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#31
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Glider crash near Reno yesterday
At 05:13 28 September 2018, 2G wrote:
On Thursday, September 27, 2018 at 8:58:23 PM UTC-7, James Betker wrote: I've got a question - let's assume that the speculation going on here is = right and that the elevator control was locked in a full nose-high station = - what is the optimal thing to do if you are ever faced with this? Am I rig= ht in assuming that it is to bail as quickly as possible before you start b= uilding G-loads which would make bailing impossible? If you somehow got you= rself into a scenario where you were endlessly looping the glider, would de= ploying full airbrakes bleed enough energy to stop the looping (and maybe i= nduce a spin instead)? =20 This is certainly a nightmare scenario. My condolences go out to the frie= nds and family of the departed. If you are being subjected to 10 g's it would be very difficult to raise yo= ur arm to pull the handle - your 10 lb arm suddenly becomes 100 lb. Tom I am posting this for a second time but you should all watch it. https://www.youtube.com/channel/UCvO...NoSro7U5LkED-Q It answers some of the questions but not why the Duo failed. |
#32
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Glider crash near Reno yesterday
Years ago my brother was involved in a midair collision in his ventus. The other glider ran into his elevator jamming it into a full up position. The ship took him for a series of high speed loops with him attempting to eject. The G load prevented the canopy from seperating, my bro was able to get his feet free to kick out the canopy and get over the side. Speaking with him after the fact, he said if he had to do it again, he would have tried to aileron roll so the G load would have ejected him instead of pinning him in the cockpit.
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#33
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Glider crash near Reno yesterday
Le vendredi 28 septembre 2018 10:05:31 UTC+2, a écritÂ*:
Years ago my brother was involved in a midair collision in his ventus. The other glider ran into his elevator jamming it into a full up position. The ship took him for a series of high speed loops with him attempting to eject. The G load prevented the canopy from seperating, my bro was able to get his feet free to kick out the canopy and get over the side. Speaking with him after the fact, he said if he had to do it again, he would have tried to aileron roll so the G load would have ejected him instead of pinning him in the cockpit. If the glider is looping, you can't decrease the g-loads without the use of the elevator. Putting aileron will just transform it into a barrel row. G-loads are the same, but the wings will break earlier. |
#34
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Glider crash near Reno yesterday
At 10:47 28 September 2018, Tango Whisky wrote:
Le vendredi 28 septembre 2018 10:05:31 UTC+2, a =C3=A9c= rit=C2=A0: Years ago my brother was involved in a midair collision in his ventus. T= he other glider ran into his elevator jamming it into a full up position. T= he ship took him for a series of high speed loops with him attempting to ej= ect. The G load prevented the canopy from seperating, my bro was able to ge= t his feet free to kick out the canopy and get over the side. Speaking with= him after the fact, he said if he had to do it again, he would have tried = to aileron roll so the G load would have ejected him instead of pinning him= in the cockpit. If the glider is looping, you can't decrease the g-loads without the use of= the elevator. Putting aileron will just transform it into a barrel row. G-= loads are the same, but the wings will break earlier. What am I missing here? Why can't the glider be maneuvered into something like a constant 80 degree bank turn? Then pull out the dive brakes to slow it down and reduce G available? As the speed bleeds off, reduce bank angle to let the nose float up and slow down more. Then, jump out before the thing stalls and starts spinning. Get the vertical gravity vector out of the picture so that the speeds don't accelerate like they might on the back side of a loop. 10 G's? For how long? I pulled 9+ G's on many occasions in the F-16, and to sustain it for any length of time required full afterburner which a DUO doesn't have. RO |
#35
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Glider crash near Reno yesterday
On Friday, September 28, 2018 at 9:15:05 AM UTC-4, Michael Opitz wrote:
