Wing Drop, Aerotow vs Winch, Grass vs Pavement.

[Brian[_1_]]

Excuse me while I turn the short "Always release on Wing Drop" into a long discussion. I least my discussion is long. But like the "Impossible Turn" for power aircraft I suspect the real answer is when you really start to analyze it we find "it Depends" or "when in doubt release" but help me educate myself and others about what is really going on here.

I have been hearing the release immediately on wing drop for over 30 years..
Yet Winch launching almost always becomes part of the conversation almost immediately during the conversations, but I have I don't recall any conversations on Winch vs Aero Tow, or Grass vs Paved launches or even Towplane type (high power vs low power) with respect wing drop on launch, does any of this make a difference? It would seem to me wing wheels vs skids would be a factor as well.
I have watched numerous aerotows off of pavement where the wing hits the pavement drags maybe 10 feet at most, and the glider maybe changes heading 10 degrees at most and then the wing comes back up and the glider repositions behind the glider and proceeds on its way. This is usually attributed to the glider hitting the propwash of the towplane. Having nearly a 1000 hours in a glider with wimpy ailerons I have had my share of wing drops under this scenario and never felt it was an issue or any worse than a no wing runner take off. In fact I recall only one glider releasing when the wing dropped under this scenario which then resulted in the wing tip continuing to drag and turn the glider off the runway into a runway light resulting in some leading edge damage to the wing. IMO if he had flown the glider for another second or two it would have been an uneventful launch. But that is just my opinion, he was PIC.

I understand Winch launches happen a lot faster with a lot more energy than most (if not all) aerotows and releasing immediately makes sense for Winch Launches.

I can also see that when launching off of Non-paved surfaces that releasing immediately on wing ground contact probably makes sense unless perhaps the plane has large wing wheels or it is a very smooth surface. But I have never heard any discussion about that, and It might be a good discussion for those of us that normally aerotow off of paved runways.

I also agree that anytime the heading change of the glider exceeds about 10 degrees one should release immediately regardless if the wing touches the ground or not. On narrow runways this should be pretty obvious because anything more than that you are probably going off the runway anyway. but even launching off wide tarmacs or runways one should still release.

But in the kind of Launch I do the most, Aerotow off of a paved runway. These are much lower energy than a Winch launch and as a result a wing drop is more likely. if there is very little heading change with the wing drop, Should we really be releasing immediately or should we wait a second or two for the controls to become effective which they nearly always do.

Adding more risk factors to consider is it pretty much a given that CG hooks are a higher Risk of Loss of control.
Do High power vs Lower power towplanes affect the risk? Which is better or worse?
Does holding the tail down (back elevator) during the early part of the takeoff roll change vs raising it early help? Pro. tailwheel will help resist turning tendency, Con, may delay aileron effectiveness.

If one is considering not releasing immediately we/they should develop a risk assessment for doing so.

What Have I not considered here?

[Tango Eight]

On Friday, March 19, 2021 at 8:26:02 PM UTC-4, Brian wrote:

> What Have I not considered here?

Wing span. :-).

T8

[Dave Nadler]

On 3/19/2021 8:26 PM, Brian wrote:
> Excuse me while I turn the short "Always release on Wing Drop" into a long discussion. I least my discussion is long. But like the "Impossible Turn" for power aircraft I suspect the real answer is when you really start to analyze it we find "it Depends" or "when in doubt release" but help me educate myself and others about what is really going on here.
>
> I have been hearing the release immediately on wing drop for over 30 years.
> Yet Winch launching almost always becomes part of the conversation almost immediately during the conversations, but I have I don't recall any conversations on Winch vs Aero Tow, or Grass vs Paved launches or even Towplane type (high power vs low power) with respect wing drop on launch, does any of this make a difference? It would seem to me wing wheels vs skids would be a factor as well.
> I have watched numerous aerotows off of pavement where the wing hits the pavement drags maybe 10 feet at most, and the glider maybe changes heading 10 degrees at most and then the wing comes back up and the glider repositions behind the glider and proceeds on its way. This is usually attributed to the glider hitting the propwash of the towplane. Having nearly a 1000 hours in a glider with wimpy ailerons I have had my share of wing drops under this scenario and never felt it was an issue or any worse than a no wing runner take off. In fact I recall only one glider releasing when the wing dropped under this scenario which then resulted in the wing tip continuing to drag and turn the glider off the runway into a runway light resulting in some leading edge damage to the wing. IMO if he had flown the glider for another second or two it would have been an uneventful launch. But that is just my opinion, he was PIC.
>
> I understand Winch launches happen a lot faster with a lot more energy than most (if not all) aerotows and releasing immediately makes sense for Winch Launches.
>
> I can also see that when launching off of Non-paved surfaces that releasing immediately on wing ground contact probably makes sense unless perhaps the plane has large wing wheels or it is a very smooth surface. But I have never heard any discussion about that, and It might be a good discussion for those of us that normally aerotow off of paved runways.
>
> I also agree that anytime the heading change of the glider exceeds about 10 degrees one should release immediately regardless if the wing touches the ground or not. On narrow runways this should be pretty obvious because anything more than that you are probably going off the runway anyway. but even launching off wide tarmacs or runways one should still release.
>
> But in the kind of Launch I do the most, Aerotow off of a paved runway. These are much lower energy than a Winch launch and as a result a wing drop is more likely. if there is very little heading change with the wing drop, Should we really be releasing immediately or should we wait a second or two for the controls to become effective which they nearly always do.
>
> Adding more risk factors to consider is it pretty much a given that CG hooks are a higher Risk of Loss of control.
> Do High power vs Lower power towplanes affect the risk? Which is better or worse?
> Does holding the tail down (back elevator) during the early part of the takeoff roll change vs raising it early help? Pro. tailwheel will help resist turning tendency, Con, may delay aileron effectiveness.
>
> If one is considering not releasing immediately we/they should develop a risk assessment for doing so.
>
> What Have I not considered here?

