When it comes to TIS-B traffic, which relies on certain FAA radar sites to relay traffic information, an ADS-B In-only operator will get some TIS-B traffic when he is in close proximity to ADS-B traffic that is receiving that TIS-B information. There is some indication this is so. When it is displaying traffic information from the GDL 39, Garmin Pilot will annunciate when this TIS-B reception is active. Garmin is working to provide even more annunciation on what traffic services the GDL 39 is currently receiving.
The display of weather and traffic worked beautifully on the GPSMap 796 that I tested as well, though you need a direct connection on that box.
Power Play
The full capability of the ADS-B system was strongly evident when using the ADS-B Out/In GDL 88 remote box playing on a GTN 750 multifunction touch-screen display. With the latest GTN software version 3.0, the touch-screen multifunction unit becomes a powerful traffic system that allows you to see ADS-B traffic in ways you’d never imagined.
For starters, ADS-B gives you all kinds of information that you don’t get from traditional traffic utilities, including N-numbers and direction of flight. You can also see what kind of target it is you’re looking at, ADS-B, TIS-B or primary radar relayed. Garmin’s panel-mount ADS-B traffic utilities when played through the latest Garmin display (the GTN 750) integrate existing active traffic utilities (like TCAS) with the new ADS-B data.
Relative Traffic
The most remarkable utility, though, is something you’ve probably never seen on a traffic display before.
With traditional traffic gear, we’re used to seeing a static view of airborne traffic. That is, we see a snapshot of where everybody is at that given moment in time. With Garmin’s patent pending relative-motion traffic display, which the company calls TargetTrend, you see not just where the traffic is, but where it is going to be over time, with the predicted track of the target airplane projected forward in time so you can see what kind of a threat it really is, or isn’t. This is, after all, what we really care about, where traffic is going to be when it really matters.
The core idea behind relative motion will twist your brain in a knot if you’re not careful, or even if you are. Take for example the idea of where our airplane and potential conflicting traffic are headed and throw that idea out the window.
Let’s say we’re flying 200 knots over the ground and an airplane ahead of us is traveling in the same direction but going 100 knots slower. Relative traffic begins with the idea that it doesn’t really matter in what direction the target is traveling; that’s immaterial. All that matters is that it is, relatively speaking, approaching us at 100 knots. It might for all intents and purposes be flying right at us. That’s the basic concept behind relative motion, and once you put that idea into action by projecting where traffic will be based on your relative motion and theirs, you get the kind of information you really want. One Garmin test pilot told me that a flight down in the Los Angeles basin on a busy afternoon revealed in no uncertain terms that the traffic they’d previously (with old-fashioned absolute motion displays) thought of as threatening wasn’t, at least not when viewed through the lens of relative motion. Moreover, the traffic they’d have previously ignored suddenly was exposed to be actually threatening.
I flew this brand-new gear last month out of Garmin’s Salem, Oregon, facility in the company’s King Air C90 and had a chance to see firsthand how relative motion works. I’ll never see traffic the same way again.
The King Air was outfitted with the GDL 88 remote-mount ADS-B unit displaying on GTN 750 display and integrating a Garmin active traffic system. After taking off from Salem we tracked a Garmin Mooney 201 also equipped with ADS-B that had taken off shortly before us. With the GTN display of the GDL 88 data, we were able to track not only where the Mooney was but where it was going to be, monitoring its projected track to see where our closest point of threat was. When an active threat is identified, the GTN display of ADS-B data shows a dashed green line leading to a solid green line showing a potential point of collision over time. The displays showed us what we needed to know to avoid a conflict.
Relative motion is a revolution. It tells you not what is happening in a static world but what is happening in the real world. It’s cool stuff, and it’s only going to get better.
The bottom line is that ADS-B is here, and with a full-up permanent ADS-B In/Out system, there are some remarkably attractive benefits waiting for pilots to equip, and those benefits — ADS-B traffic and free weather — will only get more attractive as time goes on and more airplanes equip.
As far as weather is concerned, ADS-B offers a compelling and cost-effective alternative to paying for subscription satellite weather, a welcome development.
When it comes to next-gen traffic, the message is clear. The future has officially begun. Looks like it’s time to get on board.