At 10:47 28 September 2018, Tango Whisky wrote: Le vendredi 28 septembre 2018 10:05:31 UTC+2, a =C3=A9c= rit=C2=A0: Years ago my brother was involved in a midair collision in his ventus. T= he other glider ran into his elevator jamming it into a full up position. T= he ship took him for a series of high speed loops with him attempting to ej= ect. The G load prevented the canopy from seperating, my bro was able to ge= t his feet free to kick out the canopy and get over the side. Speaking with= him after the fact, he said if he had to do it again, he would have tried = to aileron roll so the G load would have ejected him instead of pinning him= in the cockpit. If the glider is looping, you can't decrease the g-loads without the use of= the elevator. Putting aileron will just transform it into a barrel row. G-= loads are the same, but the wings will break earlier. What am I missing here? Why can't the glider be maneuvered into something like a constant 80 degree bank turn? Then pull out the dive brakes to slow it down and reduce G available? As the speed bleeds off, reduce bank angle to let the nose float up and slow down more. Then, jump out before the thing stalls and starts spinning. Get the vertical gravity vector out of the picture so that the speeds don't accelerate like they might on the back side of a loop. 10 G's? For how long? I pulled 9+ G's on many occasions in the F-16, and to sustain it for any length of time required full afterburner which a DUO doesn't have. RO I hear you, Mike and I think your and the other suggestions are all good and valid but hardly any of the folks in the glider community have flown a F16 or similar hardware or are trained for these type of high g-maneuvers. I didn't know either of the crew but would assume they were at an advanced age, i.e. not the fittest and strongest to work their way out of the seat under that high g-load. Then there is the 'oh-crap - now what' delay since whatever happened was way out of the ordinary and the correct - or any reaction - does take time to formulate and execute. If the g-load built quickly, the seating position in a Duo will not allow one to remain conscious for long and we typically don't wear anti-g flight suits to combat the effects. Remember the Reno Air Race accidents a few years back, where a P51 got pulverized on the apron? Pictures showed the pilot slumped over unconscious and he was used to higher loads encountered in these races. One can only hope that the Duo-crew was 'out of it' when they hit the ground. R.I.P! Uli 'AS' |
#36
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Glider crash near Reno yesterday
Le vendredi 28 septembre 2018 15:15:05 UTC+2, Michael Opitz a écritÂ*:
What am I missing here? Why can't the glider be maneuvered into something like a constant 80 degree bank turn? Then pull out the dive brakes to slow it down and reduce G available? As the speed bleeds off, reduce bank angle to let the nose float up and slow down more. Then, jump out before the thing stalls and starts spinning. Get the vertical gravity vector out of the picture so that the speeds don't accelerate like they might on the back side of a loop. 10 G's? For how long? I pulled 9+ G's on many occasions in the F-16, and to sustain it for any length of time required full afterburner which a DUO doesn't have. RO Michael, you are probably right that on the top of the loop, you may try to use aileron and rudder to shift the loop into an high-bank turn. This turn would still have a high g-load, and opening the airbrakes at 80 deg bank would still put the wings beyond ultimate stress load (which is 40% lower than with airbrakes closed). But then - you'd have to perform this manoeuver a second after you have blacked out at the lower part of the loop. During my early aerobatic training I once blacked out (with the instructor in the back seat) 45 deg nose up because I had relaxed my respiration to early, and it took me a couple of seconds to come around and understand what's happening - during this time, the glider had proceeded through the loop to 20 deg nose down (and it wasn't intended to be a loop). So if the description of the eye whitnesses is correct, I think that the situation was not survivable, and I join Uli in his wish that by then, the crew was out of it. Still frightening that such a situation might develop out of the blue. Bert TW |
#37
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Glider crash near Reno yesterday
Unfortunately positive G is positive whether you're upside down or right
