ABSTRACT
This chapter addresses some of the Flight Management System (FMS) interface deficiencies, and explains the potential for error and the possible effects of such an error. It shows the limitations of certification requirements in regulating such deficiencies and suggests new requirements for future use. The chapter explores the basic function of a FMS, called Lateral Navigation, which is the function mandated by air traffic control and used for navigation guidance in the horizontal plain. Many of the technical requirements exist for system design but the design requirements are mandatory for compliance regarding Human Factors when applying for a FMS certification. Aircraft design, development and certification has evolved during the years into a well structured and thorough process. As in any airworthiness certification process on aircraft, it is essential to determine the effects of each failure mode in each flight condition and decide if the combination of probability and effect is acceptable.