Brian, there are a lot of factors, including at least:
- tip wheels/skids
- surface drag
- water ballast
- tug acceleration
- hook location (no, a nose hook will not save your ass, despite proponents)
- wind direction and strength
- glider type
- spoiler and flap setting
- dumb luck

So... Do you feel lucky???

[Tony[_7_]]

On Friday, March 19, 2021 at 9:38:22 PM UTC-4, wrote:
> On 3/19/2021 8:26 PM, Brian wrote:
> > Excuse me while I turn the short "Always release on Wing Drop" into a long discussion. I least my discussion is long. But like the "Impossible Turn" for power aircraft I suspect the real answer is when you really start to analyze it we find "it Depends" or "when in doubt release" but help me educate myself and others about what is really going on here.
> >
> > I have been hearing the release immediately on wing drop for over 30 years.
> > Yet Winch launching almost always becomes part of the conversation almost immediately during the conversations, but I have I don't recall any conversations on Winch vs Aero Tow, or Grass vs Paved launches or even Towplane type (high power vs low power) with respect wing drop on launch, does any of this make a difference? It would seem to me wing wheels vs skids would be a factor as well.
> > I have watched numerous aerotows off of pavement where the wing hits the pavement drags maybe 10 feet at most, and the glider maybe changes heading 10 degrees at most and then the wing comes back up and the glider repositions behind the glider and proceeds on its way. This is usually attributed to the glider hitting the propwash of the towplane. Having nearly a 1000 hours in a glider with wimpy ailerons I have had my share of wing drops under this scenario and never felt it was an issue or any worse than a no wing runner take off. In fact I recall only one glider releasing when the wing dropped under this scenario which then resulted in the wing tip continuing to drag and turn the glider off the runway into a runway light resulting in some leading edge damage to the wing. IMO if he had flown the glider for another second or two it would have been an uneventful launch. But that is just my opinion, he was PIC.
> >
> > I understand Winch launches happen a lot faster with a lot more energy than most (if not all) aerotows and releasing immediately makes sense for Winch Launches.
> >
> > I can also see that when launching off of Non-paved surfaces that releasing immediately on wing ground contact probably makes sense unless perhaps the plane has large wing wheels or it is a very smooth surface. But I have never heard any discussion about that, and It might be a good discussion for those of us that normally aerotow off of paved runways.
> >
> > I also agree that anytime the heading change of the glider exceeds about 10 degrees one should release immediately regardless if the wing touches the ground or not. On narrow runways this should be pretty obvious because anything more than that you are probably going off the runway anyway. but even launching off wide tarmacs or runways one should still release.
> >
> > But in the kind of Launch I do the most, Aerotow off of a paved runway. These are much lower energy than a Winch launch and as a result a wing drop is more likely. if there is very little heading change with the wing drop, Should we really be releasing immediately or should we wait a second or two for the controls to become effective which they nearly always do.
> >
> > Adding more risk factors to consider is it pretty much a given that CG hooks are a higher Risk of Loss of control.
> > Do High power vs Lower power towplanes affect the risk? Which is better or worse?
> > Does holding the tail down (back elevator) during the early part of the takeoff roll change vs raising it early help? Pro. tailwheel will help resist turning tendency, Con, may delay aileron effectiveness.
> >
> > If one is considering not releasing immediately we/they should develop a risk assessment for doing so.
> >
> > What Have I not considered here?
> Brian, there are a lot of factors, including at least:
> - tip wheels/skids
> - surface drag
> - water ballast
> - tug acceleration
> - hook location (no, a nose hook will not save your ass, despite proponents)
> - wind direction and strength
> - glider type
> - spoiler and flap setting
> - dumb luck
>
> So... Do you feel lucky???
Nose hook may not save your ass but it is adding a corrective factor - with cg hook if the wing cannot be brought up immediately the release is already overdue.

[Brian[_1_]]

@nadler.com wrote:
> On 3/19/2021 8:26 PM, Brian wrote:
> > Excuse me while I turn the short "Always release on Wing Drop" into a long discussion. I least my discussion is long. But like the "Impossible Turn" for power aircraft I suspect the real answer is when you really start to analyze it we find "it Depends" or "when in doubt release" but help me educate myself and others about what is really going on here.
> >
> > I have been hearing the release immediately on wing drop for over 30 years.
> > Yet Winch launching almost always becomes part of the conversation almost immediately during the conversations, but I have I don't recall any conversations on Winch vs Aero Tow, or Grass vs Paved launches or even Towplane type (high power vs low power) with respect wing drop on launch, does any of this make a difference? It would seem to me wing wheels vs skids would be a factor as well.
> > I have watched numerous aerotows off of pavement where the wing hits the pavement drags maybe 10 feet at most, and the glider maybe changes heading 10 degrees at most and then the wing comes back up and the glider repositions behind the glider and proceeds on its way. This is usually attributed to the glider hitting the propwash of the towplane. Having nearly a 1000 hours in a glider with wimpy ailerons I have had my share of wing drops under this scenario and never felt it was an issue or any worse than a no wing runner take off. In fact I recall only one glider releasing when the wing dropped under this scenario which then resulted in the wing tip continuing to drag and turn the glider off the runway into a runway light resulting in some leading edge damage to the wing. IMO if he had flown the glider for another second or two it would have been an uneventful launch. But that is just my opinion, he was PIC.
> >
> > I understand Winch launches happen a lot faster with a lot more energy than most (if not all) aerotows and releasing immediately makes sense for Winch Launches.
> >
> > I can also see that when launching off of Non-paved surfaces that releasing immediately on wing ground contact probably makes sense unless perhaps the plane has large wing wheels or it is a very smooth surface. But I have never heard any discussion about that, and It might be a good discussion for those of us that normally aerotow off of paved runways.
> >
> > I also agree that anytime the heading change of the glider exceeds about 10 degrees one should release immediately regardless if the wing touches the ground or not. On narrow runways this should be pretty obvious because anything more than that you are probably going off the runway anyway. but even launching off wide tarmacs or runways one should still release.
> >
> > But in the kind of Launch I do the most, Aerotow off of a paved runway. These are much lower energy than a Winch launch and as a result a wing drop is more likely. if there is very little heading change with the wing drop, Should we really be releasing immediately or should we wait a second or two for the controls to become effective which they nearly always do.
> >
> > Adding more risk factors to consider is it pretty much a given that CG hooks are a higher Risk of Loss of control.
> > Do High power vs Lower power towplanes affect the risk? Which is better or worse?
> > Does holding the tail down (back elevator) during the early part of the takeoff roll change vs raising it early help? Pro. tailwheel will help resist turning tendency, Con, may delay aileron effectiveness.
> >
> > If one is considering not releasing immediately we/they should develop a risk assessment for doing so.
> >
> > What Have I not considered here?
> Brian, there are a lot of factors, including at least:
> - tip wheels/skids
> - surface drag
> - water ballast
> - tug acceleration
> - hook location (no, a nose hook will not save your ass, despite proponents)
> - wind direction and strength
> - glider type
> - spoiler and flap setting
> - dumb luck
>
> So... Do you feel lucky???

