Overspeed Recovery question

[[email protected]]

If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?

[Charlie M. (UH & 002 owner/pilot)]

On Tuesday, February 10, 2015 at 9:58:58 PM UTC-5, wrote:
> If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?

Besides the tendency for the spoilers to suck out and then bend back on the wing?????.... no problem.

Dropping the gear, easy pull back on the stick, don't look too hard at the ASI, etc........

[Bob Whelan[_3_]]

On 2/10/2015 7:58 PM, wrote:
> If you inadvertently fly into the yellow range and kiss the red range, and
> you get into the high speed vibration, what is the best way to slow before
> the wings depart the glider. My sense is to reach for the spoilers and
> slowly extend to slow. Any opinions on that matter?
>

Priority One: Undo what you last did to get yourself into that situation -
which as stated appears to have been too much forward stick. Assuming gravity
(and not your straps or "purely" centripetal force) is keeping your butt
pressed into the seat, get the stick back promptly, which will have the almost
immediate effect of reducing the rate of energy increase, and even better - if
you get the nose up high enough - reducing its accumulation.

Once you're happy with your energy-state, you can can consider doing "other
stuff"...dropping the gear (will mostly make noise), spoilers (if below their
max opening speed and you're physically/mentally prepared for a "Holy S&*%!"
experience if this is your first opening of them at any speed not fairly close
to your normal pattern entry opening speed); etc.

Priority Two: Throughout, keep your mental cool, rationally assess the effect
of everything you do before doing something else, and seriously consider
landing ASAP depending on the nature/seriousness of the vibration (which, of
course you really can't completely assess from inside a flying cockpit).

Priority Three: RTFM (if the ship has one; U.S. Exp. Amateur Built ships may
not have much of one, if any)!

Bob W.

P.S. Of course, RTFM is actually Priority One, but the question as-posed
precludes reasonably doing so. :-)

[Bill D]

On Tuesday, February 10, 2015 at 9:04:26 PM UTC-7, Bob Whelan wrote:
> On 2/10/2015 7:58 PM, wrote:
> > If you inadvertently fly into the yellow range and kiss the red range, and
> > you get into the high speed vibration, what is the best way to slow before
> > the wings depart the glider. My sense is to reach for the spoilers and
> > slowly extend to slow. Any opinions on that matter?
> >
>
> Priority One: Undo what you last did to get yourself into that situation -
> which as stated appears to have been too much forward stick. Assuming gravity
> (and not your straps or "purely" centripetal force) is keeping your butt
> pressed into the seat, get the stick back promptly, which will have the almost
> immediate effect of reducing the rate of energy increase, and even better - if
> you get the nose up high enough - reducing its accumulation.
>
> Once you're happy with your energy-state, you can can consider doing "other
> stuff"...dropping the gear (will mostly make noise), spoilers (if below their
> max opening speed and you're physically/mentally prepared for a "Holy S&*%!"
> experience if this is your first opening of them at any speed not fairly close
> to your normal pattern entry opening speed); etc.
>
> Priority Two: Throughout, keep your mental cool, rationally assess the effect
> of everything you do before doing something else, and seriously consider
> landing ASAP depending on the nature/seriousness of the vibration (which, of
> course you really can't completely assess from inside a flying cockpit).
>
> Priority Three: RTFM (if the ship has one; U.S. Exp. Amateur Built ships may
> not have much of one, if any)!
>
> Bob W.
>
> P.S. Of course, RTFM is actually Priority One, but the question as-posed
> precludes reasonably doing so. :-)

I think the key point is smoothness on the controls.

If the ground is no factor, don't try to fix things too quickly. Ease back a tiny bit until the airspeed starts a slow downward trend then let that trend ease you out of the dive. If the wings are still on, they'll probably stay on as the airspeed bleeds off.

