Flexible method for specifying CTAS aircraft trajectory predictions is undergoing testing: The new Generalized Altitude logic in the CTAS aircraft trajectory prediction software is ready for evaluation. It is being run and evaluated in the CTAS software-testing lab. This new software will be used to support NextGen Research Focus Areas such as Separation Assurance, En Route Descent Advisor, and Airspace Super Density Operations. The Generalized Altitude logic provides a flexible method for the specification of speed and altitude constraints to support new types of trajectories that include multiple step climbs and descents with various speed constraints. The new interface is able to produce trajectories for over 98% of the requests calculated by the less flexible logic it replaces. Of those requests, over 92% of the trajectories are the same or similar to the output produced from requests using the existing logic. As part of this work, the software group is continuing to investigate the removal and replacement of speed limiting code that have been part of the legacy CTAS trajectory prediction software and are a cause of inaccurate predictions.
+ Back to Top Very Closely Spaced Parallel Approaches (VCSPA): Researchers for the Airspace Systems Program at Ames are studying methods for increasing capacity at airports. One of these is simultaneous approaches on runways with 750 feet of lateral separation. The Closely Spaced Parallel Approaches study was completed last year looking at the feasibility of the concept. This study conducted in May 2008 looked at coupling of aircraft on curved approaches to maintain required separation. The primary purpose was to evaluate the acceptability and appropriateness of displays for the approach, recognition of breakout criteria, and the ability to fly these special procedures. The researchers were given specific criteria from Raytheon for the procedures, and the CVSRF staff was tasked with design and implementation of the concepts for the Advanced Concept Fight Simulator (ACFS).
The staff was presented with formidable tasks. The first was to create the airport visual and navigation databases and then build the curved flight plans and approaches. Perhaps the most daunting task was developing the guidance algorithms for the maneuvers and making the breakout trajectory dynamic. Other tasks included integration of the lead traffic and predictor symbology on the navigation display, creation of the wake vortex on the primary flight display and Navigation display, creating a playback record for lead traffic recreation, zoom capabilities for the navigation display to 0.25 miles, and integration of the Airspace Traffic Generator (ATG) traffic. The simulation engineers were an integral part of the development of this study.
Ten experienced airline pilots evaluated the maneuvers over a two-week period in May, 2008. VCSPA Phase 2 is scheduled for July 2008.