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noman3
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Joined: 09 Jan 2009
Posts: 4621
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 Posted: Wed Aug 26, 2009 2:12 pm Post subject: |
 #41 |
| BubbleBoy wrote: |
You are exactly right on Wing ... it's not the glider that is behaving different upwind to downwind, but rather WE behave differently.
JB
| Wingspan34 wrote: |
When I've found myself coming in down wind, I've experienced this "glider falling not flaring" effect as well. I attribute it to the fact that I am paying too much attention to the ground zipping by and, as a result, miss time my flare towards the late side. Basically, the higher ground speed psyches me out of feeling for the proper moment to flare.
Lesson: It's best to ignore ground speed when preparing to flare. Go by the feel of the glider, not its apparent speed over the ground.
| BubbleBoy wrote: |
| CAL wrote: |
| the funny thing is when you do flare hard in a tail wind the glider does not shoot up it just goes down |
A glider flares the same, upwind or down ... no difference of merit. It's not until feet (or other glider part) touches the ground that any practical differences come into play.
It's very common for pilots to think that the wing behaves as you describe due to wind direction, but it's simply not the case.
JB |
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this is starting to sound like a old argument that i was on the wrong side of,not to long ago. |
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therms
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Joined: 31 Mar 2008
Posts: 149
Location: australia
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| Posted: Tue Mar 09, 2010 12:15 am Post subject: dont look down |
#42 |
i agree with fly surf n ski ...looking down is the worse thing you can do...for sum reason you stand beta chance of judging flare time when your looking ahead not down  |
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jimrooney
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Joined: 23 Feb 2008
Posts: 1713
Location: Queenstown, New Zealand
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| Posted: Tue Mar 09, 2010 12:33 am Post subject: |
#43 |
| Quote: |
| DON"T LOOK AT THE GROUND. |
You should never be doing that anyway. But that's probably the #1 most important bit.
#2... get your wings level.
Try and take as much xwind component as you can, but only if you can get your wings level. Touching in a turn is going to hurt a LOT more than if you're level.
Wheels.
If you've got grass and wheels... well good for you... you're lucky while being unlucky. Here's a trick for ya...
Come in prone (if you have wheels and grass!)... slow the glider to trim... then shove that puppy out. It's the same as flaring at trim, but you'll be on the basetube... it'll help heaps though. Your belly will touch first and slow you rapidly. Hopefully enough to help you need the wheels less.
I've accomplished this at Lookout from a low weaklink break without wheels and downwind on a topless. The aluminum airfoil basebar just slid on the ground by the time it touched. Very tricky stuff and a good helping of luck.
Uphill 
But then, if you've got time to line that up... why are you landing downwind?
That being said... if my only two choices are into wind or uphill... I strongly favor uphill.
Oh yeah... and did I mention.. Don't look at the ground! ;)
Jim |
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ChattaroyMan
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Joined: 01 Nov 2009
Posts: 1790
Location: Chattaroy, WA -USA
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| Posted: Tue Mar 09, 2010 3:49 am Post subject: |
#44 |
| noman3 wrote: |
| BubbleBoy wrote: |
You are exactly right on Wing ... it's not the glider that is behaving different upwind to downwind, but rather WE behave differently.
JB
| Wingspan34 wrote: |
When I've found myself coming in down wind, I've experienced this "glider falling not flaring" effect as well. I attribute it to the fact that I am paying too much attention to the ground zipping by and, as a result, miss time my flare towards the late side. Basically, the higher ground speed psyches me out of feeling for the proper moment to flare.
Lesson: It's best to ignore ground speed when preparing to flare. Go by the feel of the glider, not its apparent speed over the ground.
| BubbleBoy wrote: |
| CAL wrote: |
| the funny thing is when you do flare hard in a tail wind the glider does not shoot up it just goes down |
A glider flares the same, upwind or down ... no difference of merit. It's not until feet (or other glider part) touches the ground that any practical differences come into play.
