When I started flying it was quite common to fly with very little spare speed compared to the wind. The glider would comfortably do about 40mph (advertised as 50mph!) and 30mph was about the limit. When we flew fast the glider was very stable but it lost height as it was basically in a dive. So we would trade height for penetration…
The gliders got faster, much faster. My glider will easily do 80 mph, and at 60mph has the same sink rate that old glider had at 40mph… but 30mph is still about the limit for comfortable flying.
I’m no longer trading the height for speed, and even in strong winds I can make good flights up wind as well as downwind. The limiting factor is, although I could safely launch in 45mph of wind I cannot safely land in such a wind, except perhaps on a laminar coastal site that is the ideal shape.
The problem is that turbulence increases with the square of the wind velocity. So the bumps in 20mph are 4 times worse when the wind is 40mph. What is manageable in 30mph will not be manageable in 40 mph. Also the turbulence will persist further downwind of an obstacle, and it will extend higher up as well as further.
The gusts percentage is likely to remain similar. So 16 mph with 50% gust taking it to 24mph, means you might hit a 12mph hole in the wind. That means you must recover from a loss of 12mph of air speed, or an increase of 12mph of air speed. Can you manage that? What about 30mph with 50% gust – well that 15 mph gust might be your entire air speed, so probably not!
So the limit for us hang gliders is still not that much more than 30mph at launch. Depending on the site we will fly stronger average winds and launch in a lull, but most of the DSC sites tend to be rather turbulent or do not have the full expected wind speed at the launch point.
Thankfully, once up my speed range gives me plenty of options. I will always have plenty of margin to fly into wind – gone or the scary days of creeping forward on full speed. In fact flying with winds up to 30mph is actually worthwhile and it is still possible to do interesting things. But on paragliders guys have to consider very very carefully about the scenario of not going forward, and not going up much either!
Flying in strong winds requires a lot of thought about where you intend to land. If you get up and away XC then you should be able to find a good choice but no matter how good the sky is looking you need a plan for what you will do if conditions turn out to be not that good.
I have seen some pretty worrying attempts at flight on paragliders recently in conditions that certainly seemed to be too windy for the aircraft to me, and there have been several accidents related to strong winds this year. Wind speed is one thing that is easy to measure and easy to asses before you fly. Launch is always optional. Once you are up there you are going to have to land somewhere, so make sure you have an achievable plan to get down safely!