If the ground is an issue, aim to scare the crap out of the worms by using all the height you have left in a low G pull out. You want to just barely miss the earth. As the airspeed drops into the yellow arc, slowly add up to 1/3 of your up elevator travel and when it gets into the green arc you can pile on more G up to your gliders useful load factor but beware of a secondary accelerated stall.

I would not recommend spoilers at all especially if you are pulling G. They shift the spanwise lift distribution outboard increasing the bending stress on the wing spar. In a low pullout, spoilers increase the radius and the likelihood of hitting the ground.

[Don Johnstone[_4_]]

At 02:58 11 February 2015, wrote:
>If you inadvertently fly into the yellow range and kiss the red range,
and
>=
>you get into the high speed vibration, what is the best way to slow
before
>=
>the wings depart the glider. My sense is to reach for the spoilers and
>slo=
>wly extend to slow. Any opinions on that matter?
>
A very experienced test pilot once told me, and several others, that if you
were faced with exceeding VNE you should pull as hard as you can, even if
it means exceeding max G load, to reduce speed as soon as you can to below
VNE. Catastrophic structural failures due to excess G are very rare unless
there are other factors, catastrophic failures due to flutter are almost
inevitable.
There is no right answer, just a less wrong one and I would stress I have
not had the opportunity to test this.
One of the requirements on a Grob 103 post major inspection test flight was
to operate the spoilers at 70kts, having done this many times I would not
recommend the spoilers option.

[Dan Marotta]

How can you "inadvertently fly into the yellow range and kiss the red
range"? Sleeping at the helm? You have to have quite a nose down
attitude to get near the red line and it doesn't sneak up on you. It's
very noisy and pitch sensitive.

Don's advice below is excellent.


On 2/11/2015 3:20 AM, Don Johnstone wrote:
> At 02:58 11 February 2015, wrote:
>> If you inadvertently fly into the yellow range and kiss the red range,
> and
>> =
>> you get into the high speed vibration, what is the best way to slow
> before
>> =
>> the wings depart the glider. My sense is to reach for the spoilers and
>> slo=
>> wly extend to slow. Any opinions on that matter?
>>
> A very experienced test pilot once told me, and several others, that if you
> were faced with exceeding VNE you should pull as hard as you can, even if
> it means exceeding max G load, to reduce speed as soon as you can to below
> VNE. Catastrophic structural failures due to excess G are very rare unless
> there are other factors, catastrophic failures due to flutter are almost
> inevitable.
> There is no right answer, just a less wrong one and I would stress I have
> not had the opportunity to test this.
> One of the requirements on a Grob 103 post major inspection test flight was
> to operate the spoilers at 70kts, having done this many times I would not
> recommend the spoilers option.
>

--
Dan Marotta

[Brian[_1_]]

On Wednesday, February 11, 2015 at 8:10:30 AM UTC-7, Dan Marotta wrote:
> How can you "inadvertently fly into the yellow range and kiss the
> red range"?* Sleeping at the helm?* You have to have quite a nose
> down attitude to get near the red line and it doesn't sneak up on
> you.* It's very noisy and pitch sensitive.
>
>
>
> Don's advice below is excellent.
>
>
>
>
>
>
> On 2/11/2015 3:20 AM, Don Johnstone
> wrote:
>
>
>
> At 02:58 11 February 2015, wrote:
>
>
> If you inadvertently fly into the yellow range and kiss the red range,
>
>
> and
>
>
> =
> you get into the high speed vibration, what is the best way to slow
>
>
> before
>
>
> =
> the wings depart the glider. My sense is to reach for the spoilers and
> slo=
> wly extend to slow. Any opinions on that matter?
>
>
>
> A very experienced test pilot once told me, and several others, that if you
> were faced with exceeding VNE you should pull as hard as you can, even if
> it means exceeding max G load, to reduce speed as soon as you can to below
> VNE. Catastrophic structural failures due to excess G are very rare unless
> there are other factors, catastrophic failures due to flutter are almost
> inevitable.
> There is no right answer, just a less wrong one and I would stress I have
> not had the opportunity to test this.
> One of the requirements on a Grob 103 post major inspection test flight was
> to operate the spoilers at 70kts, having done this many times I would not
> recommend the spoilers option.
>
>
>
>
>
>
> --
>
> Dan Marotta

