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#31
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Another stall spin
One point not reiterated yet here -- the atmosphere down low is very different from what you're used to at 2000 feet and above. It's easy to say "I haven't unintentionally stalled /spun in a thermal in a thousand hours. How much of a dope do you have to be?" A short list of what's different down low: The atmosphere is much more turbulent. Thermals, such as they are are much smaller. In this layer, many small punchy thermals will start. Many will die. The ones we use up higher consist of many little parcels of hot air that have coalesced. Most thermals are either short lived, or basically unworkable to a modern glider. You're in the boundary layer where wind is being affected by the ground, so there is wind-induced turbulence. Punches of strong lift/gust followed by sink when you make a half turn will be the norm. The ground picture will be totally different to the pilot. If you turn downwind at altitude, you don't notice that much. If you turn downwind at 300 feet, all of a sudden the ground will rush by and, this being a high stress moment, you may pull back. Just as the gust you turned in fades, or the thermal turns to sink. And when the canopy fills with trees going by at 70 mph, the urge to pull back will be really strong. You may push forward to recover at altitude, but it's really really hard to do with the ground coming up fast. So, just because you've never unintentionally spun at altitude does not mean your chances at 300 feet are the same. Not to raise a tired subject, but why we give out contest points for thermaling at 300 feet or below remains a puzzling question to me. John Cochrane |
#32
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Another stall spin
Bob, I'm not quite sure what your point is. In fact, you seem at first to suggest that practicing unusual attitude recoveries is a bad thing!
That flies completely in the face of all aviation safety training I've ever had. You have to know the beast and how to defeat it (or at least hold it at bay). If you are not practicing departure recoveries at a safe altitude, how the hell are you going to have any chance of recovering following an unplanned (aren't they all?) upset at low altitude, whether on the ridge or in the pattern. But spin training in a Blanik, while fun, may be actually counterproductive if you fly high-performance glass. You have to train in your ship, or something very similar. I agree that there is nothing new to learn - but the same old lesson has to be relearned and practiced - Plan for emergencies, practice how to cope with them, avoid situations that exceed your actual, current skill. And painfully, learn from other's tragic mistakes - their loss may save you.... Kirk 66 |
#33
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Another stall spin
On Tuesday, August 28, 2012 11:08:01 AM UTC-6, John Cochrane wrote:
snip So, just because you've never unintentionally spun at altitude does not mean your chances at 300 feet are the same. snip John Cochrane Excellent point John, and for the same reasons I think the spinning intentionally at altitude and being confident you can recover may provide a false sense of security when thermalling low. It just isn't the same when done done at 300 feet. Brian |
#34
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Another stall spin
Jim was a bit above the sight line of the trees bordering the airport and I would estimate maybe 3/4 of a mile away. Based on this, I would estimate his altitude as being on the order of 300 feet or so. That the glider rotated only a portion of a turn before impact would support this estimate.
snip UH Thanks UH, That is the information that 99% of us were missing from this accident. Would be nice to have some flight recorder evidence to confirm it if available, but understand it might not be available. Would also be nice to have similar information about the other accidents. Brian |
#35
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Another stall spin
And when the canopy fills with trees going by at 70 mph, the urge to pull back will be really strong.
