Two Italian friends lost to gliding

Bob Kuykendall wrote:

Furthermore, virtually everything you can do to improve crashworthiness
increases weight, And everything you do to increase weight increases
speed and impact energy. It's all a bunch of trade-offs.

Let me quibble with Bob a bit: a "safety cockpit" is more than just more
structure to make it stronger, but includes things like

* a steeply sloped seat pan under the thighs to reduce the chance of
submarining
* locating the seat belt anchor points so the belt stays on the hips and
does not ride up to the abdomen
* locating the shoulder harness so it doesn't compress the spine during
a crash
* making the instrument panel frangible, so it doesn't injure the pilots
legs
* making the instrument panel swivel upwards, so a pilot can bail out
more easily
* using a form of "Roeger hook" to ensure quick and clean jettisoning of
the canopy when the pilot wants to bail out

The items above involve little, if any, additional weight, yet can make
a major difference to the pilot's injuries. Older gliders might not have
any of these features; newer ones will have most of them.

Some features of the newer cockpits will add weight, but I don't think
it's a given that the speed will increase. Don't the JARs require
certain stall or landing speeds, for example? A designer can compensate
for weight with more wing area or a different airfoil to keep the speeds
the same.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

At 17:48 23 June 2005, Bob Kuykendall wrote:
[Warning: starts on-topic but heads for a trip through
the weeds]



However, you don't have to look too far to see an alternate
future in
which this is not the case. Suppose, for a moment,
that it becomes
fashionable to gamble on the outcome of certain soaring
contests.
Prizes and incentives are offered for winning. Competitive
performance
becomes not just a matter of pride and prestive, but
of serious
financial gain. Serious racing sailplanes get smaller
and lighter.
Comfort and crashworthiness yields to performance.
Pilots are hired
guns, and though they obviously have some voice in
matters of safety,
it is not a loud voice against the background of finances,
sponsorship,
media coverage, and commercial patronage. In order
to call yourself a
national champion or even a national contender, you'd
have to rise to
an entirely new level of risk exposure.

Let me be the first to admit that this is a pretty
out-there vision of
the future of contest soaring. I do not think it is
likely we'll see it
come to pass. I do not wear that kind of tinfoil beanie.
However, I do think it merits some thinking on. What
would such a
future mean for the rest of the soaring world? More
media attention?
More money and participation? More regulation and restriction?

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

Bob,

Its all fantasy land but I think that if a lot of money
came into competitive gliding the pressures towards
safer structures would increase rather than decrease.
Look at the survivabilty of those tiny F1 racing car
'fuselages' that have strengthened steadily as the
money in the sport has grown (they do race sometimes
- albeit not at Indianapolis). As competitors in sport
get better paid they value themselves more rather than
less.

John Galloway

[Apologies if this is a repeat post. Google acted like it ate the first
one I composed. Bad Google! No biscuit!]

Earlier, Eric Greenwell wrote:

Let me quibble with Bob a bit: a
"safety cockpit" is more than just more
structure to make it stronger...

Please do, Eric. We've come to expect no less from you!

But seriously, thanks for that list of basic safety items. I agree that
they all should be in any modern cockpit. And I agree that none of them
carries a substantial weight penalty. But beyond those basic elements,
crashworthiness is most effectively achieved with two basic things:

* Stuff that absorbs energy as it progressively crushes

* Space for the stuff to crush into before reaching the pilot's vital
bits

Stuff adds weight, and space adds volume, area, and drag. All of those
will have deleterious effect on perfomance.

Furthermore, I definitely disagree with the characterization of
crashworthy cockpits as simply "stronger." What you want is not
necessarily a structure that supports great loadings without failure
(that's what I think of when I hear the word "strong"). What you do
want is a structure that deflects or breaks in such a way as to
distribute an impact over the greatest amount of time possible. That
reduces G loadings to the contents of the structure.

The main point there is that the light, strong, stiff carbon fiber that
we like to build gliders out of is great for handling flight loads, but
is poor at absorbing energy. It tends to break all at once, and what's
left after that is not good at supporting any further loadings.

Modern aramids and polyethelynes (sp?) like Kevlar(tm) and Spectra(tm)
_are_ good at absorbing energy, and are also quite strong, but their
relatively low stiffness makes them much less effective at supporting
flight loads. That leaves it to the sailplane developer to arrive at
some compromise of materials. Perhaps they use the tough stuff in
greater thickness to achieve adequate stiffness. Perhaps they use a
combination of tough stuff and stiff stuff to achieve the better
properties of each. Either way, there is just plain more stuff there,
and inescapably more weight than is dictated by the basic flight and
handling loads. TANSTAAFL and all that.

