Tuesday, May 20, 2008
A Garmin-based glass-cockpit revelation
|SVT generates a runway view that perfectly mimics the view through the windscreen. Above the magenta flight director, set to seven degrees by pressing the go-around button, the HITS course to Ironwood’s airport is clearly visible.|
I did, however, notice one issue that I wouldn’t mind seeing corrected at some point in the future. For some reason, I found it necessary to click away from the checklist page while in the midst of the menu. When I went back to it, I had to check off all the items I had already acted on to get back to my place; it didn’t remember what I’d already done, contrary to the Avidyne system, though perhaps that’s not a fair comparison as the architecture of the two systems is different.
A Really Big Show
Synthetic vision systems have been around for a while. It’s only with the certification of Garmin’s SVT, however, that piston pilots can now enjoy the extraordinary situational awareness and capability that were previously the provenance of systems in higher-end aircraft. (See “Tech Talk: Garmin's Synthetic Vision Technology” for an overview of SVT in the G1000.) With SVT, Cirrus and Garmin have integrated the pilot more seamlessly into the avionics system.
On the PFD, SVT presents a 3D depiction of terrain, obstacles and traffic similar to what you’d see outside the window on a clear day. What I wasn’t prepared for, however, was how SVT depicted the runway as we were cleared for takeoff. It actually seemed more like an image from a forward-looking camera. And once in flight, the real talent of SVT was readily apparent. The depiction of terrain, obstacles, waypoints and traffic were clear and intuitive. Pilots will enjoy substantial situation awareness with this system. As we flew a short cross-country, airports we passed appeared as signposts labeled with their identifier. And as either terrain or obstacles became a potential hazard, they changed color to either yellow or red according to their relative altitude (yellow—bad, red—really bad).
|The green FPV is squarely in the center of the HITS boxes as it takes us to the end of runway 20 on a WAAS GPS/LPV approach to Sawyer County Airport.|
For navigation, the Highway In The Sky (HITS) boxes contribute immensely to a pilot’s situational awareness during en route navigation, instrument approaches and course interception. For example, on our ILS, we were receiving vectors to final, but I could see on the PFD that we were flying toward the string of rectangular boxes representing my final-approach course. On conventional glass, I’d have a map view to refer to and a still-pegged localizer needle. With HITS, I could see ATC vectoring us toward the boxes.
In addition to HITS, one of the most important and impressive features of Cirrus Perspective and SVT is the flight path vector (FPV). It’s essentially a flight director (FD), only much better. Once a pilot flies by FPV, which indicates path through the air regardless of pitch, there’s no going back to even a normal FD. To the FPV-initiated, the FD merely suggests where to place the aircraft’s nose in relation to the horizon.
The FPV, that little green-winged donut at the center of the PFD, greatly simplifies flying precisely. Want to fly a perfect steep turn? Put the FPV on the PFD’s zero-pitch line and you’ll hit your wake every time. It shows your crab angle in a crosswind, and I was completely blown away when I hand-flew the ILS to Duluth’s runway 9. It was simply the easiest ILS I had ever flown. Just keep the green FPV squarely in the magenta rectangles, and fly through them as they guide you right to the runway (which was also graphically depicted, number and all, as it would be on a HGS display). Even though conventional ILS symbology, localizer and glideslope also appeared during the approach, they never deviated from center as I put the FPV on the end of the runway symbol, flew through box after box, and “broke out” at our decision altitude in perfect position for a safe landing.
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