Primarily for general aviation discussion, but other aviation topics are also welcome.
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By defcribed
#1802573
Can anyone define this for me please?

And also please clear up the SE2 issue with this. Is it correct that it presently has SIL=1 but (for regulatory reasons) only SDA=0 and thus will not be seen by certified panel-mout TAS/TCAS systems? And that an upgrate to SDA=1 is expected shorltly?
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By Smaragd
#1802612
Wasn't Cub clear enough in response to my questions?

"Some TAS systems in CAT/MIL airframes will reject ADS-B emissions with SIL/SDA = 0.

PAW, SE2, Power FLARM and most other standalone systems aimed at GA will detect ADS-B emissions regardless SIL/SDA value.

The original intention of CAP 1391 was that EC devices were not intended to be interoperable with airborne safety nets operating as interrogative collision alerting systems, such as ACAS. This includes hybrid surveillance or TAS (Traffic Advisory System). The thinking being that achieving that interoperability would significantly drive up the cost of such devices. However, time and the market has moved on and therefore the standard achieved by some manufacturers to deliver an SDA value and the consequent additional interoperability has been acknowledged and CAP 1391 is likely to be amended on the basis of the Australian safety argument.

Nothing needs to change in SE2 (other than a software switch to change the emitted SDA value) and we await the CAP 1391 amendment.

This change should be free to our customers providing the regulatory burden of transmitting SDA 1 remains as present."
gaznav liked this
By MikeW
#1802622
I think that is clear, but isn't the bigger question whether SIL and SDA = 1 is going to be of any advantage to the typical lighter end VFR flyer within the foreseeable future?
Does anyone believe it's soon going to give access to controlled airspace and make the transponder unnecessary?
A couple of posters suggest it may be useful if you're consorting with certain commercial or military traffic or military facilities, but how many people does that affect?
I suspect it's a red herring.
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By defcribed
#1802646
Smaragd wrote:Wasn't Cub clear enough in response to my questions?

"Some TAS systems in CAT/MIL airframes will reject ADS-B emissions with SIL/SDA = 0.


Not really. A bit of further research on the subject suggests that while the above statement is not untrue, the word 'some' should probably be replaced by 'pretty much all'.

Obviously I hope the process completes quickly and SIL/SDA=1 from SE2 becomes reality, but I have learned to take any "this should be the case quite soon" in aviation with a pinch of salt.
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By defcribed
#1802652
MikeW wrote:Does anyone believe it's soon going to give access to controlled airspace and make the transponder unnecessary?


We're not going to get any greater access to controlled airspace than we already have as electronic conspicuity develops.

Well, we might do, but it won't be because we've now got these gadgets. You can be cleared through Class D with nothing but a radio, and if you don't have a transponder then it's reasonably safe to say that Class A is irrelevant.

The limitations on our access to (most) controlled airspace arise primarily because it is space reserved first and foremost for certain private business interests, with access to the rest of us permitted only where commercial traffic volume and ATC workload permits.
#1802785
Smaragd wrote:Wasn't Cub clear enough in response to my questions?

".....

Nothing needs to change in SE2 (other than a software switch to change the emitted SDA value) and we await the CAP 1391 amendment.

This change should be free to our customers providing the regulatory burden of transmitting SDA 1 remains as present."


Given how fickle GA is about costs, and with SE2 having a higher ticket price than PAW for the initial purchase price, it would help SE2 gain sales/market share if they simply stated the software change mentioned above will be free rather than should be free.
By johnm
#1802791
I think the point of the question is "What does SIL =0 and SIL= 1 imply and similarly for SDA =0 and SDA = 1 (other numbers may also be available and carry meaning)
MikeW liked this
#1802959
Tim Dawson wrote:Can’t you do it now, by simply telling the device you’re in Australia?


Which bit of Australia do you propose is used for the GPS position offset?
The PAW users would get upset they cant see the SE2 users in the UK :wink: