AIM Text
Certain light-emitting diode (LED) lighting systems fall outside the combined visible and near-infrared spectrum of night vision goggles (NVGs) and thus will not be visible to a flightcrew using NVGs.
The FAA changed specifications for LED-based red obstruction lights to make them visible to pilots using certain NVG systems, however, other colors may not be visible.
It is recommended that air carriers/operators—including part 91 operators—who use NVGs incorporate procedures into manuals and/or standard operating procedures (SOPs) requiring periodic, unaided scanning when operating at low altitudes and when performing a reconnaissance of landing areas.
Source: FAA Aeronautical Information Manual · current edition · paragraph 2-2-4.
The short answer
This AIM section is FAA advisory guidance on LED lighting systems and night vision goggles (NVGs). It warns that certain light-emitting diode lighting falls outside the combined visible and near-infrared spectrum of NVGs and may be invisible to crews using them, and recommends operators, including part 91 operators, adopt procedures for periodic unaided scanning at low altitudes.
Research Notes
Common Questions
Why might LED obstruction lights be invisible through night vision goggles?
Certain LED lighting systems fall outside the combined visible and near-infrared spectrum of night vision goggles and thus will not be visible to a flightcrew using NVGs. The FAA changed specifications for LED-based red obstruction lights to make them visible to certain NVG systems, but other colors may not be visible.
What does the AIM recommend for NVG operators flying low?
It is recommended that air carriers and operators, including part 91 operators, who use NVGs incorporate procedures into manuals and/or standard operating procedures requiring periodic, unaided scanning when operating at low altitudes and when performing a reconnaissance of landing areas.
Did the FAA fix all LED obstruction lights for NVG visibility?
No. The FAA changed specifications only for LED-based red obstruction lights to make them visible to certain NVG systems. Other colors may not be visible, which is why the unaided scanning recommendation remains important for NVG operators at low altitudes.