Lexavia sales manager Bob Yerex haslongbeen studying aviation accidents and working closely with the FAA andNTSBlooking for instances where enhanced vision system (EVS)technologymight havemitigated orprevented accidents.In analyzing 193fatal accidents that occurred between 2008 and 2010,Yerex believes thatEVS could have positively impacted more than 39 percentof those accidents.That, he said, is a great argument for further investigation of EVS technology by operators in every segment of aviation.

EVS uses infrared thermal imaging to define objects and surfaces, noting the differences between the temperatures of objects and surfaces, then displaying them in real-time on a grayscale monochromatic screen with remarkable clarity.Lexavia Integrated Systems (Booth N3013) manufactures a variety of EVS products installed on business aircraft and helicopters, including integrated controllers, stowable displays, digital recorders and high-resolution EVS cameras.

Although thermalimagers are in fixed positions on the aircraft, some have the ability tozoom in or out as required by the flight crew. EVS systems work day or nightand can see through smoke, fog and many other types of reduced visibility, providing pilots witha true image of the situation ahead.

Although useful in daytime, EVS provides the highestpotentialfor risk reduction at night, Yerex said. “Becausethe visual cues available to the pilot are diminished during periods of darkness, the pilot has a much greater potential to lose spatial orientation” he explained. The loss of situational awareness or spatial orientation is one of the principal initiatorsin a substantialpercentage of controlled flight into terrainaccidents.

The ability to use EVS to improve the pilot’s awareness ofboth terrain and atmospheric conditions during night operations provides a capability not possible with many other technologies. Night vision goggles (NVG)are an alternative technology, and theyamplify existing light, creating a monochromatic image presented through a binocular display generally worn over the operator’s head.NVG works only at nightwhileEVSworks day or nightand can be integratedmuch more simplyinto flight operations.

EVS proponents believe thermal imaging technologyhad a moderateor betterprobability of mitigating or helping to prevent75of the193 analyzedaccidents between 2008 and 2010.Darknesswas a factor in more than85 percent of thoseaccidents, withweatherbeinga factorin43 accidents.Twenty-two of the accidents involved helicopters, of which 50 percent were medevac flights.One hundred percent of the EMS helicopter accidentsoccurred at night. Yerex's research indicated that in those cases,EVS had a moderate or higher potential to positively affect the outcome of those flights, aiding crew members in mitigating or even avoiding the accident altogether had the technology been in use at the time.

“The statistics are extremely compelling,” Yerex said. “But when you break it down even further, the impact of EVS becomes even more significant.”​

More than half of the accidents Yerex studied occurred during the cruise phase of flight.Inmore than a third of those cases, YerexfoundEVScould have been a significant factor in avoiding the accident.

“What EVS won’t do is eliminate errors in judgment, thepotential forloss of situational awareness or allow flight crews to operate below FAR minimums,” Yerex cautioned. “Butthrough years ofoperatingin the field of safety and the EVS industry,the findings supported my feelings thatoperations during periods ofdarkness would be the most significant contributing factorwhere EVS would be able to help avoid potentially fatal situations. We were right.”