side up.Â* In the inverted position you'll have the benefit of the earth's gravity subtracting 1 G from the total, but getting over the cockpit rail from the semi reclined position in the cockpit will still be very difficult.Â* On the positive side, at the top of the loop, the G loading will be significantly less due to the reduced airspeed resulting from the climb.Â* In the actual situation I don't know if one would recognize this and plan his bail out at the top of the loop.Â* Most glider pilots have no experience with aerobatics or high G situations... On 9/28/2018 2:05 AM, wrote: Years ago my brother was involved in a midair collision in his ventus. The other glider ran into his elevator jamming it into a full up position. The ship took him for a series of high speed loops with him attempting to eject. The G load prevented the canopy from seperating, my bro was able to get his feet free to kick out the canopy and get over the side. Speaking with him after the fact, he said if he had to do it again, he would have tried to aileron roll so the G load would have ejected him instead of pinning him in the cockpit. -- Dan, 5J |
#38
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Glider crash near Reno yesterday
On Thursday, September 27, 2018 at 12:01:38 PM UTC-7, wrote:
I agree that this appears to be an elevator failure. What pieces of the wreckage were retrieved? Was the horizontal stabilizer/elevator retrieved? Was the elevator bolt located (ripped out of the elevator, found in a side pocket, found in the trailer, etc). I have the ability to fly my Phoenix low level over the site on a suitable light east wind day and do a close search for the horizontal stab if it is missing. Finding the stab may be the key to solving this tragedy. Maybe a tool left under the seat, which eventually jammed the elevator? A close inspection of the burned out wreckage may reveal any unusual metal tool. |
#39
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Glider crash near Reno yesterday
Thinking through this further and again, one would have to have this
planned out in advance...Â* At the top of the loop, the airspeed will be considerably lower than at the bottom.Â* So, at the top, one could perform a half roll (an Immelmann turn), and, since the glider would now be upright at lower airspeed, it would begin a climb but would stall near or before reaching vertical.Â* This would result in near zero G and would be an ideal time to bail out.Â* It might even result in negative G which would make all the easier. The half roll could even be done past the top of the loop (half Cuban Eight).Â* Again, the glider would start to climb but would not have the energy yet to complete a loop, making bail out rather easy.Â* BUT...Â* being unprepared for the first high G maneuver, the pilot(s) could simply be unconsious... I hope I never get the chance to prove this right or wrong. On 9/28/2018 9:16 AM, Tango Whisky wrote: Le vendredi 28 septembre 2018 15:15:05 UTC+2, Michael Opitz a écritÂ*: What am I missing here? Why can't the glider be maneuvered into something like a constant 80 degree bank turn? Then pull out the dive brakes to slow it down and reduce G available? As the speed bleeds off, reduce bank angle to let the nose float up and slow down more. Then, jump out before the thing stalls and starts spinning. Get the vertical gravity vector out of the picture so that the speeds don't accelerate like they might on the back side of a loop. 10 G's? For how long? I pulled 9+ G's on many occasions in the F-16, and to sustain it for any length of time required full afterburner which a DUO doesn't have. RO Michael, you are probably right that on the top of the loop, you may try to use aileron and rudder to shift the loop into an high-bank turn. This turn would still have a high g-load, and opening the airbrakes at 80 deg bank would still put the wings beyond ultimate stress load (which is 40% lower than with airbrakes closed). But then - you'd have to perform this manoeuver a second after you have blacked out at the lower part of the loop. During my early aerobatic training I once blacked out (with the instructor in the back seat) 45 deg nose up because I had relaxed my respiration to early, and it took me a couple of seconds to come around and understand what's happening - during this time, the glider had proceeded through the loop to 20 deg nose down (and it wasn't intended to be a loop). So if the description of the eye whitnesses is correct, I think that the situation was not survivable, and I join Uli in his wish that by then, the crew was out of it. Still frightening that such a situation might develop out of the blue. Bert TW -- Dan, 5J |
#40
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Glider crash near Reno yesterday
On an ASK 21, a half roll takes 6 seconds, and I wouldn't expect a Duo to roll any faster.
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