On Sunday, November 22, 2015 at 3:59:15 PM UTC-8, Jonathan St. Cloud wrote:
Wondering if there are any statistics regarding Flarm use in the the U.S.? i know at the glider port I fly from most have Flarm, but I see many gliders for sale on Wings and Wheels do not have Flarm.

You have to select the appropriate denominator when you look at "use". If you look as a percent of all FAA-registered gliders it will be pretty low - but lots of gliders on the registry are inoperative or even destroyed. If you assume a few thousand regularly flying gliders then the penetration is probably less than 30%. However, if you look at the most active gliders that represent most of the flight hours (and therefore collision threat) there are two broad groups - training and ride gliders and cross-country and racing gliders.

There have been a number of clubs and commercial operators (e.g. Soaring Club of Houston and Williams Soaring) that have equipped their entire fleets, but generally you'll see less here because of cost, lack of battery power and other reasons. They tend to spend a lot of time around the airport and in the pattern. The cross country and racing set have higher penetration - virtually all the high-hours OLC pilots on the west coast (due in part to extensive convergence and street flying at high altitudes and airspeeds) have adopted Flarm. Among racing pilots responding to this fall's poll 77% overall and 94% of pilots who flew in a Nationals have Flarm.

I'd wager that some of the gliders you are seeing for sale have not flown a lot and are being sold for that reason. I wouldn't take it as totally representative of the proportion of Flarm-equipped gliders you are likely to observe when you go flying, which is more based on hours in the air.

If you are just doing patterns and flying locally, collision avoidance will tend to be more "old-school" see-and-avoid, but it varies a lot with the local operation. If you intend to go cross country or fly in a contest it'll be a very different story. It's increasingly frowned upon to show up at a contest or OLC camp without one and some are now Flarm mandatory.

9B