I just got a response from garman they shipping the 330 now . Sugested retail price is $5,000.00 I sent them mail asking if it is avaible for sr20-22 I will post when they responed which on the last mail was in 2 hours. From Don
I heard back from garman it can be used in our planes but it is not a slide in replacement.The conecter and tray have to be replaced so that will have to be worked out. So someone will have to be the test bed. I will try to get some prices but I do remember Gordon said it may be to long and Cirrus will have to get involved so I dont think it will happen for awhile. From Don
I’m curious what the update delay is on the 330 (from the reply at the target
aircraft, until it displays on your Garmin 330)… do you know what the spec
is on this?
Michael
Don,
There’s a good discussion of the Garmin 330 (including a discussion of connector issues) at the web site for Avionics West in Santa Maria, CA (http://www.avionicswest.com/archive/gtx330preview.htmclick here).
Cheers,
Roger
I’m having a 330 installed as we speak in my own plane (not a Cirrus). I hope to pick it up next week or the week after, and after a few hours’ flying I can give a PIREP. The unit is actually in the panel now. The delay appears to be due to Garmin’s not quite having all of their STC paperwork ducks in a row on the software for the 430 that enables TIS info display (or so I am told by the avionics shop).
Roger:
Thanks for the link to the interesting review. I was surprised at the observation that the unit will NOT display primary (non-transponder) targets as traffic, a feature that was suggested in prior threads as a potential advantage over Skywatch.
I am a huge fan of in-cockpit traffic displays. I continue to be amazed at the number of aircraft that I see first on the Skywatch…and ashamed at how many (nearby!) that I pick up on the Skywatch and are very hard to visually acquire due to lighting, blind spots, etc.
The Garmin ought to provide a significant portion of the Skywatch capabilities for a much more affordable price.
In reply to:
The GTX 330 does not display primary targets (skin reflections). The GTX 330 has the capability to display primary radar targets but the FAA software isn’t current enough to allow the data to be placed on the Mode S data link. That could change over a period of time. Aircraft operating without a transponder or a transponder that isn’t correctly aligned will not be displayed on the Garmin display.
Yeah, what’s up with that, eh? Any idea what “correctly aligned” transponder means?
Cheers
Rick
In reply to:
Yeah, what’s up with that, eh? Any idea what “correctly aligned” transponder means?
The big advantage of Skywatch over a Mode S is that Skywatch is picking up the traffic signal directly from the other aircraft’s Mode C transponder. A Mode S device is actually receiving its data from the nearest ATC radar facility. THis data only includes info on other Mode C and Mode S aircraft.
The disadvantage of Mode S is that if ATC does not have radar coverage in an area (like many uncontrolled fields, Class D space and many areas below 2,000 or 3,000 feet outside of Class C space) the Mode S will not pick up ANY traffic. Skywatch will pick up MOST of this traffic if it has a Mode C transponder.
I think the “correctly aligned” point is that with both transponders, depending on the angle of the signals sometimes the aircraft actually shields the signal being transmitted. I see this on Skywatch like when a plane travels right below me. It normally only lasts a second or two.
Skywatch is most helpful to me in flying into uncontrolled fields. You still have to look for traffic (like those Piper Cubs with no radios or transponders) but those plane are slow moving and hopefully we have time to react when we see them. Skywatch is great to keep an eye out for those Citation type guys who like to make straight in approaches at uncontrolled fields without proper radio contact.
Mason
In reply to:
Skywatch is most helpful to me in flying into uncontrolled fields. You still have to look for traffic (like those Piper Cubs with no radios or transponders) but those plane are slow moving and hopefully we have time to react when we see them. Skywatch is great to keep an eye out for those Citation type guys who like to make straight in approaches at uncontrolled fields without proper radio contact.
