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#101
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Final glides are part of the Qualified Glider Pilot syllabus and competition finishes are part of the Advanced Training syllabus available in NZ http://www.gliding.co.nz/sites/glidi...ning/s_qgp.pdf http://www.gliding.co.nz/sites/glidi...ning/s_adv.pdf Regards Colin Last edited by Ventus_a : September 2nd 11 at 02:40 AM. |
#102
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IDAHO FATALITY
On Sep 1, 10:35*am, Judy Ruprecht wrote:
At 07:50 01 September 2011, Michael Vickery wrote: Hi I wonder if there may be an alternative interpretation for this accident? Some conjecture in this thread seems to center on wind gradient as a possible contributing cause. Here's an excerpt from the NTSB preliminary report: "A witness was located midfield under an awning on the east verge of the north-south runway. He was seated, and facing northwest when he heard the pilot report on the common traffic advisory frequency that he was inbound for landing. A few minutes later, his attention was drawn to a glider flying past the awning in level flight, heading north along the runway at an altitude of about 75 feet above ground level (agl). He did not see the glider prior to that moment, and while he could not accurately judge its airspeed, he surmised that it was traveling at a "fast clip." He was startled, and expressed considerable alarm at the glider's location. "The glider continued to the end of the runway, and then began a smooth pitch-up maneuver. During the initial climb, the right wing dropped slightly, and the glider proceeded to bank smoothly to the left. The turn continued until its heading had diverged by about 40 degrees, at which point the airspeed had decreased significantly. It reached an apex of about 300 feet agl, and then began a spin to the left in a near vertical, nose-down attitude. It completed one full rotation before disappearing out of his view behind trees. The flaps did not appear to be deployed at any point during the flight, and he estimated that winds were about 12 to 15 knots out of the south. "Multiple witnesses recounted similar observations, all reporting tailwinds for the downwind phase of between 10 and 20 knots. At the time of the accident, an annual Fly-In was underway at the airport. The pilot had arrived earlier in the week. Airfield records indicated that he flew the glider one time prior, 3 days before the accident. Associates of the pilot reported that he purchased the glider in 2006, and the fly-in was the first time he had flown it since purchase." -- Judy Now that this report is out, it sounds like a tragic replay of the 2001 accident in Uvalde. See slides 6 and 7 here for analysis http://faculty.chicagobooth.edu/john...est_safety.ppt We'll never know exactly what went through the pilots' minds, but the ingredients are the same Little recent time -- little recent experience landing in a variety of conditions Low pass down the middle of the runway, but not very high speed. (And in this case, an older glider with less energy retention) Downwind illusion - less airspeed than groundspeed in a decently strong tailwind Pull up give less altitude than expected 180 degree turn leaves the pilot off the edge of the runway, lower than expected and drifting downwind -- need for suddenly greater turn Possible dehydration -- no pee system installed; high temperatures The downwind illusion is very powerful. It's interesting to watch students want to run the downwind at 40 knots when there is a strong tailwind blowing. I think our discussion here has drifted too far off to contest low passes -- higher performance gliders, and 120 knots -- and less to basics like downwind illusion, glider turns on a point illusion, and ruddering a panicked turn from base to final. I guess instructors have some items to stress on BFRs. These are basics, but they are tricky basics. Learning to anticipate how wind will affect a pattern and how fast the ground will be going by are things that even quite experienced pilots get wrong. Adding a "nonstandard" pattern adds to the list of things that need to be anticipated, for example that the 180 degree turn will use up some radius. John Cochrane |
#103
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IDAHO FATALITY
On Aug 25, 2:12*pm, JJ Sinclair wrote:
Martin Gregorie wrote......... In UK high speed low finishes were banned after a photographer on the airfield boundary was killed, US Rules Committee please take note. JJ No he didn't JJ. He said 'not remotely true'. Low passes below 30ft are banned in competition. High energy go arounds are still the norm. Jim |
#104
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IDAHO FATALITY
On 9/1/2011 7:19 PM, Ventus_a wrote:
Snip... You have several times now ignored the possibility of training how to do a low pass with an instructor on board, just like any other gliding maneuver.- Uhh...of *course* it's a (theoretical only?) possibility. Are there sites in NZ where folks could travel to do this? I'm unaware of any in the U.S. that advertise zoomie instruction is part of their standard offerings. Snip... Hi Final glides are part of the Qualified Glider Pilot syllabus and competition finishes are part of the Advanced Training syllabus available in NZ http://tinyurl.com/3z7a6mh http://tinyurl.com/3s9p6eu Regards Colin More (apparently) good/usable input on the subject of zoomie instruction. (I use 'apparently' because when I tried to use the links, I was unable to obtain connections.) So now RAS readers have been informed zoomie instruction is available both in NZ and OZ...and we're told mandatory, prior to contest involvement, in OZ. From my perspective (given the severally-thin-margins associated with safe-and-sane zoomie execution [pun not intended]), the NZ and OZ approaches seem prudent, if not outright wise. Regards, Bob W. |
#105
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IDAHO FATALITY
