Validation of the Offset Precision Approach with Vertical Guidance to Landing Using LAAS as Sole Means of Navigation

摘要

This paper presents the results of flight tests conducted by FAA AFS-440 at the University of Oklahoma Airport (KOUN) on the offset approach to landing using LAAS as a sole means of navigation. The paper will detail the variety of offset approaches performed from 10 degrees to 20 degrees of offset with 1000 to 4000 feet of final approach segments. Flight parameters such as Total System Error (TSE) will be examined and compared to model expectations and the TERPS requirements. The implementation of landing systems for approaches, such as ILS and Augmented GPS, involved a process to mathematically describing the component parameters of the system tolerance, characterize the distribution of each, and combine these into a total system tolerance (TST) probabilistic model. Applications for such models have included establishing obstacle protection surfaces used in the design of precision instrument approach procedures and in development of the International Civil Aviation Organization (ICAO) collision risk model (CRM) to assess the risk of collision with obstacles in specific runway and obstacle environments as well as the evaluation of the fly ability of the approaches by a wide variety of aircraft. This paper investigates a total system tolerance model for Offset precision approaches using LAAS as a sole means of navigation and using a systematic approach through analytical studies and analyses of flight test data. First, it identifies component parameters of the errors/tolerances appropriate to precision offset approaches, and then characterizes each one. Second, it mathematically descries the component parameters and the effect on aircraft path. Finally, it combines them with aircraft and pilot models into a TST model. It will be demonstrated that the model is responsive to the changes in parameters determined by changes in system performance or observed test results, which the FAA has recently extensively collected. The analysis contained in this paper is being performed in support of the FAA and is part of the effort to develop criteria for instrument offset approach procedure design.