Sebastian_G wrote:
But you are right it will depend a lot on where you fly. In many parts of the world there will be no traffic at all or maybe one single aircraft, you hear it on the radio and it might be alright. But then you have areas with such a migh traffic intensity not having any equipment to avoid it is playing hit and miss.
In Scandinavia we have lots of space. In general the traffic density is low, but could also be super high. I would divide it into 4 categories:
There is very seldom anything in between. Either you are all alone, or you are swamped, more or less. Number 3 is typically at airsport centers and number 4 is larger controlled airports. Where would an anti collision device be useful? Beats me. For 1 and 2 such a device is redundant, but I guess it could be useful if you are lonely and looking for someone to talk to 
For 4 it is also largely redundant, because the airspace is controlled by professional people (we must assume).
This leaves us with number 3. This implies some complications. The traffic at those places is very dense, and also seemingly hugely chaotic at times. What such a device would do, is simply to show you that this is no place to be, airplanes all over the place flying in all directions. But it wouldn’t tell you anything more than you would get by listening to the radio. If you decide to fly there as planned, then you simply have to jump into it, fly as you are supposed to fly. This requires reading the info about how you are supposed to fly, perhaps also talk to people up front. The manner of flying could be hugely different, and hugely non intuitive due to odd implied restrictions by all sorts of things. When entering the circuit, such a device would do nothing but beep all the time (if beeping is what these devices do ) I’m only used to these old fashioned, micro sized FLARM devices when towing gliders. On occasion they are helpful if you lose sight of the glider in the vicinity that you are trying to fly over/below/around.
IMO the only place it could be helpful is therefore for number 1 after all. It could prevent the against all odds freak accident when you believe you are all alone. It general it will of course increase your SA, which is hard to argue is not a good thing. I don’t know. Mostly it’s a solution to a problem that don’t exist IMO.
No beeps are heard, just an overlay of 99% of nearby traffic on the VFR chart on the iPad in front of you, with their type and generally their tail number unless they don’t want it.
About once every year or two we have (or at least had) an air-to-air collision at one of the local ATC controlled airports, this is not the middle of nowhere, and I like having an avoidance tool other than random luck and looking out the window, trying to spot a fast approaching dot or several. The collisions can happen where inbound and outbound traffic to one or more of the airports is funneled in by terrain, putting a lot of planes in one place and making you track several at the same time, which is difficult. You’re likely not talking to ATC yet, neither is the other traffic, and ATC is relatively ineffective regardless – they’re too busy, they’re only communicating with a portion of the traffic in Class E airspace around and between airports and terrain often prevents their radar from being effective. In contrast having almost all nearby traffic overlayed on the chart in use was revolutionary.
ADS-B is also really good for coordinating approaches when closer in on approach to a pilot controlled airport. For example a couple of weeks ago I was on a 45 at one such airport, almost in the circuit and following a Bonanza. Just then I heard a Cessna calling that he was also on the 45, following the Bonanza. Instead of getting an elevated pulse and looking all over the sky, I glanced down at the iPad, saw him by tail number behind me and let him know. He probably didn’t have ADS-B IN but acknowledged, got me in sight and all went smoothly from there. If he hadn’t known I was in front it would have been a confusing situation for him a little later on.
ADS-B much reduces the stress of flying around airports. Obviously you still have to look out for birds and non-electrical aircraft but perfection isn’t required, close is fine.
Silvaire wrote:
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Silvaire wrote:
ADS-B much reduces the stress of flying around airports. Obviously you still have to look out for birds and non-electrical aircraft but perfection isn’t required, close is fine.
I concur. I is obviously beneficial and it´s only going to get more beneficial as more and more light aircraft are having ads-b out and flarm installed.
LeSving wrote:
For 4 it is also largely redundant, because the airspace is controlled by professional people (we must assume).
Dangerous assumption. It depends on the type of airspace. There is no traffic separation for VFR traffic in class D or E airspace, both of which are controlled airspace. Traffic information is provided on a best effort basis, but we should not assume that we will be separated from other traffic if VFR.
LeSving wrote:
When entering the circuit, such a device would do nothing but beep all the time
We have come a long way from there! This is a screen video I did last year doing traffic patterns with another aircraft (the video is 10x normal speed):
My TAS605 works great in the circuit. I used to think it would be like an xmas tree and sometimes it is but it is always useful and I would never decide to ignore what it is telling me.