No he didn't JJ. He said 'not remotely true'. Low passes below 30ft
are banned in competition. High energy go arounds are still the norm. Jim Yeah, I stand corrected. Time was that John & I were pushing for elimination of the finish line altogether and just use the finish circle to end the race. Looks like I'm alone with the safer alternative. I have done my last low pass some years back. Too bad it is seen as the "thing" to do by newbies. I believe most contests are opting for the finish cylinder for liability reasons. On the down-wind illusion, I can still remember one of my first out- landings. Picked a road in the desert near Flanigan, NV. As I started to flare, the feel of the ship was slow, but a very powerfull force was telling me, "Your going much too fast, slow her down", because I was going fast over the ground, but all I could do was to hold my attitude and accept a high speed landing. We lost a pilot at Air Sailing to this, Rope break at 800 feet on a wave tow into a 30 knot wind. He made a good 180 turn, then stalled and spun-in going down- wind. The ground was going by at 70, but he was stalling at 40. Stay safe, JJ |
#106
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IDAHO FATALITY
On 9/1/2011 6:12 PM, Bill D wrote:
On Sep 1, 4:49 pm, jim wrote: On Sep 1, 2:44 pm, Bill wrote: On Sep 1, 12:25 pm, Frank wrote: On Sep 1, 9:35 am, Judy wrote: At 07:50 01 September 2011, Michael Vickery wrote: Hi I wonder if there may be an alternative interpretation for this accident? Some conjecture in this thread seems to center on wind gradient as a possible contributing cause. Here's an excerpt from the NTSB preliminary report: "A witness was located midfield under an awning on the east verge of the north-south runway. He was seated, and facing northwest when he heard the pilot report on the common traffic advisory frequency that he was inbound for landing. A few minutes later, his attention was drawn to a glider flying past the awning in level flight, heading north along the runway at an altitude of about 75 feet above ground level (agl). He did not see the glider prior to that moment, and while he could not accurately judge its airspeed, he surmised that it was traveling at a "fast clip." He was startled, and expressed considerable alarm at the glider's location. "The glider continued to the end of the runway, and then began a smooth pitch-up maneuver. During the initial climb, the right wing dropped slightly, and the glider proceeded to bank smoothly to the left. The turn continued until its heading had diverged by about 40 degrees, at which point the airspeed had decreased significantly. It reached an apex of about 300 feet agl, and then began a spin to the left in a near vertical, nose-down attitude. It completed one full rotation before disappearing out of his view behind trees. The flaps did not appear to be deployed at any point during the flight, and he estimated that winds were about 12 to 15 knots out of the south. "Multiple witnesses recounted similar observations, all reporting tailwinds for the downwind phase of between 10 and 20 knots. At the time of the accident, an annual Fly-In was underway at the airport. The pilot had arrived earlier in the week. Airfield records indicated that he flew the glider one time prior, 3 days before the accident. Associates of the pilot reported that he purchased the glider in 2006, and the fly-in was the first time he had flown it since purchase." -- Judy Naturally, I presumed he'd turned nearer 180 degrees, but the report indicates only 40 degrees, so most of his climb was with a tail wind component. Vegetation and development is a bit spare in the area, so the gradient between the described winds at the surface and 100 meters is probably not too extreme, though the variability would suggest some turbulence also. In any event, I suspect he was climbing into an increasing tail wind component. The described wind would also exaggerate his apparent speed to the ground observers and his perceived speed across the ground. I doubt it would have had an affect on aileron effectiveness unless he also transited a boundary shear into another wind direction. http://en.wikipedia.org/wiki/Wind_gradient Our gliderport is also 5500MSL and when driving the winch, I've often observed gliders during the launch transiting two wind 'shears'. The first appears to be about 400ft agl, the second between 1100-1400ft agl. Glider pitch and yaw are both affected. (The pilots notice it too) The person who built our gliderport had started nearly five miles closer to the foot hills. I once asked him why he moved it. He mentioned, among other reasons, the difficulty in soloing new pilots due to the wind anomalies nearer the hills. Of course, this often puts our operation further from the convergence zone, which can mean later starts when the zone develops strongly as it draws cooler air from the South Platte and Poudre River valleys causing trigger temperature to be reached later, if at all some days. This surface layer can be 60 to 180 degrees out from the forecasted winds and is a 'local' effect. Our minimum pattern speed is 55knots. Frank Whiteley This is yet another case where an angle of attack indicator with stall warning stick vibrator would have saved a life. Tiny cellphone/pager vibrator motors embedded in the stick grip would be an excellent stall warning.- Hide quoted text - - Show quoted text - I respectfully disagree. Not attempting a high speed pass in a slow glider might have saved a life. Flying THAT glider more frequently may have saved a life. I don't think having the stick buzz a second before the stall/spin would have helped given the pilot's lack of experience in THAT glider. Shoving the stick forward one second before a stall break will prevent it in any glider. The commuter plane that crashed in Buffalo last year had a stick shaker and it didn't seem to help them. More gadgets won't compensate for a lack of basic airmanship. -- Mike Schumann |
