ADSB visibility with non certified GPS

Thanks, Evan, but that does not answer the question, either.Â* Sure there
might be certificate action, should a pilot get caught turning on a
not-yet-tested/certified transponder, but it seems to me it would have
been better if the Hawker had gotten a RA from its TCAS box.Â* I know
it's a rhetorical question but then so are a lot of the FARs...Â* I'd
just prefer receiving a letter from the FAA over bailing out (or worse).

BTW, my transponder was checked by a certified technician within the
preceding 24 calendar months and complies with 91.413(c) and has a
proper logbook entry.

On 10/2/2017 10:26 AM, Tango Eight wrote:
On Monday, October 2, 2017 at 12:16:22 PM UTC-4, Dan Marotta wrote:
Didn't answer the question.

What harm could have come from turning on a not-yet-approved transponder?
Violation of FAR 91.413.

best,
Evan Ludeman / T8

--
Dan, 5J

Dan, the only risk would have been if the transponder was reporting wrong altitude. Of course in this case it would have been better to turn it on, and make a simple radio call to Reno approach for a transponder check.

Ramy

That's what I thought.Â* Had I been in the same situation (untested
transponder), I would have turned it on, asked Reno if they saw me, and
what was my reported altitude.

On 10/2/2017 11:35 AM, Ramy wrote:
Dan, the only risk would have been if the transponder was reporting wrong altitude. Of course in this case it would have been better to turn it on, and make a simple radio call to Reno approach for a transponder check.

Ramy

--
Dan, 5J

On Monday, October 2, 2017 at 10:16:40 AM UTC-7, Dan Marotta wrote:
Thanks, Evan, but that does not answer the question, either.Â* Sure there
might be certificate action, should a pilot get caught turning on a
not-yet-tested/certified transponder, but it seems to me it would have
been better if the Hawker had gotten a RA from its TCAS box.Â* I know
it's a rhetorical question but then so are a lot of the FARs...Â* I'd
just prefer receiving a letter from the FAA over bailing out (or worse).

BTW, my transponder was checked by a certified technician within the
preceding 24 calendar months and complies with 91.413(c) and has a
proper logbook entry.

On 10/2/2017 10:26 AM, Tango Eight wrote:
On Monday, October 2, 2017 at 12:16:22 PM UTC-4, Dan Marotta wrote:
Didn't answer the question.

What harm could have come from turning on a not-yet-approved transponder?
Violation of FAR 91.413.

best,
Evan Ludeman / T8

--
Dan, 5J

Dan

Evan is pointing out what is believed to be the pilot's concern here.

My pragmatic safety focused answer is there was little reason not to turn that transponder on, and I would have. The 14 CFR Appendix F to Part 43, ATC Transponder Tests and Inspections required by 14 CFR 91.413(c) only test RF properties of the transponder. There are unlikely to be undetected problems with modern transponders that causes errors in operation or impact other airspace users. And a call to Reno Approach for a transponder check would have been good assurance that the basic transponder operations are working, a good idea on any new install. In some ways Appendix F seems to address concerns of older generation less reliable transponder technology, and specifically to look for know faults that do could impact operation and other users, so still useful to know that stuff is working, and still a 14CFR requirement and should be done.

One thing to note is Appendix F to Part 43 does not check altitude encoder accuracy. And that transponder reported altitude is key to interoperation with TCAS. It's a good idea to check the encoder altitude displayed on your transponder against the altimeter and other sources, or check in with ATC if the transponder does not have an encoder altitude display.

On Monday, October 2, 2017 at 11:16:40 AM UTC-6, Dan Marotta wrote:
Thanks, Evan, but that does not answer the question, either.Â* Sure there
might be certificate action, should a pilot get caught turning on a
not-yet-tested/certified transponder, but it seems to me it would have
been better if the Hawker had gotten a RA from its TCAS box.Â* I know
it's a rhetorical question but then so are a lot of the FARs...Â* I'd
just prefer receiving a letter from the FAA over bailing out (or worse).

BTW, my transponder was checked by a certified technician within the
preceding 24 calendar months and complies with 91.413(c) and has a
proper logbook entry.

On 10/2/2017 10:26 AM, Tango Eight wrote:
On Monday, October 2, 2017 at 12:16:22 PM UTC-4, Dan Marotta wrote:
Didn't answer the question.

What harm could have come from turning on a not-yet-approved transponder?
Violation of FAR 91.413.

best,
Evan Ludeman / T8

--
Dan, 5J

More information along with the link to the report.

