Spins, Spiral Dives and Training

At 19:45 04 July 2009, Derek Copeland wrote:
Nevertheless, if you get into an accidental spin, you have to make a
recovery or die, whether or not the aircraft is certified for deliberate
spinning.

I have to take issue with that statement which nicely illustrates my
point. Knowing any recovery technique is not going to help you at all if
you spin from a low final turn, the only thing that will save you is
recognising what is happening and stopping it happening.

I would go further and say that recovery in such a situation should not be
attempted. If you look at the video you see that the glider hit wingtip
first, which is what wound up the rotational speed, and then the nose
impacted, much of the impact was absorbed by this process and the crew
survived.
If you imagine the situation where the glider is just a little higher and
recovery is attempted and part suceeds, what is the first thing that
stops, the rotation so instead of impacting the ground and having some of
the the impact energy absorbed the glider hits the ground, nose first,
accelerating, known as tent pegging I believe. This is very bad news for
the crew and yet we quite happily consider recovery from spinning of
greater importance than recognition of the early signs and prevention.

Knowing the spin recovery procedure would have been of no use whatsoever
to the crew of the glider in the video.

I am not very experianced or an instructor, but see this video, ...

http://www.youtube.com/watch?v=jvK1ONl1CqE

After being slow to recoginise the cable break, the glider is stalled and
rotating, but the nose does not go down, so the crash is perhaps less
painfull than going in nose first.?

I hope I would have better recoginised/reacted to the break, but if not I
would have still lowered the nose more to unstall the wing and hopefully
flare the landing?????

David.

At 22:45 04 July 2009, Don Johnstone wrote:
At 19:45 04 July 2009, Derek Copeland wrote:
Nevertheless, if you get into an accidental spin, you have to make a
recovery or die, whether or not the aircraft is certified for
deliberate
spinning.

I have to take issue with that statement which nicely illustrates my
point. Knowing any recovery technique is not going to help you at all if
you spin from a low final turn, the only thing that will save you is
recognising what is happening and stopping it happening.

I would go further and say that recovery in such a situation should not
be
attempted. If you look at the video you see that the glider hit wingtip
first, which is what wound up the rotational speed, and then the nose
impacted, much of the impact was absorbed by this process and the crew
survived.
If you imagine the situation where the glider is just a little higher
and
recovery is attempted and part suceeds, what is the first thing that
stops, the rotation so instead of impacting the ground and having some
of
the the impact energy absorbed the glider hits the ground, nose first,
accelerating, known as tent pegging I believe. This is very bad news for
the crew and yet we quite happily consider recovery from spinning of
greater importance than recognition of the early signs and prevention.

Knowing the spin recovery procedure would have been of no use whatsoever
to the crew of the glider in the video.

At 21:15 04 July 2009, bildan wrote: (snip)

The Puchacz is not a dangerous glider. There may be dangerous pilots
who fly them, however.

How would you describe a glider in which so many people have been killed
in spinning incidents? Unlucky? Challenging? or Misunderstood perhaps?

I fully accept the reports of the pilots who tested the glider and found
that it recovered, if it had not they would not have been able to report
that it didn't.

Of course no-one is going to design a glider that cannot recover from a
spin, and of course no-one is going to design an airliner where the doors
fall off either, causing major structural failure. I do not think that the
level of expertise found at McDonnell-Douglas exists in a glider design
facility. Design faults are found in aircraft after release to service and
mostly something is done or at least restrictions are put in place to
counteract the fault, not so with the Puchacz.
The reason why no-one has reported that a Puchacz is impossible to recover
is that if it has happened the pilots have not survived to do so. It is
easy to blame someone when they are not around to challenge that finding
and this is certainly what the Canadian report does.

Is the best explanation that anyone can come up with is that the glider
attracts more than it's fair share of dangerous pilots.

I have little doubt that the Putchacz will go on killing people while it
is permitted to continue to fly, it won't be me, I will never fly in one
again.

Don,

The German DG500 pilots escaped serious injury because, being so low, they
didn't have that far to fall when the spin developed. Also DG gliders have
crash resistant cockpits. Even so I bet that hurt!

If you are in a full spin, you are decending at 50-60 knots or
5000ft/min+, which is probably enough to kill you. It certainly killed a
former syndicate partner of mine who spun off a slow autotow launch at
about 800ft and failed to make any sort of recovery. Once in a fully
developed spin it probably matters not if you spin into the ground, or
dive into it. If you have enough height to do so, it is better to recover
because you then stand a very good chance of staying alive.

