Wednesday, March 21, 2007

A scary lesson for me....

Well, while Jim was packing his wing on the Mauka side of the park, I had my own scary adventure. Jai Pal was watching from above. But let’s start at the beginning...

I was not going to fly today, but there is something addictive about checking frequently when on the computer – and so I did. Then Jeff’s messages were popping up, mentioning One-eye went out to check out Kahana (nah – will be too windy!!!). Checking back at Windlines: “One-Eye reports good conditions. Shucks!!! Can’t let that go. I abandon my chores, throw my wing into the car and call One-Eye. He is at the LZ, reports 50% clouds, more easterly conditions than the previous day, nice winds. Off I go. So are all the commuters heading up north from Kaneohe. Takes me forever to get to Kahana. 5:15pm at the LZ. Quick wind check – a bit stronger than perfect (for me) but still good. No wings flying yet, but a white helmet popping up at low launch. Hiking up. Once I got to low launch, two wings were flying, attached are Jai Pal and One-Eye. I called on the radio and Jim suggests not to hike up because they had to wait half hour for a lower cycle and rainsqualls were out there. But I am already here! Well, maybe hang out there for a while. So I did. Rain showers didn’t make it to Kahana and hit the shoreline north of us. Beautiful rainbows. Jai Pal reports he is on full speed bar at 1800ft. Jim replies that is why he is staying low and is using only half speed bar. That should have been my call to HIKE back down. I can activate my speed bar only partially. I had learned that with a somewhat unnerving experience on a previous launch a few weeks prior. Let’s not give up yet. It is getting late... I was up at launch at 5:30pm, finally unpacked my wing after 6pm... Ok, maybe a sled ride?

Jim wants to land. Jai Pal thinks so too – but says if I will take off soon, he would wait. I am not going to fly with nobody there so I start hustling (my lines were tangled again). Stronger cycles now, finally I clear the lines and pull up the wing and manage a pretty good take off. Off the brakes, onto the speed bar. Up, up but not forward. Slowly inch by inch I am going forward. I push as hard as I can onto my speed bar. Finally I get away from the launch making my way towards the ocean. My headset had unplugged from the radio. Over the ocean I relax and reconnect my headset to the radio, tell Jai Pal (in the air) and Jim (on the ground) that I am just going to head for the LZ because I am not penetrating against the wind enough to be comfortable with my partial speed bar.

I stay over the water while losing altitude; I am remaining over the water as I start my approach to landing. Then I thought I should get over the beach now (about one third down the half-circle beach approach). Oh no, though I am pointed almost exactly toward the ocean in landing direction I get sucked backwards over the trees. Speed bar, quick!! Still over the trees, not penetrating. I push as hard as I can onto the speed bar. Inch by inch I ease forward away from the trees. The trees are creating enough lift, so I don’t loose any altitude. I have my arms in torpedo position, completely off the brakes. I had taken my wrap out, pushed onto the speed bar as hard as I could. Inch by inch I move away from the trees. All of a sudden I reach the ‘downward elevator’, got over the edge of the water, felt safe, let go of my speed bar... What a mistake! I got sucked right backwards and upwards faster than I could think, back over the trees but with not much clearance now. Sh***!!!! What shall I do if I get sucked more backwards? Another mistake follows: I look into the direction I get sucked to and inadvertently must have weight shifted so that I took another leap towards the clearly threatening power lines. Double sh***!!! I’d rather choose those trees!!! Ok, just do whatever you can now. I got out of my seat and stepped onto that speed bar, my arms way up behind my back. Sometimes I had to give some brake input because it felt a bit wobbly there close over the trees but I was inching slowly forward again and sideways. Now I am almost at the wide spot, still over the trees. There is the tall dead tree. I am not going to clear it. Please lines, don’t get stuck on that dead tree... It doesn’t look soft as the others, but it sticks out and calls out. I feel one line catching on the dead tree branch and then un-catching. Sigh!!! Now sucking action gets stronger towards the bridge. I am standing on my speed bar, pushing, pushing hard against the bar. No flare needed, I come down smoothly, flip around, grabbing my B lines and pulling down the wing. Must have looked really cool for anyone watching. I was so scared though!!! It didn’t feel cool. I should not have been in this situation, but I got away with it. I escaped a tree landing by inches (or maybe worse was awaiting me behind the trees). I definitely learned a lesson from this.

As I was pulling one wingtip towards me and balling up my wing with great relief about the outcome, Jai Pal came in to land, on his speed bar, getting sucked backwards upon landing. It definitely got much stronger than it had begun this afternoon...

