Frequently Asked Questions
How EVS works and EVS specifications:
What is EFVS?
What is EVS?
What does it mean that this EVS is “Uncooled”?
How light and small is Max-Viz EVS?
How does EVS work in icy conditions?
What kinds of displays work with your EVS systems?
How EVS compares to or is used in conjunction with other systems:
Why do I need EVS if I already have SVS installed on my aircraft?
What is the difference between SVS, EVS, CVS and VCVS?
Do EVS systems and Night Vision Goggles (NVG’s) operate the same way?
Can EVS systems and NVG’s see the same thing during the day and during the night? Are there limitations?
Why is the combination of EVS and NVG such a powerful solution?
What is HTAWS?
How does HTAWS get its information?
How does HTAWS present this information?
Do HTAWS Data Bases Require Updates?
FAA Rulings on EVS and Export Controls:
Is a HUD really necessary for EFVS?
Does the EFVS NPRM apply to Helicopters as well?
Is the EFVS NPRM a good thing for Astronics Max-Viz?
Are Max-Viz EVS products export controlled and if so, where can I get more information about this process?
Questions about the value and financial justification for EVS:
How can EVS help me preserve my assets (aircraft and people)?
What are the tax and insurance implications if I buy a new EVS system?
Questions about Astronics Max-Viz:
How many years have you been in business and how solid is your financial position?
Enhanced Flight Vision Systems (EFVS) are currently defined in FAA exemption 91.175. This exemption requires the use of a Heads Up Display (HUD) or a Head Mounted Display (HMD) coupled with a specially qualified Enhanced Vision System (EVS). Under the certain conditions of this exemption (and at certain airports and in an IMC flight), if a pilot reaches the published Decision Height or Minimum Descent Altitude and is unable to see the runway landing environment except through a regulatory compliant EFVS system, the pilot is allowed to descend down to an altitude of 100 feet above touchdown zone elevation. At that point, the landing environment must be acquired with the pilots natural vision and if not, the pilot is required to abort the landing attempt. The proposed new rule would eliminate minimum height and, under certain conditions/restrictions allow the pilot to effectively land the aircraft using only the EVS displayed on the HUD. For flight crews to take advantage of EFVS, they must be specially trained and the EVS equipment needs to meet special requirements (and be tailored for use with each specific HUD).
Max-Viz EVS (Enhanced Vision Systems) is an infrared (IR) aviation system that detects differences in heat instead of differences in light as a video camera would. With thermal imaging, the EVS display lets you see when flying at night, or in smoke, haze, and light fog. It can work as an alternative to or in tandem with light-based night vision goggle (NVG) technologies. It complements your synthetic vision display, giving a real time confirmation on your environment, as well as supporting the transition from Visual Flight Rules (VFR) to Instrument Flight Rules (IFR) in marginal visual or IMC conditions. Max-Viz EVS is an affordable solution to increasing pilot safety and situational awareness as there is no head up display (HUD) required. Max-Viz has earned FAA certification for installation on over 200+ different aircraft models and types, with both Supplemental Type Certificates (STC) and Type Certificate (TC) approvals, ensuring you’ll be able to add this thermal imaging to your cockpit.
Conventional IR systems are cryogenically cooled, that is, they require a mechanical cooler to keep the detector very cold in order to “see” small temperature differences. The Max-Viz system uses new, uncooled microbolometer technology to attain equivalent performance without the need for complicated, heavy and expensive cooling mechanics. Some of the older, cooled system are sold today at up to $500,000 per system. Max-Viz technology is designed to be simply installed and incorporated into aircraft operations to improve existing operational flight safety.
The EVS has heaters that prevent the accumulation of ice that otherwise might adversely affect normal operations. Heater operations are automatic dependent on ambient temperature and are thoroughly tested during manufacturing. Qualification and production performance tests performed on our systems have met or exceed FAA requirements.
Max-Viz products produce a video signal that interfaces with RS-170/NTSC (basically black and white video) compatible displays. Max-Viz has effectively interfaced for display on PFD / PND, MFD and EFB as well as countless quality dedicated displays. Contact your authorized Max-Viz dealer or Max-Viz directly for additional details and to find out what display options are recommended with your EVS system or airframe. We have a solution that will work for you.
EVS is real time and updated every 17 milliseconds (“live” for all practical purposes); SVS data may be days or weeks old. SVS cannot show real time obstructions such as aircraft, people, wildlife, construction equipment or fuel trucks. Current SVS versions may also be missing new airport infrastructure such as buildings, taxiway markers, signs and fences. On approach, EVS can help you get a good look at unfamiliar airports before landing. In an emergency at night away from the airport, SVS doesn’t show trees, buildings, highways or streets. EVS, on the other hand, can help you find a safe place to land.
