- Tandem Flights
High Winds, Rain and Wild Dogs at Mara Lake: A Tale of Terror and Inconvenience
Posted by Edge on May 29, 2011 - 2:33pm in
Well, it wasn't truly terrifying, but it was . . . interesting is the word, I guess. Interesting enough that three of us (Ian, Audrey and I) got some really excellent experience in staying cool and adjusting our flight plans as weather conditions surprised us and then worsened steadily.
At the beginning of this late May Okanagan trip we all had three uneventful flights off Coopers in Lumby, and my first thought was that there wouldn't be much to write up except for some sled rides. We'd gotten up early on Saturday morning and were on Coopers launch by 8:30 or so. I was first off the mountain for all three flights so I didn't see anyone else launch. Students Chris and Rob were doing forwards, and Ian, Audrey, Hans and I all worked on our light wind reverses. Flights of 8 to 11 minutes, little bits of lift to turn in, easy setups and landings at Randy's LZ. All lovely and peaceful, really. We broke for lunch at Little Tex in Vernon and then headed off to Mara Lake for what we hoped would be some good altitude gains and maybe a little XC. Enderby Cliffs, maybe? I was primed and ready after last year's jaunts with Audrey and Hans. My plan, as I had told Rick before the trip, was to get up, stay up and go someplace.
We checked out the LZ first. Light to no wind, easy conditions in a big field. We left Jayson's Delica there and all piled into Rob's logging truck for the long ride up to Mara launch. We encountered patches of snow in the road at different points, and the absence of tire tracks told us we were the first up for the season. At the top we found the launch area a little worse for wear – wind socks and flags were missing or had fallen over, the carpets were runkled up and sodden, someone had built a fire in the middle of the layout area and left the cinders. We tidied up enough to lay out our gliders and put up some streamers for wind indicators, and then started to unpack and get set up. The wind was light, mostly a bit cross from the south, with little straight cycles pushing through every few minutes. Ian was first off, followed by Audrey and then me.
Chris took a video of my uneventful launch here:
I can't remember now if Ian started to have trouble before or after I launched, but at some point I heard Jayson on the radio talking to him about going on speedbar to stand a better chance of making the landing zone. I didn't think much of it – I was pushing to the south pretty well, heading down to the lower left corner of the upper clearcut to see if I could find the rough-edged thermal that tends to lurk there. Audrey was way out to the west, seemingly over the river although I learned later she wasn't, and going up at a good clip. It was curious. Lift out over the valley? Really? She was up near cloudbase, a little north of the LZ, and I decided to go over there and see if I could get up too.
Suddenly everything clicked in my head, and things took on a certain urgency. Ian was certainly not going to make the LZ, I could see Audrey being pushed north (and still going up), Jayson was on the radio advising everybody to GET ON SPEEDBAR NOW, and I could see the surface of the river stippled with waves kicked up by a pretty stiff breeze. Yikes! Time to change plans, buddy. I swung the glider back straight to the south, pushed out to full bar, and breathed a little relief as I saw the toes of my boots gaining a little on the road down to the LZ. My ground speed was still about 10 kph, and I decided to crab a little out more toward the river instead of straight south, to get down off the ridge slope a little quicker and out where landing options were better. This would prove to be a mistake, as you'll see.
By this time Ian was nearly down. He had weighed his options and decided that his best shot for a safe and uneventful landing was across the river. Jayson was giving advice about killing the glider in high wind (hands on rear risers instead of brakes as you near the ground, then a hard no-nonsense pull as your feet touch down). No sense getting dragged, especially with the water so near. Pretty soon I saw his glider go loose and drop to the ground, and then he was on the radio saying all was well. One down, two to go.
I looked around to see that Audrey had either hit some serious sink or taken steps to lose altitude. She was below me now, but also clearly not going to make the LZ. The wind must be really kicking down there, I thought. I couldn't judge her altitude from where I was, but then I lost track of her as I suddenly had a whole bunch of things to deal with myself.
For one thing, I was no longer gaining on the LZ road. I was losing ground steadily, while descending at about 2.5 meters per second. This seems like a good rate of descent, but I have to tell you, when you're sitting at 1500 feet over the ground watching the LZ slip away, it feels awfully slow. I was also very clearly aware that not making the LZ was the least of my problems – I was just east of the middle of Rosemond Lake and south of the end of Mara Lake, being blown toward a seriously large chunk of nothing but water. At some point I got down far enough that I could see by direct ground reference that I was flying backward.
I decided, as Ian had, that my best bet was to make for the little bit of land across the river. Unfortunately, I was quite a bit higher than Ian had been when I made my move. After I got over the middle of the river I turned to the northwest a little, and then found that the wind was just really honking. There was no way to stay dry where I was, so I turned to the northeast and ran kind of with the wind back to the other side of the river. There wasn't much clear land left over there, but there was more than where I was. You can see this all in the Google Earth screen shot overlaid with my ground track (choose the Original option to see it clearly). It's not clear from that image, but at turnpoint 2 I sat parked in the air over the river just dropping straight down for awhile before deciding that I had to get out of there.
