Night-vision not just for police and EMS

 - January 29, 2007, 5:03 AM

Think night-vision goggles (NVGs) are just for police and EMS operators? You might be surprised to learn that changes to Part 91 and 135 due out this year could extend the technology to all of general aviation, opening possibilities for a wide range of operators, including business aircraft flight crews, to start using NVGs.

After taking a close look at the image quality of the latest NVG gear, the FAA is close to a decision to let properly trained pilots of general aviation aircraft fly with the equipment in night VMC as an enhancement to natural vision. Basic VFR weather minimums outlined in FAR 91.155 will remain unchanged, according to the agency, meaning there won’t be any operational benefits extended to NVG users like those for operators flying with HUD-based infrared enhanced-vision systems (EVS). Still, the technology has the potential to enhance safety for business aircraft flight crews and their passengers, especially for operators that sometimes fly into unimproved fields where lighting isn’t always the best.

“A number of corporate operators have expressed interest in getting approved for NVG operations,” said Mike Atwood, president of NVG retailer Aviation Specialties Unlimited of Boise, Idaho. “For certain people it makes a lot of sense.”

Atwood’s company is a distributor for ITT Industries, a leading producer of night-vision technology for aviation. ITT has developed STCs and training programs for police and EMS operators flying with NVG equipment and plans to train Part 91 crews when the final rules emerge.

The Anatomy of NVG
The benefits of NVGs for police, EMS operators and a host of other public service sectors such as oil exploration and logging are obvious. With the proper night-vision equipment, a pilot can clearly see a person more than half a mile away on a moonless night and can make out the outline of mountains, trees and runways from impressive distances.

Twin Otter crews for a major oil company, as one example, recently started using NVGs for pipeline patrol in Alaska during the winter months when the sun never quite manages to rise. When the new rules for Part 91 are introduced, corporate jet and turboprop operators who fly into remote areas will have the same vision-enhancement technology at their disposal. Considering that current NVG technology is so much better than it was only a decade ago and prices are far lower than those for EVS, the rule change could open a fairly sizable market niche for producers.

Night vision can work in two very different ways, depending on the technology used. The first, called image intensifying, works by collecting the tiny amount of available light, including the lower portion of the infrared (IR) light spectrum that is present but imperceptible to the human eye, and amplifying it to the point that we can easily observe the image. The second technique is called thermal imaging, which operates by capturing the upper portion of the infrared light spectrum, emitted as heat by objects instead of being reflected as light. Hotter objects, such as warm bodies, emit more of this light than cooler objects such as trees or buildings.

NVG technology was initially developed for the military in the 1970s. By the late 1980s, Part 135 helicopter EMS operators began petitioning the FAA to allow NVG use, which it did in 1999.

Now that the industry has had five years of solid experience using NVGs, the FAA, using guidance developed by the RTCA, is ready to open the floodgates and let any operator fly with NVGs once it has satisfied certain training and installation requirements. In fact, part of the reason the FAA has decided to allow civil pilots to fly with NVG technology is that so many of them have come from the military, where NVG use is standard practice during night operations.

Among the most popular NVG options on the market today is the Anvis line of products from ITT Industries Night Vision. One of ITT’s newest products, the Anvis 9, is an image-intensifier device that operates in the low-visible-light spectrum and a portion of the IR spectrum. The benefits of Anvis 9 are its small size, light weight and good image quality. Drawbacks of the product (and of just about any NVG system sold today) are its limited field of view (about 40 degrees side to side) and the fact that it must be mounted to a helmet.

Most NVGs use low-profile power packs that run on standard AA alkaline or lithium batteries, Atwood said. Although NVG systems are not permanently attached to the aircraft, they still require an STC, he added.

His company sells the Anvis NVG package for $10,200, which includes the needed STC. The company can also provide pilot training to customers.