Synthetic Vision Systems (SVS) provide situational awareness by placing a 3D geographical image on a cockpit display using terrain, obstacle and other databases. Navigation and positional information is obtained from GPS and Inertial Reference Systems. SVS presents a very nice “clear day” view of the world, but is only as good as the most recent update to the database which can be days, weeks, or even months old. By contrast, Enhanced Vision Systems (EVS) provide pilots with a clear live video image of the world that he could not otherwise see at night, and in poor visibility. Combined Vision Systems (CVS) is a term applied to the combination of EVS and SVS whereby EVS is used to provide a real time confirmation (validation) of the SVS environment. In CVS the pilot is doing the comparison and alignment of the two systems. Verified Combined Vision Systems (VCVS) is a term applied to use of smart processing to verify and correct GPS positional error (if any), automatically resolve differences between SVS and EVS and align the images.
NVG’s and EVS systems are entirely different. Each system has its own strengths and weaknesses. EVS systems utilize thermal imagery based upon Infrared sensors “microbolometers “ that are heat sensitive and can detect temperature changes of less than 1/10th of 1 Degree C. These sensors detect Long-Wave Infrared (LWIR), Short-Wave Infrared (SWIR), or Mid-Wave Infrared (MWIR) energy, depending upon the manufacture and type of sensors being utilized. Max-Viz EVS systems utilize un-cooled LWIR microbolometer based sensors that detect energy in the 8-12 micron range, presenting that energy in a black and white “video appearing” format. This image can be displayed in the cockpit on dedicated displays as well as many multi-function, primary flight or primary navigational displays. The EVS image can also be presented in cabin displays as desired by the end-user.
Night Vision Goggles use light-amplifying technology. This technology takes the small amount of light that is available in the surrounding area (such as moonlight or starlight), and converts that light energy (scientists call it photons) into electrical energy (electrons) presenting an enhanced visible image to the pilot. These electrons pass through a thin disk that’s about the size of a quarter which contains more than 10 million channels. As the electrons go through these channels, they strike the channel walls and thousands more electrons are released. These multiplied electrons then bounce off of a phosphor screen which converts the electrons back into photons presenting a green- hued amplified re-creation (think T.V.) of the scene being observed through the NVG eyepiece.
- Can EVS systems and NVG’s see the same thing during the day and during the night? Are there limitations?
EVS provides daylight vision in darkness, poor visibility, smoke, haze, smog, dust, and light fog. EVS can see through these conditions because thermal energy from the environment is able to penetrate the density of the atmospheric particles when they are smaller than 12 microns. EVS can be limited in heavier atmospheric conditions or when the environment does not have thermal variation (or contrast) which is necessary to present a temperature based image. At rare times, a phenomenon called “thermal cross-over” occurs where objects in the environment transition through an identical thermal gradient. At these times, an object in the foreground may fade to very low contrast or may not be visible for a very brief period of time even during period of clear VFR operations. EVS can also be degraded during periods of heavy rain depending upon sensor mounting location, airspeed and airflow. This can be compared to driving a vehicle in heavy rain without windshield wipers.
NVGs are operationally effective at night and will not work in complete darkness without additional IR illumination. NVG’s can only be utilized during the day with training filters and prolonged use is not recommended since it can damage the image intensifier. New Gen 3 and Gen 4 NVG technology is very good and it is possible to see through thin / light obscurations such as smoke, haze, smog and fog. However, it is important to note that NVG’s may actually be lulling you into a false sense of security, since these conditions may be deteriorating to a point where visibility through the goggles is no longer possible. Continued flight into denser atmospherics can result in the NVG’s shutting down and leaving the pilot unaided in an Inadvertent Instrument Meteorological Condition (IIMC) scenario. NVG’s cannot see through dust, heavy snow, heavy rain. Degraded NVG operations can also occur in mountainous terrain due to shadow’s affecting the NVG’s ability to gather light. NVG’s can also subject to dimming during periods of high illumination that could be caused by bright moon light, ambient light from large cities or high intensity search lights. Aircraft cockpit lighting, internal lighting, and external lighting, must also be modified for use with NVG’s so that they do not cause interference or degrade NVG viewing capabilities.