So back to my risk assessment...IMO..

> - tip wheels/skids - Skids and shorter = increased Risk
> - surface drag = More Drag = Increased risk
> - water ballast = Heaver wings = Increased Risk
> - tug acceleration = I don't know. Once the wing drops, things will happen slower with a low power tug, a high power tug seems like it has more prop wash to cause the wing to drop in the 1st place and the energy in t he system is building faster, so I think I am leaning toward a High Power tug = maybe an increased risk
> - hook location (no, a nose hook will not save your ass, despite proponents) CG hook = Increased risk.
> - wind direction and strength = cross winds = increased risk, less headwind = increased risk.
> - glider type = a consideration for sure but takes some experience to know if higher or lower risk.
> - spoiler and flap setting = again likely glider dependent but I know a lot of people start with spoilers extended to prevent wing drop. would think less flap would be better. takes some experience to know.
> - dumb luck - The whole point of taking a hard look at the details., How many increased risked factor might apply.

here's a couple more
> Rope Length = I would think a shorter rope would = increased risk, more propwash to cause drop
>Brake Capacity = poor braking capacity = increased Risk
>obstructions to the side of launch area = present = increased Risk

[andy l]

On Saturday, 20 March 2021 at 01:38:22 UTC, wrote:
> On 3/19/2021 8:26 PM, Brian wrote:
> > Excuse me while I turn the short "Always release on Wing Drop" into a long discussion. I least my discussion is long. But like the "Impossible Turn" for power aircraft I suspect the real answer is when you really start to analyze it we find "it Depends" or "when in doubt release" but help me educate myself and others about what is really going on here.
> >
> > I have been hearing the release immediately on wing drop for over 30 years.
> > Yet Winch launching almost always becomes part of the conversation almost immediately during the conversations, but I have I don't recall any conversations on Winch vs Aero Tow, or Grass vs Paved launches or even Towplane type (high power vs low power) with respect wing drop on launch, does any of this make a difference? It would seem to me wing wheels vs skids would be a factor as well.
> > I have watched numerous aerotows off of pavement where the wing hits the pavement drags maybe 10 feet at most, and the glider maybe changes heading 10 degrees at most and then the wing comes back up and the glider repositions behind the glider and proceeds on its way. This is usually attributed to the glider hitting the propwash of the towplane. Having nearly a 1000 hours in a glider with wimpy ailerons I have had my share of wing drops under this scenario and never felt it was an issue or any worse than a no wing runner take off. In fact I recall only one glider releasing when the wing dropped under this scenario which then resulted in the wing tip continuing to drag and turn the glider off the runway into a runway light resulting in some leading edge damage to the wing. IMO if he had flown the glider for another second or two it would have been an uneventful launch. But that is just my opinion, he was PIC.
> >
> > I understand Winch launches happen a lot faster with a lot more energy than most (if not all) aerotows and releasing immediately makes sense for Winch Launches.
> >
> > I can also see that when launching off of Non-paved surfaces that releasing immediately on wing ground contact probably makes sense unless perhaps the plane has large wing wheels or it is a very smooth surface. But I have never heard any discussion about that, and It might be a good discussion for those of us that normally aerotow off of paved runways.
> >
> > I also agree that anytime the heading change of the glider exceeds about 10 degrees one should release immediately regardless if the wing touches the ground or not. On narrow runways this should be pretty obvious because anything more than that you are probably going off the runway anyway. but even launching off wide tarmacs or runways one should still release.
> >
> > But in the kind of Launch I do the most, Aerotow off of a paved runway. These are much lower energy than a Winch launch and as a result a wing drop is more likely. if there is very little heading change with the wing drop, Should we really be releasing immediately or should we wait a second or two for the controls to become effective which they nearly always do.
> >
> > Adding more risk factors to consider is it pretty much a given that CG hooks are a higher Risk of Loss of control.
> > Do High power vs Lower power towplanes affect the risk? Which is better or worse?
> > Does holding the tail down (back elevator) during the early part of the takeoff roll change vs raising it early help? Pro. tailwheel will help resist turning tendency, Con, may delay aileron effectiveness.
> >
> > If one is considering not releasing immediately we/they should develop a risk assessment for doing so.
> >
> > What Have I not considered here?
> Brian, there are a lot of factors, including at least:
> - tip wheels/skids
> - surface drag
> - water ballast
> - tug acceleration
> - hook location (no, a nose hook will not save your ass, despite proponents)
> - wind direction and strength
> - glider type
> - spoiler and flap setting
> - dumb luck
>
> So... Do you feel lucky???

