Abstract
This thesis assesses the pilot handling problems of a V/STOL aircraft during the approach manoeuvre to a restricted landing area in weather conditions of low cloudbase and poor visibility. The main aspects examined are: how the handling problems during the approach can be reduced by the use of automatic flight control or electronic display systems, in what way each form of augmentation can be most effectively used, and how they interact with each other. The early part of the thesis analyses the reasons for the increased pilot compensation task during the approach, and why current operational control and display systems do not permit a full instrument approach. The constraints imposed on the type of approach profile due to aircraft characteristics and external factors are next assessed, and preliminary conclusions drawn on the type of profile most suited to the handling qualities of V/STOL aircraft. Leading on from the approach profile, the range of controls and displays currently available are described and their applicability to the present problems is discussed. The main part of the document details the flight and simulator trials carried out, describes the display formats and control laws developed during the work, and justifies their use for the control and display interaction assessment. The final chapters analyse the qualitative and quantitative results obtained with the various levels of control and display systems investigated. The results illustrate the way in which the multi-variable control problems of the instrument approach can be broken down into separate tasks of inner loop and outer loop control, and demonstrate that the pilot is best employed controlling the outer loop flight path using the instrument display whilst the inner loop is controlled automatically by the flight control system.