ADSB visibility with non certified GPS

On Friday, September 22, 2017 at 9:11:34 AM UTC-7, Dan Marotta wrote:
This is very confusing.Â* So a TN72 is not a TSO device, but is compliant
and therefore can be mounted in an experimental aircraft which will be
seen by all compliant ADS-B In systems?Â* I feel cheated by having a
certificated aircraft!

On 9/21/2017 8:31 PM, Darryl Ramm wrote:
Walt, I think you are misunderstanding what Trig wrote. A TN72 GPS Source will be seen by everybody. That is why anybody doing ADS-B Out in an experimental glider with a TT22 should be equipping with at least a TN72 (or TN70, TN70 required for certified gliders).

--
Dan, 5J

You, and everybody else will continue to be confused if you keep talking about "TSO" and not specifying what TSO you are talking about. This caused lot of unneeded confusion and many posts on r.a.s. when the TN72 was announced. I don't know how many times I;ve already pointed this out.

The TN72 is a TSO-C199 Class B (aka TABS GPS source) device. Which from a regulation point of view makes no difference, since there are no installation or usage regulations that cover TSO-C199 devices. But since it is TSO-C199 we know important things about it's GPS quality, SIL parsameters, etc. and how it will interact with IFR GPS receivers and ground infrastructure.

The TN72 is Not TSO-C145 (requited for ADS-B Out in certified aircraft)

The TN72 does not meet TSO-C145 requirements (so can't be used for ADS-B Out in experimental aircraft where you want to us it to meet 2020 carriage requirements, in the case of gliders can't be used to meet requirements in the few areas where exemptions don't cover).

---

But yes I agree on the "feeling cheated" part in general, it points out the regulations are kinda stupid, especially when applied to gliders.

Darryl,

You said "The TN72 does not meet TSO-C145 requirements (so can't be used for ADS-B Out in experimental aircraft where you want to use it to meet 2020 carriage requirements, in the case of gliders can't be used to meet requirements in the few areas where exemptions don't cover)."

For those of us who cannot keep up, would you kindly list the requirements where the exemptions don't cover?

Many thanks!
-John

Thanks for your patience.

On 9/22/2017 12:38 PM, Darryl Ramm wrote:
On Friday, September 22, 2017 at 9:11:34 AM UTC-7, Dan Marotta wrote:
This is very confusing.Â* So a TN72 is not a TSO device, but is compliant
and therefore can be mounted in an experimental aircraft which will be
seen by all compliant ADS-B In systems?Â* I feel cheated by having a
certificated aircraft!

On 9/21/2017 8:31 PM, Darryl Ramm wrote:
Walt, I think you are misunderstanding what Trig wrote. A TN72 GPS Source will be seen by everybody. That is why anybody doing ADS-B Out in an experimental glider with a TT22 should be equipping with at least a TN72 (or TN70, TN70 required for certified gliders).
--
Dan, 5J
You, and everybody else will continue to be confused if you keep talking about "TSO" and not specifying what TSO you are talking about. This caused lot of unneeded confusion and many posts on r.a.s. when the TN72 was announced. I don't know how many times I;ve already pointed this out.

The TN72 is a TSO-C199 Class B (aka TABS GPS source) device. Which from a regulation point of view makes no difference, since there are no installation or usage regulations that cover TSO-C199 devices. But since it is TSO-C199 we know important things about it's GPS quality, SIL parsameters, etc. and how it will interact with IFR GPS receivers and ground infrastructure.

The TN72 is Not TSO-C145 (requited for ADS-B Out in certified aircraft)

The TN72 does not meet TSO-C145 requirements (so can't be used for ADS-B Out in experimental aircraft where you want to us it to meet 2020 carriage requirements, in the case of gliders can't be used to meet requirements in the few areas where exemptions don't cover).

---

But yes I agree on the "feeling cheated" part in general, it points out the regulations are kinda stupid, especially when applied to gliders.

--
Dan, 5J

On Thursday, September 21, 2017 at 7:31:32 PM UTC-7, Darryl Ramm wrote:
Walt, I think you are misunderstanding what Trig wrote. A TN72 GPS Source will be seen by everybody. That is why anybody doing ADS-B Out in an experimental glider with a TT22 should be equipping with at least a TN72 (or TN70, TN70 required for certified gliders).

Darryl,

OK, I'm clear now that a TN72 GPS Source from a Trig T22 will make me officially visible to all ADS-B in equipped aircraft.

I am still trying to figure out why I would want to equip with any kind of ADS-B out in my T22 equipped glider:

1) It would be great (but not necessary) to be seen by all ADS-B equipped aircraft. But, with ADS-R (rebroadcast) won't those other aircraft see me anyway since I'm equipped with a Mode-S Trig transponder? I suppose at low altitude where ADS-R is not available, direct receipt of my ADS-B out would be an advantage.