1.3.2 Glider Information

The glider was equipped with a panel mounted communication radio, global positioning system (GPS) unit, a Cambridge 302, and a Mode C transponder; however, the pilot did not turn on the GPS and transponder. According to the glider pilot, he did not turn on the transponder because he was only intending on remaining in the local glider area, and because he wanted to reserve his batteries for radio use. The glider was equipped with two batteries (one main and one spare), however, due to the previous glider flights, the pilot was unsure of the remaining charge in the battery.

https://www.ntsb.gov/_layouts/ntsb.a...A277 A&akey=1

Best. Tom #711.

On Monday, October 2, 2017 at 10:50:48 AM UTC-7, Darryl Ramm wrote:
On Monday, October 2, 2017 at 10:16:40 AM UTC-7, Dan Marotta wrote:
Thanks, Evan, but that does not answer the question, either.Â* Sure there
might be certificate action, should a pilot get caught turning on a
not-yet-tested/certified transponder, but it seems to me it would have
been better if the Hawker had gotten a RA from its TCAS box.Â* I know
it's a rhetorical question but then so are a lot of the FARs...Â* I'd
just prefer receiving a letter from the FAA over bailing out (or worse)..

BTW, my transponder was checked by a certified technician within the
preceding 24 calendar months and complies with 91.413(c) and has a
proper logbook entry.

On 10/2/2017 10:26 AM, Tango Eight wrote:
On Monday, October 2, 2017 at 12:16:22 PM UTC-4, Dan Marotta wrote:
Didn't answer the question.

What harm could have come from turning on a not-yet-approved transponder?
Violation of FAR 91.413.

best,
Evan Ludeman / T8

--
Dan, 5J

Dan

Evan is pointing out what is believed to be the pilot's concern here.

My pragmatic safety focused answer is there was little reason not to turn that transponder on, and I would have. The 14 CFR Appendix F to Part 43, ATC Transponder Tests and Inspections required by 14 CFR 91.413(c) only test RF properties of the transponder. There are unlikely to be undetected problems with modern transponders that causes errors in operation or impact other airspace users. And a call to Reno Approach for a transponder check would have been good assurance that the basic transponder operations are working, a good idea on any new install. In some ways Appendix F seems to address concerns of older generation less reliable transponder technology, and specifically to look for know faults that do could impact operation and other users, so still useful to know that stuff is working, and still a 14CFR requirement and should be done.

One thing to note is Appendix F to Part 43 does not check altitude encoder accuracy. And that transponder reported altitude is key to interoperation with TCAS. It's a good idea to check the encoder altitude displayed on your transponder against the altimeter and other sources, or check in with ATC if the transponder does not have an encoder altitude display.

Oh sorry my bad. brain fart, this was a first install so Appendix E to Part 43 applies, which *does* include an altitude encoder test.

I was rushing to try to make a point that regular biannual transponder tests that folks will have done on their glider transponders do not check the encoder accuracy.

On Sunday, October 1, 2017 at 9:02:05 PM UTC-4, Darryl Ramm wrote:
...

The actual retransmission data message via ADS-R, is very slightly different than the message it is retransmitting... the FAA system could not work it it was exactly the same. PowerFLARM coming out of Europe was apparently never developed to handle those slightly different USA focused ADS-R messages.

Wow. If this is a just a software tweak, it would make sense to request the FLARM team to do it. They would then likely sell more units in the USA, where GA traffic on UAT is definitely part of the traffic glider pilots are trying to "see". And even some small GA plane owners may buy it, like some do in Europe. And the more units sold, the lower the price me eventually be, thus yet more sold...

On Monday, 2 October 2017 11:50:48 UTC-6, Darryl Ramm wrote:
The 14 CFR Appendix F to Part 43, ATC Transponder Tests and Inspections required by 14 CFR 91.413(c) only test RF properties of the transponder. There are unlikely to be undetected problems with modern transponders that causes errors in operation or impact other airspace users. And a call to Reno Approach for a transponder check would have been good assurance that the basic transponder operations are working, a good idea on any new install. In some ways Appendix F seems to address concerns of older generation less reliable transponder technology, and specifically to look for know faults that do could impact operation and other users, so still useful to know that stuff is working, and still a 14CFR requirement and should be done.


My story - I bought a Ventus 2CX that is registered experimental with a installed transponder and appropriate log book entries and bi-annual checks. I checked the antenna and it was a L2 antenna, http://wingsandwheels.com/l2-aae.html, that was mounted behind the pilot seat on the floor of the fuselage. Seemed a bit odd to me as the fuselage is carbon but with all the signoffs, and I know the A&P that installed it, I assumed I was uninformed. I flew for a couple of months, including a number of wave flights around the Salt Lake Class B and over, through multiple arrival and departure lanes, and then put it away for the winter.

Next spring before flying I did the transponder bi-annual check, different company than one used previously, and the guy went about his business. Measured output inside the cockpit, measured output at the wingtip and measured output 100 yards away. He then asked for the log book, went through it and then placed his sticker in the book and signed it.

