Monday, September 24, 2007

Alaska helicopter wash

Heli Wash

I've flown paragliders around helicopters for filming a fair amount over the years, and always thought that flying a paraglider into helicopter wash would be a bad idea. I'm working on a series of TV shows at the moment involving a lot of paragliding and helicopters; somewhat inevitably perhaps, I've confirmed that paragliders and helicopter wash don't mix. Here's the rather long story I wrote on a recent jet trip home.

I always set up some basic rules for working with helicopters: a minimum of 1,000 feet separation to the sides, 500 behind, don't fly directly in front of me at my altitude at any distance, don't fly directly over or under me, don't fly within a 2000 feet of me while I'm under 500 feet (the most vulnerable place to be on a parglider is close to the ground, and this is also where a heli's wash spreads out the most). Rotor wash can last a surprisingly long time in the air and you can't generally see it after hover altitude, you just have to assume it's there and respect it. I've always thought heli wash would be particularly violent; the rotor is moving very fast, and moves a lot of air, especially at the slower speeds helis have to fly to match my speed. I also set some rules for myself: have a minimum of 500 feet of ground clearance, don't do anything but watch the heli pilot for the first shots so I can get a feel for his situational awareness, and keep an eye on the heli at all times. I do a thorough briefing with the pilot before each shoot that lays these protocols out, and in general it's worked well.

In Hawaii we had very good communications with the pilot, and despite shooting at cloudbase with good thermals things went well. I did have to alter course when the pilot flew directly in front of me at my altitude on my flight line (the direction I was flying would have put me into his wash maybe 5-10 seconds after he went by); I was on my normal paraglider (no motor) and had no problem turning. Part of the program with these shoots is that I'm often doing "pieces to camera," or PTCs, which just means that I'm talking to a small camera on a pole that I hold with one hand while flying the glider with the other, or just let go of the glider entirely if the air is smooth. I've done this a lot over the years and have gotten pretty good at flying one-handed even in strong air, the air in Hawaii was no problem. When the heli cut me off (he was far away from his perspective, no danger of hitting the heli or blades, just the wash) I was able to turn quickly with one hand. I still got a piece of his wash and took a small frontal, but no big deal. The pilot and I had a discussion on the radio, and worked well for the rest of the shoot.

In Morocco I again had a heli sequence, but there was a bit of a language barrier and poor coms with the heli. At one point the pilot flew directly in front of me at about 1000 feet of horizontal separation, so I wanted to turn and fly the other direction but it took a few seconds to get my hands back on the controls as I was flying a paramotor with high hook-ins and had let the brakes go in the smooth evening air. This put the controls at the limit of what I could reach, but I was able to turn away and totally missed the wash. I wanted a motor with lower hook-in points, but somehow that didn't happen despite my best efforts. High hook-in points are OK if you fly a glider with short motor-specific risers, but I also fly my glider a lot without motors, sometimes in the same day, so switching risers continually isn't an option, and I couldn't find risers with low and high hook in points for my glider. My normal motor has low hook-in points, I really prefer that system for many reasons but that's another story. High hook-in points and normal paraglider risers are a bad combination to launch as it's difficult to control the glider and impossible to front launch so a running reverse is the only way to go, but I got it done after some technique mods.

In Alaska we worked with one of the best heli pilots I've ever flown with, Dave King from Last Frontier. We were flying from near Palmer into different locations about 10 to 30 minutes of heli time into the mountains, it was always the highlight of my day to fly with Dave. He had a great feel for the air and machine, and taught me a lot about flying, truly a fine experience to fly over glaciers and among the peaks of Alaska. We did a few scenes where he dropped me high on a peak and then I flew off and landed on a massive glacier; tricky flying to put a heli on a sloped and convoluted icy glacier safely, but he did it smoothly as usual. I had a cameraman and the director in the heli shooting aerials, Dave kept distance well and I was very comfortable with him. He did fly in front of me at about 2,000 feet horizontal separation and I caught a small piece of his wash, just a "bump bump" movement, we talked about this and agreed that was about the limit for flying directly in front of me at my altitude...

