ADS-B Mandate

[ArtVandelay]

So you are saying that if I slid in the KT 74, I would have the same capability as I now have. The KT 74, a new tray and some installation costs and I am ADS-B Out compliant.

Is the rest accurate; that is, I will have no "In", but would still have to use the Stratus and IPad.

Understand that a built in solution with external antenna will provide better service, with portable antenna you will have blind spots, ditto for built in unless you go with dual antennas, but most do without the roof mount antenna cause you don't care about transmissions from jets 20k above you.

[Bob - S50]

So you are saying that if I slid in the KT 74, I would have the same capability as I now have. The KT 74, a new tray and some installation costs and I am ADS-B Out compliant.

Is the rest accurate; that is, I will have no "In", but would still have to use the Stratus and IPad.

You have a couple other options too that are not that expensive:

 

Trig TT31 slides into the same slot as the KT76A.  It used to require a new tray but I think it has been modified to use the same tray even for ADS-B but you still have to have someone hook your 430W to it for a position source.  Probably about the same amount of time as the KT74.  By the way, Trig makes the KT74 for King.  Current cost of the TT31 is $2895 at Pacific Coast Avionics.

 

My current favorite choice (subject to change) is the Trig TT22.  It is also 1090ES capable.  It uses a remote box and a small control head that fits in a round hole as small as 2.25".  It has a built in altitude encoder so I can eliminate the current encoder.  Total weight of the box and control head is 0.8 pounds.  Current price is $2649.  Don't know about the install cost.  I would remove our KT76A, increase the size of our glove box, be ADS-B out compliant, and save weight.

 

With any of those choices; KT74, TT31, or TT22 you only get ADS-B out.

 

I have not found a 1090ES In-Out box yet.  There are 978 UAT In-Out boxes.

 

It is my understanding that unless the same box does both, you will not receive non-ADS-B radar traffic.  With a separate box (I have a GDL-39-3D) you will only see ADS-B compliant traffic.  However, by 2020, everyone who flies in the most congested airspace in the US will have to be compliant.  You will still not see non-compliant traffic who never venture into class B or C airspace and who never go above 10,000'.

 

Let us know what you decide.

 

Bob

[bd32322]

It is my understanding that unless the same box does both, you will not receive non-ADS-B radar traffic.  With a separate box (I have a GDL-39-3D) you will only see ADS-B compliant traffic.  However, by 2020, everyone who flies in the most congested airspace in the US will have to be compliant.  You will still not see non-compliant traffic who never venture into class B or C airspace and who never go above 10,000'.

 

Let us know what you decide.

 

Bob

I dont think thats accurate. You can receive ADSB compliant and non-compliant traffic on 978 UAT even though your adsb out is on 1090 from a separate box. The out activates the FAA system to broadcast traffic information out for both 1090 and 978 frequencies. The FAA specifically rebroadcasts on both frequencies.

The advantage of UAT is that outside of ground ADSB coverage, you can still receive air to air data on the 978 UAT. UAT also has spare uplink bandwidth and so can receive weather and traffic and peer to peer aircraft data.

In the OP's case, if not flying above 18k and out of canada, keep the existing xpndr and use UAT. Can switch the xpndr later for not too much money if 1090 is needed.

Btw, regarding adsb ground stations, I read recently that satellite based "ground" stations work just as well and actual adsb ground stations are not required. So that could be a solution for countries with large land area but small pilot populations.

[bd32322]

Also, I am not entirely sure whether this still holds true, but a gns 430w is not an approved position source for a kt74. Go figure. Stupid FAA. The correct answer ofcourse is to buy more garmin boxes

Read link below:

http://www.faa.gov/nextgen/ga/media/AEA-ADS-B%20Installation.pdf

[mike_elliott]

I think it was approved last summer

[Bob - S50]

Also, I am not entirely sure whether this still holds true, but a gns 430w is not an approved position source for a kt74. Go figure. Stupid FAA. The correct answer ofcourse is to buy more garmin boxes

Read link below:

http://www.faa.gov/nextgen/ga/media/AEA-ADS-B%20Installation.pdf

I know it is approved for at least one of the Trig's while the GTN series is not yet approved.

 

Bob

[Bob - S50]

I dont think thats accurate. You can receive ADSB compliant and non-compliant traffic on 978 UAT even though your adsb out is on 1090 from a separate box. The out activates the FAA system to broadcast traffic information out for both 1090 and 978 frequencies. The FAA specifically rebroadcasts on both frequencies.