One should note that each one of these systems complements the other during nighttime operations. EVS utilized in combination with NVG’s provides optimal viewing results. EVS image through the various atmospheric conditions much more effectively than NVG’s. EVS additionally can better differentiate between MVFR and IFR conditions during en route flight which provides a significant improvement in IIMC avoidance. NVG’s, however, improve the lateral situational awareness and are very effective in providing good imagery during periods of low thermal contrast. It is the synergy of these two technologies looking at the environment through an enhanced visual and thermal comparison that provides this overlapping safety solution. The combination of these two systems will change the way night operations are conducted by increasing safety, while preserving precious assets such as flight crewmembers and aircraft during periods of reduced visibility and darkness.
Helicopter Terrain Awareness and Warning System (HTAWS) is a helicopter variant of the fixed wing Terrain Awareness and Warning System (TAWS) or Ground Proximity Warning System (GPWS) equipment that was developed and implemented to reduce the occurrences of Controlled Flight into Terrain (CFIT) in fixed wing aircraft. HTAWS presents both aural and visual indication of closure rates or proximity to terrain or objects that are resident within the HTAWS database.
HTAWS systems are highly developed and can take multiple inputs from the aircraft (i.e. power, airspeed, attitude, climb or descent rates, etc.) and flight path data to determine if the aircraft will approach or impact terrain and / or manmade objects that are resident within the independent database.
HTAWS indications are either aural (cautions or warnings of terrain or obstacles or proximity of the tail of the aircraft in some instances to the ground) or visually presented on multi-function displays (MFDs) or navigation displays in varied colors associated with the severity of the flight profile. The HTAWS system takes the aircraft flight profile and compares that data to the resident digitized terrain and obstacle information within the system and correlates the closure rates to provide the pilot with adequate reaction times to reduce the potential of a hazardous condition.
HTAWS data bases require regular updates to ensure that new hazards, obstacles, and terrain updates are displayed accurately. It is also important to note that HTAWS data bases could display variances depending upon GPS accuracy and actual aircraft position. Max-Viz EVS systems complement HTAWS by providing real time views of the actual position in relation to terrain, hazards, and obstacles. Pilots can process visual information quickly, confirming HTAWS reliability resulting in optimal situational awareness and safer operational parameters.
Astronics Max-Viz embraces the FAA initiative to accept Enhanced Vision Systems (EVS) as a time tested technology that is a reliable and useful tool in allowing pilots to taxi, take off, and land in situations where they are not permitted to do so today. Astronics Max-Viz agrees that a HUD is a viable means to provide EVS information to the pilot, but does not believe it is the only mechanism for safely displaying EVS information. Various members of the Canadian and European regulatory and aviation communities believe EVS information can be safely displayed on a Head Down Displays (HDD) particularly when there are two crewman in the cockpit. Astronics Max-Viz also believes that Synthetic Vision Systems (SVS) when properly registered to the real world (i.e. validated by EVS) and presented on a HDD can be used with an equivalent level of operational safety in similar approach, landing, and take-off profiles.
Not as written; unless using a system currently qualified under the specifics associated with FAA 91.175. This proposed ruling is sure to prompt discussion among helicopter operators and may lead to a separate proposed rule that is rotary specific; taking into account the unique environment and the special procedures under which helicopters operate.
Yes. This announcement will generate more discussion about EVS and we suspect the non-HUD providers will get actively involved in trying to get the ruling amended to include other kinds of devices. All of this discussion will find its way into the news and that means that more people will become aware of the current and potential benefits of EVS.
With EVS, pilots can see better in situations where natural vision may be compromised (such as at nighttime, smoke, smog, or haze); if the pilot can see, he can avoid. EVS cost is typically less than 5% of the hull value of the aircraft. Without taking into account the potential (or cost) for harm to humans, accidents involving Controlled Flight Into Terrain (CFIT), runway incursions, and ground related incidents due to loss of visual reference or spatial disorientation often exceed the cost of EVS. EVS can lower the potential for (and cost of) accidents, so insurance companies, such as Aggressive Insurance, offer discounts on aircraft insurance premiums.
Because EVS is a safety and productivity enhancement that adds value to the aircraft, you may be able to take advantage of favorable tax treatment. Please consult your accounting department and/or tax advisor for additional advice as to whether you qualify. Additionally, numerous Max-Viz customers have reported insurance savings associated with the addition of EVS to their airframe, however, we are not qualified to provide specific insurance information and therefore you should consult your insurance professional.
Max-Viz was founded in 2001 by industry veterans; supported by some of the country’s finest venture capital firms. In 2012, the company was purchased by Astronics Corporation but remains intact as a business unit and wholly owned subsidiary. As a wholly owned subsidiary, we don’t release financial information, but our parent company is publicly held (NASDAQ: ATRO) and information is available on the parent company website (www.astronics.com).
Give us a call at 866-662-9849 and ask for sales or contact us via email. The installation is easy, the learning curve is quick and the solution and answer are before you.