Tailskid or wheel, and the weight on it
Dihedral, if there's a significant crosswind

[Eric Greenwell[_4_]]

Brian wrote on 3/19/2021 8:41 PM:
.... Do you feel lucky???
>
> So back to my risk assessment...IMO..
>
>> - tip wheels/skids - Skids and shorter = increased Risk
>> - surface drag = More Drag = Increased risk
>> - water ballast = Heaver wings = Increased Risk
>> - tug acceleration = I don't know. Once the wing drops, things will happen slower with a low power tug, a high power tug seems like it has more prop wash to cause the wing to drop in the 1st place and the energy in t he system is building faster, so I think I am leaning toward a High Power tug = maybe an increased risk
>> - hook location (no, a nose hook will not save your ass, despite proponents) CG hook = Increased risk.
>> - wind direction and strength = cross winds = increased risk, less headwind = increased risk.
>> - glider type = a consideration for sure but takes some experience to know if higher or lower risk.
>> - spoiler and flap setting = again likely glider dependent but I know a lot of people start with spoilers extended to prevent wing drop. would think less flap would be better. takes some experience to know.
>> - dumb luck - The whole point of taking a hard look at the details., How many increased risked factor might apply.
>
> here's a couple more
>> Rope Length = I would think a shorter rope would = increased risk, more propwash to cause drop
>> Brake Capacity = poor braking capacity = increased Risk
>> obstructions to the side of launch area = present = increased Risk

My experience with aerotows is:

-Starting in negative flaps until about 20 knots IAS is better than using positive flaps
-Starting with spoilers extended is definitely better(especially noticed with my ASW20C)
-Using a nose hook instead of a CG hook is better with a wing runner, definitely better when
launching without a wing runner; also, much less likely to run over the rope at the very start.
(I had retrofitted my ASW20C with a nose hook, so I could try it both ways)
-Winglets are better than no winglets.\ (I noticed that because my ASH26E came without
winglets, but I retrofitted them several years later).
-A steerable tail wheel is a terrific aid: without one, you are basically ballistic until you
have 15+ knots. I suspect many of the start-of-tow accidents would be avoided if the gliders
had one. It can also be a real asset in crosswind landings, but that depends a bit on the
tailwheel design and your technique.

So, what to do:

-Every glider can use spoilers at the start, so it's worth investigating that to learn if that
will help in your glider.
-If you have flaps, find out if negative flaps help
-If you don't have a nose hook (or "forward hook" on some Schleicher gliders), see if there is
a retrofit for it.
-If you were thinking about adding winglets to your glider, you now have another reason to do it.
-Good luck finding a steerable tailwheel retrofit, but you can still nag your glider
manufacturer about it.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Hartley Falbaum[_2_]]

"What else did I miss?"---the other side of the equation in risk analysis.
What is the worst that can happen if I don't release? vs What is the worst that can happen if I do?
There may be a 1-2 second "startle factor" in some cases. So, the decision must be pre-loaded.
There is very little cost (usually) to a release.


On Saturday, March 20, 2021 at 8:41:52 AM UTC-4, Eric Greenwell wrote:
> Brian wrote on 3/19/2021 8:41 PM:
> ... Do you feel lucky???
> >
> > So back to my risk assessment...IMO..
> >
> >> - tip wheels/skids - Skids and shorter = increased Risk
> >> - surface drag = More Drag = Increased risk
> >> - water ballast = Heaver wings = Increased Risk
> >> - tug acceleration = I don't know. Once the wing drops, things will happen slower with a low power tug, a high power tug seems like it has more prop wash to cause the wing to drop in the 1st place and the energy in t he system is building faster, so I think I am leaning toward a High Power tug = maybe an increased risk
> >> - hook location (no, a nose hook will not save your ass, despite proponents) CG hook = Increased risk.
> >> - wind direction and strength = cross winds = increased risk, less headwind = increased risk.
> >> - glider type = a consideration for sure but takes some experience to know if higher or lower risk.
> >> - spoiler and flap setting = again likely glider dependent but I know a lot of people start with spoilers extended to prevent wing drop. would think less flap would be better. takes some experience to know.
> >> - dumb luck - The whole point of taking a hard look at the details., How many increased risked factor might apply.
> >
> > here's a couple more
> >> Rope Length = I would think a shorter rope would = increased risk, more propwash to cause drop
> >> Brake Capacity = poor braking capacity = increased Risk
> >> obstructions to the side of launch area = present = increased Risk
> My experience with aerotows is:
>
> -Starting in negative flaps until about 20 knots IAS is better than using positive flaps
> -Starting with spoilers extended is definitely better(especially noticed with my ASW20C)
> -Using a nose hook instead of a CG hook is better with a wing runner, definitely better when
> launching without a wing runner; also, much less likely to run over the rope at the very start.
> (I had retrofitted my ASW20C with a nose hook, so I could try it both ways)
> -Winglets are better than no winglets.\ (I noticed that because my ASH26E came without
> winglets, but I retrofitted them several years later).
> -A steerable tail wheel is a terrific aid: without one, you are basically ballistic until you
> have 15+ knots. I suspect many of the start-of-tow accidents would be avoided if the gliders
> had one. It can also be a real asset in crosswind landings, but that depends a bit on the
> tailwheel design and your technique.
>
> So, what to do:
>
> -Every glider can use spoilers at the start, so it's worth investigating that to learn if that
> will help in your glider.
> -If you have flaps, find out if negative flaps help
> -If you don't have a nose hook (or "forward hook" on some Schleicher gliders), see if there is
> a retrofit for it.
> -If you were thinking about adding winglets to your glider, you now have another reason to do it.
> -Good luck finding a steerable tailwheel retrofit, but you can still nag your glider
> manufacturer about it.
>
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Bob W.]

On 3/20/21 7:52 AM, Hartley Falbaum wrote:
> "What else did I miss?"---the other side of the equation in risk
> analysis. What is the worst that can happen if I don't release? vs
> What is the worst that can happen if I do? There may be a 1-2 second
> "startle factor" in some cases. So, the decision must be
> pre-loaded. There is very little cost (usually) to a release.

Kudos to BFC for attempting to take this particular
incident/accident/discussion beyond "mere panacea declamations" to which
the RAS medium seems (to me, dry chuckle) prone.

On the off chance there're some lurkers "somewhat earlier along" the
soaring learning curve - as opposed to long-time RAS regulars (which
includes me, and who seem to in recent years be hogging the forum :) ) -
this thread-to-date contains potentially-personally-useful,
seriously-good, food for thought.

