New Innovative Low-Cost Precision Landing System

John Stoltz and David Frazier

Abstract:	The Transponder Landing System (TLS), developed by Advanced Navigation and Positioning Corporation, is a low-cost, highly flexible precision landing system. It performs for the pilot like a standard Instrument Landing System (ILS), but with the flexibility and accuracy of a Microwave Landing System (MLS). No new avionics or instrumentation is required in the aircraft. The TLS simply uses the aircraft’s existing transponder to generate high-quality tracking information. Guidance corrections are then transmitted to the standard aircraft ILS receiver to be displayed on the Course Deviation Indicator (CDI). The autopilot will couple to the TLS exactly as it does for an ILS. The TLS uses a small set of ground-based equipment to interrogate, sense transponder replies and transmit VHF and UHF guidance signals to an approaching aircraft. The TLS can be thought of as a ground-based variant of the Global Positioning System (GPS), but it does not use GPS in any way. L-band signals are processed using multi-lateration techniques to provide an accurate three- dimensional location of the aircraft. Ground-based computers are used to perform the guidance calculations, which minimizes the need for expensive on-board computers and related equipment. Consequently, TLS is able to take advantage of a very large base of existing aircraft avionics to deliver precision approach guidance. Virtually any aircraft that can fly IFR operations today can fly the TLS. This paper describes the technology involved with TLS, and the primary and secondary applications of the technology. It also discusses the involvement of the FAA in performing flight inspection and the development of flight standards criteria. Finally, flight test results are presented that demonstrate the flexibility and accuracy of the TLS and its ability to meet International Civil Aviation Organization (ICAO), Annex 10, Category I, Precision Approach requirements.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	547 - 554
Cite this article:	Stoltz, John, Frazier, David, "New Innovative Low-Cost Precision Landing System," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 547-554.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In