I totally agree. Particularly helpful for sorting out ‘surprise’ radio traffic, like someone who pops on with a vague initial “downwind” radio call when you are a mile out on a 45 entry. It’s surprising how many people can be in the airport area, transponder on, who are not making adequate (or any) radio calls. There are a lot more people with transponders on that aren’t talking than non-transponder types that aren’t squawking…I “see” a lot more traffic than before.
Tim
In reply to:
I think the “correctly aligned” point is that with both transponders, depending on the angle of the signals sometimes the aircraft actually shields the signal being transmitted.
Apparently not.
I corresponded with Tommy Rogers at Avionics West to find out what he meant and got this explanation: “The alignment procedures are called out in the maintenance manual of the transponder. In the older transponders, we had pots to physically adjust. We check the output frequency and again on older transponders this is adjustable. For example, the transponder is allowed to deviate +/- 3meg Hz from the center frequency. When one is of around 3mhz we call it being on the ragged edge, meaning that under some conditions it may actually be off frequency more than that, thus ATC would complain about you being intermitent.”
So from that, I conclude that “transponder alignment” refers to the frequency adjustment rather than a physical alignment of the plane or antenna. Wonder if anyone has had their GTX327 transponder frequency checked?
Cheers
Rick
In reply to:
I totally agree. Particularly helpful for sorting out ‘surprise’ radio traffic, like someone who pops on with a vague initial “downwind” radio call when you are a mile out on a 45 entry. It’s surprising how many people can be in the airport area, transponder on, who are not making adequate (or any) radio calls. There are a lot more people with transponders on that aren’t talking than non-transponder types that aren’t squawking…I “see” a lot more traffic than before.
Tim,
Today I was on the ground at Jekel Island 09J and a Cessna was in the pattern doing touch and goes and low approaches with a 12 knot tailwind. I tried to contact him on unicom and no joy. When I took off I was watching for him visually and never saw him on Skywatch. I took off into the wind and did a performance climb to 2,000 feet at 1,800 FPM while keeping him off my left side as I got past this idiot.
I wish we could program common sense into people!!
Mason
If it can sort out the traffic at KWVI on a sunny Saturday, it’s truly a marvel of engineering! Maybe one of these days I’ll bum a ride from you and see it in action…
(Watsonville is an uncontrolled airport near the California coast between Monterey and Santa Cruz; on a nice weekend day you may find five or six planes in the pattern, three more waiting to take off, and several more arriving from almost any direction. Radio and piloting technique are somewhat variable.
Several of my professional pilot friends find it terrifying, particularly when flying jets, so at least the fear is mutual.)
In reply to:
I’m curious what the update delay is on the 330 (from the reply at the target aircraft, until it displays on your Garmin 330)… do you know what the spec is on this?
See the Response! post Much ado about traffic for all the details about Traffic Information Service (TIS) and its limitations.
The simple answer to your question is ~4.5 - 9 seconds, which is predicated on the rotation rate of the radar antenna. This is also why TIS (and therefore traffic info) is not available through Center radar, since those antennas only rotate every 12 seconds and the FAA deemed that update rate too slow for traffic alert purposes. (I agree with that.)
In reply to:
The simple answer to your question is ~4.5 - 9 seconds, which is predicated on the rotation rate of the radar antenna. This is also why TIS (and therefore traffic info) is not available through Center radar, since those antennas only rotate every 12 seconds and the FAA deemed that update rate too slow for traffic alert purposes. (I agree with that.)
And having access to Tommy Rogers at Avionics West, I posed the question about the update cycle on the Garmin 330.
"TIS information is collected one radar scan prior to the scan during which the uplink occurs. Based on this, the information is about five seconds old but it gets better. The way Garmin gets “Real-Time” out of this system is the TIS ground station uses what they call “predictive algorithm” in it’s tracknig software. This algorithm uses track history data to extrapolate intruders to their expected positions consistent with the time of display in the cockpit. Now and then though an aircraft maneuvering around will cause this algorithm to display errors on the 400/500 series display. These errors primarily affect relative bearing information and track vector (it will lag in most cases), intruder distance and altitude will remain quite accurate and may be used to assist in see and avoid. Below are some common examples of errors.
