Users of night vision goggles (NVGs) are acutely aware of the advantages these devices offer in improving a pilot’s ability to see in darkness and enhancing safety during night flight. They may be less cognizant, however, of some of the limitations that NVGs impose on night visual performance. As NVG use in helicopter operations increases, pilots and operators must be educated about the capabilities and limitations imposed by NVGs, and the often-misleading effects of NVG imagery on visual perception.
Since 1999, when the U.S. Federal Aviation Administration (FAA) issued the first supplemental type certificate (STC) to permit use of NVGs by a civilian helicopter emergency medical services (HEMS) operator in the United States, NVG use has steadily grown.1,2
Brighter Nights
The brighter scene provided by NVGs — which makes it possible for pilots to see objects not otherwise visible — increases situational awareness, enhan…