I got an email from Sandel saying the SN3500 will not display any ADS-B targets.
The arinc 429 that you are supplying to the SN3500 is standard traffic information. The ADSB information is at a different format which includes FIS-B data. We are not compatible with this format yet. I do not have a time frame for this at the moment.
I then obviously asked them what will happen to the product after the 2020 US ADS-B deadline … and they have stopped answering emails.
This possibly puts a different slant on this whole thing. It is a lot more likely that the Avidyne ADS-B update (assuming they do eventually produce it one day) has a better chance of generating SN3500-displayed data than say a GTX345 – if only because they say existing display devices will still work (subject to some conditions which nobody in the know is willing to comment on in detail).
One interesting angle is the 100+ SN3500 EHSIs which were installed in the RAF trainers a few years ago, after their air experience flight midair collision. The RAF will eventually want ADS-B in there. These planes have the TAS600 AFAIK.
Avionics is such a mug’s game. People wonder why I stick with the stuff I have. What almost nobody does is post in a forum which bits of their new €30k installation don’t talk to each other – because they want a fix and don’t want to p1ss off the dealer.
On the plus side, almost nobody in the UK (at relevant OCAS levels) is emitting ADS-B and that isn’t likely to change anytime soon because the spurious privacy arguments will continue. One big midair just a few hours ago – Cessna and a helicopter.
The RAF are getting rid of many of the Grob 115s that had TAS605 installed, as the MFTS contract supplier and aircraft type have changed. Since the remaining aircraft have both TAS and Flarm installed and aren’t subject to the ADS-B mandate, I doubt they’ll do ADS-B out and almost certainly not ADS-B IN.
Peter,
What is the perceived benefit of adding ADS-B in to your TAS 605?
If you mean adding it to the TAS605 (rather than going the GTX345 route), I have no idea. I am exploring the options. It does smell like more stuff will work that way, however.
If you mean why add ADS-B IN at all, the answer is: currently, virtually nil in all relevant circumstances, but it may change in the future, and if I can add ADS-B IN as a “surgical operation” that looks attractive. I much prefer doing “surgical operations” on my plane because I have poor installation (and especially debugging) options for nontrivial avionics, and I value 100% uptime on the aircraft.
Nothing in European airspace will radiate ADS-B Out without radiating Mode S at the same time. Therefore ADS-B In should add little to nothing for the safety of flight. It can add more remote targets and labels.
achimha wrote:
Therefore ADS-B In should add little to nothing for the safety of flight. It can add more remote targets and labels.
And far more accurate target position.
A couple of points to repeat from further back:
I still don’t understand the Sandel SN3500 aspect, but there seems to be no present way to clarify it.
* the attraction here would be that the “civil liberties” crowd might be radiating something which they don’t radiate currently – this is a major factor in UK flying and, from past posts here – example – in other countries too.
Peter wrote:
one Q I had was whether some of these ADS-B IN options would display “uncertified” ADS-B transmissions, coming from planes without Mode S
How can you radiate ADS-B Out legally in European airspace without also radiating Mode S?
With one of the cheap devices. Several have appeared, IIRC. SIL=0 emitters. I don’t follow the UK scene anymore however.
The ADS-B Out system can be in full compliance with the TSO or ETSO, but still be connected to a position source that does not provide all of the required data, so when required items are not available, the value being broadcast is unknown.So if the NIC (an indication of the integrity containment radius) or NACp (an indication of the 95% accuracy of the position) are not able to be determined. Values of 0 are included in the ADS-B Out message fields, which for NIC means > 20NM or unknown. For NACp it indicates > 10 NM or unknown. So it is not just a SIL = 0 issue that will cause ADS-B targets to not be displayed on a CDTI (Cockpit Display of Traffic Information) display.
An EVAcq (Enhanced Visual Acquisition) or AIRB (Basic Airborne Situation Awareness) traffic track shall (2140) only be provided to the CDTI interface when:
a2. Traffic or Ownship is airborne and traffic is reporting valid horizontal position with a NACP of 5 or greater (< 0.5 NM).
AND
b. Version 2 traffic is reporting an SDA greater than 0.
AND
c1. Traffic is reporting valid horizontal velocity with a NACV of 1 or greater (< 10
m/s).
For those targets that can’t be displayed on the basis of their ADS-B Out data, they would need to be displayed using your TAS or TCAS system based on active interrogation of the target transponder. If you don’t have a TAS/TCAS system, then these targets are not visible. In the US, these targets would be classified as NPE (Non Performing Emitter) and would cause a ground station to generate a TISB report based on their radar transponder based location if necessary. Normally an ADS-B Out equipped aircraft is considered a client of the ground station TISB service. Being a client, a TISB is not generated for the client itself as it already broadcasts its position. But since an NPE is invisible to a certified ADS-B In system, the ground station treats the NPE as not being equipped and will generate a TISB for that aircraft if they are in the vicinity (15 NM radius and +/-3500 feet) of a true client. That way, the NPE aircraft TISB target is displayed on the CDTI of the equipped client. With a non certified ADS-B In receiver, you will see both the NPE broadcast position and the TISB in close formation as a double target.
