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By TjW
#400963
The critical thing is to use an approach that goes upwind of the landing spot.
From there, you can fly either a rectangle, cuttting corners if too low, extending legs if too high, or a circular-ish approach, tightening the turn if too low, rolling out if too high.
A straight in approach with figure 8s doesn't work all that well at the Crestline LZ, for example, because the place where you would be doing figure 8s is often quite lifty. So what happens is you wind up blocking the approach for awhile, as you do what looks to the casual observer like trying to soar the training hill. Even flying a rectangular pattern, I had one day where I gained enough on the downwind leg that I had to go back out and try again from a lower altitude. Three times.
A straight in approach from downwind of the LZ that hits more sink and/or more wind than you expected can wind up landing short.
If there's someplace a rectangular pattern doesn't work well, I'd be interested in hearing about it.
By bickford frederick
#400971
When the air is predictable, like a ridge soaring site or calm without significant wind gradient and turbulence, an aircraft approach isn't really necessary. My first comment was mainly addressing videos I've seen lately at McClure. My first few flights I did do figure-8s there.

I haven't had much airtime lately, but I flew McClure at minimum almost every weekend for several years. Sometimes I think my depth perception would be different. Standing at launch, it seemed like the landing area would be farther down or more distance away than other days. Mikie and I joked about it.. This is where a DBF-ish landing approach helps with gaining orientation. Flying upwind of your intended landing area allows you to gain a better perspective for preparation and landing.

The pilot in the video should've noticed he had too much altitude before it was too late. I only used that approach direction once just to do it and a couple times when the wind from the south was strong and everywhere else was too turbulent. For what it's worth, my 610 CF with flaps on could land with as much height as it looked like the pilot had in the video no problem.
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By DAVE 858
#400972
When the air is predictable, like a ridge soaring site or calm without significant wind gradient and turbulence, an aircraft approach isn't really necessary.
If you had to choose between the two, why would you choose not to do a DBF approach? I just don't understand the logic. I cannot see, in any circumstance, why a DBF approach would be considered not necessary. I think I may have struck a nerve here. Maybe people are realizing their landing approach skills need improvement and are trying to rebut my stance in a way of saving face? I don't know you tell me.

Here is what I have observed. I see a lot of people executing figure 8 approaches in topless gliders and flying just above stall speed. This is usually followed up by a full asymmetric stall and a whack with broken metal when they attempt to transition their hands. WHY IS THIS HAPPENING? IMHO I think there are people flying very fast wings who are afraid of going fast. The solution is obvious, but that would be SUCH A BIG BLOW to the old ego now wouldn't it?
Winds over about 12-15 mph I'll often prefer a figure 8 approach unless dictated otherwise by terrain. I don't really like those screaming downwind legs
The above quote more or less proves my point. Airspeed is of paramount importance. Ground speed should not be something to be feared unless something is grossly wrong with your approach. If you don't like to go fast fly a slower glider, but FOR FUCKS SAKE DO NOT FLY SLOW!!!!!
By once&future
#400973
Never said to fly slow, but if you've actually flown in high winds and the turbulence that can result you'd know that significant unplanned altitude and heading changes can result - I don't care if your airspeed is 25, 45 or 65, I've experienced this at all of them. Under these circumstances my ability to correct and get back into a better landing position is greatly enhanced by pointing closer to the wind and not messing around with a high speed downwind leg. Don't believe me, fine. I have the funny feeling none of us are going to change our opinions here. I tire of religious debates so I'll let the DBF zealots have their inevitable last word.
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By NMERider
#400974
Yesterday I did this 9-mile long DBF and reached the LZ with a little over a foot of altitude. Of course it helps to know the terrain and local weather.
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2017-11-11 GE final glide.jpg
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By bickford frederick
#400976
Dave, pilots land at ridge soaring sites like Funston and POM doing figure-8 approaches all the time.
By bickford frederick
#400981
When I first started flying KM told me about a time in the 80's he was on final approach and flying into severe sink crashing and going unconscious.

I would always fly much faster than best glide to not experience that scenario. Once in spring of 2012 I hit strong lift followed by strong sink on final like KM had warned about. I recovered by a couple feet, but if I was flying any slower I would've crashed badly.

Yes, I was doing an aircraft approach, and yes I knew it was going to be turbulent but I wanted to land anyways.
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By EricH
#400982
bickford frederick wrote: Sun Nov 12, 2017 5:30 pm Dave, pilots land at ridge soaring sites like Funston and POM doing figure-8 approaches all the time.
I thought we were talking about McClure??
Not known for ridge lift, or conditions appropriate for figure 8s.
Figure 8s work better with a lot of wind, and laminar air, most pilots don't fly McClure when it's that windy,
and it's a site that's very much not known for laminar air.