Easier than you might think when flying at altitude, I inadvertently did it in my HP16T while going through a FAI Start for a 300k triangle at 12000 feet on a hot summer day, I was indicating 15kts under Red line when I experienced a low frequency elevator flutter, A gentle pull back on the stick and it stopped, probably lasted less than a second but definitely got my attention. A few minutes with an E6B, showed that my True Airspeed was well over VNE.

Brian

[jfitch]

On Wednesday, February 11, 2015 at 2:30:06 AM UTC-8, Don Johnstone wrote:
> At 02:58 11 February 2015, wrote:
> >If you inadvertently fly into the yellow range and kiss the red range,
> and
> >=
> >you get into the high speed vibration, what is the best way to slow
> before
> >=
> >the wings depart the glider. My sense is to reach for the spoilers and
> >slo=
> >wly extend to slow. Any opinions on that matter?
> >
> A very experienced test pilot once told me, and several others, that if you
> were faced with exceeding VNE you should pull as hard as you can, even if
> it means exceeding max G load, to reduce speed as soon as you can to below
> VNE. Catastrophic structural failures due to excess G are very rare unless
> there are other factors, catastrophic failures due to flutter are almost
> inevitable.
> There is no right answer, just a less wrong one and I would stress I have
> not had the opportunity to test this.
> One of the requirements on a Grob 103 post major inspection test flight was
> to operate the spoilers at 70kts, having done this many times I would not
> recommend the spoilers option.

Since flutter is a dynamic phenomenon related to wing stiffness, I could make a theoretical argument that loading the wing would help. But I am not going to test it.

There are a lot of pilots flying up in the mountains where I fly that are unaware that just because the placard says 146 knots IAS or whatever, that is not true at FL180. On my glider, 146 knots IAS at 10,000 ft, 122 at 18,000, 76 at 42,000.

[SF]

Well here is what I did. I was flying behind an ASW24 in my LS6. We were comparing how the two ships performed while doing some wing overs and other stuff to burn off some excess altitude. At the top of the last wing over, the pilot in front of me rolled it inverted and pulled it in to a Split S. Without thinking about it too much I repeated the Split S a few seconds later. The rapid advance of the ASI towards red line was impressive and relentless. I pulled back some, nothing much happened, I pulled back some more, nothing much happened, I pulled the stick back to the stop and started cursing at everyone involved in this stupid decision, and finally the nose came back to a normal distance below the horizon rather than its previous straight down orientation. Nothing broke, cracked, acted weird, or got bent, but when I conferred with the other pilot on the ground, we both decided that we were not going to do that again, and we both needed a beer before going home.

SF

[BobW]

On 2/11/2015 11:25 AM, SF wrote:
> Well here is what I did...
<Snip...>
> Without thinking about it too much I repeated the Split S a few seconds
> later. The rapid advance of the ASI towards red line was impressive and
> relentless.

Between this and JJ's recent "thunderstorm" thread, methinks we're seeing
evidence of winter in the northern hemisphere; contributors are willing to
share some survived sillinesses! That's a good thing, and I thank all for sharing.

I happened to read the original question posed in this thread ("If you
inadvertently fly into the yellow range and kiss the red range, and you get
into the high speed vibration, what is the best way to slow before the wings
depart the glider. My sense is to reach for the spoilers and slowly extend to
slow.") late in the PM before retiring to Zonkland, and will admit the
2nd/declarative sentence, and a personally compelling interest in soaring
safety, triggered a mental alarm bell. I'll elaborate on "Why?" shortly.