Hartley's "reduction-ad-absurdem" post above is but one example. In my
view, "panacea fixes" (should they in fact be viewed within one's mind
as such) are too-often a blind alley when it comes to such things as
future learning and "properly preparing one's mind" to commit soaring in
as personally-healthy a manner as possible.

A common example of "panacea thinking" - at least in my part of the
Rocky Mountain Front Range west - is close-minded variations of: "I'll
be OK height-wise so long as I have X-thousand feet msl at location Y
back in the hills". Well, yeah, most of the time, maybe...but how to
reconcile that thinking with the thinking inherent within H. Falbaum's
hypothetical line of thought? One size "generally" can't *possibly* fit
every situation, and it's up to Joe Glider Pilot to decide how best to
approach this conundrum.

Given the inherent imperfections in humanity - imperfect
judgment/skills, lack of omniscience, etc. - while perfection isn't an
option, Joe Glider Pilot can still do a whole lot, and go a long way, to
avoid known (to those with greater experience & skills)
situations/physical-harm/death that *should* be avoidable, given their
existing skills/knowledge.
- - - - - -

Switching here from "Sermon from the Mount" mode to (so I hope)
illustrative examples from experience, O'beer thirty, tale-telling mode...

Early in my post-1-26, 15-meter glass, "somewhat-nose-hooked", aerotow
state, while attempting to take off from a grass strip in the mountains
north of Sun Valley, ID, several things made me pre-launch nervous:
slight crosswind, new-to-me tug/pilot of unknown provenances, knee-high
grass to either side of runway. I and my wing-runner/partner discussed
the situation and pre-planned things best we could (both "local
strangers" and prolly <200 hours total time each) and off I went. Pulled
the plug after an upwind wing drop followed by progressive swerving
into-wind along w. failure of the wing to lift. No harm, no foul was the
result outside the cockpit; inside the cockpit...not so much. Serious
dismay, as I felt that "somehow" I could've done better under existing
circumstances.

And so it proved on the 2nd launch attempt following further discussion
w. my partner *and* the tow-pilot, and some refining of my mental launch
go/no-go plan as well as techniques and "overall awarenesses".

Zooming ahead mightily through time, in that and two other ships (HP-14
w. "50% nose/CG hook, >15-meter span, no negative flaps, V-tail, tail
skid; and 15-meter Zuni *with* negative flaps, "somewhat nose-hooked",
heavily-weighted tailwheel) I aborted 1-each aerotow, both times
followed by successful launches behind the same tug/pilot. Both were
>5,300'msl, summertime, concerning-but-far-less-so than the C-70
experience...because of successfully pre-planned/decided "mental
scenario-ing". In both ships, I also made more-than-one (several? many?)
no-wing-runner takeoffs entirely w/o incident.

Bragging? Not intended as such. Rather trying to illustrate how
"preparing one's mind 'properly'" can be, likely *will* be, a good thing
for Joe Glider Pilot, if avoiding adrenaline, negative-excitement, and -
potentially - accidents, is deemed personally desirable.

Other than what I've read on RAS, I know zip about the situation and the
pilot in this particular unfortunate - seemingly, avoidable - accident.
I wish him a speedy and full recovery and continued good soaring, if he
so chooses. And part of this *particular* Joe Glider Pilot would
genuinely appreciate hearing from the horse's mouth at some point in the
future, by way of refining my mental picture.

YMMV,
Bob W.

[2G]

On Saturday, March 20, 2021 at 8:40:53 AM UTC-7, Bob W. wrote:
> On 3/20/21 7:52 AM, Hartley Falbaum wrote:
> > "What else did I miss?"---the other side of the equation in risk
> > analysis. What is the worst that can happen if I don't release? vs
> > What is the worst that can happen if I do? There may be a 1-2 second
> > "startle factor" in some cases. So, the decision must be
> > pre-loaded. There is very little cost (usually) to a release.
> Kudos to BFC for attempting to take this particular
> incident/accident/discussion beyond "mere panacea declamations" to which
> the RAS medium seems (to me, dry chuckle) prone.
>
> On the off chance there're some lurkers "somewhat earlier along" the
> soaring learning curve - as opposed to long-time RAS regulars (which
> includes me, and who seem to in recent years be hogging the forum :) ) -
> this thread-to-date contains potentially-personally-useful,
> seriously-good, food for thought.
>
> Hartley's "reduction-ad-absurdem" post above is but one example. In my
> view, "panacea fixes" (should they in fact be viewed within one's mind
> as such) are too-often a blind alley when it comes to such things as
> future learning and "properly preparing one's mind" to commit soaring in
> as personally-healthy a manner as possible.
>
> A common example of "panacea thinking" - at least in my part of the
> Rocky Mountain Front Range west - is close-minded variations of: "I'll
> be OK height-wise so long as I have X-thousand feet msl at location Y
> back in the hills". Well, yeah, most of the time, maybe...but how to
> reconcile that thinking with the thinking inherent within H. Falbaum's
> hypothetical line of thought? One size "generally" can't *possibly* fit
> every situation, and it's up to Joe Glider Pilot to decide how best to
> approach this conundrum.
>
> Given the inherent imperfections in humanity - imperfect
> judgment/skills, lack of omniscience, etc. - while perfection isn't an
> option, Joe Glider Pilot can still do a whole lot, and go a long way, to
> avoid known (to those with greater experience & skills)
> situations/physical-harm/death that *should* be avoidable, given their
> existing skills/knowledge.
> - - - - - -
>
> Switching here from "Sermon from the Mount" mode to (so I hope)
> illustrative examples from experience, O'beer thirty, tale-telling mode....
>
> Early in my post-1-26, 15-meter glass, "somewhat-nose-hooked", aerotow
> state, while attempting to take off from a grass strip in the mountains
> north of Sun Valley, ID, several things made me pre-launch nervous:
> slight crosswind, new-to-me tug/pilot of unknown provenances, knee-high
> grass to either side of runway. I and my wing-runner/partner discussed
> the situation and pre-planned things best we could (both "local
> strangers" and prolly <200 hours total time each) and off I went. Pulled
> the plug after an upwind wing drop followed by progressive swerving
> into-wind along w. failure of the wing to lift. No harm, no foul was the
> result outside the cockpit; inside the cockpit...not so much. Serious
> dismay, as I felt that "somehow" I could've done better under existing
> circumstances.
>
> And so it proved on the 2nd launch attempt following further discussion
> w. my partner *and* the tow-pilot, and some refining of my mental launch
> go/no-go plan as well as techniques and "overall awarenesses".
>
> Zooming ahead mightily through time, in that and two other ships (HP-14
> w. "50% nose/CG hook, >15-meter span, no negative flaps, V-tail, tail
> skid; and 15-meter Zuni *with* negative flaps, "somewhat nose-hooked",
> heavily-weighted tailwheel) I aborted 1-each aerotow, both times
> followed by successful launches behind the same tug/pilot. Both were
> >5,300'msl, summertime, concerning-but-far-less-so than the C-70
> experience...because of successfully pre-planned/decided "mental
> scenario-ing". In both ships, I also made more-than-one (several? many?)
> no-wing-runner takeoffs entirely w/o incident.
>
> Bragging? Not intended as such. Rather trying to illustrate how
> "preparing one's mind 'properly'" can be, likely *will* be, a good thing
> for Joe Glider Pilot, if avoiding adrenaline, negative-excitement, and -
> potentially - accidents, is deemed personally desirable.
>
> Other than what I've read on RAS, I know zip about the situation and the
> pilot in this particular unfortunate - seemingly, avoidable - accident.
> I wish him a speedy and full recovery and continued good soaring, if he
> so chooses. And part of this *particular* Joe Glider Pilot would
> genuinely appreciate hearing from the horse's mouth at some point in the
> future, by way of refining my mental picture.
>
> YMMV,
> Bob W.