It's very common for pilots to think that the wing behaves as you describe due to wind direction, but it's simply not the case.
JB |
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this is starting to sound like a old argument that i was on the wrong side of,not to long ago. |
OK, I'll bite and argue that the glider does behave differently downwind than upwind - if there is a wind gradient. Flaring upwind can put your glider's nose into a slightly stronger head wind than at ground skimming level. If so, that would tend to slow your nose relative to your ground skimming level. Doing this downwind you're putting your nose up into a faster tail wind. Upwind this situation will help lift your nose. Downwind it will tend to keep you from making a decent flare.
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enormydude
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Joined: 03 May 2008
Posts: 221
Location: NSW, Australia.
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| Posted: Tue Mar 09, 2010 4:58 am Post subject: |
#45 |
Just one thing about landing cross wind which caught me out the other week - I landed my mosquito with about 5-8kts fully crossed. Approach & flare was normal but I forgot two important things:
1) After coming to a halt you just gotta get that nose down straight away or the wind will get under that windward wing and... well I nearly turtled but was saved by a lull. Turtling with a power harness would really suck!
2) Landing with a powered harness means you have two extra legs behind you which resist you from turning your body into wind so you have to stand with your body twisted to yaw the wing around if you want to get head on again. Then take side steps to get the legs in-line again. Not really a problem, it's just like driving a logging truck or something :-)
That was my first 'maintain crossed till after landing' attempt - usually I somehow arc the landing run around into the wind - level and flare. Funny I don't even know how I do it but it just seems to happen automatically. Best not to overthink it hey!
Cheers, Norm.
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johnpeace
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Joined: 01 Jun 2009
Posts: 644
Location: NE Georgia
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| Posted: Tue Mar 09, 2010 6:46 am Post subject: |
#46 |
All it takes is one weed tall enough to wrap around the basetube as you are sliding in on your belly to stop the glider instantly.
You go swinging face first up into the leading edge, keel, nose plate when that happens and can get hurt SERIOUSLY bad.
Wheels are not for landing on!!
| brandonRussell73 wrote: |
As a pilot that hasn't had enough experience yet to have a down wind landing I've wondered this as well. I agree with flare aggressive and run like you stole something but ... other than ego ... why don't H3 pilots (and from the stories I've read even some H4's) just put it down on the wheels (assuming you fly with wheels). Is there risk involved with landing on wheels downwind that I'm missing?
Thanks all
-Brandon- |
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DBrose
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| Posted: Tue Mar 09, 2010 8:24 am Post subject: |
#47 |
fly super fast then throw your parachute!
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Alex
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Joined: 21 Jul 2006
Posts: 261
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| Posted: Tue Mar 09, 2010 8:36 am Post subject: Re: Tips for landing downwind |
#48 |
| Sky_Walker wrote: |
So what techniques do you use when you find yourself already on final and realize the wind has shifted and you have no choice but to land downwind. I had a pretty nasty wack this weekend, I tried dragging my feet to slow myself down as much as possible before flairing but couldn't manage to run hard enough to keep the glider from wacking.
Obviously the best idea is not to land downwind but what are you guys thinking when its unavoidable ??? |
Make it a crosswind--better chance of survival. |
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Wingspan34
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Joined: 14 Mar 2007
Posts: 5652
Location: Central NY
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| Posted: Tue Mar 09, 2010 8:50 am Post subject: |
#49 |
| ChattaroyMan wrote: |
| OK, I'll bite and argue that the glider does behave differently downwind than upwind - if there is a wind gradient. Flaring upwind can put your glider's nose into a slightly stronger head wind than at ground skimming level. If so, that would tend to slow your nose relative to your ground skimming level. Doing this downwind you're putting your nose up into a faster tail wind. Upwind this situation will help lift your nose. Downwind it will tend to keep you from making a decent flare. |
I agree with this theoretically. But I do wonder how many times there is significant gradient between 8 feet (2 meters) and 12 feet (4 meters) of altitude? That's about where your nose is between level flight and full flair.
