Mooney_Driver wrote:
Apart, Power Flarm costs close to 2500 Euros and all flarm appliances require some sort of power. So how do people use them in gliders if they have no power?And a Trigg TT21 Transponder which would be ideal for gliders currrently costs something like 1200 Euros…. so likely the folks who fly old gliders will not have money for Flarm either…
Gliders don’t use PowerFLARM, they use FLARM which costs a fraction of the price. PowerFLARM tends to get used in powered aircraft.
FLARM uses much less power than a transponder (transmit power of tens of milliwatts rather than tens of watts) and is designed specifically for the collision avoidance problem in gliders. It’s a very smart system. Transponders won’t help in glider-to-glider collision avoidance, where the highest danger is (by MANY orders of magnitude). By contrast most powered aircraft near misses/collisions are around aerodromes with ATC, which is typically somewhere where gliders are not.
A more effective EC solution for gliders to power planes are inexpensive portable ADS-B emitters: powered aircraft owners have inexpensive options of receiving and displaying ADS-B traffic, which they don’t for transponders (you can display ADS-B traffic for less than £50 worth of gear, but it costs thousands to be able to see range and direction of a transponder). Transponders are absolutely the wrong solution for gliders.
alioth wrote:
Gliders don’t use PowerFLARM, they use FLARM which costs a fraction of the price
Ca. 600 Euro?
alioth wrote:
FLARM [….] It’s a very smart system.
I wouldn’t say flarm is smart at all because it uses a very simple CPU or processor which performs all calculations on it’s predictive algorithms. I heard that lifts use the same class of CPU as flarm. What “smartness” would you expect from a lift? Move from floor X to floor Y. Not much more.
Of course I haven’t seen flarm’s code it’s closed sourced therefore all one would say about it’s algorithms is a guessing game.
Robin_253 wrote:
I wouldn’t say flarm is smart at all because it uses a very simple CPU or processor which performs all calculations on it’s predictive algorithms. I heard that lifts use the same class of CPU as flarm. What “smartness” would you expect from a lift? Move from floor X to floor Y. Not much more.
What is the relevance of the “simplicity” of the processor…?
Well, how would you define smartness?
Would you say that a lift is smart?
Or a smartphone is smart?
Or would you rather say that a Tesla with its’ autopilot is a smart car? Maybe yes, and maybe no.
Processing power installed in the above mentioned devices is orders of magnitude different, I mean a smartphone is orders of magnitude more powerful in terms of processing power than a lift and Tesla is orders of magnitude more powerfull than a smartphone.
IMHO, based on available data, Flarm is a rather dumb system running on outdated hardware and using primitive algorithms.
Robin_253 wrote:
Well, how would you define smartness?
I wouldn’t — it doesn’t really mean anything. A “smart house” is one where the lights can be controlled remotely. A “smartphone” is one that can run arbitrary (in principle) software. What’s “smart” about that?
But I would understand the word in practise to refer to a certain degree of useful functionality beyond what would be obvious. Again, that has very little to do with processing power. Slightly more to do with the sophistication of algorithms, but not even that to a major extent.
As far as I understand how the FLARM system works for gliders, it does not give a warning just because another glider is close but it tries to predict the flight path and suppresses the warning if there is no major collision risk. That could be said to be “smart” with my understanding of the word.
Transponders are absolutely the wrong solution for gliders.
Except that I had two scary airproxes with what were almost certainly gliders. One over the Sussex Downs very close to the Shoreham 20 approach path (I climbed at 1000fpm and so did he, for quite a while, right under / behind me). The other was when departing from Zell am See. On the former one, ATC were sure it was a glider; we get lots of them there, flying from a glider base at Parham right across the Shoreham final approach path.
If I was flying a glider, cross country, I would radiate both FLARM and Mode C. The lithium battery is not big these days.
Mooney_Driver wrote:
Have you actually flown to an airfield which has AFIS?
Certainly have, and I stand by my comments. IMO the ‘Flugleiter / AFIS’ only muddies the waters (or the air, if you prefer…).
Airborne_Again wrote:
A “smartphone” is one that can run arbitrary (in principle) software. What’s “smart” about that?
You can’t expect smart behaviour from something that can only add integers. Example: 2+3=5. An elevator is at floor 2, someone presses button “5” and off we go. Is this a smart behaviour? I wouldn’t say so.
Now a smartphone would try to predict what you are trying to type and suggest some letters which would complete the word. Processing power required to execute this task is an order of magnitude greater than the one installed in an elevator. Or a Flarm.
Airborne_Again wrote:
As far as I understand how the FLARM system works for gliders, it does not give a warning just because another glider is close but it tries to predict the flight path and suppresses the warning if there is no major collision risk.
This is flarm’s marketing message or even Unique selling proposition, and it’s a lie. 2 reasons:
1. Flying a glider is unpredictable because the atmosphere is unpredictable. If someone would be flying a glider in a predictable way he would land. Of course with today’s advanced ships one can be a lousy pilot and stay airborne 
2. Even if we would disregard point 1 above, flarm’s processing power is just too low to execute any meaningful prediction algorithm.
You don’t have to trust me. Ask world’s best gliding pilot. Here he is. A very approachable guy, just ask him if flarm can “predict”.
Peter wrote:
If I was flying a glider, cross country, I would radiate both FLARM and Mode C. The lithium battery is not big these days.
Peter, please do try, I even invited you for a ride. And I bet a bottle of good slivovica that you would turn the flarm off after 15 minutes in a gaggle.
Why does the flarm have to be smart ?
Age of the machine or do I just need traffic info ?
Robin_253 wrote:
You can’t expect smart behaviour from something that can only add integers.Now I find it hard to take you seriously. Do you know how computers work?
Now a smartphone would try to predict what you are trying to type and suggest some letters which would complete the word. Processing power required to execute this task is an order of magnitude greater than the one installed in an elevator. Or a Flarm.
I agree that the processing power required is greater but the processing power installed is not the same as the power required. Also, I fail to see what the relevance of elevators are in this discussion.Robin_253 wrote:
This is flarm’s marketing message or even Unique selling proposition, and it’s a lie. 2 reasons:
1. Flying a glider is unpredictable because the atmosphere is unpredictable. If someone would be flying a glider in a predictable way he would land. Of course with today’s advanced ships one can be a lousy pilot and stay airborne
Of course you can only do short-term prediction and predication doesn’t mean you know the future.
2. Even if we would disregard point 1 above, flarm’s processing power is just too low to execute any meaningful prediction algorithm.How have you reached that conclusion? Excuse me, but judging from your first comment above, you don’t seem to have much expertise with computers and programming.
