Over the past decade, new technology that promises to make instrument flying almost as easy as (and arguably even safer than) flying visually has been introduced into the general aviation (GA) fleet. Synthetic vision takes the idea of an artificial horizon and expands it to an artificial view of the outside world, allowing pilots to fly by visual reference even in the clouds. Terrain, runways, obstacles and (optionally) traffic appear on the PFD (primary flight display), along with typical glass-panel indicators for heading, altitude and airspeed. Optionally, a pilot can also display Highway in the Sky (HITS) as a set of rectangles defining the flight path. A typical instrument flight with synthetic vision starts with a takeoff from a virtual runway thatâs always clear (regardless of the actual visibility); it then intercepts a path in space (defined by HITS boxes) to the first waypoint and continues until itâs time to descend, at which point the HITS boxes (along with more conventional horizontal and vertical deviation indicators and/or flight director command bars) guide the plane to another virtual runway for landing.
At this writing, three companies offer synthetic vision products aimed at GA aircraft; two more plan major announcements.
|The Garmin G1000 equipped with SVT (top, right) on short final to runway 18 at New Century AirCenter Airport in Olathe, Kans. Compare Garminâs depiction with the real outside view of the same runway and airport from a G1000-equipped Diamond DA40 (above).|
Chelton Flight Systems (now a division of Englandâs Cobham plc) has been selling synthetic vision systems for GA aircraft since the FAAâs Capstone Program in 2001âitâs now the market leader, with almost 1,500 systems installed. Of the FlightLogic Synthetic Vision Electronic Flight Information System (EFIS), Chelton Western Region Sales Manager Greg Schmidt says, â[Itâs like] eye candyâit sometimes gets a pilotâs head down to the point where it can be dangerous because the display is so beautiful. Especially down low, you see the mountains and obstacles as you get close to them.â
Like other synthetic vision systems, FlightLogic puts synthetic terrain on a PFD in front of the pilot, next to an MFD (multi-function display) for moving map and other auxiliary functions. Unlike other vendors, Chelton hasnât attempted to duplicate the typical âover-and-underâ attitude indicator (AI) and horizontal situation indicator (HSI) on the PFD. According to Schmidt, âThatâs what you get when you replicate analog instrumentsâwhich isnât what we do. Our PFD is an AI with a flight-path marker. We find that pilots experience extreme task reduction when they donât get the typical AI/HSI combination.â Instead, Chelton superimposes all critical flight information over an AI, including horizontal and vertical deviation (as appropriate), much like the heads-up display on a modern jet fighter. Users who want an âanalog-styleâ HSI display can get it on the MFD. Cheltonâs terrain display is different from competing systems; it offers six-arc-second resolution (versus 30 arc seconds with most others), but doesnât display rivers, lakes and other water features. The terrain on Cheltonâs display is always brown, instead of the color-coding used in competing systems. âWe were told initially by the FAA that you couldnât have flashing yellow or red on the PFD,â says Schmidt. âTherefore, we couldnât display it. We followed the TSO that was in place at the time. We do use TAWS coloring on the MFD.â
|Avidyneâs synthetic vision upgrade for the Entegra glass panel should offer features comparable to other synthetic vision systems.|
Chelton just introduced upgraded software that provides support for the FAAâs NextGen Automatic Dependent Surveillance-Broadcast (ADS-B) and WSI satellite weather. The software also features improved autopilot support, an additional tape-style vertical indicator on the right of the PFD (which can display deviation from an ILS glideslope or GPS-derived vertical guidance), vertical speed bugs, V-speeds, Mach indicators for jet aircraft, a navigation log on the MFD and easier waypoint insertion into existing flight plans. The $2,000 upgrade covers software and, if necessary, a hardware upgrade to the display.
In addition to two (or more) integrated display units, a typical FlightLogic system has an integrated GPS connected to one or two conventional NAV/COM units. Most can be automatically tuned by Cheltonâs flight-management system (FMS); Garminâs GNS 430 and 530 are exceptions. Options include a physical slip/skid ball instead of (or in addition to) the digital slip/skid indicator typical on other PFDs. Pricing for a two-display FlightLogic system begins at $52,000, plus dealer mark-up and installation, which Schmidt says can require up to 200 shop hours: âA huge factor is whether you already have the system opened up for an interior change, panel replacement, etc.â The complexity (and time in the shop) also depends on what kind of autopilot the user has or adds to the airplane.
