Modified Touchdown Zone Lighting

A simulator evaluation was conducted to determine the adequacy of the standard touchdown zone (TDZ) lighting system under extremely low visibility conditions and to develop, if necessary, a modified TDZ lighting system. All testing was
conducted using the Federal Aviation Administration (FAAs) B-727 simulator at the Mike Monroney Aeronautical Center, Oklahoma City. The adequacy of the lighting system guidance was determined through pilot comments and by noting the aircraft track during the rollout. A post-flight questionnaire was completed by the test pilots. Only 10 out of 14 (71 percent) pilots were able to determine their location relative to centerline at 300 feet runway visual range (RVR) with the
standard TDZ lighting system. Some of the pilots could only determine their location down to 500 feet RVR, so a modified system was developed. With the modified system all pilots were able to achieve adequate centerline orientation
at 300 feet RVR. From the results of this simulator evaluation we must conclude that, given a true reduced visibility condition of 300 to 500 feet RVR and with an automatic landing (auto-land) system malfunction which delivered the aircraft to a touchdown point immediately over the TDZ lighting system, a pilot would not have sufficient lateral guidance to achieve adequate centerline orientation during rollout.