2) It sounds like with the TN72 GPS source, I will not be compliant if wanting to enter Class B, C, and a few other little used airspace. My question is this... If equipped with a TN72 GPS source, do you think that ATC will allow temporary access to Class B and C... such a for passing through their airspace? That was ONE reason for equipping with a transponder in the past.. I have no intention of OPERATING in Class B and C so as to use full ATC services. Also, do you think that controllers for restricted airspace MIGHT allow transiting that airspace without fully compliant ADS-B out?

If ATC uniformly will disallow temporary transiting of Class B, C and restricted airspace unless equipping with a fully compliant GPS source (i.e. TN70), then there is VERY LITTLE REASON TO EQUIP WITH A TN72.

I see small potential justification for equipping with a TN72:

A) visibility to all ADS-B official aircraft directly without rebroadcast (ADS-R) which means they can see me in the pattern a low altitude.

B) Potenially, a TN72 will also give me an alternative to a Satellite tracker if Flight Aware or Aerion makes tracking of ADS-B aircraft less expensive than the current vendors (Spot and Garmin Inreach).

comments...

Walt Rogers WX

On Sunday, September 24, 2017 at 11:59:19 AM UTC-7, WaltWX wrote:
On Thursday, September 21, 2017 at 7:31:32 PM UTC-7, Darryl Ramm wrote:
Walt, I think you are misunderstanding what Trig wrote. A TN72 GPS Source will be seen by everybody. That is why anybody doing ADS-B Out in an experimental glider with a TT22 should be equipping with at least a TN72 (or TN70, TN70 required for certified gliders).

Darryl,


Everybody need to stop saying "ADS-B Out" and say 109ES Out or UAT Out where it matters. I try to only say ADS-B where the link layer does not matter. Saying "ADS-B" where you need to be clear about 1090ES or UAT is as useful as saying "TSO" without being clear if we are talking about TSO-C145 or TSO-C199, and can cause much confusion.

OK, I'm clear now that a TN72 GPS Source from a Trig T22 will make me officially visible to all ADS-B in equipped aircraft.

Well all aircraft with 1090ES In, or via ADS-R if they have UAT In (and it's properly set up with some type of ADS-B Out etc.) and in range of ADS-B ground stations.

I am still trying to figure out why I would want to equip with any kind of ADS-B out in my T22 equipped glider:

1) It would be great (but not necessary) to be seen by all ADS-B equipped aircraft. But, with ADS-R (rebroadcast) won't those other aircraft see me anyway since I'm equipped with a Mode-S Trig transponder? I suppose at low altitude where ADS-R is not available, direct receipt of my ADS-B out would be an advantage.

ADS-R no, you are confusing ADS-R and TIS-B.

TIS-B broadcasts information for SSR targets, it requires
1. Your aircraft has a transponder
2. Your aircraft is within SSR coverage
3. The TIS-B client aircraft has ADS-B In
4. The TIS-B client aircraft has ADS-B Out that is correctly configured to describe it's ADS-B In capabilities.

TIS-B position reports are SSR based and should be expected to be less accurate than either ADS-B direct or ADS-R.

There are many places where gliders and gliders, or towplanes or GA aircraft that might have 1090ES In will be together that won't have TIS-B service coverage. Think of lots of GA airports that glider operations may tow out of or gliders may land at. And many busy airports I can think of where you lose SSR coverage as you decent to pattern height, they concern me as pilots may stop seeing TIS-B targets and be lulled into assurance the target is not longer a threat. Ditto for aircraft without properly configured ADS-B Out that are piggybacking on nearby aircraft to cause TIS-B (and ADS-R) message broadcasts, things going quiet on the traffic displays does no mean there is no traffic.

2) It sounds like with the TN72 GPS source, I will not be compliant if wanting to enter Class B, C, and a few other little used airspace. My question is this... If equipped with a TN72 GPS source, do you think that ATC will allow temporary access to Class B and C... such a for passing through their airspace? That was ONE reason for equipping with a transponder in the past. I have no intention of OPERATING in Class B and C so as to use full ATC services. Also, do you think that controllers for restricted airspace MIGHT allow transiting that airspace without fully compliant ADS-B out?

Don't know, talk to your local ATC folks.

If ATC uniformly will disallow temporary transiting of Class B, C and restricted airspace unless equipping with a fully compliant GPS source (i.e. TN70), then there is VERY LITTLE REASON TO EQUIP WITH A TN72.

Again I talk to your local ATC folks. I would not want to ask any national authorities about uniform ATC treatment if any special situation. Work out things locally and use that to guide what you do.

I see small potential justification for equipping with a TN72:

A) visibility to all ADS-B official aircraft directly without rebroadcast (ADS-R) which means they can see me in the pattern a low altitude.

