During an aircraft’s arrival phase of flight, it flies through a series of airspace fixes where scheduling constraints, called metering constraints, are applied. The current FAA arrival scheduler applies scheduling constraints at two types of airspace fixes in the terminal area – the meter fix (near transition from en route to terminal airspace) and the runway threshold. At the meter fix, en route air traffic controllers are required to maintain at least 5 NM [5]; typically, they would expect an additional separation buffer of approximately 1–3 NM to avoid separation violations during transition into terminal airspace and to account for the natural compression that occurs downstream as each aircraft slows in preparation for landing. At the runway threshold, terminal air traffic controllers must maintain 2.5 NM or 3 NM for most aircraft pairs (see Footnote 1) depending on the runway configuration and tower operation) [5]; typically, they would expect an additional separation buffer of approximately 0.3–0.5 NM to avoid missed approaches, go-arounds, or excessive vectoring to prevent separation violations on final approach. The ATD-1 arrival scheduler calculates scheduled times-of-arrival for each aircraft that satisfy these constraints as well as additional constraints at intermediate meter points between the meter fix and runway threshold. For a FIM-capable aircraft, the schedule’s interarrival time (i.e., in-trail spacing) is provided to the FIM aircraft for execution of airborne spacing with a so-called Target aircraft. Figure 1 illustrates the key elements of the pairwise FIM operation used for ATD-1 arrival operations. The solid green line represents the arrival procedure associated with the two aircraft. The dashed green lines represent the other arrival routes merging to the runway. The meter fix is indicated by the small black triangle. FIM is designed to achieve the assigned in-trail spacing (known as the Assigned Spacing Goal, or ASG) between the FIM and Target aircraft before the FIM aircraft crosses a downstream fix shared with the Target aircraft (known as the Achieve-By Point, or ABP). The ASG is the conversion of the desired intrail separation at the ABP from distance to time, and it is typically expressed in terms of seconds. Throughout this paper, the term “separation” will |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.aviationsystemsdivision.arc.nasa.gov/publications/2014/DASC2014_Robinson.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