But first, even if the question is simply a cleverly designed attempt to
initiate a broad-in-scope discussion (as distinct from reflecting the O.P.'s
personal/presently-felt state of knowledge), it's a good one! The devil is
always in the details, and the details of gliders' load-bearing construction
commonly include structures composed of wood, steel tube and fabric, sheet
aluminum, 1st-generation fiberglass, and carbon fiber. Each has distinctly
different toleration to "high speed vibration"...which itself is a concept
worthy of lengthy definition, perhaps! Bottom line is these details may prove
to be compellingly important to Joe PIC, particularly in the time granted by
the structure to implement "the proper response." Arguably, 1st-generation
glass structures may simultaneously be most likely display to "high speed
vibration", and, to grant Joe PIC the greatest length of time to correct it
before something disastrous happens to the structure; wood and sheet metal may
be least generous with pre-failure time. Regardless of structure, "high speed
vibration" *will* get your attention...as well it should!

I could be reading way too much into original question/and "sense" of the
O.P., but here's why the sentence pair triggered an alarm bell. Is any reader
aware of any glider manufacturer's ship documentation that recommends as the
*first* corrective step for anything (other than pattern work, and perhaps,
tow-related height correction) to open the spoilers? Others have sensibly
noted several structural reasons that doing so at "too high a speed" may be
distinctly unwise, and I'm a fan of undoing first what caused the
problem...which in the case of high speed, certainly wasn't the spoilers.

So...no snark intended in my original reply. Anyone who finds themselves with
a case of "inadvertent imminent overspeed" surely had BETTER be alarmed, and,
have a sensible, pre-planned course of action ready for immediate implementation.

Good, thought-provoking scenario...

Bob W.

P.S. My own glider thunderstorm story involves the usual "made sense at the
time" rationales, resulted in a go-around initiated on short final from the
full-flap condition in an HP-14, in blinding rain and strong lift, in order to
avoid an overshoot into a tree lined mini-canyon/defile. It happened with
somewhere between 300 and 400 total hours...and served as "fair warning"
regarding thunderstorms...not that I should have needed - or been granted -
any. Even though I got away with it, I really should've landed out at the last
usable field 10 or so miles away. My most compelling rationale for continuing
was a really lousy trailer, though wanting to complete the contest task played
a part too. As I recall, only 4 or 5 of 30 did...and it wasn't the
thunderstorm over the field that put 'em on the ground!

[[email protected]]

On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8, wrote:
> If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?

Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.

[Don Johnstone[_4_]]

At 23:07 11 February 2015, wrote:
>On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8,
>wro=
>te:
>> If you inadvertently fly into the yellow range and kiss the red range,
>an=
>d you get into the high speed vibration, what is the best way to slow
>befor=
>e the wings depart the glider. My sense is to reach for the spoilers and
>s=
>lowly extend to slow. Any opinions on that matter?
>
>Thanks all for your input. The senario as stated in my quest has
happened
>=
>to me several times whilst flying Condor - Glider flight Simulation
>softwar=
>e. I've been deploying spoilers to slow down but that I would ask this
>gro=
>up in case it happens in a real glider. Your inputs, as I suspected, are
>w=
>ell thought out and are convincing. My thoughts to control highspeed
>fligh=
>t (overspeed flight) will be pitch.

My reluctance to recommend the spoilers is mainly, but not only, for
aerodynamic reasons, a scaphoid fracture is extremely painful, which is
best avoided unless faced with a life or death situation. The very loud
bang as the airbrakes hit the stop is more than a bit scary as well.
>

[Bruce Hoult]

On Thursday, February 12, 2015 at 12:07:31 PM UTC+13, wrote:
> On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8, wrote:
> > If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?
>
> Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.

The flutter in condor is nasty, and happens at speeds well below where any real glider would probably experience flutter. The simulated glider also falls apart very very quickly!

Quickly pulling the nose up above the horizon is really the only sensible thing to do there.

