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-   -   How Low to Spin?? (http://www.aviationbanter.com/showthread.php?t=24699)

Paul M. Cordell August 23rd 04 06:00 PM

How Low to Spin??
 
How Low to Spin??

I was proudly shown a IGC file this weekend. This file show the aero tow
thru a thermal and a release into sink. Our proud pilot was unable to
find the thermal and started a downwind leg for a landing. As he turned
base leg, he flew into a 2-5 kt thermal. Instead of completing the
pattern and landing, he turned and climbed in this thermal. The IGC file
showed that his altitude at the time of encountering lift was 300 ft. I
asked him 1 question as he displayed this flight on See You. How Low do
you want to spin?

His response scared me silly&&..My glider does not spin and there was no
wind.

He then continued to display the same flight where he bragged of
spending a considerable amount of time in the mountains within 500 feet
of the terrain. I am doubtful as to his ability to reach a landable area
during this portion of the flight.

This pilot is in his first year of private ownership, cross county
soaring and may have almost 200 hours of total time. He has embraced
soaring completely. I left the gliderport feeling that my suggestions as
to his safety practices were just hollow words. I know that he reads RAS
and would hope that the response to this post may give him some food for
thought.


[email protected] August 23rd 04 06:29 PM

He definitely sounds like an accident waiting to happen.

Not so much the fact that he did some questionable things, but the fact
that he brags about them.

Eventually he will hit some big sink while over the mountains, and
realize he doesn't have an escape route. Hopefully the sink will let
up before he crashes, and it will cause him to reevaluate his risk
taking practices.

Of course, it might just be occasion for him to brag again about what
he got away with.


Bill Daniels August 23rd 04 06:49 PM


"Paul M. Cordell" wrote in message
...
How Low to Spin??

I was proudly shown a IGC file this weekend. This file show the aero tow
thru a thermal and a release into sink. Our proud pilot was unable to
find the thermal and started a downwind leg for a landing. As he turned
base leg, he flew into a 2-5 kt thermal. Instead of completing the
pattern and landing, he turned and climbed in this thermal. The IGC file
showed that his altitude at the time of encountering lift was 300 ft. I
asked him 1 question as he displayed this flight on See You. How Low do
you want to spin?

His response scared me silly&&..My glider does not spin and there was no
wind.

He then continued to display the same flight where he bragged of
spending a considerable amount of time in the mountains within 500 feet
of the terrain. I am doubtful as to his ability to reach a landable area
during this portion of the flight.

This pilot is in his first year of private ownership, cross county
soaring and may have almost 200 hours of total time. He has embraced
soaring completely. I left the gliderport feeling that my suggestions as
to his safety practices were just hollow words. I know that he reads RAS
and would hope that the response to this post may give him some food for
thought.


I heard the following comment at an informal gathering of older pilots:

"We old, cautious pilots were once young, bold pilots who scared ourselves
badly enough to engender some wisdom before the youth and boldness killed
us." And, "Good judgement is the distillation of bad experiences."

Perhaps your pilot simply hasn't experienced the silent, deadly spin
departure that can result from a turning stall in turbulent air. Maybe we
just have to hope that he scares himself into wisdom.

Maybe he needs a flight with a good instructor in an easily spinable trainer
like a Blanik L-23 or most any eastern European two-seater. Practicing
cross-controlled stalls in rough, mid-afternoon thermals will usually do the
trick.

By way of setting some perspective, I won't universally condemn low altitude
saves. Sometimes thermalling away is the best option available. However,
they are almost always the result of earlier bad decisions that placed the
pilot in that situation. Getting low is the most common way of losing a
contest day.

Still, there are many pilots with whom I would feel comfortable as a
passenger riding in the back seat as they thermalled up from 300 feet. They
are good enough at sensing the early symptoms of a stall/spin that they
would relax the backpressure for a moment and then continue the thermal turn
without anyone but the most perceptive noticing what had happened. Usually,
these are not pilots trained in 2-33's.

Bill Daniels


Stewart Kissel August 23rd 04 07:59 PM

Well 300'agl sounds about right for a proper base leg,
and if he had landable fields in all directions....so
that if he circled in sink on the outside of the thermal...then
in theory he might have been able to land even if he
had not centered it and could not make the runway.
I have experimented thermalling low right next to
a runway when conditions and traffic permit...and u
can burn 300' in one orbit. IMHO 600'-800'agl gives
you more leeway, take another tow if u get below that...it
is cheaper then funeral expenses.

And never thermal in the pattern without thorough knowledge
of the field and traffic procedures, and with a working
radio I would think :)




Stewart Kissel August 23rd 04 08:16 PM

Part 2 of response-

Pushing limits safely is one of the appealing aspects
of our sport...once one can actually stay up, this
progression seems to be...

