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UK CAA call for evidence on electronic conspicuity

Yesterday while flying with some friends and passing over La Roche sur Yon at around 3000 ft the AFIS advised that there were 3 gliders in the air and close by. The 2 sets of mark one eyeballs in the front seats eventually managed to spot one of the gliders before the passenger in the back announced he could see all 3 to the left of us on his smartphone. He was able to point out their exact location and we were able to identify all 3 looking outside. He was using the free version of Flight Radar. I have only ever used this app on the ground and assumed it only identified mode s transponders. I thought that most gliders in France equipped with Flarm not mode s.
However the accuracy of identifying these gliders was very impressive and I do wonder about the value of spending large sums on ADS B in or TCAS if you can do this with a smartphone and a free app.

France

That data comes from the OGN (since FLARM is encrypted and its protocol secret, OGN receives FLARM and others and feeds them into various other things).

http://wiki.glidernet.org/

However, your reception of it on FR24 required internet access which is generally not assured when airborne. I think OGN are planning some kind of retransmission service which will at the very least work with the inexpensive PilotAware system, so PilotAware users will be able to see gliders as well as ADS-B and PilotAware devices.

Andreas IOM

Could also be that the gliders were on FR24 because they had Mode C transponders. Some do, especially on longer flights.

Administrator
Shoreham EGKA, United Kingdom

The OGN stream is fed into FlightRadar24. The OGN stream mainly has FLARM in it but there are also some stations picking up P3I (PilotAware)(mainly in Southern England).

Mode C is not enough to be on FR24. You need Mode S to allow multilateration.

Nympsfield, United Kingdom

Sorry, yes, I meant Mode S.

I have seen plenty of gliders here in the UK, and I believe elsewhere, on my TAS605 system, but they could have been just Mode C.

I can’t see anybody installing Mode S when they can meet regulatory / ATC / conspicuity requirements with a Mode C box which doesn’t radiate their aircraft reg, is not visible on FR24, and which can be picked up on Ebay…

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

Some do, especially on longer flights

Very few gliders carry a transponder, even fewer for long flights (powering a Mode-S transponder for a diamond distance is problematic). Maybe 1 in 20 (and they will most likely be motor gliders). It’ll be FLARM fed in by the OGN for sure.

Last Edited by alioth at 22 Aug 09:22
Andreas IOM
16 Posts
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