Overall, though, Schmidt (a pilot himself) says, âFlightLogic is a real pleasure to fly! Iâve heard numerous times from ex-airline pilots who say they feel comfortable flying IFR with these systems, but wouldnât be comfortable with steam gauges, especially on a long flight.â Visit www.cheltonflightsystems.com.
|Cheltonâs FlightLogic provides a synthetic view of terrain, obstacles and traffic, and also has HITS guidance.|
Honeywell Bendix/King VistaNav
Honeywell Bendix/Kingâs first synthetic vision product aimed at GA pilots is quite different from competing systems. VistaNav, which Honeywell acquired from Mercury Computer Systems earlier this year, operates on a PC running Microsoft Windows XP and configured as an electronic flight bag (EFB); its functions include GPS/WAAS, moving-map navigation, satellite-based weather, terrain awareness and digital approach plates. In addition to the display hardware, VistaNav requires input from a proprietary inertial navigation unit (INU), a WAAS-enabled GPS and, optionally, an XM Satellite Weather receiver and Zaon XRX portable traffic detector. Display options include both Class I and Class II EFBs (the latter is certified for use in commercial aircraft). VistaNavâs software offers the ability to see the aircraft position on airport diagrams, âtouch and dragâ map and chart panning, and long-range weather zoom, along with HITS guidance for both nonprecision and precision approaches.
Hosted on a portable device, VistaNav canât be TSOâd for primary navigation in IFR conditionsâso, unlike the other systems covered here, it canât replace conventional instruments. But, just as with a conventional yoke-mount GPS, itâs legal to use VistaNav for âsituational awarenessâ on Part 91 flights, provided that you also tune the built-in instrumentation thatâs appropriate for the approach being flown.
VistaNav technology may appear in other Bendix/King avionics. Chad Cundiff, Honeywellâs vice president for crew interface products, says, âWeâre very interested in synthetic vision technology, and thatâs what drove us to license VistaNav. Right now, weâre figuring out how it fits into our road map. They did interesting things in synthetic vision and image fusion. Honeywell already offers high-end synthetic vision products in the Primus Epic line for business aircraft. We expect to add a synthetic vision feature to our KFD 840 PFD at some point. Stay tuned!â
Meanwhile, the portable VistaNav products are available; prices start at $4,399 for Class I systems and $5,999 for Class II systems. For more information, visit www.vistanav.com.
|VistaNav, now a Honeywell Bendix/King product, offers synthetic vision on a portable device.|
Garmin G1000 With SVT
Over the past few years, Garmin has had a major hit with its G1000 glass panel. From a standing start, the product put the Olathe, Kans., GPS vendor into first place among glass-panel avionics makers (with more than 5,000 installations at this writing). In April, Garmin announced a synthetic vision upgrade, which puts color-coded terrain, obstacles and runways on the PFD. Under an experimental license, the G1000 with Synthetic Vision Technology (SVT) initially flew in a Cessna 182; itâs now FAA-certificated in Diamondâs DA40 and as part of the new Cirrus Perspective glass panel for the SR22-GTS.
According to Garmin Director of Flight Operations Tom Carr, SVT consists of three major components. First, synthetic terrain derived from the TAWS database is displayed on the PFD and includes both terrain and obstacles. Second, a flight-path marker (displayed as a green circle with fins) shows how youâre going through space, taking into account wind, based on the aircraftâs attitude and heading reference. âYou need something like that with synthetic terrainâif not, youâd misunderstand where youâre pointed,â says Carr. âIt can be used to crab to a landing, with no outside view. In pitch, it shows where youâre going, as opposed to where the nose is pointedâso, for example, in a slow climb, it will show whether or not youâre going to miss terrain.â SVTâs third element is called Pathways, which is Garminâs implementation of HITS. It displays rectangles that are 700 feet wide and 200 feet high, centered on the selected flight path and based on the terrain database. Unlike most other people weâve spoken to about synthetic vision, Carr doesnât buy into the notion of using Pathways (or any HITS implementation) as a primary form of guidance because of its sensitivity. Instead, Carr strongly recommends flying with guidance from a flight director, if the aircraft is so equipped (as are both the DA40 and SR22-GTS).
|With SVT enabled, the G1000 PFD immediately indicates that the flight path will not clear high terrain (left). Even if SVT isnât enabled (right), the same high terrain is shown on the G1000 MFD, but the pilot has to look at the MFD to see it.|
Carr sees Pathways mainly as providing situational awareness: One glance tells you immediately whether youâre on course. Obstacles and traffic get larger as you get closer; they also change color, becoming yellow when they begin to present a possible threat and red if you get too close. And the color-coded terrain display makes it immediately obvious if your flight path will lead you to an unintended landing. According to Carr, âJust flying along at cruise altitudes, SVT doesnât make that much difference; but itâs really neat in low-visibility conditions. IFR, night, hills and unfamiliar airports all benefit from it. Essentially, if you want it to work, it just does. For the vast majority of flights, youâll never press a button related to SVT. Just put in the flight plan, and youâll get lateral guidance from the flight plan; add vertical guidance from the approach or altitude preselect.â During development, Carr told us that some pilots asked for a quick way to turn off the Pathways display during final approach; this can be done using soft keys on the G1000 PFD bezel, which also allow you to selectively disable other synthetic vision functionsâindeed, you can turn them off completely and revert to standard blue-over-brown PFD functionality (though after flying with SVT, it looks awfully bare).
