Mode S Transponder


Does having a Mode S transponder affect the tracks picked up on flight aware? When I search on my tail number, it shows the information for the last IFR flight I completed. However, the track on the map changes from day to day – as I have flown numerous VFR flights since my last IFR flight, and it seems to pick up (partial) tracks from these VFR flights…

BTW, I bought the Mode S transponder to display TIS on the GNS430, only to discover while the A/C was in the shop for the installation, the FAA made the decision to discontinue TIS capability as ASR 7/8 radars are replaced with the ASR 11…one of which is in my home area – so I lose TIS by January 2007 at KPNS. Needless to say, I’m not a happy camper and will be “venting” at the FAA hangar during this year’s Sun-n-Fun…


I haven’t heard any reports of mode s transponders having an impact on FA coverage/service and what you describe sounds like pretty normal operations for most aircraft.


DOESN’t THAT SUCK…the FAA does it again…

TIS in NY AREA is a must…



TIS is/will be available with ADS-B. Unfortunately, MODE-S is a victim of the state-of-the-art moving faster than the state-of-the-union.

A while back I paid big money for a PC with a 386 40-Mhz processor that impressed all my friends! “How could you possibly fill up that 32MB hard drive?” they asked.


Well thats just wonderfull, at least my 386 is still in use today… :imp:


Well that depends. If he was getting flight following for those VFR flights, then yes it sounds perfectly normal (not ideal, but normal). But if he wasn’t, then that’s a far more interesting outcome. He didn’t say one way or another.



Mode S and TIS will be around a long time- 2009 at least - 2012 most likely. since the FAA is sloooooowly upgrading the radars to ADS-11 or whatever it is called - but they are NOT going shut down TIS-B in the northeast at all - there is no schedule to do so and the announced shutdowns of TIS-B are in the scattered areas of the midwest, south and west where there is one or two TIS-B sites surrounded by other no-datalink sites.

So, buying a Garmin 330 TIS-b will continue to work in the northeast / mid-atlantc for probably longer than the garmin boxes they work in or the airplane you have will be operable without replacement or overhaul.


While it may be true that Mode-S may continue to function, I’m not sure that I would want to buy “last year’s” technology when ADS-B can do more. There is an interesting letter from Phil Boyer on the subject (link here) and another link within that letter on a more in-depth article that might only be accessible to AOPA members.

However, as far as I know, ADS-B has not yet been FAA mandated, although it is probably on the horizon. It has been a successful and popular system so far. Me? I can’t afford either one!


well - I already have a GNS430 and a GPS 396 - but I do NOT have an MX-20.

I can get TIS-B traffic in the northeast region, where I live, work and travel [mostly south to SC] for $4200 installed which will work in the NE to Southern VA until 2013 at a minimum and likely past to 2015. Am I going to haev the same technology in this airplane then? Will I even own the same airplane?

Or, I can get the latest ADS-B - and get the TIS-B and FIS-B displayed [nexrad weather is not free nor operative yet under ABD -S I do not believe] and spend $7500 for GDL-90 and $12000 for an MX-20 plus ANOTHER monthly database subscription.

$4200 is ALOT less than $20k for essentially the same service I get now with my GNS-430 and my portable GPS 396.

That and for $49million the FAA Can retrofit TIS-B to ALL the ADS-11 radars - that will likely happen given the drunken sailor way we have the gov’t spending money these days.


Agreed. And note that I said I can’t afford either one!

My next upgrade project is going to be a panel mounted approach certified GPS. It won’t have TIS or ADB-B unless I take so long saving the money that the FAA mandates ADS-B and subsidizes it! There is talk that they might subsidize because it’s cheaper than their commitment to update radars, but I just don’t see it happening.

I’m impressed with your 396, but why would you buy one of those if you also have a 430? Seems pretty redundant. I bought a 196 several years ago when they first came out. Been pretty happy with it but I still look at the 396’s with envy. Still, not going to spend the money there because I want to put it in the panel. I also hate the thought of subscription fees.

I’m afraid that if everyone get comfy with paying for subscriptions for aviation services that it will only pave the way to similar fees, like FAA User Fees. Nexrad is free on ADS-B right now, but if the FAA thinks they can charge for it they probably will. If they do it free, they will probably kill XM in aviation so there would be lot’s of lobbying either way.


I am a firm beleiver in never buying avionics in an exisitng airplane - it is never cost effective - I bought my Viking with a GNS-430 and a JPI-800 installed. GREAT devices.

I’m buying the GTX330 because of all the traffic in the northeast and the stuff I NEVER see - was VFR last week and had crossing traffioc, same alt [and wrong VFR for them] never called out to me that WOULD have been a mid-air if we did not seem them - they NEVER saw us- never turned an inch. Save my my life once and it’s worth $4000.

Now, the 396 displays weather - and can operate as a time to destination counter while an IFR flightplan is in the 430. And music or news or sports. To get that in a 430 you need a GDL-69 which OLD tech now - the NEW ones [GDL-90] do NOT interface with the 430 and thus will NOT display traffic on the 430 and to get weather it is $7500 installed for the GDL box and another $13000k for the MX-20 - I have the panel room, not the money.

So, i’ll get traffic on the 430 and weather on the GPS-396 -displayed simultaneously . . . and both of them go into my audio panel AND I get terrain database warnings from the 396 - best of both worlds I think. All for $4500 instead of $20,000. Once south of Virginia I think I traffic called to me once or two a 2 hour trip distance - usually F-15’s over Seymour Johnson!

When the FAA gets the money ini 2012 to startupgrading the NE radars and discontinues TIS-B - THEN I’ll worry. In thenext 5-10 years, I’ve got a modern traffic display.


The whole TIS thing facinates me. I’m a little confused on how it all fits together though and I was hoping some more experienced people could clear things up for me.

It sounds like in order to receive TIS you need a special transponder (mode “S”) and something that can decode the data and display it on something. You also need to be in a coverage area that supports this special transponder mode (it looks like all of the major aiports in the country do from a map I saw somewhere). With all of those things in place you are able to see the traffic around you on something like the Garmin GPSMAP 396 or other in-cockpit display.

Are these Mode S tranponders pretty widespread now? Is it likely to be found in an FBO aircraft? If you want to use the 396 to display TIS does it require the Garmin transponder unit or is that data transfer standardized?

Is anyone here using a 396 to display TIS? If so, how does it work for you and what are your opinions on it?


I could be wrong here - but TIS-B involves a receiver in the transponder that RECEIVES FAA broadcast info - you do not need Mode S to get the other area transponders since the GTX-330 displays ALL traffic within your bubble (well, Mode C , S and tagged] - not just Mode S traffic.

As for using the 396 for TIS - there are too many darn cables as it is with the unit - the last thing I need is ANOTHER cable coming OUT of the panel into the 396.

In my case the GTX330 will display traffic in the GNS430 . . .like it was designed to do.


I can say for MX-20 wasnt all it is cracked up to be in reality, had one in new XLS and while it did show all the traffic and such and was supposed to also display the approach plates, ours often failed or rebooted in flight and the information was no better than a Garmin 530 in my opinion.
I have TIS in our Mooney and garmin430 and 330, found out the TIS apparently doesnt work in Europe either and and nowcan see why it wasnt working properly in the usa before the plane was purchased.
Subscription services will always be around i think, mostly to give folks what they wnt since the government takes so long and then upgrade to to old technology, if they even do sometimes. Some parts of Europe take years to upgrade a system then when they start have to halt the process because now that system is out of date and not usuable. Italy is aclassic example. I actually like visiting there though.