Canada ADS-B Diversity Requirement

[Charles]

The benefits may be limited for GA, but you have to recognize that the ability to provide radar-like coverage worldwide, including in oceanic areas, is of great value.

[TimS]

The benefits may be limited for GA, but you have to recognize that the ability to provide radar-like coverage worldwide, including in oceanic areas, is of great value.

This only works if all countries decide to participate.
I am going on information posted by others, and a few articles I have read. So, please double check anything I state here:

1. I believe Aireon still only has a single customer, Transport-Canada.
2. The expected life of the satellites deployed by Aireon is 15 years before they run out of positioning fuel to maintain station. They are now 5 years into the life of the satellites; and no replacement plan has been published (including funding sources).
3. Aireon supposedly conducted a study on bottom mounted antennas which was paid for by Transport Canada, to see if bottom mount antennas meet performance requirements. However the company has yet to publish actual data in reference to the study; and the actual study result seems to have buried. I recall one article the author stated Aireon refused to provide the report (no idea who the author talked too).

The new requirements pretty much mean I will not be doing the Canada border trip we started planning back in 2019 to do in 2021. We wanted to fly along the border from Maine all the way to Washington with stops all over Canada before going to Alaska. We stopped the planning due to COVID, and now both my wife and I are involved in multi-year projects which preclude us doing such a trip for at least five years; by which time this requirement will kill it.

Tim

[Rich]

There's another service the US provides. Note there is no requirement for repetitive recertification of your system, as there is for Mode C/altitude encoding. But the ADS-B performance readout is available anytime. You can request a report on any recent flight to see how your system is performing.

I inquired of Aireon if I could get such a report from them. Supposedly this system is operational right now and I was curious what it would report on my flights. I was informed in no uncertain terms there was no plan to provide such a thing.

I have my suspicions that the system isn't necessarily as robust as advertised and there may be little improvement gained by having that second antenna. Our transponder output power wasn't designed to communicate over distances of 500-800 miles. In the US, other than terrain obstructions, you're going to be hitting one or more ADS-B ground stations within 20 nm and direct airborne targets more than that are of no interest.

[Rich]

FWIW, I just noticed in the current SATNAV news that Canada does not actually require diversity. To quote the publication:

The ADS-B Out avionics performance standards required is RTCA DO-260B or newer. This requirement can be met either through antenna diversity (the use of a top and bottom antenna) or with a single antenna that is capable of transmitting both towards the ground and up towards satellites.

So for non-metallic airframes it would seem feasible to use an existing ADS-B transponder with an internally mounted antenna with the appropriate radiation pattern.

I would note as perhaps relevant the fact that my ELT antenna is internal to the fuselage and communicates just fine with satellites, even from inside a steel maintenance hangar. Kindly Air Force personnel have told me so .

[Charles]

FWIW, I just noticed in the current SATNAV news that Canada does not actually require diversity. To quote the publication:

The ADS-B Out avionics performance standards required is RTCA DO-260B or newer. This requirement can be met either through antenna diversity (the use of a top and bottom antenna) or with a single antenna that is capable of transmitting both towards the ground and up towards satellites.

So for non-metallic airframes it would seem feasible to use an existing ADS-B transponder with an internally mounted antenna with the appropriate radiation pattern.

I would note as perhaps relevant the fact that my ELT antenna is internal to the fuselage and communicates just fine with satellites, even from inside a steel maintenance hangar. Kindly Air Force personnel have told me so .

Do you know of any such antenna that would work with a GTX345?

[Rich]

FWIW, I just noticed in the current SATNAV news that Canada does not actually require diversity. To quote the publication:

The ADS-B Out avionics performance standards required is RTCA DO-260B or newer. This requirement can be met either through antenna diversity (the use of a top and bottom antenna) or with a single antenna that is capable of transmitting both towards the ground and up towards satellites.

So for non-metallic airframes it would seem feasible to use an existing ADS-B transponder with an internally mounted antenna with the appropriate radiation pattern.

I would note as perhaps relevant the fact that my ELT antenna is internal to the fuselage and communicates just fine with satellites, even from inside a steel maintenance hangar. Kindly Air Force personnel have told me so .

Do you know of any such antenna that would work with a GTX345?

I know of no current antenna that would work. But hopefully someone (uAvionics?) might step up.

[Diamond_Dan]

I wonder what Diamond's solution will be. They took orders for airplanes that will have limited usefulness by delivery time and will be grounded within 3 years. They must be hastily working on it.

[Ed McDonald]

For those of us that want to go above 12,500 ft, i.e. The Rockies, next February is the cut-off date.

13 industry groups sent a strongly worded letter to NAV CANADA’s lapdog, Transport Canada, last month protesting the ADS-B implementation. No word on what effect it is having.

[Rich]

I wonder what Diamond's solution will be. They took orders for airplanes that will have limited usefulness by delivery time and will be grounded within 3 years. They must be hastily working on it.

For new aircraft this wouldn't be a big deal. The 335 and 345 (R or not) can both be ordered with diversity, as long as you provide GPS position from an external source. So probably just the additional antenna.

I must admit I'm having trouble figuring out the diagram for applicable Canadian airspace. It doesn't really jibe with the US required airspace.

[Diamond_Dan]

I was wondering if there are any new thoughts or updates on this topic now that diversity is a requirement for Canadian Class A airspace (as of 10-August). I have a bucket list item to fly to Alaska through the Yukon Territory, but I don't see that as possible with my current equipment (Legacy G1000) before Class B is added to the mix 14-May-2024 which will make it all but impossible.