Another factor not mentioned is what do you have on the wing tip: a skid or a wheel. If it is a wheel and you are towing on a hard surfaced runway a wing drop will be a non-event. If fact, when I self launch (with a wing tip wheel) I want the wing down even if offered a wing runner. A wing that starts down can't drop.
If, however, you are launching off of turf there will be more resistance than a hard surface. I don't ever fly off of turf so I can't say if it would make a difference. Probably depends upon how long the grass is.
A nose hook does provide some self-correcting force, but how much? the nose hook is, at most, one meter ahead of the main; an 18m glider gives forces on the wing tip a 9:1 lever arm to the nose hook. While that is better than nothing, what are the restorative forces? Say the towplane is exerting 200lb on the glider and the nose is 10 degrees off centerline; the restorative force is 35lb. This would only offset about a 5lb force on the wing tip - not very much.

Tom

[Frank Whiteley]

On Saturday, March 20, 2021 at 8:56:44 PM UTC-6, 2G wrote:
> On Saturday, March 20, 2021 at 8:40:53 AM UTC-7, Bob W. wrote:
> > On 3/20/21 7:52 AM, Hartley Falbaum wrote:
> > > "What else did I miss?"---the other side of the equation in risk
> > > analysis. What is the worst that can happen if I don't release? vs
> > > What is the worst that can happen if I do? There may be a 1-2 second
> > > "startle factor" in some cases. So, the decision must be
> > > pre-loaded. There is very little cost (usually) to a release.
> > Kudos to BFC for attempting to take this particular
> > incident/accident/discussion beyond "mere panacea declamations" to which
> > the RAS medium seems (to me, dry chuckle) prone.
> >
> > On the off chance there're some lurkers "somewhat earlier along" the
> > soaring learning curve - as opposed to long-time RAS regulars (which
> > includes me, and who seem to in recent years be hogging the forum :) ) -
> > this thread-to-date contains potentially-personally-useful,
> > seriously-good, food for thought.
> >
> > Hartley's "reduction-ad-absurdem" post above is but one example. In my
> > view, "panacea fixes" (should they in fact be viewed within one's mind
> > as such) are too-often a blind alley when it comes to such things as
> > future learning and "properly preparing one's mind" to commit soaring in
> > as personally-healthy a manner as possible.
> >
> > A common example of "panacea thinking" - at least in my part of the
> > Rocky Mountain Front Range west - is close-minded variations of: "I'll
> > be OK height-wise so long as I have X-thousand feet msl at location Y
> > back in the hills". Well, yeah, most of the time, maybe...but how to
> > reconcile that thinking with the thinking inherent within H. Falbaum's
> > hypothetical line of thought? One size "generally" can't *possibly* fit
> > every situation, and it's up to Joe Glider Pilot to decide how best to
> > approach this conundrum.
> >
> > Given the inherent imperfections in humanity - imperfect
> > judgment/skills, lack of omniscience, etc. - while perfection isn't an
> > option, Joe Glider Pilot can still do a whole lot, and go a long way, to
> > avoid known (to those with greater experience & skills)
> > situations/physical-harm/death that *should* be avoidable, given their
> > existing skills/knowledge.
> > - - - - - -
> >
> > Switching here from "Sermon from the Mount" mode to (so I hope)
> > illustrative examples from experience, O'beer thirty, tale-telling mode....
> >
> > Early in my post-1-26, 15-meter glass, "somewhat-nose-hooked", aerotow
> > state, while attempting to take off from a grass strip in the mountains
> > north of Sun Valley, ID, several things made me pre-launch nervous:
> > slight crosswind, new-to-me tug/pilot of unknown provenances, knee-high
> > grass to either side of runway. I and my wing-runner/partner discussed
> > the situation and pre-planned things best we could (both "local
> > strangers" and prolly <200 hours total time each) and off I went. Pulled
> > the plug after an upwind wing drop followed by progressive swerving
> > into-wind along w. failure of the wing to lift. No harm, no foul was the
> > result outside the cockpit; inside the cockpit...not so much. Serious
> > dismay, as I felt that "somehow" I could've done better under existing
> > circumstances.
> >
> > And so it proved on the 2nd launch attempt following further discussion
> > w. my partner *and* the tow-pilot, and some refining of my mental launch
> > go/no-go plan as well as techniques and "overall awarenesses".
> >
> > Zooming ahead mightily through time, in that and two other ships (HP-14
> > w. "50% nose/CG hook, >15-meter span, no negative flaps, V-tail, tail
> > skid; and 15-meter Zuni *with* negative flaps, "somewhat nose-hooked",
> > heavily-weighted tailwheel) I aborted 1-each aerotow, both times
> > followed by successful launches behind the same tug/pilot. Both were
> > >5,300'msl, summertime, concerning-but-far-less-so than the C-70
> > experience...because of successfully pre-planned/decided "mental
> > scenario-ing". In both ships, I also made more-than-one (several? many?)
> > no-wing-runner takeoffs entirely w/o incident.
> >
> > Bragging? Not intended as such. Rather trying to illustrate how
> > "preparing one's mind 'properly'" can be, likely *will* be, a good thing
> > for Joe Glider Pilot, if avoiding adrenaline, negative-excitement, and -
> > potentially - accidents, is deemed personally desirable.
> >
> > Other than what I've read on RAS, I know zip about the situation and the
> > pilot in this particular unfortunate - seemingly, avoidable - accident.
> > I wish him a speedy and full recovery and continued good soaring, if he
> > so chooses. And part of this *particular* Joe Glider Pilot would
> > genuinely appreciate hearing from the horse's mouth at some point in the
> > future, by way of refining my mental picture.
> >
> > YMMV,
> > Bob W.
> Another factor not mentioned is what do you have on the wing tip: a skid or a wheel. If it is a wheel and you are towing on a hard surfaced runway a wing drop will be a non-event. If fact, when I self launch (with a wing tip wheel) I want the wing down even if offered a wing runner. A wing that starts down can't drop.
> If, however, you are launching off of turf there will be more resistance than a hard surface. I don't ever fly off of turf so I can't say if it would make a difference. Probably depends upon how long the grass is.
> A nose hook does provide some self-correcting force, but how much? the nose hook is, at most, one meter ahead of the main; an 18m glider gives forces on the wing tip a 9:1 lever arm to the nose hook. While that is better than nothing, what are the restorative forces? Say the towplane is exerting 200lb on the glider and the nose is 10 degrees off centerline; the restorative force is 35lb. This would only offset about a 5lb force on the wing tip - not very much.
>
> Tom
Lush turf is pretty grabby and if a pilot tries to roll the glider with ailerons, the down wing aileron only grabs more turf and makes the situation worse. Only opposite rudder should be used until the wing starts to rise.