You may push forward to recover at altitude, but it's really really hard to do with the ground coming up fast. This reminds me of personal aerobatic experience and being inverted at 45 deg nose down at 1000ft. The normal pushing and rolling then goes against everything your gut tells you to do. It also reminded me of this crash in the UK, by an aerobatic pilot who was obviously very familiar with spinning this particular glider (although not at gusty weather I suspect): https://www.youtube.com/watch?v=zxbulrrQVig Roel |
#36
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Another stall spin
On Saturday, August 25, 2012 10:11:45 PM UTC-6, Jp Stewart wrote:
From TA's Dansville contest write-up: "Unfortunately, we were also saddened to hear of yet another apparent stall-spin fatality; Jim Rizzo, Finger Lakes club president and FAA Designated Examiner for the area was killed when his glider crashed into a farmer’s field not far from the Dansville airport. Jim was not part of the contest and was just flying locally when the accident occurred. All we know is what the farmer said (and this is 3rd hand to me) that apparently Jim was trying to thermal away from a low altitude and spun in (sound familiar? – it should – this is the 3rd almost identical fatality this season here on the east coast)." http://soaringcafe.com/2012/08/day-6...ille-region-3/ JP "She's not answering the helm, Capt'n" - departure from controlled flight. I think there was an article in some aviation publication with the above title. It holds the key to maintaining control. If you look carefully at Bruno's video of the inadvertent, incipient spin, you will see a moment where the stick is moving progressively left even as the glider accelerates its roll to the right. That's the instant he departed from controlled flight - the glider was not 'answering' his aileron input.. It should set off all the alarms in your head as it did in his. For me, it's like an electric shock. Bruno's recovery was not textbook but it worked extremely well. He unloaded the wing by moving the stick forward unstalling the wing and reentering the realm of controlled flight where his ailerons worked normally. Even his narration indicated he didn't apply opposite rudder in a timely manner as the text books call for. Actually, I think he did the right thing - first unload the wing then, after it unstalls, fly the glider normally. So far, I like every single post in this thread. It's about avoiding accidents by flying well enough to avoid them. That's the secret to safety. |
#37
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Another stall spin
On Monday, August 27, 2012 10:53:21 PM UTC-7, Ramy wrote:
Tom, easy said than done. We all agree that circling too close to the ground is not a good idea, but there is no always a clear indication when it is too close. I don't know why many of you insist that there is nothing to learn from this accident without knowing the most important fact: how low was he circling?? If we find out it was 800 feet, will you go and claim that it is dumb to circle below 1000 feet? This is why we need to know the details, so we can make more informed conclusions. Ramy Ramy, I listened to one pilot explain how he is confiddent to thermal at an altitude of 100 ft: do you think that is high enough? Minimum thermalling altitude would reasonably be high enough to recover (demonstrated) from a stall/spin plus (at least, triple that for lower time cross country pilots) a 200 ft safety margin. This is REALLY not that difficult to figure out. Tom 2G |
#38
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Another stall spin
At 18:35 28 August 2012, 2G wrote:
On Monday, August 27, 2012 10:53:21 PM UTC-7, Ramy wrote: Tom, easy said than done. We all agree that circling too close to the gro= und is not a good idea, but there is no always a clear indication when it = is too close. I don't know why many of you insist that there is nothing to = learn from this accident without knowing the most important fact: how low w= as he circling?? If we find out it was 800 feet, will you go and claim that= it is dumb to circle below 1000 feet? This is why we need to know the deta= ils, so we can make more informed conclusions. =20 =20 =20 Ramy Ramy, I listened to one pilot explain how he is confiddent to thermal at an altit= ude of 100 ft: do you think that is high enough? Minimum thermalling altitude would reasonably be high enough to recover (de= monstrated) from a stall/spin plus (at least, triple that for lower time cr= oss country pilots) a 200 ft safety margin. This is REALLY not that difficu= lt to figure out. Tom 2G This is so similar to the others that I can only say the same things ,was there a situation in the cockpit we don't know. Insect bite,medical problem,PDA fell off in the chop??? The only thing I know it is depressing me to keep loosing people from our small community . These days I fly a duo discus turbo and our rule is 1000ft AGL and the engine comes out or we set up a circuit into our chosen field.We don't fight about it but when the gear goes down you know your partner is making the point. We are only a small voice but I would suggest changing the rules to the affect that if you are less than 600ft AGL that is your GPNS land out position This would mean there are no points to be gained from low scrapes. |