As I flew over the water, approaching the lovely plowed field where I eventually put down, I saw Audrey fighting valiantly in pretty much the same place I was going. She had gotten pushed back into a little pocket behind a house and some trees and was getting thrashed by a rotor, but she held on and managed to move into a bit of smoother air. I turned back into the wind, staying out in the clear instead of behind the clump of trees at the edge of the field, now down to a couple hundred feet, still dropping at about 2.5 m/s and still watching the ground go by the wrong way. Jayson was on the radio giving advice and sounding pretty cool, but you could hear a bit of stress in his voice. It must be quite a helpless feeling, knowing you're an hour away by truck and there's nothing you can do but watch and try to guide. It was all good advice, though, and I was glad to have it.
At this point, while Audrey and I were still whanging around in the rough air, Ian got on the radio to say it was starting to rain. Just then I felt drops in my face, and all I could think of was a recent glider advisory I had seen about some brand and model that had been found to become so unstable when mildly wet that it basically would just wad up and fall out of the sky. Not my Sport 4, I hoped. Audrey and I compared notes a little later as we were packing up, and we both felt a little overstressed just then. Just picture this: you're being blown toward a large lake and maybe not getting down as fast as you'd like, the air is rough, jittery, turbulent and unforgiving, your glider is all over the sky, your head is full of instruction coming in through the radio, you're trying to think as fast as you can, the clouds are scudding by and looking dark and menacing, and then it starts to rain. What next?!? you wonder. Tornadoes? Earthquakes? Lightning? Is it 2012 already??
Just then, at about 100 feet, some big wad of snarly, squirrelly air hit me and the glider had a frontal collapse. I had stayed out from behind the trees specifically to avoid such a thing, so I don't know where it came from. The collapse was centered about a third of the way from the glider center to the right tip so the left quarter stayed inflated. I dumped the speed bar, felt myself falling away to the right, and as I swung to the end of my slack lines the whole thing reinflated with a whack and a lurch. No time to worry or do anything, it sorted itself out admirably and all I could do was be relieved. Ian saw this clearly from where he was, and told me later that after that I took at least two more 30% right-tip collapses, but I don't even remember those happening.
Everything got resolved pretty quickly after that. Audrey landed nicely and killed her glider, not 50 feet from where I was headed. My approach had the feel of the moon landing – 2 meters down, 1 meter back, another 2 down, now at 10 feet above the ground, hands on rear risers, my boots scraped the plowed surface and I pulled the risers down hard and fast, and then all was still. Engines off. The eagle has landed.
I gathered up the glider in the breeze and headed over to the lee side of the trees to pack up. Audrey and I had a big hug and leaped around going "We're alive!" Ian got on the radio the first of probably four times to say he was being accosted by rabid dogs on his hike out. He didn't seem overly fond of the dogs, but apparently escaped without injury. After we were all down and safe, Jayson said they were heading down the mountain and would see us in about an hour. Audrey and I hiked out to the road and then about a kilometer back to the LZ road and waited there; Ian got a lift after the last of the dogs had a go at him and ended up back on our side of the river.
By the side of the road I laid propped up against my glider as we waited for our ride, and I mulled over what we had just been through. It was an interesting set of circumstances that led to questions. What exactly happened? Why was there so much lift over the valley? How were conditions different from what we could reasonably expect, given what we could see was happening? I think I figured out some of it. My best guess is that we were basically seeing a gust front blow north from Vernon up the river valley. At first I thought the valley lift must be convergence lift, and in a sense I think it was – the gust front came screaming up from the south, hit the stationary mass of air in the valley, and all the air could do was go up. That lift took Audrey way up high in an area where she should have been losing altitude. Obviously none of us detected the gust front until it was too late. The wind was calm in the LZ when we checked it before going up, calm to light on launch, and we didn't have a clear view of the river surface from that altitude (actually, this last thing isn't true - you can see it fine in the photo of Ian, so it was not windy when we launched!). The big question for me was why the wind near the ground was stronger than at altitude instead of the opposite. You should have friction drag near the ground that slows the wind. Maybe we did, maybe the friction layer was just compressed to really thin for some reason.
In retrospect, I think we all handled ourselves with grace and levelheadedness, although it's clear there were things we could have done better. With this new experience I think we will all three have a better feel for how to handle high winds. As Jayson pointed out to me later, there was a better approach possible once we knew that the wind had come up strong. We could have hugged the slope more and stayed higher, where the south wind was not nearly so strong, until we were well past the LZ and then worked down into the valley and backed into a landing. At the very least that would have given us more landing options than the worrying approach to the last bits of land before the giant lake. I was probably the one in the best position to take that path, but I committed to getting out and low and putting down as close to the LZ as I could, not anticipating how much the wind was going to limit my options.
Still, with all that, it was a wonderful flight! At some level you have to fly in marginal conditions to gain the experience to deal with marginal conditions, and the experience necessarily changes you. We all did that, and we did it well, and we came out stronger and more confident. To quote William Least Heat-Moon: "If you leave a journey exactly who you were before you departed, the trip has been much wasted, even if it's just to the Quickee-Mart".