And, yes, the sailplane developer is free to add wing area and to
choose docile airfoils that bring the stall speed down. However, both
of those choices will tend to have an adverse effect on performance.
And that's not a bad thing in and of itself. But as DG has discovered,
performance sells a lot better than safety does. You can make the
safest sailplane there ever was, but its performance might be so poor
that you don't sell a single example. Net safety gain for the sport:
zero. Somewhere between there and the ultimate performing thin-skinned
racing ship is a reasonable compromise. Choose wisely, and y'all be
careful now, y'hear?

Thanks again, and best regards to all

Bob "Grasshopper, why wrists say 'Hibachai?'" K.
http://www.hpaircraft.com

On 23 Jun 2005 10:33:46 -0700, "Bob Kuykendall"
wrote:

One interesting tangent to this issue is that there is a clear
competitive advantage to small, light fuselages with small cockpits.
.... and small pilots.
Unfortunately reality shows that an extremely small cockpit
(Ventus/Discus a, Diana 1) does not influence the outcome of a
competition - gliders with bigger cockpits don't show an disadvantage
in reality.


However, you don't have to look too far to see an alternate future in
which this is not the case. Suppose, for a moment, that it becomes
fashionable to gamble on the outcome of certain soaring contests.
Prizes and incentives are offered for winning. Competitive performance
becomes not just a matter of pride and prestive, but of serious
financial gain.

In other words: Formula One.
The racing class that has created the fastest and safest cars on
planet Earth within the last decade.



Bye
Andreas

Andreas Maurer wrote:

Unfortunately reality shows that an
extremely small cockpit (Ventus/
Discus a, Diana 1) does not influence
the outcome of a
competition - gliders with bigger
cockpits don't show an disadvantage
in reality.

Hmmm. What results are you citing?

In other words: Formula One.
The racing class that has created
the fastest and safest cars on
planet Earth within the last decade.

Tell that to the families of the drivers killed through the mid-1970s.

Bob K.

I have to smile at all these musings about safety cockpits because it
will have virtually no effect on the injury/death rate in soaring. Even
if every new glider had a "safety" cockpit there would be no
significant increase in the percentage of such cockpits for decades to
come. Gliders, as well as other aircraft, will be, and are, kept in
service until it is overwhelmingly uneconomical to do so. And spare me
the "well we have to start somewhere" comment. Personally, I am not
going to spend an extra $100K to replace my current motorglider with a
"safer" one.

That last fatal accident I posted shows you where you need to spend
your effort: influencing the judgement of pilots. This is not an
impossible task; the GA accident rate has been declining even with an
ageing fleet.

Tom

wrote:

I have to smile at all these musings about safety cockpits because it
will have virtually no effect on the injury/death rate in soaring. Even
if every new glider had a "safety" cockpit there would be no
significant increase in the percentage of such cockpits for decades to
come. Gliders, as well as other aircraft, will be, and are, kept in
service until it is overwhelmingly uneconomical to do so.


I'm encouraged by all the discussion, because I believe it will
increase
the rate of change, and even though new safety features take a while to
be a significant part of the fleet, the value of the feature is
durable:
a safer glider bought now will provide that extra safety for the life
of
the glider.

And spare me
the "well we have to start somewhere" comment.


We have "started somewhere", and in my opinion, the big "somewhere" was
over 20 years ago, when Schleicher and Waibel made a big investment in
the design of the ASW 24 cockpit. We didn't have the Internet to
discuss
things at the time, but I recall many pilots were not impressed because
the cockpit design and disk brake added weight and size. I know
Schliecher lost some sales because of it (but gained some, also).

Even earlier, Waibel expressed his deep disappointment that some pilots
ordered the new ASW 20 B/C models with the older ASW 20 "A" fuselage,
which lacked the stronger cockpit, the tilting instrument panel that
made it easier to bail out, and the shock absorbing landing gear with
disk brake, just to save a few pounds. I think we've come a long ways
from that attitude, and it's been in good part because of discussions
about the value of these changes.

Of course, the discussions about safer gliders began before the ASW 24,
about such things as better spin behavior, automatic control
connections, spoiler effectiveness, and so on. Still, for me, that is
when pilots were offered a real choice.

Personally, I am not
going to spend an extra $100K to replace my current motorglider with a
"safer" one.


That would buy you a new motorglider, but you could buy a used DG
800/808 (or equivalent Schleicher or Schmepp-Hirth) for more like
$60,000, and gain most of the improvements in the new models. For less
than $1000, you could upgrade the safety of your current glider with a
Roeger hook, available from DG as a retrofit.


That last fatal accident I posted shows you where you need to spend
your effort: influencing the judgement of pilots. This is not an
impossible task; the GA accident rate has been declining even with an
ageing fleet.


It is not only in the air that a glider pilot must use good judgment,
but also on the ground. For me, these discussions ARE about influencing
the judgment of pilots: choosing the glider you intend to trust with
your body is an important decision.