#39
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Another stall spin
On Aug 27, 8:38*pm, 2G wrote:
Everybody likes to get back and tell their story about a low save; everybody OOHs and AWHs. Nobody says "You DUMB ****, YOU COULD HAVE KILLED YOURSELF!" So in my first contest, there was a tough day trying to work our way back uphill to higher terrain (and home). I ended up making 3 low saves in a row, each only about 300' AGL. I could have soared out to lower terrain if needed each time, but I was making thermalling turns only a couple of hundred feet off the ground. When I got home, I was chuffed that only Gary Ittner and I made it home (everyone else landed out). Upon reviewing the traces it appears that he and I did virtually the same thing, making low-save after low-save at almost identical points on the route home (though I was 15-20 minutes behind him). Just a few weeks later I was at another contest, proudly relaying this story to Tom Kelly ("711"). He basically said exactly the same thing - that I was an idiot and could have killed myself quite easily, and to get the hell away from him. At first I was very hurt, and then I was really ****ed off. Wasn't Gary a legend in the sport? Wasn't I "smart" to have figured this out and emulated him (even if unintentionally)? Wasn't I skilled to have pulled it off and gotten home? Here I was, a budding contest pilot, doing well on a tough day and hanging (sorta) with one of the best pilots around! Why the hell should I be raked over the coals for my accomplishment?? Over time, I've come to the realization that Tom's attitude is a lot closer to the right attitude. A lot of good, skilled, experienced pilots do dumb things. Even if I am the hottest pilot in the universe (breaking news: I'm not), it isn't always smart to mirror the behavior of top pilots. Following someone else's lead into a trap is just dumb. I'll admit that I still sometimes take moderate risks in my contest flying; but I'm far more cognizant of them and I don't simply use other pilots as a measuring-stick for safety or what's "right" to do. --Noel |
#40
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Another stall spin
On Tuesday, August 28, 2012 12:20:10 PM UTC-7, noel.wade wrote:
On Aug 27, 8:38*pm, 2G wrote: Everybody likes to get back and tell their story about a low save; everybody OOHs and AWHs. Nobody says "You DUMB ****, YOU COULD HAVE KILLED YOURSELF!" So in my first contest, there was a tough day trying to work our way back uphill to higher terrain (and home). I ended up making 3 low saves in a row, each only about 300' AGL. I could have soared out to lower terrain if needed each time, but I was making thermalling turns only a couple of hundred feet off the ground. When I got home, I was chuffed that only Gary Ittner and I made it home (everyone else landed out). Upon reviewing the traces it appears that he and I did virtually the same thing, making low-save after low-save at almost identical points on the route home (though I was 15-20 minutes behind him). Just a few weeks later I was at another contest, proudly relaying this story to Tom Kelly ("711"). He basically said exactly the same thing - that I was an idiot and could have killed myself quite easily, and to get the hell away from him. At first I was very hurt, and then I was really ****ed off. Wasn't Gary a legend in the sport? Wasn't I "smart" to have figured this out and emulated him (even if unintentionally)? Wasn't I skilled to have pulled it off and gotten home? Here I was, a budding contest pilot, doing well on a tough day and hanging (sorta) with one of the best pilots around! Why the hell should I be raked over the coals for my accomplishment?? Over time, I've come to the realization that Tom's attitude is a lot closer to the right attitude. A lot of good, skilled, experienced pilots do dumb things. Even if I am the hottest pilot in the universe (breaking news: I'm not), it isn't always smart to mirror the behavior of top pilots. Following someone else's lead into a trap is just dumb. I'll admit that I still sometimes take moderate risks in my contest flying; but I'm far more cognizant of them and I don't simply use other pilots as a measuring-stick for safety or what's "right" to do. --Noel This is exactly why those kind of discussions on RAS are so important. You will hear opinions that you will normally wouldn't hear elsewhere or face to face. I will definitely think twice next time before deciding to thermal below 500 ft AGL. Sad news but great discussion. Ramy |
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