On Sunday, June 3, 2018 at 3:55:32 PM UTC-7, jfitch wrote:
On Sunday, June 3, 2018 at 11:15:00 AM UTC-7, 2G wrote:
On Sunday, June 3, 2018 at 1:10:46 AM UTC-7, Darryl Ramm wrote:
On Saturday, June 2, 2018 at 10:38:50 PM UTC-7, 2G wrote:
On Friday, June 1, 2018 at 10:31:39 PM UTC-7, Darryl Ramm wrote:
On Friday, June 1, 2018 at 6:01:43 PM UTC-7, Charles Longley wrote:
One of our Pawnees has an ADSB out transponder now. (Evergreen Soaring) We’ve had glider pilots we’re towing that have FLARM ask us to turn off our transponder. We’ve told the glider pilots to turn their FLARM down or off. My recommendation is to either have a switch for your FLARM or know you can turn the volume down to a suitable level..

The question I have is does FLARM show up on ADSB in?

As discussed here before the solution to spurious PowerFLARM alerts in the glider to the towplane ADS-B Out may be to put a PowerFLARM in the towplane so the PowerFLARM in the glider knows it's a towplane and more tolerant of it being close to the glider. There is unfortunately no way for an ADS-B out signal to contain any information to tell PowerFLARM it's a towplane. The FLARM signal does carry that information. it would be great if somebody could experiment with a PowerFLARM portable in the towplane to see if it indeed does solve the issue.

Be careful turning those transponders off, they provide visibility to other aircraft with ADS-B In, TCAS, ATC, all gliders with PowerFLARM with 1090ES In option etc. And if in controlled airspace its a violation of 14 CFR 91.215... and since the towplane is transmitting ADS-B data for all to see and the signal starts going of in flight that may well get noticed. The likely better option if necessary here is for the glider to turn off or turn down the volume on their PowerFLARM while on tow.

If you have a transponder installed, you are required to operate it at all times unless otherwise directed by ATC (i.e. Oshkosh).

Tom

That's not quite accurate, you are required to operate an installed transponder at all times in *controlled airspace*. 14 CFR § 91.215 (c). So they can be turned off in Class G airspace. Maybe a good aviation quiz night question, or BFR question. But to the point, yes turning them off is a bad idea.

Wrong: 91.215 states where you MUST operate your transponder - it says nothing about allowing a pilot to turn it off. The matter is addressed in section 4−1−20 of the AIM (https://www.faa.gov/air_traffic/publ..._10-12-17.pdf), "Transponder Operation:"

4. Transponder and ADS-B Operations in
the Air. EACH PILOT OPERATING AN AIRCRAFT EQUIPPED WITH AN OPERABLE ATC TRANSPONDER, MAINTAINED IN ACCORDANCE WITH 14 CFR SECTION 91.413 OR ADS-B TRANSMITTER, MUST OPERATE THE TRANSPONDER/TRANSMITTER, INCLUDING MODE C/S IF INSTALLED, ON THE APPROPRIATE MODE 3/A CODE OR AS ASSIGNED BY ATC. EACH PERSON OPERATING AN AIRCRAFT EQUIPPED WITH ADS-B OUT MUST OPERATE THIS EQUIPMENT IN HE TRANSMIT MODE AT ALL TIMES WHILE AIRBORNE UNLESS OTHERWISE REQUESTED BY ATC.

Notice the use of ALL CAPS: the FAA is shouting this requirement out at us. Furthermore, the glider involved in the Minden mid-air collision with the Hawker jet was faulted for not operating his transponder (https://www.ntsb.gov/_layouts/ntsb.a...A277 A&akey=1) even though they were not in controlled airspace at the time.

Tom

And yet, the regulation does not say that. The relevant section 91.215 (c) is quoted here in it's entirety:

"(c) Transponder-on operation. While in the airspace as specified in paragraph (b) of this section or in all controlled airspace, each person operating an air- craft equipped with an operable ATC transponder maintained in accordance with §91.413 of this part shall operate the transponder, including Mode C equipment if installed, and shall reply on the appropriate code or as assigned by ATC."

The airspace specified in paragraph (b) is controlled airspace. The AIM can say whatever it likes, the regulation is clearly worded and is the law. I'd agree that keeping it on at all times is a good idea, and do myself. But it is not required outside of controlled airspace.

The AIM clearly states that it must be on in no uncertain terms (did you not read that?), so there is no wiggle room as far as the FAA is concerned. There are times when ATC will direct pilots to turn off their transponders, such as the EAA fly-in at Oshkosh, but they must be on otherwise. 91.215 nowhere gives the pilot the discretion of turning off the transponder in uncontrolled airspace. And the glider pilot was, indeed, found liable in the Minden mid-air.

Tom