[dbrunone]

I was always taught that if you exceed VNE and open the spoilers, they will push the airflow outwards and snap off the wing tips. Never tested the theory but I'm not sure I want to.

[Bill D]

On Wednesday, February 11, 2015 at 6:49:09 PM UTC-7, Bruce Hoult wrote:
> On Thursday, February 12, 2015 at 12:07:31 PM UTC+13, wrote:
> > On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8, wrote:
> > > If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?
> >
> > Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.
>
> The flutter in condor is nasty, and happens at speeds well below where any real glider would probably experience flutter. The simulated glider also falls apart very very quickly!
>
Have a lot of experience at that?

[Jonathan St. Cloud]

Level the wings and pull. DO NOT OPEN spoilers! The spoilers will be sucked open and now you are creating more bending moments on the wing. Lowering gear usually requires switching hands on the stick, probably not a good idea. Also mindful actions can keep you from exceeding VNE. Other than non-approved aerobatics, and flight into IMC a common reason to get into a VNE exceed would be a spin that has turned into a "death spiral. Go get some training in a 2-32, those will easily go from spin to spiral.

Stay safe

[Jonathan St. Cloud]

Oh, a quick way to tell if a spin has turned into a spiral, when the rudder does not stop the spin.

[jfitch]

On Wednesday, February 11, 2015 at 5:30:05 PM UTC-8, Don Johnstone wrote:
> At 23:07 11 February 2015, wrote:
> >On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8,
> >wro=
> >te:
> >> If you inadvertently fly into the yellow range and kiss the red range,
> >an=
> >d you get into the high speed vibration, what is the best way to slow
> >befor=
> >e the wings depart the glider. My sense is to reach for the spoilers and
> >s=
> >lowly extend to slow. Any opinions on that matter?
> >
> >Thanks all for your input. The senario as stated in my quest has
> happened
> >=
> >to me several times whilst flying Condor - Glider flight Simulation
> >softwar=
> >e. I've been deploying spoilers to slow down but that I would ask this
> >gro=
> >up in case it happens in a real glider. Your inputs, as I suspected, are
> >w=
> >ell thought out and are convincing. My thoughts to control highspeed
> >fligh=
> >t (overspeed flight) will be pitch.
>
> My reluctance to recommend the spoilers is mainly, but not only, for
> aerodynamic reasons, a scaphoid fracture is extremely painful, which is
> best avoided unless faced with a life or death situation. The very loud
> bang as the airbrakes hit the stop is more than a bit scary as well.
> >

I have extended the spoilers at over 100 knots IAS at 18,000 ft a few times (mainly to get out from under clouds) and I brace myself and wince with a death grip on the handle when I do it. Stuff is going to fly around and my head is probably going to hit the canopy. I sure wouldn't want to be doing that while the wings were fluttering.

[[email protected]]

If you can get to Williams, California on March 7-8...we are having AcroFest.
AcroFest is an introduction to glider aerobatics for the average glider pilot and an opportunity to learn what it feels like to fly upside down and how to get back upright.
We can show you how to recover from an overspeed.
We can show you how to safely get your upside down glider right side up.
We can let you experience a spin in our Fox and how to recover.
We fly both Saturday and Sunday.
We have presentations and a BBQ on Saturday evening.
Go to: www.williamssoaring.com
We fly ASK-21s and a Fox.

[Tango Eight]

On Wednesday, February 11, 2015 at 6:07:31 PM UTC-5, wrote:

> Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.

Illustrating nicely the perils of self directed training in Condor. You did well to ask for the benefit of real world experience.

Evan Ludeman / T8

[Bruce Hoult]

On Thursday, February 12, 2015 at 3:59:16 PM UTC+13, Bill D wrote:
> On Wednesday, February 11, 2015 at 6:49:09 PM UTC-7, Bruce Hoult wrote:
> > On Thursday, February 12, 2015 at 12:07:31 PM UTC+13, wrote:
> > > On Tuesday, February 10, 2015 at 6:58:58 PM UTC-8, wrote:
> > > > If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?
> > >
> > > Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.
> >
> > The flutter in condor is nasty, and happens at speeds well below where any real glider would probably experience flutter. The simulated glider also falls apart very very quickly!
> >
> Have a lot of experience at that?