He called me over to the cockpit and asked me to show him the antenna setup which I did and he just shook his head and smiled. He then gave me the logbook and asked 'Do your testicles tingle or glow after a long flight?'

He went to explain that he measured 250 watts in the cockpit, ~125 watts at the wingtip and 50 watts at 100 yards. Basically I was just bombarding my body.

He *did* signoff on the bi-annual test as the transponder was operating correctly!

Yes I quickly got a external shark fin antenna installed and verified it was operating correctly with SLC ATC during the next flight.

Yes we all must understand how our equipment works and use common sense when needed.

Ron Gleason

On Monday, October 2, 2017 at 11:22:14 AM UTC-7, wrote:
On Sunday, October 1, 2017 at 9:02:05 PM UTC-4, Darryl Ramm wrote:
...

The actual retransmission data message via ADS-R, is very slightly different than the message it is retransmitting... the FAA system could not work it it was exactly the same. PowerFLARM coming out of Europe was apparently never developed to handle those slightly different USA focused ADS-R messages.

Wow. If this is a just a software tweak, it would make sense to request the FLARM team to do it. They would then likely sell more units in the USA, where GA traffic on UAT is definitely part of the traffic glider pilots are trying to "see". And even some small GA plane owners may buy it, like some do in Europe. And the more units sold, the lower the price me eventually be, thus yet more sold...

FLARM would also need to do TIS-B support (more complex), and actually provide UAT In and support FIS-B data displays, etc. to be competitive in the USA GA market. And that is a lot of work for a market that already has lots of other options.

Assuming things are as I believe, adding ADS-R support should be a relatively simple change in PowerFLARM. A slight decreases in position accuracy need to be thought through. But my handwaving is easy, reality is always more complex. Right now with no real significant adoption of TABS or ADS-B Out in gliders in the USA its not an immediate issue, but I would encourage folks to let FLARM know they want this support. And include in that if/when your glider will have ADS-B or TABS out. I've been trying to encourage FLARM to do this this for years now.

On Sunday, October 1, 2017 at 4:24:46 PM UTC-5, Ramy wrote:
While we at it, will be good to know if we can connect any non TSO amplified GPS antenna to the TN72 and save an additional $300, and if anyone has a recommendation.

Ramy


I wondered about this too because the TA70 is HUGE and really designed for external mounting.

I also found this quote online related to the TN72. "Where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB."

Below are some code definitions, and then one data set each from a TN70 Antenna and then a GPS antenna borrowed from a CAI 302. I replaced my specific coordinates with "z", but the rest of the data looks to be there. I googled $RAIM, but didn't find anything on that other than it's related to GPS accuracy, etc.



$GPGGA - Global Positioning System Fix Data
$GPVTG - Track made good and ground speed
$GPGSA - GPS DOP and active satellites
$GPZDA - Date & Time
$GPGLL - Geographic position, latitude / longitude
$GPGSV - GPS Satellites in view
$GPRMC - Recommended minimum specific GPS/Transit data


TA70 Antenna
$RAIM,128443,103224,012335,012471,020000,020000,00 0887,000896,111,5,11111111*36
$GPGGA,202757.00,zzzz.zzzzz,N,zzzzz.zzzzz,W,1,06,2 .44,-8.2,M,,M,,*73
$ACVT,1,W,000012,N,000004,U,000014*53
$GPVTG,291.94,T,,M,0.026,N,0.048,K,A*32
$GPGSA,A,3,13,15,20,21,18,10,,,,,,,3.47,2.44,2.47, 1*13
$GPZDA,202757.00,02,10,2017,,*64
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,202757.00,A,A*7B
$GPGSV,2,1,06,13,35,048,33,15,68,069,49,20,50,033, 48,21,52,330,47,1*6D
$GPGSV,2,2,06,18,44,285,47,10,17,264,38,1*6B
$GPRMC,202758.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.04 4,261.96,021017,,,A,V*08

CAI 302 Antenna
$RAIM,150175,112197,013718,013213,020000,020000,00 2021,001947,111,5,11111111*31
$GPGGA,203009.00,zzzz.zzzz,N,zzzzz.zzzzz,W,1,06,2. 54,-10.0,M,,M,,*4E
$ACVT,1,E,000001,N,000004,U,000074*45
$GPVTG,14.73,T,,M,0.008,N,0.015,K,A*00
$GPGSA,A,3,20,13,15,18,21,10,,,,,,,3.53,2.54,2.45, 1*15
$GPZDA,203009.00,02,10,2017,,*69
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,203009.00,A,A*7C
$GPGSV,2,1,06,20,49,034,46,13,35,048,28,15,67,067, 46,18,44,286,48,1*66
$GPGSV,2,2,06,21,53,331,41,10,17,265,30,1*66
$GPRMC,203010.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.06 7,267.22,021017,,,A,V*0E