We then did a paramotor (paraglider with a motor on my back driving a small prop) scene late one evening. We were all tired from a long day of shooting, but I managed to get into the air with yet another motor with high hook-in points, a real hassle. We were in a rush as it would be dark in about an hour, so I climbed to about 600 AGL as Dave took off and the camera team started shooting aerials. As the light was going I immediately started doing my lines to camera, which meant letting go of the glider completely due to the high hook-in points. The air was very smooth evening "glass," not a bump in it, so no big deal. When I do pieces to camera my situational awareness is greatly reduced, but I was trying to keep an eye on the heli as best I could. It flew in front of me at about 2,000 feet and slightly lower than me, no wash, no problem, I became more focused on doing my lines to camera before I lost the sun. Out of the corner of my eye I saw the heli cross in front of me exactly at my altitude and kinda close, but I was tired and the heli was only kinda close but not crazy close, and getting ahold of the brakes and turning would have taken time, plus the cruise control on the motor was broken (I'd rigged it to work with a sock I somehow had in my camera bag) so I didn't want to move my legs where I had it pinched and then have to mess with it again, and I'd just had a thought about how to do the PTC better, nah, it'll be OK. I did check my altitude quickly, still at least 500 feet, back to work. BANG!

The glider folded up violently. I haven't had an unexpected massive collapse like that in about ten years, it just doesn't happen. I knew immediately that I'd hit the heli wash. I dropped the camera onto its safety, and went for the brakes, which were harder to reach than normal due to the high hook ins. The glider re-inflated behind and to my left side judging by tension, then shot violently overhead and sideways to the right. With no brake input it carried on flying well below the horizon and to the side with one wing still stuck into the right lines, collapsed hard again as expected, and I fell back under it with the brakes finally in my hands. Quick ground check, still plenty of altitude to throw the reserve, good, glider doing a funky spin thing right, left brake, surge, start to stall left side, get it flying, easy, OK, stable smooth turn to the right with about 20 percent of the right wing still locked into the lines but the rest clear. I was able to hold flight heading with light left brake. I wanted to get the stuck side sorted but was totally unable to reach the lines that would help me do that, and a tentative pump on the right side caused an aggressive turn/stall feeling, nope. By this time I was only about 200 feet off the ground, and figured maybe I could motor back up and work on it with more altitude. I managed to find the throttle, which I'd lost during the maneuvers, but when I gently powered up the glider didn't like it, stall/spin feeling, nope. Throw reserve or not? I decided the glider was landable in its current configuration as I could fly it straight so I pointed it into the wind and sunk toward on the huge gravel flat below me. I had a clean landing then sat down and shook like a leaf for a bit, that sucked. I had about a half second of anger towards Dave, but that passed quickly as the real reasons for the situation had far less to do with Dave than a long string of poor decisions on my part:

1. I was flying late in the day when I was really tired, as was Dave. It was the fifth straight day of shooting and dong a lot of intense activity. I should have called the day.
2. I didn't repeat a thorough pre-flight planning session and briefing with Dave as we had done with the other flights; I was so focused on getting into the air that I forgot that any "stunt" with more than one person involved is a team effort, and it's my job to keep that team organized.
3. I rushed the situation to try and get a job done on a tight schedule (and because I wanted to fly).
4. I was flying a motor with high hook-in points on a glider with long risers. This greatly increased my reaction time 'cause I couldn't immediately grab the brakes.
5. The same high hook in points prevented me from reaching the proper lines (stabio) and possibly sorting out the stuck wing.
6. Everyone in the air was working to make a film and distracted to some degree. Dave is an excellent pilot I trust, but he is listening to the film crew and trying to get shots for them. I'd talked with the director and cameraman about safe distances and watching out for me, but they are primarily focused on their job, which is getting great shots. Nobody in the heli was paying full attention to absolutely keep that heli a set distance and position from me, nor was I properly watching the heli.
7. I did not have good coms with the heli.
8. I was not following my own protocol for distance, and was also letting the heli fly directly in front of me rather than all heli turns going away from my flight line and not crossing my path. I'd been lulled into a false sense of security with the heli's wash.
9. I was lazy about turning away from the heli when it crossed my path. Tired, etc.