When client or intruder aircraft maneuvers excessively or abruptly the tracking algorithm may report incorrect horizontal position until the maneuvering aircraft stabilizes.
When a rapidly closing intruder is on a course that crosses the client aircraft course at a shallow angle (either overtaking or head-on) and either aircraft abruptly changes their course within 1/4 nm, TIS may display the intruder on the opposite side of the client aircraft.
I’ve experienced the above issues with ATC and I’m sure most pilots have but they seldom happen. In my “opinion” the above conditions are often at fault when ATC points out traffic and we never see it.
I talked to one person about the 330 that has it displayed on the 530 (non-certified software) and they say it’s just as accurate as the SkyWatch when operating in mode S airspace. Anything else just drop me a note.
Cheers,
tom"
Cheers
Rick
When you really need the data (aircraft are close), it would seem to me that
even 4.5 seconds would be too much of a delay… say in the case where
someone enters the pattern near you at an uncontrolled airport, which happened
to me recently… Or recently in the LA basin (while under flight following), one
Cessna 600 ft below me from 10 o’clock then seconds later another 600 ft
above me from 2 o’clock… only one of which was called out by ATC. I was
looking/finding both of them, right up until they were within the 2 mile Skywatch
ring. With them that close, 4.5-9 seconds seems like forever.
Michael
David: I was intrigued by your post. I was just at KWVI this weekend. I didn’t know there was a SR22 in 'Cruz. We had a nice weekend. Stayed at Casa Blanca, dinner at Oswolds and breakfast at Zacharys. I saw an article in the New York Times called “36 hours in Santa Cruz” followed up on it. I can see why you live there.
So far as the arrival is concerned, I thought the traffic there was very professional. I canceled IFR about 10 miles south and found out that Rwy 20 was the active runway. I called my position and announced 8 miles south. I got a reply from one aircraft who said he was 10 miles south and about 1000’ higher. He asked my speed across the ground and I said 138 knots, since I had already began to slow for the landing. On departure this afternoon, I had been with Monterey Departure on 127.15 and got the clearance and the IFR release. I then went back to the CTAF frequency and waited for three arrivals before departing. I wasn’t 100 percent that there were no more on final, but we left without incident. I always park for the runup at an angle facing the final approach course so that I can take a look for sure. While I was getting the clearance there were four additional departures all of which left before I did.
I am looking at a Ryan TCAS which may be the first Cirrus installation by STC. I will keep all posted about this venture. Either this or the Skywatch are the only way to really have a good idea of where everybody is in the pattern, assuming they have their transponder on.
I see you are based at SAF. Are you lucky enough to have a winter home in Santa Fe and then hit the surf at 'Cruz in the summer?
…I conclude that “transponder alignment” refers to the frequency adjustment rather than a physical alignment of the plane or antenna.
Darn! And I though this meant that the transponder’s chakras had to be aligned with the qi of the airplane… or maybe that’s the other way around.
Rick: Thanks for this great information. Maybe that explains some of those situations where the traffic called out can’t be seen.
Does Tommy Rogers have any information as to whether the Garmin 330 will display on the Avidyne map and Avidyne dedicated traffic page? Does the Garmin display include a dedicated traffic page?
Also, this thread is the first that explained the reason that Center radar is not providing TIS.
"I talked to one person about the 330 that has it displayed on the 530 (non-certified software) and they say it’s just as accurate as the SkyWatch when operating in mode S airspace. "
It’s just that “noncertified software” that’s holding up my 330 installation. Garmin actually shipped the units out for installation before having the STC approved for the TIS software. An uncharacteristic miscue by an otherwise very on-the-ball outfit.
Maybe Feng Shui is the answer for transponder woes. It may be necessary to rearrange the avionics stack to achieve harmony.
-Mike