I have already pointed out that you cannot afford to spin once down to
circuit height, so you have to have to fly accurately at a safe airspeed.


Derek Copeland


At 22:45 04 July 2009, Don Johnstone wrote:
At 19:45 04 July 2009, Derek Copeland wrote:
Nevertheless, if you get into an accidental spin, you have to make a
recovery or die, whether or not the aircraft is certified for
deliberate
spinning.

I have to take issue with that statement which nicely illustrates my
point. Knowing any recovery technique is not going to help you at all if
you spin from a low final turn, the only thing that will save you is
recognising what is happening and stopping it happening.

I would go further and say that recovery in such a situation should not
be
attempted. If you look at the video you see that the glider hit wingtip
first, which is what wound up the rotational speed, and then the nose
impacted, much of the impact was absorbed by this process and the crew
survived.
If you imagine the situation where the glider is just a little higher
and
recovery is attempted and part suceeds, what is the first thing that
stops, the rotation so instead of impacting the ground and having some
of
the the impact energy absorbed the glider hits the ground, nose first,
accelerating, known as tent pegging I believe. This is very bad news for
the crew and yet we quite happily consider recovery from spinning of
greater importance than recognition of the early signs and prevention.

Knowing the spin recovery procedure would have been of no use whatsoever
to the crew of the glider in the video.

I have done quite a few flights in the Puchacz. It is a perfectly nice
glider, albeit with a slightly greater tendency to spin than most West
European designs. Ditto the Junior. They will both recover using the
standard spin recovery, although you may have to get the stick well
forward and hold it there until the spin stops. I personally prefer
training gliders that spin properly and require a positive recovery. With
the K13 for example, you are never quite sure whether it will go into a
spin or a spiral dive, and it will usually recover from a spin as soon as
the stick is moved off the backstop. not very realistic!

Derek Copeland


At 23:30 04 July 2009, Don Johnstone wrote:
At 21:15 04 July 2009, bildan wrote: (snip)

The Puchacz is not a dangerous glider. There may be dangerous pilots
who fly them, however.

How would you describe a glider in which so many people have been killed
in spinning incidents? Unlucky? Challenging? or Misunderstood perhaps?

I fully accept the reports of the pilots who tested the glider and found
that it recovered, if it had not they would not have been able to report
that it didn't.

Of course no-one is going to design a glider that cannot recover from a
spin, and of course no-one is going to design an airliner where the
doors
fall off either, causing major structural failure. I do not think that
the
level of expertise found at McDonnell-Douglas exists in a glider design
facility. Design faults are found in aircraft after release to service
and
mostly something is done or at least restrictions are put in place to
counteract the fault, not so with the Puchacz.
The reason why no-one has reported that a Puchacz is impossible to
recover
is that if it has happened the pilots have not survived to do so. It is
easy to blame someone when they are not around to challenge that finding
and this is certainly what the Canadian report does.

Is the best explanation that anyone can come up with is that the glider
attracts more than it's fair share of dangerous pilots.

I have little doubt that the Putchacz will go on killing people while it
is permitted to continue to fly, it won't be me, I will never fly in
one
again.

On Jul 3, 12:00*am, Derek Copeland wrote:

If Noel Wade came to visit the UK, he would probably not be able to climb
at all in our often tiny little thermals using the techniques he suggests..
The necessary skill is to be able to fly in accurate well banked turns at
not more than about 5 knots over the turning stall speed. Otherwise he
will be going round in thesinksurrounding the thermal.

Derek -

Thanks for attacking my skills rather than arguing the point from a
logical perspective... I trained and fly in places that have both
weak lift and narrow lift, and I stay in them just fine - for the
record.

Now, to actually defend the point:

If your argument is that you have to fly slowly in order to stay in a
small thermal, you're ignoring an alternate solution: tighten your
bank angle. It is true that a slower speed gives you a smaller
turning radius at the same bank-angle, but it has a number of
drawbacks (many of which I touched on with my post - you're closer to
stall speed, you're possibly below min-sink - and therefore not flying
the glider as cleanly or efficiently as you could be). If you simply
keep your speed up and tighten your bank angle, you'll achieve a
smaller turning radius and you won't be in danger of stalling.

