Infrared LEDs Required By FAA’s August 17 Advisory
An important FAA tower lighting change became effective September 6.
A new FAA Obstruction Marking and Lighting Advisory Circular 70/7460-1L Change 2 was released on August 17, 2018. Flash Technology Director of Business Development Wade Collins tells Inside Towers: It is his company’s understanding the new Advisory Circular requires towers with an FAA determination after this release date should include infrared (IR) LEDs in the L864 and L810 fixtures to make the lighting systems more visible to Night Vision Imaging Systems (NVIS). Changes to Section 5.2 of the Advisory Circular read as follows:
“Note: In response to a Safety Risk Assessment of LED Lighting in Aircraft Operations, the FAA has established IR specifications for LED-based red obstruction lights. Specifications are contained in Airport Engineering Brief 98, Infrared Specifications for Aviation Obstruction Light Compatibility with Night Vision Goggles (NVGs), published December 18, 2017, and AC 150/5345-43H, Specification for Obstruction Lighting Equipment, dated September 28, 2016.”
Airport Engineering Brief 98 provides information about the interaction of LEDs used in obstruction lighting fixtures with NVG. There are two key specifications:
IR (infrared) LEDS should be in the same horizontal beam pattern as the red visible LEDs
IR LEDs should mimic the same pulse and duration as the red visible light. Failure of the IR LEDs is considered a fail status and a Notice to Airmen (NOTAM) is required Comments? Email us.
By Leslie Stimson, Inside Towers Washington Bureau Chief