FLIGHTDECK TECHNOLOGY

Garmin SVT

Integrating synthetic vision with the PFD.

By Glenn Connor
Pres, Discover Technology Intl


Garmin's SVT is now available as a software upgrade to the G1000 flightdeck.

A new flightdeck for a seasoned aircraft can be a wise investment.

If your selection takes you to the same equipment on a new jet, it's obviously modern, but normally not affordable-but the folks at Garmin have managed 2 spectrums of the market in a way that seems to defy the laws of both physics and economics.

They call it synthetic vision technology (SVT). SVT is now certified for Garmin's G1000 flightdeck avionics. SVT tackles both the practical problems of integrating a new system into that beloved older airframe or providing the modern finish to your new airplane.

Having a pretty PFD is good for a while, but a new glass cockpit with a 20-year-old autopilot and patchwork nav systems is more like an electric toothbrush without the batteries. For a new jet-or an older aircraft that you intend to operate well into the future-you need modern functions like ADS-B and synthetic vision, but also autopilots and radar.

Using the G1000 as the basis for SVT, Garmin now also provides the rest of the basic systems, like autopilot, WAAS GPS, radios and a radar. It's all by Garmin, and has been placed in a price range within easy reach for every class of aircraft.

SVT details

For the G1000 the new element of change is synthetic vision (SV) on the PFD. The SV is a perspective display, replacing the older concepts of earth horizon/attitude indicator.

The SVT PFD shows the actual terrain that you are flying over in a manner with enough detail to determine not only your attitude but relative position-in other words, situational awareness (SA).

Garmin SVT has integrated TAWS with the PFD. The digital terrain perspective provided by the SVS shows the landscape as well as threatening terrain. The green flightpath marker symbol sitting on the horizon line shows the aircraft's current actual flightpath.

The PFD shows the terrain using a Garmin-developed digital terrain database, and is also integrated with obstacle and airport data provided by a Jeppesen database service. Obstacles are stored within the database. They are viewed in perspective mode and grow as you get closer.

It is not long before you get the hang of seeing the obstacle some 6 miles out on the SVT and how it relates to your route of flight. If you are curious, slew the cursor on the MFD over to the obstacle, and data concerning its location and height above terrain are instantly available. Airport runways and obstacles are also shown in a perspective or real-world manner exactly where they are in real space.

You could actually navigate the aircraft around these obstacles and terrain to the runway, but as one well-meaning regulator implies, perish the thought. Some top-level items to note about the SVT are the PFD's digital terrain quality and accuracy, and how it is integrated with TAWS.

If the aircraft is headed to a terrain or obstacle which is a threat, the SVT display changes colors-just as it does with expensive TAWS.

Obstacles are also colored and are tailored to grow according to their distance from the aircraft. This helps to get the pilot's attention to the TAWS and obstacle warning. Several other features have been added to the SVT that are pilot performance tools.

The first is the flightpath marker symbol, a relative newcomer to general aviation flight instruments. The velocity vector has been a major part of military aircraft displays to project exact direction and energy state of the aircraft.

This is useful for bombing and shooting things. In the commercial world, the flightpath marker symbol is the principal element in the success of the head-up display (HUD). In flying the HUD, the pilot maneuvers the flightpath marker symbol on top of the flight director cue, and achieves precision that is more typical of a Cat III autopilot.

Several high end manufacturers have introduced the flightpath marker symbol on the PFD, but Garmin's introduction of the flightpath marker symbol is likely to set a standard for all SVS-style displays as another safety tool in flightdeck evolution.

In a recent flight demonstration of SVT by Garmin, the flightpath marker symbol was placed on the display's runway symbol during the approach and landing. The runway symbol shown on the PFD is based on data stored in the SVT database as well as the GPS position of the aircraft.

The flightpath marker is generated from Garmin's air data attitude heading reference system (AHRS), and functions at the same level of quality and performance as if it came from an expensive inertial navigation system (INS) typically used with HUDs.

When the flightpath marker symbol is pointed at a spot on the runway, that's where the aircraft is going to land. In a short experiment conducted during Pro Pilot's visit, the symbol was aimed at the touchdown zone markers and runway centerline.

Traffic awareness is another innovation provided by Garmin SVT. The standard diamond TCAS traffic symbol is displayed on the PFD in terms of its relative position, making it much easier for the pilot to search for nearby aircraft.

At touchdown we were one paint stripe off to the right as the nosewheel rolled onto the runway. Part of the SVT is its use of Highway-in-the-Sky (HITS).

This symbol and its operation is a box presentation on the PFD in perspective mode that shows your location relative to the course and selected altitude, and is there mainly to show your position relative to your selection.

In a sense it is a way to keep up your awareness of course and heading deviations, but it is also there to support approach operations. During an approach the boxes in the HITS mode show the descent path with ±100 ft, and for the approach the display is designed to prompt you to a deviation of 1/2 of the full-scale azimuth during the approach.

At minimums it is no more than 50% full-scale deflection-a good tool for all to keep track of flight technical error. In terms of pilot operation, several other new capabilities have been implemented in the Garmin SVT that have not been seen in competing systems-namely, traffic awareness with a 3D-perspective TCAS-like system.

1


1 | 2| Next