Unfortunately reality shows that an extremely small cockpit
(Ventus/Discus a, Diana 1) does not influence the outcome of a
competition - gliders with bigger cockpits don't show an disadvantage
in reality.

Well, let's see:

Leszno 2003 WGC, standard class: Discus 2a placed 1, 2, 3, 6 (other top
ten gliders were LS8, and a lone ASW 28 and Discus 2).
Leszno 2003 WGC, 15 m class: 5 Ventus 2a or 2ax in the top ten (with 4
ASW-27 and a lone Ventus 2bxr prototype).

It seems at least to indicate that the better pilots like the small
cockpits!


--
stephanevdv
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

I'm newer to soaring than most posters to this
group. I and perhaps a dozen of the folks I soar
with have been quite careful about the
gliders we choose to fly and purchase. At the very
top of the list are the safety features and characteristics
and
insurability of the gliders we fly.

When I talk to folks at the BASA meetings or at Byron
or at
Avenal or Hollister, we ultimately always end up discussing
safety. Hoe about adding a T&B in the glider? Oh
yeah,
you were in haze at dusk one time and that might have
helped?
Hmm...what do you think of the stall/wing drop?
Yeah, maybe I can give up a few points of L/D to avoid
that. Automatic hookups are a must for me...etc.

The crowd I hang with is interested in avoiding risk,
rather than counting on supernatural skill. We think
that
the guys who died thought that they were current and
skilled,
just as much as we think we are. But we realize that
really we are just average pilots too, and need to
'sandbag' in our favor instead of relying on our
overconfidence to save us.

Right or wrong, I have seen a half-dozen purchases

of gliders that were definitely compromises. Selecting
a glider with no flaps, fixed gear, and mild stall/spin
characteristics has become commonplace. Maybe a few
retracts purchased, after a goodly number of flights
in a non-owned retract.

Right or wrong, safety is a selling point...

At 15:06 01 July 2005, wrote:
wrote:

I have to smile at all these musings about safety
cockpits because it
will have virtually no effect on the injury/death
rate in soaring. Even
if every new glider had a 'safety' cockpit there would
be no
significant increase in the percentage of such cockpits
for decades to
come. Gliders, as well as other aircraft, will be,
and are, kept in
service until it is overwhelmingly uneconomical to
do so.


I'm encouraged by all the discussion, because I believe
it will
increase
the rate of change, and even though new safety features
take a while to
be a significant part of the fleet, the value of the
feature is
durable:
a safer glider bought now will provide that extra safety
for the life
of
the glider.

And spare me
the 'well we have to start somewhere' comment.


We have 'started somewhere', and in my opinion, the
big 'somewhere' was
over 20 years ago, when Schleicher and Waibel made
a big investment in
the design of the ASW 24 cockpit. We didn't have the
Internet to
discuss
things at the time, but I recall many pilots were not
impressed because
the cockpit design and disk brake added weight and
size. I know
Schliecher lost some sales because of it (but gained
some, also).

Even earlier, Waibel expressed his deep disappointment
that some pilots
ordered the new ASW 20 B/C models with the older ASW
20 'A' fuselage,
which lacked the stronger cockpit, the tilting instrument
panel that
made it easier to bail out, and the shock absorbing
landing gear with
disk brake, just to save a few pounds. I think we've
come a long ways
from that attitude, and it's been in good part because
of discussions
about the value of these changes.

Of course, the discussions about safer gliders began
before the ASW 24,
about such things as better spin behavior, automatic
control
connections, spoiler effectiveness, and so on. Still,
for me, that is
when pilots were offered a real choice.

Personally, I am not
going to spend an extra $100K to replace my current
motorglider with a
'safer' one.


That would buy you a new motorglider, but you could
buy a used DG
800/808 (or equivalent Schleicher or Schmepp-Hirth)
for more like
$60,000, and gain most of the improvements in the new
models. For less
than $1000, you could upgrade the safety of your current
glider with a
Roeger hook, available from DG as a retrofit.


That last fatal accident I posted shows you where
you need to spend
your effort: influencing the judgement of pilots.
This is not an
impossible task; the GA accident rate has been declining
even with an
ageing fleet.


It is not only in the air that a glider pilot must
use good judgment,
but also on the ground. For me, these discussions ARE
about influencing
the judgment of pilots: choosing the glider you intend
to trust with
your body is an important decision.


Mark J. Boyd

"Bob Kuykendall" writes:

Tell that to the families of the drivers killed through the
mid-1970s.

Do you know one of the main causes of death back then?

Dry Powder fire extiguishers, followed by burnt lungs. It
is when the big saftey push started, by Jackie Stewart AIR.

--
Paul Repacholi 1 Crescent Rd.,
+61 (08) 9257-1001 Kalamunda.
West Australia 6076
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