1.) How long(duration)
2.) How high
3.) How far
4.) How fast

(How low) seems to fit in there somewhere...but it
can bite harder then the others. One drill I was taught..figure
out what the sink rate might be for a particular day
if you hit the wrong part of a thermal...at a safe
altitude pop your spoilers to that sink rate...then
start circling to learn how much altitude you loose.

As with many learning guidelines...the best instructors/mentors
can relay this sort of information in a non-confrontional
tone...which may aid learning. Sometimes RAS is lacking
in this area :)




scurry August 23rd 04 09:11 PM

Paul M. Cordell wrote:

How Low to Spin??

I was proudly shown a IGC file this weekend. This file show the aero tow
thru a thermal and a release into sink. Our proud pilot was unable to
find the thermal and started a downwind leg for a landing. As he turned
base leg, he flew into a 2-5 kt thermal. Instead of completing the
pattern and landing, he turned and climbed in this thermal. The IGC file
showed that his altitude at the time of encountering lift was 300 ft. I
asked him 1 question as he displayed this flight on See You. How Low do
you want to spin?

His response scared me silly&&..My glider does not spin and there was no
wind.

He then continued to display the same flight where he bragged of
spending a considerable amount of time in the mountains within 500 feet
of the terrain. I am doubtful as to his ability to reach a landable area
during this portion of the flight.

This pilot is in his first year of private ownership, cross county
soaring and may have almost 200 hours of total time. He has embraced
soaring completely. I left the gliderport feeling that my suggestions as
to his safety practices were just hollow words. I know that he reads RAS
and would hope that the response to this post may give him some food for
thought.


While getting shot down west of Boulder the other day, I was
contemplating the "How low to circle?" equation. While always within
EASY glide of the airport, I was low over the foothills. It wasn't a
particularly "sinky" day, but down low the thermals were really just
narrow threads of lift coming off the rocks. I realized that I'd need
500' or so to recover from a spin in a panic situation, and still need
glide to the airport once I recovered my composure. If I got into a
spin I'd also better have room to maneuver on the heading I recovered
with. How many of us practice spin recovery to a heading, low, over
rocks? =0
Circling down low whether over hills or flat ground presents
complications in visual perspective that have been thoroughly addressed
here in the past (Google some or Eric June's posts about his crash for a
start) As Stu said, 600-800 feet of air underneath is a pretty good
recommendation to *live* by.
Interesting thing about the flight; By following the ridge lines
keeping wind and sun in mind, I was able to run out of the hills at
300-400 feet over the ridges, maintaining my altitude until I had enough
altitude to circle comfortably (which, remember includes the thermals
spreading out enough to be useful).
Just for good measure, later in the flight I did some practice turning
stalls, to make sure my stall warning calibration was reasonable.
YMMV, but for recreational pilots like me, these are good guidelines.

Shawn

Ted Wagner August 23rd 04 09:44 PM

Paul,

First and foremost, I was not "proud" of the flight I showed you, and I'm
disappointed (in fact, a little shocked) that you took it that way. Maybe I
should work on my presentation a little (I know it can be a little eager
sometimes). I learn from my experiences (positive and negative) by being
honest and open about them, not by pretending they didn't happen, and this
was no different (if I couldn't take the slings and arrows, I'd just keep
everything to myself). I had already told two other highly experienced
pilots (GY and AZ2) that I wondered at the time if I'd made the right
decisions. That isn't pride; it's concern about wanting to do it better
next time.

When I made my statement "My glider doesn't spin", you quickly (and
appropriately) noted that they were the famous last words of many a dead
pilot. I immediately recognized the ridiculousness of my statement and
offered you an honest correction: I haven't been able to get *my* glider to
spin (which is certainly not to say that it can't happen). Now, we can
argue about the relative safety value of that attitude, but I was
maintaining minimum 58 knots AIS, much higher than my normal dry thermaling
speed, so the stall/spin risk at that point was no higher than at any point
in any normal landing pattern.

(My CFIGs were very good at instilling in me the importance of maintaining
airspeed close to the ground. I have read all the stories about pilots
flying low, looking at the ground and thinking they have lots of airspeed,
and learning the hard way they didn't, and of pilots flying low over
mountains and getting bit by wind sheer. Not for a second am I so proud to
think that these things can't happen to me.)