In retrospect, if I had not been successful inching forward, if I was going to be pushed beyond the trees, I probably would have been better off stalling the wing into the trees. Any comments are appreciated (other than to update my speed bar, which I will definitely do).


launch potato said...

Amazing that tree branch became unstuck. While waiting for wiser heads to chime in about that stalling idea, I will just relate some experience from stalling into Lake Shasta on a maneuvers clinic - OUCH!.

That's for a brakeline stall: the canopy drag snaps you backwards and swings you up, then the worse thing is when you are too low to recover from your horizontal position. You land hard on your back onto water, ground, or tree = shishkabob.

I never tried a b-line stall but have seen very scary ones done low. Check your PG manual about them being hard to modulate (stop and start delays and quirky transitions).

I have a good feeling about being able to modulate bigears, although dangers of this are noted more and more. Your PG manual may say it's stability (and sink) is helped by combining with speed bar.

A crazy idea for extreme need to sink down low is gotten from a ram-air kitesurf manual, so don't try this. If you can't pull in enough tip line, bring your hands together to put both lines in one hand. Then pull in hand over hand. BUT DON'T, just a brainstorm.

P.S. diamond head sensor fix ETA is 2 weeks. when chatterbox was last down, i had tried to say it looked kinda good.

JeffMc said...

Christine, good write-up on a potentially bad situation. I've similarly needed speedbar on my last two landings at Kahana - Not what you'd call "fun" :)

Let me be the first to say the following... "FIX THAT SPEEDBAR!". You should be able to get the pulleys on the risers to touch together ("100% bar", aka "full speed") when your legs are fully, but comfortably, extended with your feet on the metal bar (not the loop). With my Hobbit legs, you'd be amazed at how much speedbar line I had to chop to get it to the length I needed.

Good job on killing the wing too. Some good info on the subject here - Wing Kill


sandy said...

Wow Christine! I am so glad you made it out of that one!

Advice from Alex to me on one of those days where the wind picks up to such strong levels where you're likely to be going backwards is to back into the LZ. That is, line yourself directly in front where you want to land (or rather the most suitable of the most likely alternate LZs) then lose your altitude somewhere in front of your LZ. If the winds dip low enough that you actually have some forward penetration, great! As you now know, just a slight turn can get you closer to the LZ if needed. If you find yourself going forward more than expected (without speedbar), it can be kind of tricky to negotiate going backwards and so maybe then you can return to the normal approach. But if you are using speedbar, then you might be able to vary the amount to get you where you want to be (I'd stay out in front as long as possible). Landing in the water would be preferable to all of the hard stabby snaggy objects onshore.

You have described well the lift and venturi effect above the tree line. Be aware that the venturi in the "wide" area in front of the bridge has sucked one very strong man (aka Airborne) into the water and against the bridge at great peril. And I think that was after a successful landing. He got out okay, but it was a close one for him as well. On such a strong day then, I would prefer to land in front of the trees, as I think there is a lesser hazard in backing into or snagging my wing in a tree as compared to getting dragged through the stream under the bridge (ask Airborne). Landing in front of the trees does pose a significant challenge, though, with the strong venturi trying to pull you over the trees while you are above or near their highest point (stay way out front at that altitude) dropping to a lower windspeed while passing the height of the bulk of the trees, and then possibly some higher wind near ground where the wind can rush between the trunks. But the good thing is that the wind speed in front of the trees will be lower than in the wide stream (venturi) area, and so more likely for you to be able pull your wing down safely.

In answer to your direct question -- would I try to drop down into the trees to avoid the power lines? Yikes, I don't know. Tough call. If getting past the trees just isn't an option, I might try to get as much lift-->height above them then take my chances with the coconut grove behind, but I don't know if rotor from the trees might send you down right around the power lines. Very possible, too scary to think about. Better to just stay out front until at half the tree height then crab back.

Christine said...

Thanks Launch-Potatoe, Jeff and Sandy. Very valuable info. Jeff, great link - tons of information. Sandy, thanks for sharing, that is very helpful, very good advise. Ofcourse I didn't even realize what I was up to until I was already over the trees, but then ofcourse when I got myself in front briefly I could have applied this. Good to think this all through BEFORE having to use it, my brain was going 1000mph and I didn't have any better ideas than what I was doing. Since I was still going slightly sideways towards the widespot I must NOT have pointed DIRECTLY into the wind, thus didn't use all fwd potential I could have had.

Nick said...