The advantage of UAT is that outside of ground ADSB coverage, you can still receive air to air data on the 978 UAT. UAT also has spare uplink bandwidth and so can receive weather and traffic and peer to peer aircraft data.

In the OP's case, if not flying above 18k and out of canada, keep the existing xpndr and use UAT. Can switch the xpndr later for not too much money if 1090 is needed.

Btw, regarding adsb ground stations, I read recently that satellite based "ground" stations work just as well and actual adsb ground stations are not required. So that could be a solution for countries with large land area but small pilot populations.

Here's my reasoning.

 

I have the GDL39 and when I fly, I only see airliners, I do not see any other planes even though Seattle is calling them out as traffic.  My GDL is getting its info directly from the aircraft, not ATC.

 

ATC's transmitters are not directional.  That is, they don't point it at your plane.  They just broadcast and it goes in all directions.  Same for our planes.  We use an encoded transmission that ATC and other planes see.  Based on our transmission they know who we are.  If ADS-B out triggers sending TIS-B radar traffic, then ...any... ADS-B out plane would trigger the service.  Since the GDL39 receives both 978 and 1090 I should then see all traffic, but I don't.  That tells me the system must send out TIS-B traffic via an encoded message to ADS-B compliant traffic.  That message must be tagged for the specific squawk code of your plane.  If the ADS-B in device doesn't know what that squawk is, how can it receive it?

 

So my reasoning is that your in device must either be the same box as the out device or they must be connected so the in device knows what code the out device is using.

 

Usual government clear as mud.

 

Bob

[Cruiser]

from the GDL39 manual.......  "The FAA ground station will only broadcast TIS-B traffic that is within ±15 NM

and ±3500 feet of an aircraft with ADS-B Out. To get the full benefits of ADS-B

traffic it is recommended that the aircraft be equipped with an ADS-B transmitter

(such as a GTX 330 w/ES). "

 

from the Garmin Pilot manual....... "The Traffic information

includes the number and source (i.e., ADS-B air-to-air, or TIS-B of traffic the GDL 39

is currently tracking. "

 

"Configuring Traffic Alerts:

1) From any page touch Home > Devices.

2) Touch the GDL 39 Tab.

3) Use the slider to select Traffic Alerts On/Off"

 

"Only traffic that is within 15 nm lateral

and 3,500’ vertical of the ADS-B participating aircraft is provided in the

broadcast. Non-participating traffic aircraft located farther than 15 nm laterally and

3,500’ vertically from the participating aircraft is are excluded from the information

transmitted by the GBT."

 

for more information see the Garmin Pilot manual.

Bob, there is no encryption in the data, you are either out of the volume range of the aircraft transmitting ADS-B or your unit is not configured properly.

[bd32322]

 

from the GDL39 manual.......  "The FAA ground station will only broadcast TIS-B traffic that is within ±15 NM

and ±3500 feet of an aircraft with ADS-B Out. To get the full benefits of ADS-B

traffic it is recommended that the aircraft be equipped with an ADS-B transmitter

(such as a GTX 330 w/ES). "

 

from the Garmin Pilot manual....... "The Traffic information

includes the number and source (i.e., ADS-B air-to-air, or TIS-B of traffic the GDL 39

is currently tracking. "

 

"Configuring Traffic Alerts:

1) From any page touch Home > Devices.

2) Touch the GDL 39 Tab.

3) Use the slider to select Traffic Alerts On/Off"

 

"Only traffic that is within 15 nm lateral

and 3,500’ vertical of the ADS-B participating aircraft is provided in the

broadcast. Non-participating traffic aircraft located farther than 15 nm laterally and

3,500’ vertically from the participating aircraft is are excluded from the information

transmitted by the GBT."

 

for more information see the Garmin Pilot manual.

Bob, there is no encryption in the data, you are either out of the volume range of the aircraft transmitting ADS-B or your unit is not configured properly.

 

 

 

Cool - didnt know about the volume restriction for broadcast - i.e., 3500 feet, 15nm

 

So in summary Bob - S50 couldnt see all the traffic because he was outside that volume. So - just confirming that its still fine to ADSB-out on one device (1090 ES for example) and ADSB-in on another device (978 UAT for example) because the FAA will broadcast TIS-B on both 1090 and 978.