The IGC file shows the lowest point on my downwind leg at 310'. I was up to
400' when I turned onto base. (There is a big difference between 300' and
400'.) At 58 knots AIS, 4 knots up, no traffic anywhere, and no wind, I
simply continued the turn as I had started it. If it turned into sink, there
was still plenty of altitude to finish the turn and land. Did I make the
right decision? I will eagerly absorb any and all constructive feedback I
get on that question, positive and negative (the "you-stupid-idiot" lectures
some people so enjoy giving are more entertaining than they are useful).

As far as I'm concerned, the most glaring mistake I made was allowing myself
to get into the position of being at 300' AGL halfway through my downwind
leg. Now *that* was dumb, and I need no feedback on that count.

About the mountain flying: at no point in my flight was I not within easy
gliding distance of at least two safe landing areas (one dirt strip and one
airport). If you had a question about that, I wish you would have asked. If
there's anything I consistently do right in my flying, it's staying within
safe distance of good landing areas (see previous paragraph); I always have
the nearest landing spot dialed in on my flight computer, maintaining a
positive arrival at MC 3. I am particularly satisfied with this aspect of
my x/c flying -- I can even call myself "proud" on this count, though it
usually puts a damper on my contest speeds

Paul, the next time I say something that scares you silly, just call me on
it, *especially* if it looks like my pride is in the way. I have a
tremoundous amount of respect for the feedback I get from guys like you and
GY and you will NOT hurt my feelings by speaking up in person.

That I promise, my friend --

-ted

P.s. At the time of the flight I had 232 hours total time in the glider and
340 total PIC.





scurry August 23rd 04 10:10 PM

Ted Wagner wrote:
Paul,


Snip 1st hand account.

I can understand the temptation to keep turning. Its *safe* to say
everyone should land in under same circumstances. Doesn't mean it can't
be done, just that IMHO (and most everyone else's too) it shouldn't.
The trail of blood is pretty compelling in this case, Ted.
Scroll to the bottom for a survivor's account.
http://tinyurl.com/3jw2w

Shawn

Steve Hill August 23rd 04 10:36 PM

Ted,
in my humble opinion you are doing one of the healthiest things you can
do for yourself for your long term survival as a sailplane pilot. Expose
your mistakes and share them. As a cross over hang glider pilot, I have made
all sorts of small mistakes, I like to think I learned from most of them.
What I am completely convinced of is the need to not evaluate your successes
or failures at this early point in your soaring by the "how high, how far,
how fast" methodology, but instead, to evaluate your process...download your
flights and determine how many of your decisions were ones that could have
had bad conclusions, and then use those as a means to improve your decision
making with each subsequent flight...I generally don't say much here, it's
more fun to simply watch the banter, but on this front I do feel compelled
to suggest that ALL cross country soaring pilots should be trying to share
more of the information we use in our own process. To me, 300 feet is WAY
too low to be trying to climb back up...once in awhile you'll get away with
it...but not every time. And the one time it kills you, the pundits here
will have more fodder for the tireless " Well anyone could see it was gonna
happen sooner or later"'s...My two cents worth ain't worth what it used to
be, but keep sharing those flights...if you aren't sure if it was dumb...ask
somebody.."Hey would YOU have done this..?" and then be prepared for the
outcome.

In this case you got away with something. We've probably ALL gotten away
with something ourselves...but if we share a bit more of what was going
through our head, we can hopefully relegate some of the future visits to
funerals...


Steve
DG-400
4-93





Ted Wagner August 23rd 04 11:12 PM

Thanks Shawn, I'll take a look.

Btw, so say "It's *safe* to say everyone should land (blah blah blah)" is,
well, stating the obvious (kinda like saying "It's safe to stay on the
ground"). The pertinent question is whether it was *unsafe* for me to
continue the turn in the precise circumstances in which I found myself. I
remain open to the possibility that it was not, but in the same spirit,
being over tiger country out of reach of landable points is questionably
unsafe, yet I hear regularly of pilots doing this as a matter of routine,
especially in contests, and if I continue flying contests long enough (and I
hope to be doing them for many years), I will have to take that step many
times myself. I want to err on the side of safety, but at the same time, I
want to be reasonable and competitive.

I treat my flights like I do my skydives (4500 safe ones and counting, knock
on wood) -- from the time the plane leaves the ground, I am a dead man,
until my feet are safely back upon it; it is my responsibility to make the
right decisions and pull the right handles at the right times to avert that
fate.

-ted

"scurry" wrote in message
...
Ted Wagner wrote:
Paul,


Snip 1st hand account.

I can understand the temptation to keep turning. Its *safe* to say
everyone should land in under same circumstances. Doesn't mean it can't
be done, just that IMHO (and most everyone else's too) it shouldn't.
The trail of blood is pretty compelling in this case, Ted.
Scroll to the bottom for a survivor's account.
http://tinyurl.com/3jw2w

Shawn





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