MLS guidance errors due to runway approach-light structures

A data analysis program utilizing the boundary discrete points (BDP) technique is developed to predict the effect of runway approach-light systems (ALSs) on the microwave landing system (MLS) signal in space in terms of angle guidance error, path following error (PFE) and control motion noise (CMN). Various ALS configurations are modelled and field-tested. In this study, the MLS peak guidance errors caused by the presence of the ALS are found to be small, but such that they could cause out-of-tolerance conditions. Initial field-test results are in agreement with those predicted by the developed model.