Because Garmin licenses the G1000 to aircraft manufacturers, it doesnât control pricing, but Carr told us that he expects it will be âvery attractive.â Diamond offers SVT as a $9,995 option on the DA40, while Cirrus offers it as part of the $48,000 Cirrus Perspective package (including larger displays) on the SR22-GTS. Cessna has announced plans (but not pricing) to offer SVT on all of its G1000-equipped aircraft, beginning with the Citation Mustang, and Garmin itself expects to offer SVT on its G1000 upgrade to King Air C90 aircraft next year. For more information, visit www.garmin.com.
|L-3âs synthetic vision upgrade to the SmartDeck glass panel will offer simulated terrain on the PFD.|
Avidyne Synthetic Vision
Steve Jacobson, Avidyneâs vice president of engineering, tells us that synthetic vision will be added as an upgrade to the Entegra flat panel: âOur intent is to support the entire [Entegra] installed base.â Avidyneâs synthetic vision will offer comparable features to competing systems, including simulated terrain, obstacles, traffic and HITS boxes displayed on the Entegra PFD. Jacobson was personally involved in NASAâs Advanced General Aviation Transport Experiment (AGATE) program in the 1990s, during which Avidyne provided an experimental glass panel with synthetic vision that was flown on Columbia 300 and 400 aircraft. âExactly what will be involved in an upgrade will depend on what the customer has,â says Jacobson. âWeâve identified every possible combination of Avidyne gear in the field. Thereâs an STC in existence that would allow installation of a PFD into an older six-pack airplane.â Initially, it will be focused on Avidyneâs FMS, which is being offered as an upgrade from the typical dual Garmin GNS 430 radio stack in most Entegra-equipped airplanes, but âthereâs no reason why we couldnât offer synthetic vision on Garmin-based systems if thereâs customer demand for it,â says Jacobson. He wasnât surprised by the recent announcement that Cirrus, which had been exclusively using Entegra in the SR20 and SR22 product line, now offers a G1000-based flight deck on the SR22-GTS: âAlan Klapmeier [Cirrusâ President] has a long-standing wish to offer multiple flight-deck options. While weâd love to have the entire Cirrus line, this wasnât a surprise. Weâre still standard at Cirrus, and we expect to offer our upgrades to those customers as well.â Learn more at www.avidyne.com.
L-3 SmartDeck With Synthetic Vision
At this writing, L-3 Communications planned to announce a synthetic vision upgrade to its SmartDeck glass panel (which has just achieved FAA certification for the Cirrus SR22 2008) at EAA AirVenture 2008. According to Larry Riddle, L-3âs vice president for business development, the upgrade will offer a wider field of view (75 degrees) and higher terrain mesh resolution (six arc seconds) than competing systems. Riddle is particularly proud of the systemâs human factors and aesthetics: âOur oval-shaped HSI was designed to make a natural transition to synthetic vision; it doesnât stick out like a sore thumb, and itâs opaque, which makes it easier to see compared with some of our competitors.â The software upgrade will provide simulated terrain, but while traffic display and HITS symbology are planned, Riddle says they wonât be in the initial release. Besides Cirrus, Riddle says that L-3 is âworking with a second vendor,â but couldnât provide details yet. Pricing for the upgrade hadnât been determined at press time, but Riddle told us âour price point will be competitive.â Visit www.l-3com.com.
|A Different Kind Of Synthetic Vision
Universal Avionics Vision-1
|While synthetic vision is a new development for entry-level GA pilots, it has been around for quite some time on corporate jets and twins. Universal Avionics Vision-1 has been TSOâd for Part 23 and 25 aircraft for a while now. The system generates simulated 3D views by combining data from a terrain database with GPS position. Unlike competing systems, Vision-1 offers an âexocentricâ or âwingmanâ view, in which the âcameraâ is above, behind and to the right of the aircraft, as well as the more familiar âegocentricâ straight-ahead view (pictured above). Itâs capable of rendering the horizon up to 55,000 feet, at which point the curvature of the earth can be visible when operating over water. And the system combines simulated terrain with PFD information from the aircraftâs FMS; so you can see a flight plan or a localizer/glideslope superimposed over simulated terrain on an 8.9-inch PFD. According to Universal Avionics Marketing Communications Manager John Hamby, the system is certified for use in aircraft ranging from the single-turboprop Pilatus PC-12 up to a Boeing 737. Installation requires extensive modifications, among them replacing any existing EFIS, and adding several line-replaceable âblack boxâ units. The system usually works with the IFR GPS already installed in the aircraft. A two-display system for a plane like the Pilatus PC-12 costs about $250,000, installed. System weight and electrical power requirements vary depending on the specific installation. For additional details, browse www.universalavionics.com.|