Yes. Real gliders I've flown have never fluttered at indicated Vne at low altitude. Condor does every time.

[Charlie M. (UH & 002 owner/pilot)]

On Thursday, February 12, 2015 at 7:55:09 AM UTC-5, Tango Eight wrote:
> On Wednesday, February 11, 2015 at 6:07:31 PM UTC-5, wrote:
>
> > Thanks all for your input. The senario as stated in my quest has happened to me several times whilst flying Condor - Glider flight Simulation software. I've been deploying spoilers to slow down but that I would ask this group in case it happens in a real glider. Your inputs, as I suspected, are well thought out and are convincing. My thoughts to control highspeed flight (overspeed flight) will be pitch.
>
> Illustrating nicely the perils of self directed training in Condor. You did well to ask for the benefit of real world experience.
>
> Evan Ludeman / T8

Yes, good to ask real world experience. While I've never been in the scenario as described (over VNE unintentionally) I have had dive brakes open at speed.
Coming back from a day of flying, I did a speed pass over the field (in a ASW-24) aiming to do a pull up and enter late downwind. At ~300' (in the pull up), I hit a gust that slammed the spoilers full open (speed was likely close to 180MPH) and aimed away from the field.
The glider felt like it hit a wall.
I went from, "Life is good, lets do a nice pattern" to "I'm low, losing speed quickly and am getting a wee bit busy".
The spoilers DID close and everything turned out well.
We did spend some time checking spoiler linkages & alignments before de-rigging.

As to flutter, I would hazard it's more of the control surface balance, hinge condition & linkage slop than the wing itself. The wing tends to be involved AFTER the control surface flutters.
Right on up there with old/cheap safety tape that peels up its leading edge and blanks a surface. Especially newer designs with small chord control surfaces.

[Michael Corcoran[_2_]]

At 15:10 11 February 2015, Dan Marotta wrote:
>How can you "inadvertently fly into the yellow range and kiss the red
>range"? Sleeping at the helm? You have to have quite a nose down
>attitude to get near the red line and it doesn't sneak up on you. It's
>very noisy and pitch sensitive.
>
>Don's advice below is excellent.
>
>
>On 2/11/2015 3:20 AM, Don Johnstone wrote:
>> At 02:58 11 February 2015, wrote:
>>> If you inadvertently fly into the yellow range and kiss the red range,
>> and
>>>
>>> you get into the high speed vibration, what is the best way to slow
>> before
>>>
>>> the wings depart the glider. My sense is to reach for the spoilers
and
>>> slo
>>> wly extend to slow. Any opinions on that matter?
>>>
>> A very experienced test pilot once told me, and several others, that if
>you
>> were faced with exceeding VNE you should pull as hard as you can, even
if
>> it means exceeding max G load, to reduce speed as soon as you can to
>below
>> VNE. Catastrophic structural failures due to excess G are very rare
>unless
>> there are other factors, catastrophic failures due to flutter are
almost


>> inevitable.
>> There is no right answer, just a less wrong one and I would stress I
have
>> not had the opportunity to test this.
>> One of the requirements on a Grob 103 post major inspection test flight
>was
>> to operate the spoilers at 70kts, having done this many times I would
not
>> recommend the spoilers option.
>>
>
>--
>Dan Marotta
>

Once, while practicing aerobatics in my Pilatus B4, and entirely due to my

own clumsiness, I found myself in a 45 degree inverted dive and rapidly
approaching Vne. Fortunately, I did what I was trained to do, which was to

push hard until the nose was above the horizon, then roll out. It was all
captured on my cockpit mounted Go-Pro. This shows the momentary
hesitation while I overcame the instinct to pull. The ASI shows 130knots
(Vne) was just touched, and the accelerometer, after initially being
obscured
by my left arm rising to be firmly held against the canopy, showed -4g.

