Transponder installation article- Soaring Magazine

2G wrote on 12/28/2020 9:43 PM:
On Monday, December 28, 2020 at 6:29:38 AM UTC-8, Eric Greenwell wrote:
2G wrote on 12/27/2020 9:10 PM:
On Sunday, December 27, 2020 at 8:27:59 PM UTC-8, Eric Greenwell wrote:
2G wrote on 12/27/2020 7:49 PM:
On Sunday, December 27, 2020 at 5:57:32 AM UTC-8, Eric Greenwell wrote:


Not only can't you fly IN those airspaces, you can't fly OVER them either, which may be the
bigger limitation. Going back to Minden from the north the shortest distance may be over the
Reno class C airspace, which only goes up to 8,400 ft. But you will need to be in compliance
with class C airspace to even over-fly this airspace. The non-compliant aircraft will either
have to get a waiver from ATC or fly 20 nm either east or west to avoid it altogether. Never
mind that this might put you into conflict with air traffic flying in and out of Reno.

Tom



But aren't gliders exempt from the ADS-B rules? Or is a non-equipped glider not allowed to fly
over the top of the airspace?

I'm equipped, BTW.
My understanding is gliders can fly over Class C airspace above 10,000' without a transponder,
so you could fly over Reno on the way home to Minden - just don't sink below 10,000'. Of
course, I think it's too risky to fly without transponder in the Minden/Reno area (mode C on my
glider), and if I had a TT21, I put in a TN72 with a TA50 antenna. The next glider will have a
TT22/TN72 combo.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

The governing regulation is 91.225:
https://www.law.cornell.edu/cfr/text/14/91.225
You can overfly class B and C airspace if you are at 10,500 and above (not 10,000) - below that you will need a transponder equipped with ADS-B out. This is further explained in:
http://ourdigitalmags.com/publicatio...er&v er=html5

This is the relevant part of 91.225:

(d) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft in the following airspace unless the aircraft has equipment installed that meets the requirements in paragraph (b) of this section:

(1) Class B and Class C airspace areas;

(2) Except as provided for in paragraph (e) of this section, within 30 nautical miles of an airport listed in appendix D, section 1 to this part from the surface upward to 10,000 feet MSL;

(3) Above the ceiling and within the lateral boundaries of a Class B or Class C airspace area designated for an airport upward to 10,000 feet MSL;

(4) Except as provided in paragraph (e) of this section, Class E airspace within the 48 contiguous states and the District of Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface; and

(5) Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles.

(e) The requirements of paragraph (b) of this section do not apply to any aircraft that was not originally certificated with an electrical system, or that has not subsequently been certified with such a system installed, including balloons and gliders. These aircraft may conduct operations without ADS-B Out in the airspace specified in paragraphs (d)(2) and (d)(4) of this section. Operations authorized by this section must be conducted -

(1) Outside any Class B or Class C airspace area; and

(2) Below the altitude of the ceiling of a Class B or Class C airspace area designated for an airport, or 10,000 feet MSL, whichever is lower.

Tom

The only reference to 10,500' I see is this:

"A glider may fly over Reno at 10,500 ft MSL without a transponder, but you must have a
transponder if you go below 10,000 ft MSL over this airspace or if you go into the Reno Class C
airspace itself."

It sure looks like the "must have a transponder" requirement begins below 10,000', not 10,500,
which is consistent with the regulations listed. 10,500' might be a sensible personal choice to
avoid inadvertently going below 10,000', but I don't think it's a requirement.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)

The regs say "an airport upward to 10,000 feet MSL." The FAA interprets this in increments of 500 ft.

But that's not a TT21 vs TT22 issue, or even a transponder issue, right? Which is what we are
discussing. And what is the reg that says you have to stay 500' from the airspace top - I don't
recall that requirement.
--


It's called vertical separation. ATC assumes they know the position of all aircraft in their airspace. If you are at 10,001 ft there is no separation with an aircraft at 10,000. It is covered in the article I cited.

Tom
My main point is you do not need a TT22 to overfly Class C in Reno, or Class C anywhere. Do you
agree the requirement is a glider needs a transponder below 10,000' to overfly Class C, but
does not need one when doing it above 10,000'?
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

No, that is not true per my previous comments. You must be at 10,500 or higher.


And is a transponder of any type required for a glider at 10,500?