Christine, I'm really glad you made it unscathed. I would definitely readjust the speed system prior to your next flight! Getting blown back or going OTB is a high concern for me. That's why my next glider will *have* to be faster than my current one (55 kph vs. 48 kph). I will also *have* be overweight in my glider. In other words, speed is VERY important to me. I think it would be beneficial to have a short discussion on what to do if being blown over the back. I only have limited experience since I’ve been blown over the back only once…and it was really a being drug over the back situation.

Here is my OTB story. I was in California, soaring my “backyard” 200’ hill (38°19'57.63"N, 122° 0'20.11"W). In this area, we get a weather phenomenon known as the “delta breeze”. It’s basically a venture funneling/sucking the sea breeze from San Fran to Sacramento. When the breeze is on, it’s about 85F in the summer. When it’s off, it’s about 100F. Well anyhoo, Lagoon valley is in the middle of the delta breeze, so it can be breezy at times from the SW. The delta breeze is much like moderate Hawaiian trade winds, but more gusty.

Well I’m soaring around for about 30 minutes, which is a long time for a 200’ hill, and the conditions are getting stronger. Had I been more experienced, I would have landed, but I stayed up and got into a situation of being blown over the back. The consequences of getting blown over the back in this situation was a barb wire fence, a few trees, and of course rotor.

I recognize the blow back situation and I’m on full speed bar coming down vertically. The middle of the hill is directly below me. Unfortunately I decide to come down in the “valley” of the hill since that is my normal lift off/comfort point. There is a venture in this part of the hill that pushes me towards the top of the hill as I descent. My grand plan was to land and kill the wing immediately. What ended up happening is that I landed with full speed bar, but as soon as I released the speed bar(upon landing) the resulted pitch back made me “miss” grabbing my D risers (which in hindsight was the wrong risers anyway…should be C risers). By the time I found my D risers, I was airborne again. My glider cleared the barb-wire fence, but unfortunately my body almost cleared it. “Almost” costed me a scar on my right arm and leg as the barbs hungrily tore in as I bounced off the top rung. Thank goodness my tetanus shots were current. Thanks goodness that I was not pinned against the fence with the full force of the glider trying to pull me through! I landed flat on my back after being drug over the fence with D risers in hand. My harness cushioning saved me from further injury. My helmet took a nice hit too. So Sandy, even though your harness has an exceeding big crusty butt, I can understand why you want it.

20/20 hindsight what could I have done better? Well, future OTB occurrences from my friends proved that you could land behind the fence w/o rotor. I could have also tried to kill the wing moments BEFORE landing, instead of AFTER landing. After that, I repeatedly practiced killing the wing before landing. I am now confident that I can kill the wing immediately upon landing.

This brings us back to Oahu scenarios. The consequences of being blown back are much more severe here. In contrast, Bill Heaner, a top pilot from Point of the Mountain, Utah teaches his students/visitors to immediately throw their reserve after being blown OTB. I’m not sure if that can be applied here.

Any thoughts from the more experienced pilots here? There comes a critical point in the OTB scenario where you have to determine whether you’re going to make it back in front (taking in account the venture effect as you get closer to the cliff/hill) or whether you’re going to turn and burn with altitude and ride it out.

My 2 cents.

firedave said...

Christine: It sounds like just another fun day at Kahana!

Just a few comments from someone who has inadvertantly gone over the back only once, with a tandem. and who has sweated being blown back (like you) countless times.

If you are pinned at launch, you should expect similar treatment at the LZ. So the approach should have been as low and out front as possible only passing over the beach to put your feet down. The wraps were probably unnecessary. Do you use any brake when on speedbar? Only use it for strong ossicilations. Most of the speedbar problems have to do with riser/harness incompatibility, the speedbar in regular flight should be almost flush to the bottom of the seatboard with minimal slack, half inch or less. Another option for applying speedbar if not to bumpy is to grab the Brummel hooks and pull down, it is a little strain but you get the full effect.

Standing up on your speedbar was an excellent idea in three ways: 1)it sometimes allows you more pull do to the changed harness geometry, 2)it increases your sink rate and forward speed, how you ask? Standing up causes more drag on the pilot, this causes the pilot to be pulled back while the wing moves forward essentially degrading your glide while sending you down a steeper glide angle; and 3) you have your feet below to brace for any sudden impacts.

If you are still making progress moving perpendicular to the wind, then you are not using all of your speed against the wind, it doesn't take much angle to really slow your forward progress.

