Pilots flying aircraft at night and during low-light conditions know how difficult it can be to perform flight operations when visibility is limited. Not seeing clearly can seriously affect what could already be a dangerous task. Medical responders and search-and-rescue units, law enforcement teams, and others who must fly in the dark near offshore oil rigs, power lines or high rises, for example, are especially at risk. Now, in an attempt to alleviate the dangers, the Federal Aviation Administration has approved certified military-use-only night-vision aviator goggles (NVAG-6) for civilian pilots. Shown is a pilot looking through the NVAG-6 goggles. Inside an aircraft, the pilot must shift his eyes below the goggles to see the instrument panel because the binoculars allow visibility only in the near-infrared spectrum. Courtesy of Nivisys Industries. “Night vision is a phenomenal asset to be using,” said Lee A. Stephens, senior technical applications manager at Nivisys Industries LLC. “They help any night operation in the form of greater visibility and situational awareness.” The goggles are made by Nivisys, a manufacturer of thermal and night-vision equipment specializing in Aviator Night Vision Imaging Systems (ANVIS), which feature high-resolution, lightweight, easy-to-operate binoculars designed to fit helmets worn by helicopter pilots and fixed-wing aircraft aviators. The night-vision goggles, which can be mounted on the helmets of fixed- or rotary-wing aircraft pilots, can be adjusted for each individual. Distance from the eye, alignment and tilt can be adjusted. Courtesy of Nivisys Industries. According to Stephens, the equipment must go through environmental performance requirements to gain Technical Standard Order (TSO) certification, a minimum performance standard issued by the FAA for civil aircraft equipment. “The NVAG-6 meets TSO-C164 approval,” he said. “We’re the only night-vision goggle manufacturer to receive this certification.” A C164 order is specific to head-mounted, binocular, night-vision goggles. The NVAG-6 binoculars operate from a wavelength of approximately 600 to 900 nm. Image intensifier tube performance levels provide the system with high resolution for sharper imaging, higher gain, brightness control and low-distortion output optics. When the helmet mount is flipped up, by a button release, the goggles shut off to preserve power and to prevent the tube damage that would occur if the unit were exposed to bright light. Basic vision specifications include a 40° field of view, a focus range set at 25 cm to infinity, a 1× magnification, an optical lens diopter range of +2 to –6 and full-field eye relief of 25 mm. According to Stephens, there is no distance rating for night-vision goggles because atmospheric conditions such as clouds or dust may reduce visibility. An advantage to the system is that the goggles can be configured to the pilot’s face. Because interpupillary distance can be adjusted from 52 to 72 mm, the eyepieces can be centered directly in front of both eyes. A 27-mm fore-and-aft adjustment of the flip-up base moves the lenses closer to, or farther from, the eyes, and the module also has a 25-mm up-and-down adjustment and minimum tilt angle of 10°, enabling pilots to look beneath the goggles to see the instrument panel. Illumination within the cockpit must be viewed without the goggles, which do not operate at the visible wavelength. The equipment also can be adjusted for those who wear contacts or glasses. Stephens said the goggles are made of anodized aluminum, as opposed to plastic, such as those of other ANVIS night-vision goggles, making them lighter in weight at only 514 g. “Pilots bear the weight of the helmet and any radio or communication set that he has to wear on his head,” he said. During aggressive maneuvers, the goggles’ lighter weight will help to lessen any additional g force stresses that a pilot may have to endure, given the heavy strain already on the head and neck. Differences between the NVAG-6 and standard ANVIS equipment are that the battery pack is low-profile – it is ear-mounted and protrudes only half as far from the back of the helmet, although it is slightly wider than on standard models; the curved housing conforms to the back of the helmet, eliminating any obstruction or interference with equipment inside the aircraft; and the rear-mounted battery is connected to a cable that extends over the top of the helmet. The dual-battery power module, which takes regular AA batteries, has a lifetime of more than 40 h; with the reserve pack, the user has a total of more than 80 h of operation.