We have a saying "never land in a field you could thermal out of," if you're not flying upwind of where you're going to land, how would you even know if a thermal is coming or already there?
That's one of my main reasons for dbf, to test the air that's coming, especially with a top landing, since there will often be lift over the top of a hill.

While I don't necessarily agree about not landing if there's a thermal, I certainly never want to try and land while there's a butt kicking boomer breaking off.
A couple days ago I realllly wanted to top land because of no driver or retrieve, especially with a forecast of rain and a dirt road that turns to muck immediately. But it was also a very active day, very borderline for my top landing preferences.
The conditions were thermic with fairly sharp edges and the prevailing wind was too light for ridge lift, so I flew in front of launch to make sure the air filling in was smooth. I risked getting too low with lack of ridge lift, but that would be better than dealing with an active top of the mountain. I lucked out and there was a nice, smooth thermal, so I just flew around a little to make sure it had filled in all the way back in to my intended approach area.
Ended up with one of my nicest top landings: https://www.youtube.com/watch?v=ZhLHNMgYqg8

I not only couldn't have landed that accurately with figure 8s, I could have put myself in a potentially dangerous situation by not testing the air I was about to land into.

I used to think flying my approach very fast every time was the best way, but now, just as I like to sample the air upwind, I like to have a good maneuvering speed, but fly slow enough to feel the texture of the air so I have a better idea what to expect as I slow it down for flair. I also found that if you're coming in as fast as you can and something bumps you and you need a correction, there is no pull in left, so sometimes I was forced to let the bar out in order to complete a maneuver.
Of course, I pull in for extra speed on final, at about 50-100 feet.

I totally disagree that figure 8s are easier and/or safer in turbulence because you're doing a lot more turning, and it's a lot easier to get turned downwind. Doing all that extra turning, often with extra speed can wear you out, and with all that time flying perpendicular to your final glide the chance of an upwind wing getting lifted increases greatly. DBF gives only one leg perpendicular to the wind, and performing a diving or slipping turn toward your target should never prevent you from turning onto your projected final.

Nice 9 mile dbf NME :thumbsup:
By bickford frederick
#400983
Eric, Dave was talking about Woodrat (I guess) hg/pg pilots not doing aircraft approaches and asking in what situation would figure-8s or s-turns be acceptable. Earlier or later in the day is just fine.

"don't land if it's still soarable" is how I remember it going.

I also don't fly super fast anymore to get a better feel of air texture. I gauge my landing approach speed depending on wind conditions while simultaneously not trying to rely on wind socks or streamers because that only shows a portion of what's happening with the air above the ground and always needing streamers gets you in a rut. I won't ever fly at places like McClure if it's too windy again. That's no fun trying to land in and the flying is better elsewhere when it's like that.

"9 mile DBF" and barely making it back to AJX.. Like I said, that's stupid. Always leave yourself good options for landing.
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By NMERider
#400984
bickford frederick wrote: Sun Nov 12, 2017 8:00 pm.... "9 mile DBF" and barely making it back to AJX.. Like I said, that's stupid. Always leave yourself good options for landing.
Gosh Fred, I didn't realize you were such an expert on my glide path yesterday. Ya mean ta tell me that none of the dozen or so well-established bailouts along that path is safe to land at any longer? Or the hundreds of times I've flown virtually every inch of this same line hasn't taught me anything?
OMG, I could have died or at least skinned a knee or something. :owned: :rofl:
By bickford frederick
#400985
I don't know that site other than flying there a couple times. There didn't appear to be many decent spots to land other than the built up LZ or out in the flats. I'm more inclined to think of bail-out lz's as screw ups, not as reliable options..
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By NMERider
#400987
bickford frederick wrote: Sun Nov 12, 2017 8:30 pm I don't know that site other than flying there a couple times. There didn't appear to be many decent spots to land other than the built up LZ or out in the flats. I'm more inclined to think of bail-out lz's as screw ups, not as reliable options..
Gosh Fred, Isn't that a rather sad inclination "to think of bail-out lz's as screw ups, not as reliable options.." rather than merely places to land during the process of enjoying the freedom of the open skies as opposed to the stifling restraint of fishbowl flying? Don't you think that calling something you don't understand, "stupid" is in itself more than a little bit ignorant? Come on Fred. You can do better than just shoot from the hip without asking intelligent questions. I know ya can. :thumbsup:

Here's a really tight DBF....

http://www.youtube.com/watch?v=ih6PUKYyERU
By bickford frederick
#400990
I've managed to land in much smaller spaces. Do I want to do it again? No.

Wasn't that the configuration you were flying with when you fractured a vertebra in your neck at AJX from stalling into the ground?
By bickford frederick
#400992
Well what happened? I remember something with a drag chute and a crash and you didn't fly for awhile.
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