Reduced Configuration Approach Lighting System: Simulator Evaluation

Recent advances in Global Positioning System (GPS) capabilities have heightened the prospect of providing Category I, II, and III approach and landing capabilities at numerous airports. In addition to the considerable expense of installing approach lighting systems to support these approaches, many airports do not have the necessary real estate that would be required for the installation of standard approach lighting systems. In response to these concerns, an evaluation was needed to help determine if modified approach lighting system configurations could be developed that would be less expensive and occupy less real estate without compromising safety.

This report describes an evaluation of a number of proposed approach lighting systems (ALS) modifications involving a reduction in the number of required lights, either through providing a lesser density within the standard configuration or through shortening the pattern length. The evaluation was conducted using the Federal Aviation Administration Boeing 727 flight simulator and employing the services of experienced air carrier and FAA pilots as volunteer subjects.

Results of the test effort revealed that the guidance that was provided by the medium-intensity approach lighting system with runway alignment indicator lights (Configuration E) and the high-intensity approach lighting system with sequenced flashers (Configuration H) that contain three lights, in lieu of five, per centerline barrette allowed all of the subject pilots to complete the approaches and landings safely. However, configurational changes to the standard approach lighting systems should not be made until these results are validated by actual weather flight testing.

Author: Eric S. Katz