Concept of Operations for the Use of Synthetic Vision System (SVS) Display During Precision Instrument Approach

This paper describes a concept of operations for the use of Synthetic Vision System (SVS) display technology with Category (CAT) I, straight-in instrument landing system (ILS) approach. A concept is proposed, which extends the current authorization available under Code of Federal Regulations (CFR) Part 91.175 of the Federal Air Regulations (FAR) to begin descent from the published Decision Altitude (DA), based on visual sighting of approach lights. It is proposed that an extended runway centerline feature displayed on an SVS could be substituted for visual contact with the approach lights, as authorized in 91.175, as long as this information is cross checked with the ILS signal. It requires the use of ILS signals for navigation down to 100 ft height above altitude (HAT), which is available for many ILS installations. Descent below 100 ft HAT would not be allowed unless other visual cues associated with the runway environment are clearly visible and identifiable by the pilot. Issues and areas for future research to support this concept of operations are presented.