What I did right:

1. I had 600 feet of altitude. There was some discussion of flying lower for the shot, but I kept to that protocol for exactly this situation. At the time I questioned whether I was being too safety oriented; my glider doesn't fold up very often, etc...
2. I was still one step away from a really bad crash as I was high enough to throw my reserve, which I had carefully attached to the motor that day. I actually had the option of flying another motor I'll call "B" that showed up at the last minute, but choose to fly the original motor as I'd hooked the reserve up to it. I knew the air was smooth, I've never needed my reserve in over 3,000 hours of flying, and motor "B" was lighter with slightly better hook-in points... It was very tempting to fly it, but I choose to fly the original motor with the reserve "just in case." What woke me up in a cold sweat was not the collapse, that's happened lots over the years, but realizing how close I had been to flying motor B without a reserve. Maybe things would have been totally different, but then again maybe I wouldn't have gotten control of the glider as quickly or I could not have recovered it in a flyable configuration... I would really have hated to be in that position without a reserve parachute, I literally woke up in the middle of the night with that realization.
3. I was flying a Gin Rebel, a DHV 2 glider that recovers well with no pilot input. I really blew that wing up, and it did recover. Thanks to Gin for that one. I often fly comp gliders, but I take the game down a bit for filming so I don't have to pay as much attention to the glider, and so it will recover better if it all goes bad. It all went bad.

What I'll do differently on the next shoot with a heli:

Go through the list above and correct each and every item on it. I also won't fly around helis again unless there is someone in the heli who knows paragliders and whose sole job is to watch the overall situation.

I also now know what it's like to fly a glider directly into rotor wash; it's been a bit abstract to this point, it's not anymore. If the heli had of been 100 feet lower or 100 feet higher it would have been fine I think, but I got the direct "slap." I can communicate this to future heli pilots based on personal experience and not, "Here's what I think will happen..." Concrete experience is better than abstract theory.

Some broader lessons learned:

1. Getting away with something stupid doesn't mean it's a good idea to continue doing the same thing. I let the heli fly directly in front of me, and then let it fly closer. The first clear sign of serious trouble could have been much worse. We do this in the mountains sometimes; ski a slope that's questionable, OK, that worked, little more questionable, OK, gee, I must be working with a "too safe" attitude, boom, it all slides. Apparently heli ski guides are very conscious of this progression and try to minimize it, but it happens in all risk activities, including things like trading stocks... A bad decision can work out OK for the wrong reasons, but it's still a bad decision that may have harsh consequences when that realization is finally made.

2. I do a lot of TV work and am very familiar with the "just one more shot" program. I've done hundreds of days of film/stunt work with no accidents, always under time pressure. There's never enough time on TV shoots, but I never let that define my safety margin. I let this one get away from me a bit, not due to any sort of direct pressure (in fact the director encouraged me to quit for the day, respect to him for that), but because I like working hard, and so did the team of good people I was working with. I normally try operate at less than about 75 percent of my "max" mental or physical capacity on a TV gig to keep myself sharp and strong enough to deal with the unexpected. I was operating near my mental and physical limit on this day, and it bit me. A good lesson to re-learn.

3. Like most accidents or near misses, this one wasn't the result of just one mistake. We use protocols in risk sports to safeguard not only against the obvious problems but to have a margin of error for the unexpected, including our own inevitable bad decisions. I broke most of my protocols but the two that I respected may have saved my life or at least prevented serious injury: I kept enough altitude to recover a fully collapsed glider, and I had a reserve "just in case." There have been a lot of times in the mountains where the "just in case" bit of thinking has appeared useless, but the few times I've needed the "bonus" it's been very, very important. In the long term respecting basic protocols and having the "just in case" mindset is very important for survival. You can shave the margin only so thin for so long before it isn't there when you really need it.

I'm off to Australia and then Arizona for more of the same great job, this experience will help me do a safer job of it all both on this shoot and on my own adventures. I hope the above makes it clear that I have no bad feelings toward anyone on the shoot, but just to make it clear I absolutely don't. I would definitely do the same job again with the same people, and would actually prefer that as the experience has made us all a bit more heads up. When we do a stunt or anything dangerous it all looks easy and like there is loads of margin--until there isn't. Experiences like this drive home the point. I'm very glad I had a reserve, as I was still one "level" away from this being a "I survived by the skin of my teeth" story, but that doesn't make it right. Play safe out there.

PS--The aerial shots look fantastic, the whole reason for doing this sort of flying in the first place!