[Eric Greenwell[_4_]]

Frank Whiteley wrote on 3/21/2021 10:51 AM:
> On Saturday, March 20, 2021 at 8:56:44 PM UTC-6, 2G wrote:
....
>>> Bragging? Not intended as such. Rather trying to illustrate how
>>> "preparing one's mind 'properly'" can be, likely *will* be, a good thing
>>> for Joe Glider Pilot, if avoiding adrenaline, negative-excitement, and -
>>> potentially - accidents, is deemed personally desirable.
>>>
>>> Other than what I've read on RAS, I know zip about the situation and the
>>> pilot in this particular unfortunate - seemingly, avoidable - accident.
>>> I wish him a speedy and full recovery and continued good soaring, if he
>>> so chooses. And part of this *particular* Joe Glider Pilot would
>>> genuinely appreciate hearing from the horse's mouth at some point in the
>>> future, by way of refining my mental picture.
>>>
>>> YMMV,
>>> Bob W.
>> Another factor not mentioned is what do you have on the wing tip: a skid or a wheel. If it is a wheel and you are towing on a hard surfaced runway a wing drop will be a non-event. If fact, when I self launch (with a wing tip wheel) I want the wing down even if offered a wing runner. A wing that starts down can't drop.
>> If, however, you are launching off of turf there will be more resistance than a hard surface. I don't ever fly off of turf so I can't say if it would make a difference. Probably depends upon how long the grass is.
>> A nose hook does provide some self-correcting force, but how much? the nose hook is, at most, one meter ahead of the main; an 18m glider gives forces on the wing tip a 9:1 lever arm to the nose hook. While that is better than nothing, what are the restorative forces? Say the towplane is exerting 200lb on the glider and the nose is 10 degrees off centerline; the restorative force is 35lb. This would only offset about a 5lb force on the wing tip - not very much.
>>
>> Tom
> Lush turf is pretty grabby and if a pilot tries to roll the glider with ailerons, the down wing aileron only grabs more turf and makes the situation worse. Only opposite rudder should be used until the wing starts to rise.

Flapped ships can start in a negative setting, and avoid the turf grabbing by the ailerons.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[[email protected]]

Before a wing tip even touches the ground, any tailwind component counteracts any aerodynamic control input. The more deflection, the more OPPOSITE effect you get, causing pilot-induced problems. (Why is this glider shooting off to the left when I have full right deflections **!!) It can be mistakenly blamed on the wing runner, prop blast, rogue gust, etc. Hang on a split second longer, and you suddenly have positive control, maybe (?), when forward speed overcomes the tailwind. But by then you just scared yourself and innocent people. Neutralizing the controls, or using "opposite" inputs for the brave, until the tailwind vanishes should help.

Better yet, I just avoid any tailwind tow (for multiple good reasons), especially on an unassisted wing-down takeoff.

[Aldo Cernezzi]

I suggest everyone have a look at this accident report from France.
It is significant and unusual, as a tow operation lead to a violent groundloop with the sailplane landing inverted, as in a classic and tragic winch accident.
The reason is most probably to be found in the strong headwind.
The accident started with a wing drop, and was irrecuperable within 3 seconds.
The French text shouldn't be a big issue, as the photographic sequence illustrates the event very well and is self-explanatory (especially if you look at the time stamp of each picture.

https://www.bea.aero/uploads/tx_elydbrapports/f-dd140430.pdf

Safe flights,
Aldo Cernezzi
www.voloavela.it

[Accounts Receivable]

On the winch, if the wing drops, release immediately, you don't have time to consider your options. There's a good chance you can't do it fast enough, and it's going to hurt.
The wing runner isn't going to do a lot of running, if they start you from a balanced position, (which might be slightly different than wings level), and your control inputs are neutral, you will have aileron control and flying speed very quickly after the "All Out" calls.