For the most part gradient will be much more pronounced somewhere between 100 feet (30 meters) and 20 feet (6 meters). As long as significant gradient conditions exist only above 15 feet (5 meters) they won't have any effect on a pilot's down wind flair.
I could see your described scenario occurring if a pilot dropped down on final with 10 foot tall (wind blocking) obstacle directly behind them. But that would be very unusual.
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remmoore
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Joined: 24 Jul 2008
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| Posted: Tue Mar 09, 2010 9:19 am Post subject: |
#50 |
Forgive me if someone has already posted this type of answer - I didn't read every comment befoe posting.
I think the trick to beating a downwind landing on a flat slope is focusing hard on feeling the glider's flare window open - despite the visual sensation of going much too fast.
In the few times I've been caught in this situation, I will already be aware that there is a chance that I might choose incorrectly. Typically, this will have been during an XC flight, where the wind is fairly light on the deck, and I haven't been able to pick up a decent ground-based wind indicator. I'm especially prepared to feel what the glider is telling me as I come into ground effect.
Even using perepheral vision, I know what the ground rush will look like if I'm going into the wind, or in no wind. When the wing is rushing along the ground faster than normal, but the glider is starting to enter the flare window (air speed reducing, feeling a bit mushy) I know what's going on. I try to jamb that flare as quickly as possible, and get ready to run if needed.
Having a good feel for the glider's behavior as it enters the flare window is the key, IMO. When you flare because it feels right, instead of when it looks right, you've conquered the biggest part of many landing scenarios.
RM |
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Jason
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Joined: 02 Jan 2007
Posts: 7530
Location: Stapleton, Colorado
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| Posted: Tue Mar 09, 2010 9:54 am Post subject: |
#51 |
| remmoore wrote: |
Forgive me if someone has already posted this type of answer - I didn't read every comment befoe posting.
I think the trick to beating a downwind landing on a flat slope is focusing hard on feeling the glider's flare window open - despite the visual sensation of going much too fast.
In the few times I've been caught in this situation, I will already be aware that there is a chance that I might choose incorrectly. Typically, this will have been during an XC flight, where the wind is fairly light on the deck, and I haven't been able to pick up a decent ground-based wind indicator. I'm especially prepared to feel what the glider is telling me as I come into ground effect.
Even using perepheral vision, I know what the ground rush will look like if I'm going into the wind, or in no wind. When the wing is rushing along the ground faster than normal, but the glider is starting to enter the flare window (air speed reducing, feeling a bit mushy) I know what's going on. I try to jamb that flare as quickly as possible, and get ready to run if needed.
Having a good feel for the glider's behavior as it enters the flare window is the key, IMO. When you flare because it feels right, instead of when it looks right, you've conquered the biggest part of many landing scenarios.
RM |
thats a pretty good answer
I would add one thing---on ANY flare, you flare when it feels right by knowing what the gliders airspeed is by feel
How hard you flare is a different matter entirely...
and this is based on visual references(groundspeed) from which you can determine if you are in a headwind/tailwind and how strong it is.... ie if you are coming in and its time to flare(say 15 mph airspeed)..but you are only doing 3 mph ground speed. clearly you don't want to JAM a flare since you will grind to a halt airspeed wise..which means you will be going backwards at 12 mph---turtle time
if its time to flare and you are doing 15 groundspeed (no wind).. you want to give it a solid flare
if its time to flare and you are doing 25 ground speed. (10 mph tailwind) hit that flare like it was talking bad about your mother. and run after that mother *********
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troll
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Joined: 05 Mar 2010
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| Posted: Tue Mar 09, 2010 10:20 am Post subject: |
#52 |
The random chance of landing downwind seems like enough reason to practice and use 'full' flares and one step landings on every flight.
