On Sunday, 19 January 2020 10:06:16 UTC, mart wrote:
I have heard from several pilots that it is very easy to crack flarm instruments to give full information.

I don't know that there's any cracking involved.

For the watchers, if someone can set their own instrument or web browser to apply a label to an anonymous contact, all they need to do is wander around the launch grid or watch it take off.

There have been some interesting responses in this discussion.

The technical possibilities and rules and the way people react with them are in a constant state of evolution.

At the first international contest I went to, I was in a car, attempting to drive around a bit in front of the pilots and report on the weather. When I agreed to do it, I assumed it would be a waste for 80 or 90% of the time, but if it paid off once or twice it could be worth it. And that's about how it turned out. Several other teams were doing this too. Were we all cheating? I don't think so.

Before the internet, crews could visit the organisation's met person and get updates on the weather, including satellite pictures, and broadcast this to the pilots. Maybe some teams did this and others not. One or two teams even brought their own met. I can remember one day winner saying he'd watched a thunderstorm at midnight over what would turn out to be part of that day's task, and decided it might be not quite as good just there as the forecast.

At one contest (before GPS), another team manager told me afterwards one of his pilots said the pilots from another country had just missed the turn point. A few seconds later the error was announced on the other team's frequency ...

At another, one of our pilots said he was just approaching being back overhead on the way north. Eight knots right over the aerials, I replied. Someone in another team had said this a few seconds earlier.

At yet another, our two pilots in one class were about 30 km to the south, wondering where they were going to get the final decent climb in a not very promising sky. There might be a useful cloud a mile or two south of the last turn, I said. How did you spot that, I was asked afterwards. To be honest, I'd been watching it a few minutes, and I wasn't sure. It looked like it might be falling apart as you got a chance to approach it, so I nearly didn't mention it, then George Moffat said something nice about it.

If information is available, someone will be using it. Until or unless new policy and/or rule is drawn up to exclude it.

I understand the sophisticated end of variometer/navigation development has reached the point where integration of Flarm derived info can tell you on the screen what the nearby gliders' climb rates are. People are asking what skills are actually still being tested in a contest, whether gaggle flying is likely to increase even more, how to avoid mass starts, and so on.

So to some extent I'm surprised ground crews might still see a need or temptation to be stuck to a screen on the off chance they could spot and announce the slightly better thermal just ahead of their pilot, and risk being annoying by saying so.

As Al McN said above, we've now changed our UK rules so crews don't give any information at all to pilots. This will cut out any boring info from watching live tracking sites, though some of us might still look a couple of times, especially as the finishes get more likely, but it would also cut out all the old occasional other info we might have been able to send, like there was a heavy shower 20 minutes ago a few km out, probably still some sink as several people still landing short, or the sea air has just come in, or those two rivals have just landed out so you don't need to panic that last climb is a bit slow.

At one international event, the win in one class was joint by three in the same team. They'd been a handful of points apart in the morning (indeed all the way through the comp), so the ideal result entailed some ground help calculating the required synchronisation of finishes. I can remember the whole team jumping for joy in the evening as they discovered it had worked. No radio would cut that out too. Is this an individual or team sport, or both?

So no radio is one solution, but would it be what people want?