I just brought my 260se/stol back home from Kansas, where it had a new GTX330 transponder with traffic information exchanged for the GTX327. Bevan-Rabell in Wichita performed the GTX330 installation. There was an initial hiccup in that Garmin shipped the units for installation before the FAA had approved their TIS software for the 430/530 units, an atypical gaffe by an otherwise very heads-up company. This resulted in a 2-3 week delay in completing the installation for delivery. Total installed price, including a credit for the GTX327, was just shy of $4100.
As noted in another thread, I do not view mid-air collision as one of the main risks in flying, and statistics back me up on this. Moreover, Aviation Consumer listed collision avoidance equipment 10th on their list of 10 priorities for improving one’s safety (“Setting Priorities,” August 2001 issue). Thus I personally could not justify the $20K+ bill for Skywatch or TCAD. However $4K for the GTX330 was just low enough to win me over.
It works as promised–and doesn’t work as promised, too. Near Wichita it displayed traffic as little white-outlined diamond icons. Each icon has a “trend line” displayed with it, indicating the target’s projected flight path. I like this feature, as it allows one to assess whether a given target is of potential concern. However when a target was making a turn or maneuvering, the software seemed indecisive and the trend line would change erratically with each “refreshing” of the data. Next to each target is also a number such as “+07” or “-10” to indicate its altitude relative to you. I was pleased that I was able to find the aircraft visually in the area suggested by the TIS virtually every time. One exception: ATC called out a plane to me that was close laterally but about 2000 feet below, which the TIS did not detect. I suspect that we were not receiving his transponder due to his antenna position (bottom of the plane?). I suppose this means that a plane could climb into you from below and behind undetected, but I would judge the chances of that happening to be slim.
When a target is closer than 2 nm and within 1000 feet (I believe) of your altitude, the icon changes to yellow and an aural “traffic” alert sounds through your headset. The voice is female, with a British accent, agreeable yet attention-getting at the same time. Aural alerts can be disabled via the audio panel. I might be inclined to do this when nonpilot passengers are in the plane, especially when departing or arriving at a busy airport.
I made a short flight from ICT to EQA in trail behind another 330-equipped 260se, and we were able to track each other on the way back to EQA. At just below pattern altitude, the signal was lost as we sank below Wichita Approach’s radar coverage. The British Lady informed me of this by announcing, “traffic not available,” which was also noted on the 430 display. On the trip home, as predicted I lost coverage about 50 nm southwest of ICT, but surprisingly didn’t get it again until descending into the Phoeni| area. The service map on the Garmin website suggests availability in the Albuquerque area, but it was not active on that day at least. Amarillo is class C airspace, but I guess they don’t have the appropriate radar equipment. Descending towards Phoenix Deer Valley from the northeast, service was intermittent below about 6000 feet, presumably obscured by some mountains in the valley. Once I cleared those mountains, we were in business. Departing DVT, service was available west of the Phoenix area until 40 or 50 nm east of Blythe, and did not pick up again until 30 miles or so west of Palm Springs. It was intermittent while transiting Banning Pass at 4500 feet, and then available until between Santa Barbara and Santa Maria. It picked up again near Salinas and worked well when entering the Bay Area. It was both reassuring and cool to report to ATC that I “had on Skywatch” a Saratoga paralleling my course inbound to PAO even though I didn’t have it in sight.
As I do much of my flying in airspace where coverage is available, I feel that this unit is a good choice. However unlike Skywatch or TCAD it certainly won’t provide coverage at uncontrolled fields that are below approach control radar service. Compared to Skywatch, I will get more than 50% of the utility at less than 20% of the price, and I’m happy with that.