But you still won't be seen by aircraft in those situations. that only have UAT In. You *need* ADS-R ground service coverage for that.

B) Potenially, a TN72 will also give me an alternative to a Satellite tracker if Flight Aware or Aerion makes tracking of ADS-B aircraft less expensive than the current vendors (Spot and Garmin Inreach).

The current Garmin InReach tracker is relatively low cost and already more capable (esp. two way messaging and reliable operation on the ground (as long as you have line of sight of satellites) than what ADS-B will be able to do. Having ADS-B Out is further information, that might be be very useful in a SAR situation. I would certainly include that in discussions with club members, FBOs, written down as part of your emergency information/plan that you have (everybody has one right?) make sure it is noted on your NOAA ELT/PLB registration, SPOT or InReach tracker registration, etc. But I'd not be upgrading to 1090ES Out for SAR reasons--I'd buy a Garmin InReach first if I did not already have one.

And the FAA/SAR organizations today can get to ADS-B flight traces, so if an ADS-B out equipped glider should go missing it's important to make sure SAR groups are aware that it was so equipped.

comments...

Walt Rogers WX

You may also want to have 109ES Out to provide better long-term visibility via PowerFLARM when buddy flying.

Many aircraft are going to equip with ADS-B Out by 2020. I'm anecdotally seeing a lot of GA aircraft equip with ADS-B In, with most new potable and fixed systems being dual-link receive. Given all that if you fly near busy GA aircraft areas I expect equipping with ADS-B Out to be interesting to consider, fast jets and airliners can see you today via TCAS, in all airspace at all times. 1090ES Out starts also providing that "all airspace and all time" capability to GA aircraft as they equip with (1090ES or dual-link) ADS-B In.

Oops left off thing...

TIS-B broadcasts information for SSR targets, it requires
1. Your aircraft has a transponder
2. Your aircraft is within SSR coverage
3. The TIS-B client aircraft has ADS-B In
4. The TIS-B client aircraft has ADS-B Out that is correctly configured to describe it's ADS-B In capabilities.
5. The TIS-B client aircraft is within ADS-B ground service coverage.


On Sunday, September 24, 2017 at 3:32:38 PM UTC-7, Darryl Ramm wrote:
On Sunday, September 24, 2017 at 11:59:19 AM UTC-7, WaltWX wrote:
On Thursday, September 21, 2017 at 7:31:32 PM UTC-7, Darryl Ramm wrote:
Walt, I think you are misunderstanding what Trig wrote. A TN72 GPS Source will be seen by everybody. That is why anybody doing ADS-B Out in an experimental glider with a TT22 should be equipping with at least a TN72 (or TN70, TN70 required for certified gliders).

Darryl,


Everybody need to stop saying "ADS-B Out" and say 109ES Out or UAT Out where it matters. I try to only say ADS-B where the link layer does not matter. Saying "ADS-B" where you need to be clear about 1090ES or UAT is as useful as saying "TSO" without being clear if we are talking about TSO-C145 or TSO-C199, and can cause much confusion.

OK, I'm clear now that a TN72 GPS Source from a Trig T22 will make me officially visible to all ADS-B in equipped aircraft.

Well all aircraft with 1090ES In, or via ADS-R if they have UAT In (and it's properly set up with some type of ADS-B Out etc.) and in range of ADS-B ground stations.

I am still trying to figure out why I would want to equip with any kind of ADS-B out in my T22 equipped glider:

1) It would be great (but not necessary) to be seen by all ADS-B equipped aircraft. But, with ADS-R (rebroadcast) won't those other aircraft see me anyway since I'm equipped with a Mode-S Trig transponder? I suppose at low altitude where ADS-R is not available, direct receipt of my ADS-B out would be an advantage.

ADS-R no, you are confusing ADS-R and TIS-B.

TIS-B broadcasts information for SSR targets, it requires
1. Your aircraft has a transponder
2. Your aircraft is within SSR coverage
3. The TIS-B client aircraft has ADS-B In
4. The TIS-B client aircraft has ADS-B Out that is correctly configured to describe it's ADS-B In capabilities.

TIS-B position reports are SSR based and should be expected to be less accurate than either ADS-B direct or ADS-R.

There are many places where gliders and gliders, or towplanes or GA aircraft that might have 1090ES In will be together that won't have TIS-B service coverage. Think of lots of GA airports that glider operations may tow out of or gliders may land at. And many busy airports I can think of where you lose SSR coverage as you decent to pattern height, they concern me as pilots may stop seeing TIS-B targets and be lulled into assurance the target is not longer a threat. Ditto for aircraft without properly configured ADS-B Out that are piggybacking on nearby aircraft to cause TIS-B (and ADS-R) message broadcasts, things going quiet on the traffic displays does no mean there is no traffic.