#107
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IDAHO FATALITY
On Sep 3, 12:27*pm, Mike Schumann
The commuter plane that crashed in Buffalo last year had a stick shaker and it didn't seem to help them. *More gadgets won't compensate for a lack of basic airmanship. True, but the point of the "gadgets" as you call them is to attract attention to a condition so that the pilot can apply basic airmanship and save the day (and his life). Just saying "gadgets wont help" is like saying "ban all low passes" - it totally ignores the fact that stick shakers have in the past and will continue in the future save many lives - and that low passes are done all the time in perfect safety by careful pilots without any problem, while other pilots continue to crash while attempting a simple landing. I agree, though, that at the bottom of all this (and to our appalling safety record in soaring) lies an amazing lack of discipline and "airmanship" in our glider pilot population, coupled with what I consider a haphazard system of instruction - good individual instructors hampered by a lack of standardization, etc... Kirk 66 |
#108
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IDAHO FATALITY
On Sep 4, 11:47*am, "kirk.stant" wrote:
On Sep 3, 12:27*pm, Mike Schumann The commuter plane that crashed in Buffalo last year had a stick shaker and it didn't seem to help them. *More gadgets won't compensate for a lack of basic airmanship. True, but the point of the "gadgets" as you call them is to attract attention to a condition so that the pilot can apply basic airmanship and save the day (and his life). Just saying "gadgets wont help" is like saying "ban all low passes" - it totally ignores the fact that stick shakers have in the past and will continue in the future save many lives - and that low passes are done all the time in perfect safety by careful pilots without any problem, while other pilots continue to crash while attempting a simple landing. I agree, though, that at the bottom of all this (and to our appalling safety record in soaring) lies an amazing lack of discipline and "airmanship" in our glider pilot population, coupled with what I consider a haphazard system of instruction - good individual instructors hampered by a lack of standardization, etc... Kirk 66 Kirk - "haphazard system of instruction" ... BINGO |
#109
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IDAHO FATALITY
On 9/4/2011 11:47 AM, kirk.stant wrote:
On Sep 3, 12:27 pm, Mike The commuter plane that crashed in Buffalo last year had a stick shaker and it didn't seem to help them. More gadgets won't compensate for a lack of basic airmanship. True, but the point of the "gadgets" as you call them is to attract attention to a condition so that the pilot can apply basic airmanship and save the day (and his life). Just saying "gadgets wont help" is like saying "ban all low passes" - it totally ignores the fact that stick shakers have in the past and will continue in the future save many lives - and that low passes are done all the time in perfect safety by careful pilots without any problem, while other pilots continue to crash while attempting a simple landing. I agree, though, that at the bottom of all this (and to our appalling safety record in soaring) lies an amazing lack of discipline and "airmanship" in our glider pilot population, coupled with what I consider a haphazard system of instruction - good individual instructors hampered by a lack of standardization, etc... Kirk 66 I am not against all "gadgets". I just think that we need to prioritize, given the limited amount of panel space, and equally importantly, the limited ability of people to learn how to use all the stuff they are putting into their cockpits. At the top of my list would be collision avoidance gear (PowerFlarm / ADS-B / transponder type stuff). This will potentially save a properly trained pilot. My personal feeling is that you really aren't trained properly if you can't sense and feel a stall coming on and don't instinctively know what to do about it. Adding another instrument to tell you what you should already know, just adds another item to your scan, which distracts you from more important stuff, like looking for traffic. -- Mike Schumann |
#110
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IDAHO FATALITY
On Sep 5, 7:54*pm, Mike Schumann
wrote: I am not against all "gadgets". *I just think that we need to prioritize, given the limited amount of panel space, and equally importantly, the limited ability of people to learn how to use all the stuff they are putting into their cockpits. I agree with respect to a lot of the fancy PNA programs - they have the potential to display so much useless info! However, we were discussing stick shakers/stall warning systems specifically - which are pretty bone-simple - even a caveman can understand how they work! At the top of my list would be collision avoidance gear (PowerFlarm / ADS-B / transponder type stuff). *This will potentially save a properly trained pilot. *My personal feeling is that you really aren't trained properly if you can't sense and feel a stall coming on and don't instinctively know what to do about it. *Adding another instrument to tell you what you should already know, just adds another item to your scan, which distracts you from more important stuff, like looking for traffic. Apparently the FAA, NASA, Air Force, Boeing, Airbus, and airlines do not share you opinion... Modern gliders give very little indications of a stall (another reason why training in old clunkers like the 2-33 is counterproductive). Add a little distraction or a higher priority task (Bee in the cockpit!) and you can be in a high-AOA situation without being aware of it. Add to that a pilot who flies infrequently, and the benefit of a stall warning system becomes even more clear. Kirk 66 |
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