A STOL terminal area navigation system

The mechanization and performance of a STOL terminal area navigation system are described. The purpose of the navigation system is to allow flying with precision 4D-guidance along complex flight paths in the terminal area, and to develop requirements for STOL operations in the 1980s. The navigation aids include an experimental microwave landing system, MODILS. The systems description begins with the navigation aids. It is shown how the data are transformed and combined with other data to obtain position and velocity estimates. Also presented are some of the design changes and other features that were introduced as a result of flight testing. The various ways of displaying navigation-derived data are given. Finally, simulator and flight test results are discussed.