I urge you to do the math, as I have done (or at least look it up
online, there are webpages that illustrate this - such as:
http://www.soarns.ca/crclmotn.html)... Down around the speeds we're
talking about, you will have a _smaller_ turn radius at a 45-degree
bank-angle than at a 30-degree bank-angle, EVEN if you add 5 - 7 knots
of speed in the higher bank-angle turn. AND the additional G-loading
does not increase your sink rate by that much (around 20 ft/min in my
DG-300). Even in a small 2-knot thermal you're really only giving up
a small percentage of performance in order to be a lot safer. And
there are plenty of ways that the average pilot can "make up" that
performance, by flying more cleanly in other phases of flight.
Finally, if you _have_ been flying below min-sink speed (for a given
bank-angle), you may actually find _improved_ climb performance by
keeping your speed up and tightening your bank-angle.

Take care,

--Noel

Noel,

It was not my intention to attack your flying skills, but just to state a
fact of life about flying in UK conditions. The tighter you turn, the more
the stalling speed increases, due to the extra g loading, and the more the
sink rate increases. Our thermals can also be quite weak, so excessive
angles of bank can increase the glider's sink rate enough to cancel out
the thermal.

5 knots over the turning stall speed at a 35-40 degree angle of bank
usually works well in the UK, and that puts you at about the effective min
sink speed.

I have flown in central France, where the thermals are normally huge and
strong. In the UK you normally turn as soon as you encounter lift, but
there you had to wait for maybe twenty seconds before you reached the core
of the thermal. The French pilots seem to thermal at only about 15 degrees
angle of bank. One holiday I had over there consisted of a whole
fortnight of low inversion blue days, so somewhat UK like conditions with
small weak thermals. My syndicate partner and I where able to do a number
of 200-300k flights when most of the locals (with one exception, who was a
world class competition pilot) couldn't stay up at all. Maybe that is why
the UK has produced so many World Gliding Champions, although I am not
quite in that league myself.

Derek Copeland


At 23:06 05 July 2009, noel.wade wrote:
On Jul 3, 12:00=A0am, Derek Copeland wrote:

If Noel Wade came to visit the UK, he would probably not be able to
climb
at all in our often tiny little thermals using the techniques he
suggests=
..
The necessary skill is to be able to fly in accurate well banked turns
at
not more than about 5 knots over the turning stall speed. Otherwise he
will be going round in thesinksurrounding the thermal.

Derek -

Thanks for attacking my skills rather than arguing the point from a
logical perspective... I trained and fly in places that have both
weak lift and narrow lift, and I stay in them just fine - for the
record.

Now, to actually defend the point:

If your argument is that you have to fly slowly in order to stay in a
small thermal, you're ignoring an alternate solution: tighten your
bank angle. It is true that a slower speed gives you a smaller
turning radius at the same bank-angle, but it has a number of
drawbacks (many of which I touched on with my post - you're closer to
stall speed, you're possibly below min-sink - and therefore not flying
the glider as cleanly or efficiently as you could be). If you simply
keep your speed up and tighten your bank angle, you'll achieve a
smaller turning radius and you won't be in danger of stalling.

I urge you to do the math, as I have done (or at least look it up
online, there are webpages that illustrate this - such as:
http://www.soarns.ca/crclmotn.html)... Down around the speeds we're
talking about, you will have a _smaller_ turn radius at a 45-degree
bank-angle than at a 30-degree bank-angle, EVEN if you add 5 - 7 knots
of speed in the higher bank-angle turn. AND the additional G-loading
does not increase your sink rate by that much (around 20 ft/min in my
DG-300). Even in a small 2-knot thermal you're really only giving up
a small percentage of performance in order to be a lot safer. And
there are plenty of ways that the average pilot can "make up" that
performance, by flying more cleanly in other phases of flight.
Finally, if you _have_ been flying below min-sink speed (for a given
bank-angle), you may actually find _improved_ climb performance by
keeping your speed up and tightening your bank-angle.

Take care,

--Noel

At 20:04 04 July 2009, Jim Logajan wrote:
John Smith wrote:
Jim Logajan wrote:

Did it involve a fatality?

Listen to the text: The pilot suffered only slight injuries.

You elided the essential part where I pointed out that one can't view
the
video (and therefore "listen to the text") without first creating an
account on Youtube and atesting that one is 18 or over.

If it didn't involve a fatality, why is the video considered
inappropriate for some viewers?

Possibly because of the rude word in German uttered by a lady witness that
you can also hear in the soundtrack!

Even if there were no fatalities or serious injuries, this video should be
X or 18 rated, and not viewed by those of a nervous disposition.

Fortunately such accidents are quite rare, at least in Europe, so this
video should not put you off gliding or winch launching.

Derek Copeland