In other words teaching the moonwalk or wheel landings seems like a disservice to those who plan on flying in anything but the most predictable coastal conditions. |
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gotandem
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Location: Jackson Hole, WY
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| Posted: Tue Mar 09, 2010 12:46 pm Post subject: |
#53 |
In the late '90's in Laragne, I repeatedly saw a Frenchman land downwind on purpose. Sometimes the wind would be more than 10 mph.
He stuck one wingtip in the ground before he reached trimspeed.
Once he ended up with the glider pointed straight into the wind. He had to step a few step backwards. Another time the glider did not loop all the way around. That's when he had to run sideways with it. Both times looked very controlled. No damage at all. He didn't have to run hard.
I'll just remember that trick for when I really F up. I think it's a good alternative for when you run out of room. People with RC glider experience have probably seen this technique. It can be allright but only if you go downwind!
Bart
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blindrodie
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| Posted: Tue Mar 09, 2010 12:49 pm Post subject: |
#54 |
So you are suggesting an intentional ground loop?
Hmm interesting theory. 
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Erik Boehm
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| Posted: Tue Mar 09, 2010 12:50 pm Post subject: |
#55 |
| gasdive wrote: |
If you flare right on stall all you get is a mush to the ground right on stall speed. So you hit the ground with stall speed plus tail wind. That's not just a whack, that's a crash and a possibly fatal one.
Flare as you normally would (assuming you flare normally 2-3 knts above stall, ie trim). So flare at trim on most gliders. The only difference: flare **Fast**. You want a big stall across the *entire* wing, root to tip. Feet well back.
At Stanwell the LZ often goes katabatic. The summer sand would be soft and not much fun to run in. Could usually land them with one or two steps, often no stepper even in a light tail wind.
As other posters have noted, uphill is even easier. We would often land "fly on the wall" tail wind up hill in light but soarable winds. There is tussock grass that is impossible to run through and they were all landed no steppers. Key is to come in with plenty of energy. Allowing the glider to drop down near stall would be a *disaster*.
Cheers Jason = |
Right..... flare at stall= contact ground with airspeed just below stall speed.
This may result in a runout in no wind, but with even a little downwind, its far too fast too run...
But as he was saying about the weight of the glider....
If you flare above stall speed, you will gain some altitude... lets say 5-10 feet *10 feet being a premature flare IMO) - now considering your AOA, you will decelerate rapidly, when you make contact with the ground, you should be at pretty close to zero airspeed.
But with a tailwind.... that means you need to hit the ground running... no easy feat when you're trying to hold 70+ pounds up with your arms over your head.
Its hardly the running form/technique of an olympic sprinter, and you've also got to absorb the shock of falling, even if your vertical velocity is only equivalent to a fall from 3 feet (the air resistance is significant and a falling from a full flare at 10 feet, isn't as bad as just falling from 10 feet with no glider attached), its still going to require you to adjust your stride.... combined with the up-stretched arms and the glider putting you off balance... and the fact the ground will be uneven (which is why your wheels, if you have them, are next to useless), running it out is pretty hard, even if you can run fast enough on the track.
They are avoided for a reason.... but a good flare, started before you reach stall, can ensure you only whack at windspeed - focusing on the ground can get you whacking at significantly higher than windspeed.
And hey... if you are nimble on your feet, you can further reduce the impact forces, or avoid them entirely.... but I wouldn't count on it
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gotandem
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Location: Jackson Hole, WY
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| Posted: Tue Mar 09, 2010 12:51 pm Post subject: |
#56 |
Yep. You could call it that. Groundloops into wind are very dangerous. In a tailwind they are much more benign.
Bart
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Jason
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| Posted: Tue Mar 09, 2010 1:00 pm Post subject: |
#57 |
| gotandem wrote: |
Yep. You could call it that. Groundloops into wind are very dangerous. In a tailwind they are much more benign.