[waremark]

On Monday, 22 March 2021 at 20:03:39 UTC, Accounts Receivable wrote:
> On the winch, if the wing drops, release immediately, you don't have time to consider your options. There's a good chance you can't do it fast enough, and it's going to hurt.
> The wing runner isn't going to do a lot of running, if they start you from a balanced position, (which might be slightly different than wings level), and your control inputs are neutral, you will have aileron control and flying speed very quickly after the "All Out" calls.

At my club we try to emphasise that the wing runner should not allow the launch to start if there is a significant up or down force on the wingtip.

Someone mentioned water ballast - I think that is very significant, as a low wing allows water to flow towards the tip and make that wing heavier, making recovery less likely.

[Martin Gregorie[_6_]]

On Mon, 22 Mar 2021 17:41:30 -0700, waremark wrote:

>
> At my club we try to emphasise that the wing runner should not allow the
> launch to start if there is a significant up or down force on the
> wingtip.
>
Same at my club. In addition, if there's a cross wind for a winch launch
and the pilot is using aileron to hold the downwind tip up rather than
leaving the stick central while the wing runner moves the tip up or down
to zero the force he's feeling, the wing runner is encouraged to stop the
launch until the stick is centralised.

This is safer because the pilot can't feel what the up- or down-force of
the wingtip is - only the wing runner knows that. And so, if the
balancing is left to the pilot, the chances of an immediate tip drop is
raised.

> Someone mentioned water ballast - I think that is very significant, as a
> low wing allows water to flow towards the tip and make that wing
> heavier, making recovery less likely.
>
Agreed.


--
Martin | martin at
Gregorie | gregorie dot org

[Brian[_1_]]

On Monday, March 22, 2021 at 10:50:24 AM UTC-6, Aldo Cernezzi wrote:
> I suggest everyone have a look at this accident report from France.
> It is significant and unusual, as a tow operation lead to a violent groundloop with the sailplane landing inverted, as in a classic and tragic winch accident.
> The reason is most probably to be found in the strong headwind.
> The accident started with a wing drop, and was irrecuperable within 3 seconds.
> The French text shouldn't be a big issue, as the photographic sequence illustrates the event very well and is self-explanatory (especially if you look at the time stamp of each picture.
>
> https://www.bea.aero/uploads/tx_elydbrapports/f-dd140430.pdf
>
> Safe flights,
> Aldo Cernezzi
> www.voloavela.it

Very interesting and worth translating.
This data point would seem to indicate higher energy tows are a higher risk of having an issue wshould a wing drop occur. In this event it appear the strong headwind made it an even higher energy tow.
With that much headwind I would not have expected a wing drop as I would have expected to have good aileron and rudder control immediately. But as the report hints to, the combination of a gust and the prop wash may have overpowered the controls.

Thanks for posting.

Brian

[Brian[_1_]]

On Monday, March 22, 2021 at 6:57:59 PM UTC-6, Martin Gregorie wrote:
> On Mon, 22 Mar 2021 17:41:30 -0700, waremark wrote:
>
> >
> > At my club we try to emphasise that the wing runner should not allow the
> > launch to start if there is a significant up or down force on the
> > wingtip.
> >
> Same at my club. In addition, if there's a cross wind for a winch launch
> and the pilot is using aileron to hold the downwind tip up rather than
> leaving the stick central while the wing runner moves the tip up or down
> to zero the force he's feeling, the wing runner is encouraged to stop the
> launch until the stick is centralised.
>
> This is safer because the pilot can't feel what the up- or down-force of
> the wingtip is - only the wing runner knows that. And so, if the
> balancing is left to the pilot, the chances of an immediate tip drop is
> raised.
> > Someone mentioned water ballast - I think that is very significant, as a
> > low wing allows water to flow towards the tip and make that wing
> > heavier, making recovery less likely.
> >
> Agreed.
>
>
> --
> Martin | martin at
> Gregorie | gregorie dot org

Good point about wing runners. What I teach wing runners is if the wing wants to go up, to let it go up as high as you can reach. If it goes low, let it go as low as is practical, as this will signal the pilot to put the correct input in to correct for wing low or wing high condition.

Brian

[Dan Marotta]

Not so much if the wing tanks are full and not interconnected.

Dan
5J

On 3/22/21 6:41 PM, waremark wrote:
> Someone mentioned water ballast - I think that is very significant, as a low wing allows water to flow towards the tip and make that wing heavier, making recovery less likely.

[John Sinclair[_5_]]

On Tuesday, March 23, 2021 at 9:20:53 AM UTC-7, Dan Marotta wrote:
> Not so much if the wing tanks are full and not interconnected.
>
> Dan
> 5J
> On 3/22/21 6:41 PM, waremark wrote:
> > Someone mentioned water ballast - I think that is very significant, as a low wing allows water to flow towards the tip and make that wing heavier, making recovery less likely.


I believe a nose tow hook reduces lateral excursions, but not all ! There was a Genesis-2 take off accident where the slack was not all taken out before starting tow. This resulted in glider pitching down on the nose wheel which is mounted on a 36” fiberglass shock strut which then sprung the nose up! It’s called the Hobby-horse effect which is annoying, but not all that dangerous, unless a wing tip touches the ground as the fuselage is pitching down. This can (and has) resulted in the glider cartwheeling and ended up inverted!
If you’d ship doesn’t have a nose tow hook I’d investigate having one installed!
Be safe out there and keep a hand on the tow release during takeoff!
JJ

[Tango Eight]

On Tuesday, March 23, 2021 at 1:28:47 PM UTC-4, John Sinclair wrote:
> I believe a nose tow hook reduces lateral excursions, but not all !

It's true that at the very beginning of the launch, the nose hook improves tracking. It's also true that once aerodynamic control is achieved that the rudder works better with a CG hook, and the rudder often (this is type dependent) works better for picking up a low wing than aileron input.

In all cases, the only thing that beats pilot skill is pilot judgement.

The release knob is the most under rated control in the cockpit.

T8