Modelling the effects of maintenance engineering errors in air navigational systems

Abstract; Instrument Landing System (ILS) is a ground-based instrument approach system that
provides precision guidance to aircrafts approaching and landing on a runway using combinations of radio signals. The problem of monitoring the ILS signal has been investigated for a number of years. Both experimental and theoretical studies have yielded information about system performance, but little has been done to model effects of maintenance engineering errors in the ILS localizer. The composite signal from the ILS localizer operates in a manner to maintain stable equilibrium by ensuring that its courseline information is in tandem with the runway centerline. However, errors due to drifts in electronic component values have the tendency to destabilize this equilibrium. The bearing of drift errors on parameters of signal quantities and their subsequent effects on lateral courseline information has significant impact on approaching and landing aircrafts. The purpose of this study is to conduct a test experiment based on linear continuous-time state equations and develop models for analyzing ILS localizer maintenance engineering errors. The second purpose is to design a MATLAB tool to be used in predicting the effects of these errors on aircrafts approaching Kenyan airports. It will be ascertained that this study shall contribute in enhancing the design process of instrument flight approach procedures for air traffic control services and thus reducing
the number of aircraft accidents that occur within airport zone boundary.