Until about a year ago, infrared enhanced vision systems (EVS) were exclusively the bailiwick of operators of large aircraft, in which they were installed as upgrades to the standard head-up display. Primarily, the aircraft were the Gulfstream IV/IV-SP/G300/G400, GV/ G500/G550 and Bombardier Global Express, and their EVS add-ons– built by Kollsman of Merrimack, N.Y. for the Gulfstream and by CMC Electronics of Montreal for the Global–were priced appropriately to those ships at around $500,000 apiece.
But what a difference a year makes. Newcomer Max-Viz, of Portland, Ore., jumped into the corporate aircraft market last fall with a lower-cost EVS designed to be installed in non-HUD aircraft, where its infrared images are portrayed on a multifunction or other head-down display in the flight deck.
The company’s market strategy was simple. Having established itself as an EVS manufacturer in 2001, the firm proceeded with the development of two EVS units, one being its EVS-2000 HUD add-on, and the other being its stand-alone, non-HUD EVS-1000. But it quickly became clear that the HUD add-on market was quite small, while the potential non-HUD EVS market was very large. And since the simpler non-HUD unit was not intended for use as a landing aid, it neatly sidestepped the need for FAA critical software certification and associated approach guidance requirements and could therefore come on board for between $100,000 and $125,000 installed.
In the FAA’s view, in fact, a non-HUD EVS is regarded as being similar to a TV camera or other device, and certainly not flight essential. On the other hand, while its value as an aid to situational awareness on the airport surface and as a complement to EGPWS/TAWS in CFIT avoidance is well understood by the FAA, it is not subject to regulation, other than by the normal STC process to certify installation airworthiness.
Max-Viz reports that it has EVS-1000 STCs issued or in process for a number of airplanes and helicopters, including the GIV-SP, Challenger 601/604, Falcon 50/50EX and 900EX, Learjet 35, Bell 206/212, Eurocopter AS 350 and Bell/Agusta AB139. At the Paris Air Show in June, Max-Viz announced its first corporate rotary-wing contract for a Sikorsky S-76 operated by an East Coast Fortune 500 company, where the EVS images will be displayed on two dedicated LCDs (one for each pilot) and on the Honeywell MFD-880 radar screen. Max-Viz has also sold its more capable EVS-2000 system to Cessna for the Citation X and Sovereign, and to a private Boeing 767 operator for use in non-HUD environments.
But all this activity has not gone unnoticed by Kollsman and CMC Electronics: both firms are girding for a major confrontation with what they regard as an intruder on their turf. Both companies admit, somewhat ruefully, that Max-Viz has stolen a march on them with its EVS-1000, and both firms are now burning the midnight oil to introduce competitive products. Kollsman expects to have its Night Window system on the market early next year, while CMC Electronics is forecasting availability of its SureSight M-series around the same time. Both companies anticipate installed prices around $100,000, or possibly even less.
However, the promotional war is already under way, with a shoot-out expected at this October’s NBAA Convention in Orlando, Fla. The key issues in this battle will be the somewhat exotic questions of what frequency bands in the infrared spectrum give best results, and whether cooled or uncooled systems are more desirable. While these might sound like unusual purchase considerations for a corporate flight department, a broad understanding of their principles could be helpful in sorting out the forthcoming barrage of claims and counterclaims, and in making a buying decision.
What’s the Frequency?
An EVS sensor detects the infrared energy radiated by all objects–aircraft, runways, people, the chair you may be sitting on and even this magazine, among others–with the amount of radiation being roughly proportional to the warmth of the object. But infrared radiation is odd stuff.
While it’s emitted at extremely high frequencies, just below that of visible light, atmospheric effects prevent a detector from “seeing” radiating sources except through three narrow “windows” across the total infrared spectrum. These windows occur roughly between one and two microns, between three and five microns and between eight and 14 microns, and are sometimes referred to as the short-, medium- and long-wave infrared bands. (A micron is a millionth of a meter.)
As a general rule of thumb, things like approach and runway lights–but not terrain or weather–can be seen only through the one- to two-micron window, while terrain and all other objects are best seen through the other two windows, where lights don’t show up reliably.
For the $100,000 non-HUD market, small, lightweight (less than five pounds) sensor units–known technically as microbolometers–are being used. They operate solely in the long-wave band and are thus unable to detect lights. Max-Viz’s system uses a small, separate electronics unit, while the other manufacturers have opted for integrated units.
The sensor is typically installed in an unpressurized area at the top of the fin leading edge, where it has an unrestricted forward view. Sometimes it can be installed in a fin cavity originally provided by the airframe manufacturer to accommodate a video camera. In helicopters, the preferred sensor location is above the cabin, forward of the rotor head.
But while this broad description possibly sounds straight forward enough, prospective buyers are bound to become entangled with earnest salesmen who want to “clarify” the frequency issue. It’s a complex and controversial topic, and also something of an eye-glazer. So it’s probably better to cover it objectively here than to be ambushed by a company representative at a booth at the NBAA show.
Reducing it to basics, Kollsman and CMC Electronics have up to now built EVS add-on systems for HUDs, and for this both opted for a single, one- to five-micron sensor, which covers both the short- and medium-wave bands. In so doing, the sensor positively detects the runway and approach lights and also stays within the medium-wave band, which the companies stress provides the best weather penetration and terrain detail.
Max-Viz, on the other hand, opted for a dual-frequency system in its EVS-2000 for HUD applications, with a one- to two-micron sensor to detect the lights and an eight-to 14-micron sensor to penetrate weather and map terrain, which it says does a better job than a three- to five-micron sensor. The data from the two sensors are then “fused” to provide a single composite picture on the display.
But that’s all HUD-related stuff, and we’re talking about non-HUD EVS. Yes, except that in the Citation X and the Sovereign and in the private 767–none of which have HUDs–Max-Viz will install its dual-frequency EVS-2000 for head-down use to provide the operator with both terrain and lights, since its cheaper EVS-1000 cannot provide the latter. As a result, you can expect that Kollsman and CMC Electronics will respond by offering their up-market Gulfstream and Global Express EVS systems for head-down use to operators who don’t have HUDs. The likely price range of these three systems is not known, but is expected to be between $200,000 and $300,000 installed.
However, there’s possibly an added complication with this approach. With these more sophisticated systems, all three companies’ sensor heads are too big for fin mounting, and must be installed in the nose.
The lower-cost systems all use uncooled sensors, as does the Max-Viz two-frequency EVS-2000.
For all the arguing over technology, the two big EVS firms are probably quietly grateful that newcomer Max-Viz has opened a potentially enormous market. There seems little doubt that as the benefits of EVS become more widely known, all three companies will benefit.