Had I pulled through, I would probably have exceeded Vne by 30knots.

On landing, the aircraft was thoroughly checked, and found to have suffered

no ill effects.

I am thankful for the thoroughness of my training, and for the robustness
of
the B4.

[Jonathon May[_2_]]

At 16:12 12 February 2015, Michael Corcoran wrote:
>At 15:10 11 February 2015, Dan Marotta wrote:
>>How can you "inadvertently fly into the yellow range and kiss the red
>>range"? Sleeping at the helm? You have to have quite a nose down
>>attitude to get near the red line and it doesn't sneak up on you. It's
>>very noisy and pitch sensitive.
>>
>>Don's advice below is excellent.
>>
>>
>>On 2/11/2015 3:20 AM, Don Johnstone wrote:
>>> At 02:58 11 February 2015, wrote:
>>>> If you inadvertently fly into the yellow range and kiss the red
range,
>>> and
>>>>
>>>> you get into the high speed vibration, what is the best way to slow
>>> before
>>>>
>>>> the wings depart the glider. My sense is to reach for the spoiler
>and
>>>> slo
>>>> wly extend to slow. Any opinions on that matter?
>>>>
>>> A very experienced test pilot once told me, and several others, that
if
>>you
>>> were faced with exceeding VNE you should pull as hard as you can,
even
>if
>>> it means exceeding max G load, to reduce speed as soon as you can to
>>below
>>> VNE. Catastrophic structural failures due to excess G are very rare
>>unless
>>> there are other factors, catastrophic failures due to flutter ar
>almost
>
>
>>> inevitable.
>>> There is no right answer, just a less wrong one and I would stress
>have
>>> not had the opportunity to test this.
>>> One of the requirements on a Grob 103 post major inspection test
flight
>>was
>>> to operate the spoilers at 70kts, having done this many times I woul
>not
>>> recommend the spoilers option.
>>>
>>
>>--
>>Dan Marotta
>>
>
>Once, while practicing aerobatics in my Pilatus B4, and entirely due to m
>
>own clumsiness, I found myself in a 45 degree inverted dive and rapidly
>approaching Vne. Fortunately, I did what I was trained to do, which was t
>
>push hard until the nose was above the horizon, then roll out. It was all

>captured on my cockpit mounted Go-Pro. This shows the momentary
>hesitation while I overcame the instinct to pull. The ASI shows 130knots
>(Vne) was just touched, and the accelerometer, after initially bein
>obscured
>by my left arm rising to be firmly held against the canopy, showed -4g.
>
>Had I pulled through, I would probably have exceeded Vne by 30knots.
>
>On landing, the aircraft was thoroughly checked, and found to have
suffere
>
>no ill effects.
>
>I am thankful for the thoroughness of my training, and for the robustnes
>of
>the B4
>
>

I'm Genuinely relieved that the original poster is not a trained glider
pilot,because most people once trained are so used to speed control the
situation does not occur.
Which is why we have been talking about loosing control in clouds or
failing
to allow for the reduced VNE at altitude.
Presumably if you fly high enough you can get to a coffin corner where the

stall speed is higher than the hight adjusted VNE but we should be so lucky

as to get there.
I was impressed with the pushing to recover from an inverted dive ,not
something to try without proper training.
Fun thread ,hope the snow melts soon.
>

[[email protected]]

