Inverted and Broken, Part 2: All hell breaks loose

A couple of weeks earlier, Tom had come to my house to help me repack my reserve. At his suggestion, I rigged some webbing in my garage to hang my harness from, and stretched a big tarp out to keep things clean. We strung an old control bar from a rope to simulate the control frame so that I could do a practice reserve throw. I got into the harness with my helmet on, and Tom grabbed me by the ankles and started bumping me around to simulate turbulence. When the bumping got sufficiently violent, he said, “Okay, it’s no longer a glider!”, which was my signal. I grabbed the chute handle, threw it, and managed to get it out in the direction that I intended. We did it a second time so that I could try it with my left hand. Tom said that I did pretty well, he put me in the top 25% among people trying their first practice throw, and said that a lot of people don’t even manage to get the chute out of the container, or any number of other problems. I was glad that I did well, though I figured the chances that I’d ever need the chute were very slim. I had often said that I considered my reserve chute to be the most expensive thing I had ever bought that I had no intention of ever using.

The rest of this installment describes what happened during a period of about 60 seconds.

1600 feet or so directly above the LZ, and Jeff was already on the ground. The simplest thing would have been to just fly around and slowly burn off altitude, but it wasn’t the most interesting option. At times like this in the past, I had done things like stalls, or with my Mark IV, wingovers. And a mild wang or two was what I had in mind. Same technique that I had used before, pull in, pick up a little speed, let the bar out, and swing over to one side when the glider starts to climb. So I pulled in for about a count of three, then let the control bar out.

In general, I had not noticed much about the handling of the Ultrasport that seemed surprising, up to this point. One detail is that I had pulled full VG when I left the mountain, and I don’t remember releasing it. When I let the control bar out, I suddenly learned what it means to have a glider that’s very responsive in pitch, but stiff in roll. The roll input that I gave it was too little, too late, and I very abruptly found myself fully inverted. The glider had not just climbed, it had done a complete 180 in pitch, half a loop, and from my perspective, I saw the ground above my wing and the sky below me. This was accompanied by a sickening silence as I completely ran out of airspeed. With no more centrifugal or aerodynamic forces at work, the glider stopped flying and I lost my grip on the control bar and fell backwards into the sail.

I’m not sure if I’ve ever learned what you’re supposed to do if you stall a glider inverted. I might have made the mistake of trying to figure it out, trying to grab wires and pull my weight forward if I’d had a chance at that moment, which could have been a very dangerous thing. But something unexpected, unfortunate, and paradoxically fortunate happened just then: the glider broke. Specifically, the one of the outboard leading edges broke. I don’t know off the top of my head how many negative gees a glider is purportedly good for, but I wasn’t pulling very many at that moment. HG pilots give paraglider pilots a lot of grief about how they fly wings that can fold up in midair, but I can attest that, aluminum tubes or not, it can happen to our craft as well. As an indication of how quickly this happened, Jeff said that he heard the wind noise through my wires as I sped up, and by the time he had a chance to look up, the wing was folded. (Let me note here that although he had a camera with him, Jeff failed to take pictures, and instead concentrated on seeing to it that I was okay. That boy clearly doesn’t have the instincts to be a senationalist reporter!)

I say it was fortunate that the airframe failed, and that’s because as soon as it did, a voice in my head said, “It’s no longer a glider!”, and I immediately knew that throwing the chute was an absolute necessity. I did not go through any five step process of “Look, grab, pull…”, I just yanked the handle and got the chute the hell out of there. I don’t really remember that part very clearly, though I have a vague memory of trying to find a direction where there was clear air, which wasn’t so easy because the glider was spinning. I do remember seeing the bridle snaking away and knowing that was a good sign. Jeff said later that it was a strong throw, horizontal, and to the north. There was no sudden jerk when the canopy opened, and in fact I wasn’t sure whether it had opened or not until I pulled my head around the wing and saw the big red blossom. I also noted that there was some twist in the bridle, but that’s to be expected, the swivel won’t turn until a certain amount of twist builds up. There was debris in the air, mostly falling faster than I was. I remember seeing the nosecone and at least one tip batten; the deployment bag, the other tip batten, and the tip fairings were presumably out there as well.

I wasn’t happy about what was happening, but I couldn’t worry about that yet. At that moment the concern was where I was going to be coming down. I had started the wingover above the LZ, but this is New England, and fields are small. I had drifted back over the trees, and it looked like I might land in Mile-Long, the next field to the west, which we don’t land in because it has too much of a slope downward into the normal wind direction. I was still spinning, and I remember grabbing the floppy wingtip to see if I could do something about that. At some point the other outboard leading edge broke as well, but I’m not certain of whether that happened while the glider was still falling (I think it did). I remembered that there was some wisdom that said you should try to climb into the control frame, but I couldn’t find the control frame. The glider was hanging inverted from the reserve bridle, and I had slid off the trailing edge and was suspended beneath the glider, down by the reflex bridles.

My speed had dropped considerably. The fastest rate of descent recorded by my GPS was 2500 fpm down, and the parachute had slowed me over the course of 20 seconds to about 1000 fpm down. I spent about another 30 seconds under it, wondering what would happen next. Since I wasn’t alert enough to take any pictures during this particularly hectic minute, we’ll have to settle for some computer generated images.

First, a graph of my altitude, extracted from my GPS. Points are three seconds apart:

Next, perhaps more interesting, the first derivative of the graph above, that is, my rate of descent. Due to the granularity of the GPS, these graphs don’t really show the climb when the glider ent inverted, though it does appear as a brief lessening of my downward speed. After that, I was seriously accelerating toward the ground until the chute opened, and it took a while to get back to steady state. When I hit the trees, it looks like it still took about 12 seconds until I completely stopped moving:

And finally, a view of my trajectory as seen in Google Earth, as viewed from the north:

What happened was not a landing in the intended LZ, nor in Mile-Long. Instead, I came down in the strip of forest between the two, maybe only 50 feet or so from the edge of Mile-Long. I wasn’t on the ground yet, not by a long shot. Aside from the actual tossing of the chute, the other thing that I don’t remember clearly is coming down through the tree canopy. When everything stopped moving, I took a quick look around, saw a branch in front of me, and grabbed it. It was about 3 inches in diameter, maple, and I was holding on at least 10 feet from the trunk, but it was something. I looked down, and saw that I was about 50 feet up. I had stopped falling, but I had a long way yet to go, including the most dangerous part. After all, it it’s not the fall that kills you, it’s the sudden stop when you hit the ground.

To be continued…

Advertisements

About cleversky

Hang glider pilot in New England since 2004. Also an avid orienteer, and an embedded systems firmware engineer. And some other outdoor stuff.
This entry was posted in Ascutney, Flying days. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s