Italianjon, in UK class G airspace, it seems to be the case that most GA power typically cruises at 1000 to 2500 feet, and most glider cross country flying is in weather conditions where gliders will normally be higher than that. Statistics show that glider/glider collisions are one of the three big fatal collision causes, accounting for typically one fatality a year. Glider/other GA collisions happen at far lower rates – about four in the last 30 years, not all fatal. So, FLARM for gliders in class G in the UK make sense to me, and is making sense to growing numbers of glider pilots, and we are fitting them voluntarily. So far, in small but growing numbers. Worldwide, I understand that over 9000 units have been sold.
In terms of risk analysis, and bang for the buck, I believe it is the right place for us to spend money. I believe that widespread adoption of FLARM for gliders will save more lives than the equivalent amount of money spent on mode S. Not only that, but as I and others have repeatedly pointed out, FLARM is physically achievable in most gliders, whereas mode S Power and space requirements preclude it for many, as well as there being few EASA-approved installation schemes.
For some gliders, transponders may have worth while benefits for their cost. I am planning to fit one, partly because I fly close to controlled airspace where it is a choke point for GA traffic to skirt round Stansted, and partly because sometimes I want to penetrate controlled airspace myself. I have solved the power problem in my glider, but not the EASA-approved installation.
I have a simple response to airline or GA power pilots who think we should have interoperability between gliders and the rest. If they think it worth spending money on, they can spend it, by fitting FLARM. It is the only thing in the foreseeable future which will assist in detecting most gliders. If they don’t think it worth the money for them, why should anyone think it’s worth only some glider pilots spending far higher costs on mode S, for the limited number of gliders where it is actually practicable?
If they don’t want an extra piece of equipment in the cockpit, which gives no interoperability with transponder equipped aircraft but does with the low threat of glider collisions, why do they think gliders should fit transponders which give no interoperability with other gliders, although that is where the biggest threat of glider collisions remains?
By the way, I totally agree that any of these electronic aids must be used to aid, and not replace, “see” and avoid. I also agree with those who recognize that the eyeball on its own is a very imperfect collision avoidance tool. We can never overcome blindspots with eyeball alone, and human beings seem incapable of perfect lookout even where blindspots are not a factor. I saw a safety presentation which showed that most collisions involving gliders are from behind one of them. Only one pair of eyes, and sometimes not even that, had the chance of seeing and avoiding. Collision geometry such as the rearmost higher glider catching up lower glider in front can result in blindspots for both pilots. Whatever the cause, certainly that has happened.
Chris N.
[edited - few, not necessarily no, EASA-approved glider installation schemes]
Last edited by chrisN; 23rd July 2008 at 11:18.