On Thursday, July 18, 2019 at 1:41:09 PM UTC-6, Ramy wrote:
> On Thursday, July 18, 2019 at 11:02:08 AM UTC-7, ProfJ wrote:
> > On Thursday, 18 July 2019 08:39:25 UTC-6, Waveguru wrote:
> > > I am very sorry to report that there has been another fatality in our sport. Yesterday, July 17th, at the annual Alvord Desert Safari, Dave Kibby crashed during an auto tow launch. All I have at this time is that as he rotated into his climb he was hit with a gust, rolled to the left and hit the deck. He was killed instantly. I wasn't there, and I didn't know Dave, but I know most of the other people involved at this event. My thoughts go out to friends and family.
> > >
> > > Boggs
> >
> > My condolences to his friends and family. It seems to me that we are having a horrible streak of tragedies at the moment - or is this typical and I just never paid attention before?
> Unfortunately and tragically this is typical, although this year so far it is more concentrated in the last few weeks. Last year we lost 11 pilots to glider accidents as far as I know. we loosing 6 pilots on average per year in the US, mostly during the summer.
>
> Ramy
I don't mean to dig up an old thread, but I was finally able to find the NTSB accident report, and I believe there are lessons we can learn from this one. Here it is:

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99876/pdf

Thanks for sending the NTSB report. Can't be sure that this is directly related but it is certainly similar.
At Moriarty flying my 27. A nice active day. Start the tow and a strong gust crosses the runway; the Pawnee towplane bobbled but I got the full gust (post-incident rationalisation wth Mike Stogner an experienced western tow pilot) and the 27 popped off the ground to maybe 6-7 feet; as it started to sink back I added a bit of back stick. Ground reports said that the glider hit level -- nevertheless it created a bounce exactly when the tow plane removed the slack in the line that had emerged. Bounce plus a sort of bungee launch set the 27 off sharply upward. Immediate release -- at least at my reaction time, which even now is not bad. The glider kited to maybe 40 feet before I had the speed back under control, so I eased to the right to aim for the taxiway, to see to my left Mike accelerating hard, taking off and getting away from the runway. At which I moved back over the runway and flew the remaining half mile plus to land at the 08 end and get out of the way of the next tows (and to gather my wits, breath and knees ...)
My thought re the accident from my experience above is that there was likely rope slack which the glider ran over and that the accelerating tow car, though not at full speed, was going fast enough to create the same effect I had, though clearly to much larger effect. Is there anything in any reporting whether the glider released and if so when? Reports say the glider overran the rope -- the subsequent result could have been similar to my incident writ large -- a loop of slack rope then pulled tight like a bungee. Isn't there some rule suggesting that if the rope is overrun on any towed launch then release immediately, though I have often wondered how the pilot is supposed to know it has happened completely out of sight in any glider type I flew.

On Thursday, September 22, 2022 at 3:22:48 PM UTC-4, johngf...@gmail.com wrote:
> On Thursday, July 18, 2019 at 1:41:09 PM UTC-6, Ramy wrote:
> > On Thursday, July 18, 2019 at 11:02:08 AM UTC-7, ProfJ wrote:
> > > On Thursday, 18 July 2019 08:39:25 UTC-6, Waveguru wrote:
> > > > I am very sorry to report that there has been another fatality in our sport. Yesterday, July 17th, at the annual Alvord Desert Safari, Dave Kibby crashed during an auto tow launch. All I have at this time is that as he rotated into his climb he was hit with a gust, rolled to the left and hit the deck. He was killed instantly. I wasn't there, and I didn't know Dave, but I know most of the other people involved at this event. My thoughts go out to friends and family.
> > > >
> > > > Boggs
> > >
> > > My condolences to his friends and family. It seems to me that we are having a horrible streak of tragedies at the moment - or is this typical and I just never paid attention before?
> > Unfortunately and tragically this is typical, although this year so far it is more concentrated in the last few weeks. Last year we lost 11 pilots to glider accidents as far as I know. we loosing 6 pilots on average per year in the US, mostly during the summer.
> >
> > Ramy
> I don't mean to dig up an old thread, but I was finally able to find the NTSB accident report, and I believe there are lessons we can learn from this one. Here it is:
>
> https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99876/pdf

On Thursday, September 22, 2022 at 2:21:51 PM UTC-6, howard...@gmail.com wrote:
> Thanks for sending the NTSB report. Can't be sure that this is directly related but it is certainly similar.
> At Moriarty flying my 27. A nice active day. Start the tow and a strong gust crosses the runway; the Pawnee towplane bobbled but I got the full gust (post-incident rationalisation wth Mike Stogner an experienced western tow pilot) and the 27 popped off the ground to maybe 6-7 feet; as it started to sink back I added a bit of back stick. Ground reports said that the glider hit level -- nevertheless it created a bounce exactly when the tow plane removed the slack in the line that had emerged. Bounce plus a sort of bungee launch set the 27 off sharply upward. Immediate release -- at least at my reaction time, which even now is not bad. The glider kited to maybe 40 feet before I had the speed back under control, so I eased to the right to aim for the taxiway, to see to my left Mike accelerating hard, taking off and getting away from the runway. At which I moved back over the runway and flew the remaining half mile plus to land at the 08 end and get out of the way of the next tows (and to gather my wits, breath and knees ...)
> My thought re the accident from my experience above is that there was likely rope slack which the glider ran over and that the accelerating tow car, though not at full speed, was going fast enough to create the same effect I had, though clearly to much larger effect. Is there anything in any reporting whether the glider released and if so when? Reports say the glider overran the rope -- the subsequent result could have been similar to my incident writ large -- a loop of slack rope then pulled tight like a bungee. Isn't there some rule suggesting that if the rope is overrun on any towed launch then release immediately, though I have often wondered how the pilot is supposed to know it has happened completely out of sight in any glider type I flew.
> On Thursday, September 22, 2022 at 3:22:48 PM UTC-4, johngf...@gmail.com wrote:
> > On Thursday, July 18, 2019 at 1:41:09 PM UTC-6, Ramy wrote:
> > > On Thursday, July 18, 2019 at 11:02:08 AM UTC-7, ProfJ wrote:
> > > > On Thursday, 18 July 2019 08:39:25 UTC-6, Waveguru wrote:
> > > > > I am very sorry to report that there has been another fatality in our sport. Yesterday, July 17th, at the annual Alvord Desert Safari, Dave Kibby crashed during an auto tow launch. All I have at this time is that as he rotated into his climb he was hit with a gust, rolled to the left and hit the deck. He was killed instantly. I wasn't there, and I didn't know Dave, but I know most of the other people involved at this event. My thoughts go out to friends and family.
> > > > >
> > > > > Boggs
> > > >
> > > > My condolences to his friends and family. It seems to me that we are having a horrible streak of tragedies at the moment - or is this typical and I just never paid attention before?
> > > Unfortunately and tragically this is typical, although this year so far it is more concentrated in the last few weeks. Last year we lost 11 pilots to glider accidents as far as I know. we loosing 6 pilots on average per year in the US, mostly during the summer.
> > >
> > > Ramy
> > I don't mean to dig up an old thread, but I was finally able to find the NTSB accident report, and I believe there are lessons we can learn from this one. Here it is:
> >
> > https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99876/pdf

