The T-Advisor AND Flarm are NOT anticollision system.
Anticollision systems are those who tell the pilot what to do (like TCAS), in case of emergency. Neither system does this.
BOTH systems are NOT anticollision systems.

Cleared this, those who talk about the "predictive algorithm", can please explain:

1) how it works, since they must know how it works, to be in the position of saying that it works or it doesn't

2) how they know that such an algorithm has been implemented into a Flarm system: what proof do they have of this ?

3) if they have ever seen the trace of at least 10 glider flights in different conditions (competition, cross country, around-the-airfield, ridge soaring,....); whoever has seen some, not many, traces of flights, without the need to be a glider pilot, can understand that a prediction of the position of a glider in a future time beyond a fistful of seconds is impossible, exactly IMPOSSIBLE, since not even its pilot knows it, apart from some cases, like straight flying and constant turn rate thermaling. A glider pilot knows that he will be changing the trajectory of the glider to search for the best netto value, which depends on the micro air movements, which are unknown to the pilot in terms of exact location. Is there a machine capable of predicting these locations ? And even if there was, is there a machine capable of predicting what a glider pilot will do in the next 30-60-80 seconds ? Because this is what the rumored (never verified) "prediction algorithm" does. This is spectacular indeed !

4) even if they found a system to predict the position of the glider with a certain probability, would they trust as optimal a system that has (obviously) a probability to fail the prediction and miss a danger of collision ? Even if the probability was low (all but sure, since never demonstrated with objective tests and calculated data), 2, 3, 10 collisions (and deads) out of XX'XXX flights are too much. In aeronautics, this approach is wrong: this is not the way we work in professional aeronautics, that has taken us where we are in aviation


Kevin Neave, can you show in which website you read that the T-Advisor tells you "that there are lots of gliders flying within 7 km" ?
Please indicate the source of this concept. Because this is completely FALSE.
The T-Advisor does NOT USE (not that it does not calculate, a very different story) a prediction coming from an unverified, unknown algorithm (if it is at all) to give warnings to the pilot. Its approach is down to what is sure, real, objectively undeniable and at the basis of a collision: the relative approach speed of the aircraft and their distance, calculating the time to possible impact. Depending on some parameters (time to impact, approach speed, difference of altitude, etc.) the communication to the pilot is given at three different levels of warning.
No predictions based on extrapolations or assumptions of pilot's behavior, that are impossible to know beforehand.
Nevertheless, to make the Flarm systems work with the T-Advisor, it calculates the prediction in a very similar way to these systems, and transmits the data. But it does not, and will not use these hypothetical data to give warning of a possible fatal collision to a pilot.
The consistent behavior of the Flarm systems flying with the T-Advisor systems like with other Flarms has demonstrated, in some hundreds thousand hours of flight, that the prediction of position calculated by the T-Advisor is very similar to the one calculated by the Flarm. I will not say here how this is done, because it might destroy your faith (on not proved basis) in what was always told to you, but this is enough to prove that the two systems work well together, and the same could happen with other new systems around.
The reports of many pilots, during 10 years of operations and the hundreds thousand hours of flight of the T-Advisor are a clear demonstration that it is just an excuse that two different systems can't work well together.
Apart from all the above, Kevin, there is NO PILOT that can see all air traffic of gliders within a range of up to 17 km (this is the maximum range of the T-Advisor correctly installed onboard). If you are capable of that, you are the only one, and you are an outlayer when considering the behavior of the average glider pilot.


Tango Eight, your statement is lacking of a scientific base: WHAT demonstrates that the "prediction algorithm works very well" ? Not the number of hours. That is senseless, obviously.
The collisions avoided thanks to the system would demonstrate that.
So: have you got the statistics "before and after" the introduction of these systems ?
Do you know if these systems have failed anytime ? And why ? (There have been collisions between gliders equipped with Flarm).
Obviously these systems increase the awareness of the surrounding traffic, there is no doubt about that, but from this to saying that it demonstrates that the prediction algorithm is correct the step is huge, and scientifically honestly, impossible.
The technical chats without FACTS are of poor use.
If anybody wants to convince somebody else of something in aviation, and engineering in general, should do it with FACTS, not declarations without basis.
Prediction algorithm ?
Patented method from Onera implemented ? Who proved that it's implemented ? (btw: discussing with Mr. Le Tallec, the inventor of the "prediction method" rumored to be adopted in these systems, he agreed that his method doesn't work well in ridge soaring, where the only method that is sensible is the one based on the approach speed and distance).
A radio protocol copyrighted or patented ? (It is impossible, by law)
Assigned patents ? (Make a check first: you will find only one, valid just for Germany, accepted after it was refused twice - Nothing more).

This way of working has been and still is very far away from what is a sounding procedure in aeronautics.
This doesn't mean spending the money to certify a system (which, btw, with so many units around, could be spent, no ?).
- It means adopting a procedure that is sound and clear, in the design (not starting with an electronic design that is old and, i.e. without the proper radio performance: the declared range of that system was 3 km - written in the official presentation of 2005 - while the T-Advisor was reaching 15 km, with the same transmission chip and power output)
- What is used for safety has to prove its full effectiveness with facts and objective quantitative tests (marketing doesn't save lives)
- What is used for safety has to be verified by an independent party, not hidden (who hides it, is because he fears to be uncovered, usually; patents protect what can be be protected, the rest is fog and chats)
- When a firmware update is mandatory, it must be managed in a way that there isn't a situation of a part of the systems (of the same manufacturer) incompatible with the rest of the same systems, creating a situation of high risk (for example for a change of radio protocol, it can be done with three lines of code like this: if (date XX); transmit like this; else transmit like that).

The origin of the discussion appears to be a commercial attitude of Flarm. They are perfectly right in doing what they do: they are not a charity foundation and they try to protect what they did in all ways possible.
It is then up to the sector (gliding) and customers to accept this or not.
It is then up to the authorities to make and impose the rules for the well being of the community and the continuous development.
What is sure is that what has happened until now is far from the standard practices adopted in aeronautics (and in many ways, engineering in general): it's not a matter of increasing costs (the excuse so often brought up to scare people), it is about being capable of acting according to principles established during decades of (sometimes tragic) history of aviation.
Forgetting these principles might bring something quick today (as it has happened for this topic), but it will be painful tomorrow, when a correction to the path is required. Better founding it well as soon as possible and keep on along a way that has made aviation safe.