What is the best way to kill your glider when landing in strong wind?
Flying last weekend at Blossom Valley outside of San Diego, I got caught out by a strong increase in wind. Winds were forecast to peak around 10 knots (18 km/hr). When I arrived, it was already mid afternoon, so I waited around another hour for the winds to decrease, which usually occurs at that site. Pilots on the launch were split - most of the experienced pilots took off, with the lower airtime pilots choosing not to wait it out.
I took off and found conditions windy but managable. Thermals were strong but windblown, and there were strong areas of lift where you could fly straight into wind and go up. But there were also some strong areas of sink, which in hindsight should have been a warning sign that the wind was not only strong but gusty. Later looking at my tracklog, I saw some my max speed in one thermal was 62 km/hr, which means the wind must have been around 24km/hr - strong but manageable, and 25% higher than forecast. Several pilots had taken these thermals that drifted back well behind launch, and got enough height to penetrate or make short out and back XC.
I flew for about 40 minutes, and then noticed the wind had started to increase even more, so I decided to land. At that point I was about three hundred feet above launch, and 1000 ft crosswind. As I went crosswind towards the launch, instead of the increasing lift closer to the slope of the hill, there was sink. My forward speed crept down to almost nothing, then backwards, so I pushed half bar to in order to stay in front of the slope. This site is not forgiving of being blown over the back. You have to land on a ridge top, with boulder strewn hillsides on the downwind side with zero places to land and significant turbulence.
As I came into to land, it was clear because of the wind strength and sink, there were no good options for a go around. I would get blown over the back if I didn't commit to the landing and keep on speedbar until I was right on the ground. At that point the wind speed was probably close to 45km/hr. I ended up running out of lift about 200 feet of the main landing area, and landed on the access road up to launch. I had taken a wrap to help kill the wing, but made the mistake of stepping off the speedbar once on the ground, at the same time as pulling both brakes to kill the wing. This effectively caused the angle of attack to move upwards sharply and the trailing edge to lower. Instead of a aerodynamic wing, there was just a sail for a second catching the full force of the wind. The result was that I was yanked hard upwards and backwards for maybe one second, with then the glider collapsing behind me. Onlookers said later that I was probably 6-8 feet off the ground and flew backwards about 10 feet. I landed directly on my back, and distinctly heard the whoosh of air going out of my airbag harness. Once the airbag and back protection had taken the impact out, I rolled to the side with the glider ending up in nearby bushes completely collapsed. Before moving I immediately did a self assessment in terms of "I am conscious, I didn't black out, I have no pain". However, I was instantly dazed and shaken by the impact. Fortunately other pilots were on hand within seconds to help get my glider out of the bushes and walk it back to relative shelter to pack up.
Insights
- This was the first time in twenty years of paragliding I had landed in wind that strong. I didn't have a strategy for killing the wing effectively, because I had been careful to not expose myself to those sorts of conditions.
- This sort of incident could have resulted in a broken neck or major spinal injury if I have somersaulted over further in my harness and landed on my head rather than directly on my harness.
- I landed three feet away from a granite boulder that stuck a foot out of the ground. Landing on that would have challenged even the best harness protection
- My heavy race pod hardness, with its airbag plus 20cm back protection took a huge impact, and performed perfectly. Many lightweight modern harnesses that are becoming popular these days don't have this level of protection.
- Having clear wind speed on a flight instrument is vital
Thinking about the incident later, several things were clear:
- After mentally reviewing what happened, and considering all possible ways to kill a wing in high wind, I concluded that a full frontal (grabbing and pulling both A rises with brakes still in my hands) would have been most effective way to kill the wing
- The full frontal approach is not pretty. But it leaves almost not chance of the wing reinflating, and stops the wing turning into a sail momentarily as it collapses
- I needed more wind speed visibility on my flight instrument (XC Track) in order to become aware more clearly just how much the wind had increased
- If you are not thermalling, wind speed calculations on flight instruments are not that accurate. It is better to watch your forward speed and keep and eye on the ground as an additional reference
- Always check both forecast wind speed and gust speed, and prepare yourself for the maximum possible wind situation
This video from Flybubble provides some great tips, and confirms my thoughts that inducing a full frontal is going to be the most effective technique for completely disabling your paraglider in strong wind.
In addition to a full frontal, landing on bar with my feet still in the pod, then bending my knees or even deliberately falling into the ground might have helped. Anything that reduces the tension in the paraglider lines would have reduced the ability of the glider to convert momentarily into a dangerous sail as it collapsed.
I modified my XC Track screens to add wind speed as a separate large number, rather than just relying on the small figure and arrow that is included on the task map.