My impression is that there was something that happened to cause the slack in the tow rope--possibly the tow vehicle loosing power temporarily while shifting gears? Then the pilot pulled back on the stick to take up slack or start the kiting phase, but was too slow and at too steep an angle of attack when the slack got taken up, which caused the wing to stall and spin in. Keep in mind that if the glider is in too high of a nose up attitude when the slack comes out, it can take a normal angle of attack relative to the motion of the glider (climbing), and suddenly change it to exceed the critical angle of attack when tension on the tow rope pulls in a more forward direction. In any event, I believe the pilot should have dropped the nose and released the tow rope. Someone more knowledgeable correct me if I'm wrong.

BGA "Safe Winch Launching" section of their website cautions against rotation to climb attitude below 300.

A rapid rotation can produce a snap roll.

I was driving our Roman winch when a visiting Puchaz broke the weak link at maybe 150' with a rapid rotation. The Roman winch is more powerful than their's.

On 9/22/22 15:45, John Foster wrote:
<Snip...>> My impression is that there was something that happened to
cause the
> slack in the tow rope--possibly the tow vehicle loosing power
> temporarily while shifting gears? Then the pilot pulled back on the
> stick to take up slack or start the kiting phase...

Entirely speculatively possible, even if "aft stick to take up on-tow
slack" is nowhere-that-I-know-taught as part of routine slack rope
recovery procedures.

>...but was too slow
> and at too steep an angle of attack when the slack got taken up,
> which caused the wing to stall and spin in. Keep in mind that if the
> glider is in too high of a nose up attitude when the slack comes out,
> it can take a normal angle of attack relative to the motion of the
> glider (climbing), and suddenly change it to exceed the critical
> angle of attack when tension on the tow rope pulls in a more forward
> direction. In any event, I believe the pilot should have dropped the
> nose and released the tow rope. Someone more knowledgeable correct
> me if I'm wrong.

"AOA is life" whenever at "too-low-to-recover departures from controlled
flight" heights. No rational, sane, actively-thinking, glider pilot
should *ever* (actively or passively) take/assist actions at those
heights that simultaneously increase AOA, reduce their glider's
(not-presently-outside-source-assisted) kinetic energy state, and have
potential to demand a quick return to a kinetic-energy-increasing energy
state that is obtainable only by stick-required, time-eating, pilot
inputs. Feel free to rephrase the above into whatever verbiage that
helps you internalize the intended concepts...

On Friday, September 23, 2022 at 6:19:49 AM UTC-7, Bob W. wrote:
> On 9/22/22 15:45, John Foster wrote:
> <Snip...>> My impression is that there was something that happened to
> cause the
> > slack in the tow rope--possibly the tow vehicle loosing power
> > temporarily while shifting gears? Then the pilot pulled back on the
> > stick to take up slack or start the kiting phase...
>
> Entirely speculatively possible, even if "aft stick to take up on-tow
> slack" is nowhere-that-I-know-taught as part of routine slack rope
> recovery procedures.
>
>
> >...but was too slow
> > and at too steep an angle of attack when the slack got taken up,
> > which caused the wing to stall and spin in. Keep in mind that if the
> > glider is in too high of a nose up attitude when the slack comes out,
> > it can take a normal angle of attack relative to the motion of the
> > glider (climbing), and suddenly change it to exceed the critical
> > angle of attack when tension on the tow rope pulls in a more forward
> > direction. In any event, I believe the pilot should have dropped the
> > nose and released the tow rope. Someone more knowledgeable correct
> > me if I'm wrong.
> "AOA is life" whenever at "too-low-to-recover departures from controlled
> flight" heights. No rational, sane, actively-thinking, glider pilot
> should *ever* (actively or passively) take/assist actions at those
> heights that simultaneously increase AOA, reduce their glider's
> (not-presently-outside-source-assisted) kinetic energy state, and have
> potential to demand a quick return to a kinetic-energy-increasing energy
> state that is obtainable only by stick-required, time-eating, pilot
> inputs. Feel free to rephrase the above into whatever verbiage that
> helps you internalize the intended concepts...

I read the NTSB report and the conditions do not support the theory that their was a tail gust. Most likely, the pilot tried to rotate to soon, exceeded the critical AOA, stalled, and crashed.

Tom