[rbridges]

Also, I am not entirely sure whether this still holds true, but a gns 430w is not an approved position source for a kt74. Go figure. Stupid FAA. The correct answer ofcourse is to buy more garmin boxes

Read link below:

http://www.faa.gov/nextgen/ga/media/AEA-ADS-B%20Installation.pdf

 

I believe the STC got approved a few months ago.  I'm installing the KT74 this Friday, so I hope it is.  

[larryb]

 "So - just confirming that its still fine to ADSB-out on one device (1090 ES for example) and ADSB-in on another device (978 UAT for example) because the FAA will broadcast TIS-B on both 1090 and 978."

 

Yes, sort of. When the ADSB-out device is installed it is configured to tell the GBT what frequency to use for "in" services. So your 1090 ES device can tell the GBT to transmit data for you on 978.

 

The system is designed to not waste bandwidth. The GBT will not transmit info that you could/should have received directly. So if there is an ADSB-out equipped aircraft in your service volume transmitting on 978, and you are receiving on 978, the GBT is not going to re-broadcast the data. But you are only listening on 1090 and the other guy is transmitting "out" on 978, then the system will re-broadcast that data to you on 1090. Not wasting bandwidth is a primary reason that all traffic is not repeated. If everybody were equipped with "in" listening on both bands, and everybody were equipped with either flavor of "out" then the GBT's would not need to re-transmit any location data because all aircraft would receive it directly from the sender.

[mike_elliott]

King, Aspen, and maybe more offer the free flight wireless box for meeting your ads b in needs if you want to go installed route, display on various certified devices As well as ipad. It shouldn't take long to change out the tray in your plane Don. I was quoted 3 hr install with new tray and antenna on the Bravo. Your stratus will also serve for an in source strictly for display using foreflight on the ipad, which for traffic and wx, is better than on some of the certified boxes IMHO

[Bob - S50]

 

from the GDL39 manual.......  "The FAA ground station will only broadcast TIS-B traffic that is within ±15 NM

and ±3500 feet of an aircraft with ADS-B Out. To get the full benefits of ADS-B

traffic it is recommended that the aircraft be equipped with an ADS-B transmitter

(such as a GTX 330 w/ES). "

 

from the Garmin Pilot manual....... "The Traffic information

includes the number and source (i.e., ADS-B air-to-air, or TIS-B of traffic the GDL 39

is currently tracking. "

 

"Configuring Traffic Alerts:

1) From any page touch Home > Devices.

2) Touch the GDL 39 Tab.

3) Use the slider to select Traffic Alerts On/Off"

 

"Only traffic that is within 15 nm lateral

and 3,500’ vertical of the ADS-B participating aircraft is provided in the

broadcast. Non-participating traffic aircraft located farther than 15 nm laterally and

3,500’ vertically from the participating aircraft is are excluded from the information

transmitted by the GBT."

 

for more information see the Garmin Pilot manual.

Bob, there is no encryption in the data, you are either out of the volume range of the aircraft transmitting ADS-B or your unit is not configured properly.

 

Cruiser,

 

Thanks.  Now I think I understand.  Since we do not have ADS-B out, it does not look to see who is within 15 nm of me.  Once we go ADS-B out, it will look at all traffic (participating or not) and if they are within the specified volume they will broadcast that information.  My GDL will receive it and put it on my tablet.

 

If I understand that correctly, I'm guessing I will also see traffic that is within the alert area for other participating traffic.  That is, if an ADS-B aircraft has traffic 5 miles away, the ground station will broadcast the traffic position and I will see it too.

 

Thanks!

 

Bob

[Marauder]

Cruiser,

Thanks. Now I think I understand. Since we do not have ADS-B out, it does not look to see who is within 15 nm of me. Once we go ADS-B out, it will look at all traffic (participating or not) and if they are within the specified volume they will broadcast that information. My GDL will receive it and put it on my tablet.

If I understand that correctly, I'm guessing I will also see traffic that is within the alert area for other participating traffic. That is, if an ADS-B aircraft has traffic 5 miles away, the ground station will broadcast the traffic position and I will see it too.

Thanks!

Bob

Bob -- you may see on your GDL-39 the periodic TIS-B coverage when someone is broadcasting an "out" nearby and you are in the hockey puck coverage area.

This guy was broadcasting an out on the 978 and he enabled me to see TIS-B.