HAI Convention News

EVS vs NVG: Both better

 - March 5, 2011, 4:50 AM

The adoption of infrared imaging enhanced vision systems (EVS) in rotary-wing applications has been slow because of a common misconception, that night safety is an “either/or” choice between EVS or night-vision goggles (NVG). So suggests Chuck Crompton, business development director for Lexavia Integrated Systems, Pensacola, Fla., adding that using the two technologies in combination may provide the best of both possible worlds.

Many professional helicopter pilots are retired military with previous extensive NVG training, he said, and could be expected to prefer NVGs to deal with the risks of night operations. Lexavia (Booth No. 3333), relatively new to the EVS marketplace, and Max-Viz (Booth No. 4408), a pioneer in lower-cost EVS with uncooled IR cameras, are both at Heli-Expo championing complementary use of EVS and NVG for night helicopter operations.

Many fleet operators, especially in HEMS and offshore work, have an “NVG first” policy, Crompton said. However, starting a new NVG program takes much time and training before new civilian-trained pilots equal the capabilities of ex-military pilots. EVS supporters tout the intuitive nature of gaining fast proficiency with infrared imagery, but Crompton noted that EVS operation does not require FAA oversight of initial pilot training and certification and proficiency tracking as does NVG and that in most cases an EVS project can be implemented for less cost than an NVG commitment.

Military pilots with extensive night experience using both NVGs and  forward-looking infrared (FLIR) sensors almost universally say, “The best capability is to have both,” Crompton said.

Bob Yerex, Max-Viz v-p of sales, added, “Both [EVS and NVG] by themselves are very good; used together they’re the biggest piece of the silver bullet that I’ve ever seen for unmasking unrecognized risks.” Yerex compares EVS and NVG to HTAWS, a solution favored by the NTSB. “The HTAWS is an IFR environment system that doesn’t show the real world and may not reveal all the obstructions out there. The ability to detect something visually gives you the ability to avoid it.” Max-Viz and Night Flight Concepts (Booth No. 3428), a provider of NVG equipment, lighting and training, have entered a strategic alignment to promote and put together joint applications of NVG and EVS.

These different technologies operate synergistically, as one’s strengths compensate for the other’s drawbacks, Crompton said. “Heads-up” NVGs intensify visible light frequencies but do not provide images in total darkness. “Heads-down” EVS creates video images from long-wave infrared energy, even in low/no light situations. “EVS systems work great when someone in the cockpit actually has time to look at them,” Crompton said.

Many helicopter operators, Crompton added, have asked the EVS industry, “Can you build an EVS that we can use to profile the landing zone before we get there, when we have time to look at the EVS display?” One answer, he said, may be coming from Lexavia, which is offering EVS products to give pilots the ability to view landing zones at longer stand-off distance.