The venturi is a terrible place to land in strong wind, for all the reasons that the owner of the "crusty puffball" stated.

I personally don't let go of my brakes in any wind. I find better results surging the wing forward momentarily, then burying my brakes while walking downwind toward the wing, for both the solo or tandem. ( for tandem you just need your passenger to walk downwind ahead of you).

My other favorite landing technique for high wind is the kitesurf drop. I just touchdown with the wing moving laterally and let the momentum of the wing crumple it into a nice pile by your side, that one is the winner on the beach at Diamond Head where you are concerned about water and kiawe bushes.

As far as stalling it into the trees, the outcome would be too unpredictable and I would never recommend it. In a stall the glider falls behind you and you essentially fall back under the glider to regain flight If you were somewhat high you could turn and burn to get behind the powerlines, but it doesn't sound like it was much of an option. I think the only reasonable thing to do at that point would be to ride it out, straight into the wind, as soon as you got into the rotor of the trees you would probably gotten spanked around quite a bit and probably surged into a tree landing or if lucky onto the grass. But job number one at that point is to keep the glider above your head, period. Hitting the powerlines could be bad as it would probably deflate your wing and you could fall a distance.

Blah, blah, blah. I talk too much.
I guess you just need to take it as an intense learning experience and walk away with a healthy level of respect for excessively strong flying conditions. Oh....and have fun!

Brazilian Ray said...

to keep it short:
- learn from experience(s). Thanks for sharing yours!

- fix your speedbar;

- Avoid putting yourself in bad situations: pay attention to the weather (it changes), follow your instincts (and always choose in favor of safety);

- in windy conditions set up way upwind... and "flare" is just a touch in the brakes.

everybody is right about their inputs. check the web (thanks Jeff McCloud) set up upwind (Alex/Sandy), practice killing the glider (personally I like to kite in high winds, so I can turn arround to kill it, but Nick's approach is great and recommended).

aloha and fly safe :)

Christine said...

Thx for all comments. Dave, I don't use brake (much) with speedbar since it seems contradictive. I do keep just enough brake pressure on though to feel the wing. I released all of it when I didn't move fwd.

Weird: Yesterday Billy and I attached my speedbbar to my risers with the harness and me in a playground made simulator and I seem to get nearly all the travel up to the pulleys together. One side of my footrest was twisted (the speedbar is channeled through my footrest). I untwisted that but it doesn't look like I could shorten the speedbar lines without engaging in neutral flight. On a previous flight, after Alex suggested I should test whether I get "pulley-to-pulley" when engaging the speedbar, I did NOT get it. On the decribed flight I didn't even look how the pulleys looked because my mind was occupied with getting away from the trees. Could I get a different result in the simulator than in flight? I guess I have to try it again in flight on a less windy day. What I noticed and hadn't thought about before is that it seemed to be very important to use both legs equally so that not just one side of the leading edge gets compressed. Maybe when I tried it before I got only the untwisted side engaged and looked at the other pulleys? But the wing flew straight?!

firedave said...

yeah christine, it has ben a long standing problem over the years that with the speedbar adjusted as high as possible the pulleys on the harness just won't speed systen to go pulley-to pulley. I fly with a couple of different gliders so I don't have any interest in modifying my harness, so I re-routed the speedlines on my Mantra to be a 2to1 instead of the standard 3to1. The downside is increased bar pressure, the upside is a cool short throw speedbar. I lock my knees in the bottom loop and I get half bar, on the top bar I go pulley to pulley.
Another option I have done is to put pulleys on the corners of my speedbar and attach the speedline back to the harness, this one gives you a 1.5 to 1 pull, but the friction of the pulleys makes it a little stiff.
Anytime a pilot needs to be on bar, such as the guys before you, to maintain normal flight is a potentially bad time to fly.

Small gliders rule!

Christine said...

SPEEDBAR UPDATE: In flight (tested today at Kahana) it is different (from the sim). Got about halfways between the pulleys, so I might need to do a two stepper after all. Maybe the difference is because of streched lines in flight???

Christine said...

Thx Dave, maybe I will bring harness and speedbar to the party tomorrow (just kidding, it's not a paraglider party, its a BIRTHDAY PARTY!!!!) I do have my original speedbar (somewhere). Rob Sporrer updated mine to a speedbar integrated to a stirup

Brazilian Ray said...

yes, it is different. the sim uses some other brand or set of risers.... and it is totally not like in flight.... it is "ok" to adjust the harness, but not the speed bar.
and bring your harness to the party.... we'll check it out!