> I'm Genuinely relieved that the original poster is not a trained glider
> pilot,because most people once trained are so used to speed control the
> situation does not occur.
> Which is why we have been talking about loosing control in clouds or
> failing
> to allow for the reduced VNE at altitude.
> Presumably if you fly high enough you can get to a coffin corner where the
>
> stall speed is higher than the hight adjusted VNE but we should be so lucky
>
> as to get there.
> I was impressed with the pushing to recover from an inverted dive ,not
> something to try without proper training.
> Fun thread ,hope the snow melts soon.
> >
I originally posted the question and actually, I am a trained and rated glider pilot and in addition to my 28,000 hours of flight time, I'm type rated in 747, 767, 737, DA20. In my glider training, I was trained to avoid VNE but am aware that there are circumstances where one can find himself (in this case it was in CONDOR flight simulaton) in rapid buildup of speed that continues on through the yellow arch and rapidly approaches VNE. I've encountered that very situation at high altitude in Jet aircraft, in heavy mountain wave conditions. In those instances, the only available action is to kill some lift by carefully extending spoilers - it works well but gliders are a different animal and and this forum is an excellent place to go when one has a question.

[Bruce Hoult]

On Thursday, February 12, 2015 at 4:41:17 PM UTC+13, Jonathan St. Cloud wrote:
> Oh, a quick way to tell if a spin has turned into a spiral, when the rudder does not stop the spin.

Should have thought the rapidly increasing wind noise and G forces would rather give it away...

[Jonathan St. Cloud]

I would recommend going up with a competent instructor and trying it for yourself. First thing I noticed was rudder did not stop the spin. By the time you notice the increase in airspeed you will be going very fast. Nothing beats first hand experience!

[Dave Nadler]

On Friday, February 13, 2015 at 3:30:09 AM UTC-5, Bruce Hoult wrote:
> On Thursday, February 12, 2015 at 4:41:17 PM UTC+13, Jonathan St. Cloud wrote:
> > Oh, a quick way to tell if a spin has turned into a spiral,
> > when the rudder does not stop the spin.
>
> Should have thought the rapidly increasing wind noise and G forces
> would rather give it away...

Some very experienced pilots have made the mistake of
interpreting a spiral dive as a spin. IIRC this was how
an Eta was lost during spin test (pilots bailed out OK).

So, its not necessarily so easy to distinguish,
especially in clean quiet fast gliders...
In the briefing prior I first flew an Antares I was
specifically warned on this...

Be careful out there,
Best Regards, Dave

[ND]

On Tuesday, February 10, 2015 at 9:58:58 PM UTC-5, wrote:
> If you inadvertently fly into the yellow range and kiss the red range, and you get into the high speed vibration, what is the best way to slow before the wings depart the glider. My sense is to reach for the spoilers and slowly extend to slow. Any opinions on that matter?

ask this guy:

https://www.youtube.com/watch?v=kQI3AWpTWhM

[[email protected]]

Quoting from The Handbook of Glider Aerobatics by Peter Mallinson and Mike Woollard.

"Effect of Airbrakes
Contrary to popular belief, use of the airbrakes does cause a significant increase in the loads applied to the glider, requiring a moderation of the Flight Envelope in a similar way to the ailerons..The reasons are twofold:

(a)the airbrakes destroy lift over a fairly large inboard section of the wing causing the spanwise wing lift distribution to move outboard. This substantially increases wing bending moments.

(b)the airbrakes also generate drag loads on the wing, a proportion of which become an additional load in the pitch plane direction.

JAR22.345 specifies that the maximum positive load factor limits should reduce to not less than 3.5G with airbrakes fully deployed.

It is nearly always better to slow a glider by pulling G rather than opening the airbrakes."

[Jonathan St. Cloud]

The above post is spot on and much better conveys what I attempted to say earlier, that the spoilers cause increase bending moment. Thank you for the post and research. No one has mentioned this, but remember a number of years ago a Nimbus 4dm broke up over Minden, when it entered a spiral drive. Witnesses said the outboard wings departed the aircraft when the spoilers were opened. I know another pilot that left the sport when the spoilers on his ASW-20 opened at high speed. He almost lost control of the aircraft, and he did scare himself enough to stop flying. Spoilers on gliders are not dive brakes, and should not be used as such.