2) It sounds like with the TN72 GPS source, I will not be compliant if wanting to enter Class B, C, and a few other little used airspace. My question is this... If equipped with a TN72 GPS source, do you think that ATC will allow temporary access to Class B and C... such a for passing through their airspace? That was ONE reason for equipping with a transponder in the past. I have no intention of OPERATING in Class B and C so as to use full ATC services. Also, do you think that controllers for restricted airspace MIGHT allow transiting that airspace without fully compliant ADS-B out?

Don't know, talk to your local ATC folks.

If ATC uniformly will disallow temporary transiting of Class B, C and restricted airspace unless equipping with a fully compliant GPS source (i.e. TN70), then there is VERY LITTLE REASON TO EQUIP WITH A TN72.

Again I talk to your local ATC folks. I would not want to ask any national authorities about uniform ATC treatment if any special situation. Work out things locally and use that to guide what you do.

I see small potential justification for equipping with a TN72:

A) visibility to all ADS-B official aircraft directly without rebroadcast (ADS-R) which means they can see me in the pattern a low altitude.

But you still won't be seen by aircraft in those situations. that only have UAT In. You *need* ADS-R ground service coverage for that.

B) Potenially, a TN72 will also give me an alternative to a Satellite tracker if Flight Aware or Aerion makes tracking of ADS-B aircraft less expensive than the current vendors (Spot and Garmin Inreach).

The current Garmin InReach tracker is relatively low cost and already more capable (esp. two way messaging and reliable operation on the ground (as long as you have line of sight of satellites) than what ADS-B will be able to do. Having ADS-B Out is further information, that might be be very useful in a SAR situation. I would certainly include that in discussions with club members, FBOs, written down as part of your emergency information/plan that you have (everybody has one right?) make sure it is noted on your NOAA ELT/PLB registration, SPOT or InReach tracker registration, etc. But I'd not be upgrading to 1090ES Out for SAR reasons--I'd buy a Garmin InReach first if I did not already have one.

And the FAA/SAR organizations today can get to ADS-B flight traces, so if an ADS-B out equipped glider should go missing it's important to make sure SAR groups are aware that it was so equipped.

comments...

Walt Rogers WX

You may also want to have 109ES Out to provide better long-term visibility via PowerFLARM when buddy flying.

Many aircraft are going to equip with ADS-B Out by 2020. I'm anecdotally seeing a lot of GA aircraft equip with ADS-B In, with most new potable and fixed systems being dual-link receive. Given all that if you fly near busy GA aircraft areas I expect equipping with ADS-B Out to be interesting to consider, fast jets and airliners can see you today via TCAS, in all airspace at all times. 1090ES Out starts also providing that "all airspace and all time" capability to GA aircraft as they equip with (1090ES or dual-link) ADS-B In.

Dan- You pretty much HAD to buy the TT22, as the 250 watt transmit is required for altitudes over 10,000 MSL. And out here in Moriarty, we are tempted to put the landing gear down if we get below that!

On 09/23/2017 09:27 AM, wrote:
Dan- You pretty much HAD to buy the TT22, as the 250 watt transmit is required for altitudes over 10,000 MSL. And out here in Moriarty, we are tempted to put the landing gear down if we get below that!


Trig says the TT21 is good to 15,000 msl, but yeah, the cost and average
current consumption of the TT22 are only slightly higher for the TT22.
I wouldn't consider a TT21 for a new installation, even forgetting about
the ADS-B issue.

My mistake- the 175 watt units are good to 15,000 MSL, 200+ watts necessary above that. So, Moriarty and most high altitude western US sites with potential flight altitudes to 17,999 MSL (and higher in ARTCC authorized airspace such as wave windows or SAGE II clearance in the Sierra Nevada Wave etc.) would imply utilization of the higher transmit power of the TT22 over the TT21.

On Saturday, September 23, 2017 at 6:20:38 PM UTC-7, wrote:
My mistake- the 175 watt units are good to 15,000 MSL, 200+ watts necessary above that. So, Moriarty and most high altitude western US sites with potential flight altitudes to 17,999 MSL (and higher in ARTCC authorized airspace such as wave windows or SAGE II clearance in the Sierra Nevada Wave etc.) would imply utilization of the higher transmit power of the TT22 over the TT21.

Yes but nobody really cares about this, and lots of lower power transponders have been flying in gliders for years and provide good visibility to ATC and TCAS etc.

The pressing reason to use a TT22 over a TT21 is for ADS-B Out compliance, especially in a certified glider the TT21 cannot be installed or used for ADS-B Out for any purpose.You will not get installation approval for it, and I don't want folks having tears when they discover that.

The important things are focusing in safety and installing and using a transponder at all if you are near busy airspace. Please install and use whatever transponder you have/can get/afford. For ADS-B future use reasons it is a good idea to install a TT-22.