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Tuesday, December 29, 2020 at 5:42:12 AM UTC-8, Eric Greenwell wrote:
2G wrote on 12/28/2020 9:43 PM:
On Monday, December 28, 2020 at 6:29:38 AM UTC-8, Eric Greenwell wrote:
2G wrote on 12/27/2020 9:10 PM:
On Sunday, December 27, 2020 at 8:27:59 PM UTC-8, Eric Greenwell wrote:
2G wrote on 12/27/2020 7:49 PM:
On Sunday, December 27, 2020 at 5:57:32 AM UTC-8, Eric Greenwell wrote:


Not only can't you fly IN those airspaces, you can't fly OVER them either, which may be the
bigger limitation. Going back to Minden from the north the shortest distance may be over the
Reno class C airspace, which only goes up to 8,400 ft. But you will need to be in compliance
with class C airspace to even over-fly this airspace. The non-compliant aircraft will either
have to get a waiver from ATC or fly 20 nm either east or west to avoid it altogether. Never
mind that this might put you into conflict with air traffic flying in and out of Reno.

Tom



But aren't gliders exempt from the ADS-B rules? Or is a non-equipped glider not allowed to fly
over the top of the airspace?

I'm equipped, BTW.
My understanding is gliders can fly over Class C airspace above 10,000' without a transponder,
so you could fly over Reno on the way home to Minden - just don't sink below 10,000'. Of
course, I think it's too risky to fly without transponder in the Minden/Reno area (mode C on my
glider), and if I had a TT21, I put in a TN72 with a TA50 antenna. The next glider will have a
TT22/TN72 combo.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

The governing regulation is 91.225:
https://www.law.cornell.edu/cfr/text/14/91.225
You can overfly class B and C airspace if you are at 10,500 and above (not 10,000) - below that you will need a transponder equipped with ADS-B out. This is further explained in:
http://ourdigitalmags.com/publicatio...er&v er=html5

This is the relevant part of 91.225:

(d) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft in the following airspace unless the aircraft has equipment installed that meets the requirements in paragraph (b) of this section:

(1) Class B and Class C airspace areas;

(2) Except as provided for in paragraph (e) of this section, within 30 nautical miles of an airport listed in appendix D, section 1 to this part from the surface upward to 10,000 feet MSL;

(3) Above the ceiling and within the lateral boundaries of a Class B or Class C airspace area designated for an airport upward to 10,000 feet MSL;

(4) Except as provided in paragraph (e) of this section, Class E airspace within the 48 contiguous states and the District of Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface; and

(5) Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles.

(e) The requirements of paragraph (b) of this section do not apply to any aircraft that was not originally certificated with an electrical system, or that has not subsequently been certified with such a system installed, including balloons and gliders. These aircraft may conduct operations without ADS-B Out in the airspace specified in paragraphs (d)(2) and (d)(4) of this section. Operations authorized by this section must be conducted -

(1) Outside any Class B or Class C airspace area; and

(2) Below the altitude of the ceiling of a Class B or Class C airspace area designated for an airport, or 10,000 feet MSL, whichever is lower.

Tom

The only reference to 10,500' I see is this:

"A glider may fly over Reno at 10,500 ft MSL without a transponder, but you must have a
transponder if you go below 10,000 ft MSL over this airspace or if you go into the Reno Class C
airspace itself."

It sure looks like the "must have a transponder" requirement begins below 10,000', not 10,500,
which is consistent with the regulations listed. 10,500' might be a sensible personal choice to
avoid inadvertently going below 10,000', but I don't think it's a requirement.
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)

The regs say "an airport upward to 10,000 feet MSL." The FAA interprets this in increments of 500 ft.

But that's not a TT21 vs TT22 issue, or even a transponder issue, right? Which is what we are
discussing. And what is the reg that says you have to stay 500' from the airspace top - I don't
recall that requirement.
--


It's called vertical separation. ATC assumes they know the position of all aircraft in their airspace. If you are at 10,001 ft there is no separation with an aircraft at 10,000. It is covered in the article I cited.

Tom
My main point is you do not need a TT22 to overfly Class C in Reno, or Class C anywhere. Do you
agree the requirement is a glider needs a transponder below 10,000' to overfly Class C, but
does not need one when doing it above 10,000'?
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

No, that is not true per my previous comments. You must be at 10,500 or higher.

And is a transponder of any type required for a glider at 10,500?
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

I have posted a link to the governing FAR - try reading it.

Tom