Bart |
I have seen this work wonders.....my old man when I was younger found himself heading downwind at low altitude flying straight at a barb wire fence witha road a barb wire fence on the other side
he figured he could pop over one fence..but not both......so he grabbed the left downtube with both hands and curled into the fetal position around it....his body swung thru putting his arms in tension. and slide the glider to a halt dragging the wingtip. walked away with out a scracth. he claims he didn't break a downtube.....i don't really remember if he did or not.......the one he was holding definitely bent
one thing to keep in mind though...its pretty much impossible to break a bone in tension like this----he refers to it as a crash technique
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hiflioz
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| Posted: Tue Mar 09, 2010 3:07 pm Post subject: |
#58 |
This is a fascinating discussion, with lots of different ideas to mull over (and hopefully not need to try!).
I've never done this but my flying buddy Easterly Plumbing, as another pilot mentioned, sometimes comes deliberately in downwind. He flares hard and fast *from the back wires* when coming in downwind. He holds it and runs a few steps. I've seen him do several on flat sand in up to 6 kts tail and I have never seen him whack.
I have a bad feeling that this would not be the case for me, though, because my flare timing and strength is far from impeccable! I misjudged glide at Corryong earlier this year, in an undulating paddock, and came in downwind AND downhill (missed the crest of the undulation). No damage to me or glider after a big flare but I was VERY grateful for my hard plastic Rohan Holtkamp wheels, which rolled several feet on the hard dry paddock (the nose didn't drop at all). THere were random small scattered rocks about - not big enough to see from the air, but big enough to damage a kneecap should I have come down on one.
A few people have mentioned wheel/no wheel benefit, but in this case I think it was *the combination* of full flare PLUS wheels that saved me and my glider from injury. If I'd tried either one without the other (ie no stepper flare OR coming in on wheels) , I suspect the consequences would have been more severe.
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Spark
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| Posted: Tue Mar 09, 2010 3:50 pm Post subject: |
#59 |
| JohnPeace wrote: |
| Wheels are not for landing on!! |
not to be contentious, but like most everything .... it depends. peace.
I agree that you can be hurt badly by choosing to land on wheels.
There will be a time in my future when I either have to give up the sport, or choose to land on wheels.
So far, the only deliberate wheel landings I've done is once to test the wheels and a couple dozen tandem landings.
The only time I've ever really needed wheels (and didn't have them), I spiraled my L humerus landing downwind at Slide Mtn. and had to pay a fortune for a helicopter ride to the hospital. (side story ... I stayed out of the news through loud profanity and obscene hand-gestures with my unbroken arm)
The velocity of the downwind is very relevant in this decision process.
I ditto Jim Rooney ... if I've screwed up enough to be landing in a downwind situation, I'll look for some uphill. Only because I've had a bit of practice at it.
I wouldn't recommend an uphill downwind landing to a low-time pilot with decent wheels.
Best to avoid the situation.
So a relevant thing for all pilots to know is ... how to avoid downwind landings.
Is there a thread on catabatic flow ?
Anyone fly with a drop-streamer ?
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Cloudhopper
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| Posted: Tue Mar 09, 2010 5:46 pm Post subject: |
#60 |
Wingspan
If you cant's manage 5 mph with a glider, how do you foot launch? Are you a tow-only pilot?
In all this discussion, no one has mentioned using the rear wires to flare. I used to do it all the time, and if you have the right kind of harness (cocoon) it is really easy. Takes the timing almost completely out of the flare calculation.
Finally, landing at high density altitude is like having a tailwind no mater which direction you land, although I guess in thinking about it, it might still be possible to touchdown with zero airspeed, and (in no wind) zero forward speed. Just that the groundspeed in the final seconds before flare will be higher than usual. Many of the same techniques apply to high elevation landings. The biggest difference is that you know when you launch from Gold Hill in Telluride that you're going to be landing at 9 grand. |
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