I am still waiting to swap it for a TAS605A (ADS-B IN) but need to get an exchange box.
Traffic avoidance system is helpful when descending on an instrument approach to an unmanned uncontrolled airport in G airspace. There often can be a few VFR aircraft below the cloud layer around the airport with vague position reports (“west of airport, 5 minutes to pattern” or “over lake Puddly”) which make it hard to understand if these aircraft pose a potential threat to your approach. With TAS system you get a fairly good traffic awareness and usually immediately identify the aircrafts on the frequency on your TAS screen.
I understand that TAS does not completely eliminate risk of collisions in G airspace but I believe it significantly reduces the risk. It is still legal to fly in G airspace without radio / transponder, so in any case there can always be aircrafts around which don’t give position reports by radio or show in TAS system.
I have active traffic from KTA 870 and ADS-B traffic from GTX 345. I would also like to have FLARM traffic as we have a lot of gliders when weather is favourable (also IFR gliders).
From here
ADS-B is more complicated; it isn’t doable with cheap aircraft boxes in the context of an ICAO compliant ATC service.
I think US ATC already do vectoring based on aircraft ADSB data (including data radiated from those uncertified IFR Lancairs with PT6 in front)
@NCYankee will know if they can use targets from ADS-B instead of those from ModeC?
I don’t think there is ModeS requirement for IFR in US: pilots operate using ModeC+ADSB and everything works beautifully
My understanding TXP is only required near Bravo or above 10kft, I wonder even if one can fly IFR in say Echo with ADSB alone? the answer from FAR is not obvious and likely at ATC descretion
There is one reason why EU/UK never went for ModeC+ADSB instead of ModeS or zillions of toy likes of SkyEcho, FLARM, PAW…, this is because we can make our own solutions (problems), we can encourage our own innovation, we support local firms…so, we don’t have to use US standard for ADSB, however, this will still come with time as frankly it’s the only reliable & economic solution out there…
I think US ATC already do vectoring based on aircraft ADSB data
Possibly, but not SIL=0/1 which the portable boxes do.
The % of GA emitting SIL=3 is really small. It is basically higher end IFR types which have an ADS-B OUT capable Mode S transponder (in Europe it is not possible to emit certified ADS-B OUT without Mode S) fed from an SBAS (WAAS/EGNOS) GPS.
There is one reason why EU/UK never went for ModeC+ADSB instead of ModeS or zillions of toy likes of SkyEcho, FLARM, PAW…, this is because we can make our own solutions (problems), we can encourage our own innovation, we support local firms
That’s all true but also there is the ICAO certification framework which prevents “official” usage of the “velcro stuff”.
In the UK, due to the mad no-prisoners CAS policy, a lot of people are flying non-TXP but using the “velcro boxes” to get traffic warnings while not getting picked up by ATC radar. How effective this is I don’t know, but probably OK within the low flying (<2000ft) community within which most non-TXP stuff exists.
It would be an interesting project to merge SIL=3 (i.e. certified ADS-B) data (from a TAS605A) with SIL=0/1 (uncertified ADS-B) data (from some “velcro box”) and feed that to the panel display. Not possible legally but would be rather good 
It would show the “velcro box flyers” on your panel mount displays. Presently that traffic can be displayed only on a tablet, which is ok if you like that sort of thing, are happy with it shutting down in sunlight, etc. More context.
Silvaire wrote:
The collisions can happen where inbound and outbound traffic to one or more of the airports is funneled in by terrain, putting a lot of planes in one place and making you track several at the same time, which is difficult.
This is definitely a category missing from LeSving’s list, and I would expand this to include areas where uncontrolled VFR traffic is compressed into a small space or corridor due to complex airspace (big terminal areas, restrictions, VFR corridors, etc). I fly in the region surrounding Amsterdam, and for a large chunk of airspace you have all the VFR traffic flying below 1500, which means everyone is basically at the same altitude. I had a very close call a couple years ago and just yesterday on a 45 min flight back from my shop I had to actively avoid 3 aircraft, one of which I did not see (and did not see me) until Dutch Mil alerted me. This is why I always ask for traffic service.
