The Ultimate Navigation System
Posted by: Stephen Wildstrom on February 18, 2008
In-dash satellite navigation systems are becoming much more common in cars and they are pretty cool. But they are nothing compared to Honeywell’s Integrated Primary Flight Display/Synthetic Vision System. I got a chance to see this state-of-the-art system, which demonstrates the enormous amount of computer power that keeps airplanes flying safely these days, from the cockpit jump seat of a Gulfstream 450. The IPFD/SVS—aviation uses abbreviations like that a lot—will be installed in commercial airliners including the Airbus 380 and the Boeing 787.
The system is designed to solve two problems for pilots: Too little information and too much. Modern avionics, which add ground and aircraft collision avoidance systems, moving maps, electronic navigation charts, and other data to the slew of traditional instruments--generate more information than a pilot’s brain can hope to process unless it is somehow integrated. Bit, at the same time, the pilot can still lack critical information about the plane’s situation.
The SVS part of the Honeywell system fixes that by reinventing the central display in the instrument panel, the attitude indicator. A traditional attitude indicator is a circle divided in half, with the blue upper half representing the sky, the brown lower half the earth, and a line in the middle the horizon. In flight, the attitude indicator rotates and pivots to show the plane’s bank and pitch angles. The goal is to let the pilot know what the plane’s position is relative to the ground and whether it is flying level and straight or turning—all of which can be difficult to determine in clouds or at night.
SVS enhances this information by replacing the ground portion with a three-dimensional map of the terrain, giving the pilot clues about the plane’s location as well as its attitude. As we approsached Dulles International Airport, the terrain clearly showed the location of the runway, as well as the Potomac River to the east of the airport and the Bull Run Mountains to the west. The terrain information is generated by a method very similar to that used in video games: a wire frame of triangles is built using a database of terrain and the texture of the land is mapped onto the polygons.
The IPFD integrates many of the other key flight instruments, including heading, altitude, air speed and vertical speed. In the “glass cockpit” used in contemporary planes, computer-style displays replace conventional instruments, allowing the flight crew to select the most relevant information at all times. The Gulfstream’s PlaneView has four big side-by-side screens. The two screens on the ends will usually show the IPFD for the pilot and co-pilot. En route, the middle screens will most often be used to show a moving map—similar to the display of a car navigation system—and a navigation chart, a schematic showing waypoints, flight paths, and other navigation information.
I’m not a pilot, though I’ve spent a little time in the cockpits of small aircraft, where I have always been baffled by the flood of data the crew has to contend with. If the IPFD could make a flod of information coherent to me, I imagine it does a great deal more for a pilot.