Another stall spin

I guess we were reading different posts, Bob, or, at least coming from
different mindsets. Having directly witnessed a low altitude departure and
the results, I'm just hard core about maintaining airspeed and NEVER getting
low enough that I need to claw my way out or crash.

Learn to recognize low airspeed by sound and control pressures and high AoA
by control feedback, buffeting, reversal, etc. Learn to extract the maximum
from your glider at altitude and learn to regain control with a simple flick
of the wrist at the first indication of a departure. Of course you should
also know how to recover from an incipient spin. You should learn none of
these things at low altitude because you most likely won't get the chance to
try a second time. That's my whole point - don't put yourself in a position
to kill yourself.


"BobW" wrote in message
...
On 9/5/2012 6:34 PM, Dan Marotta wrote:
In my last post I talked about making an early decision to land out and
never
attempting low saves ala 300' AGL. The many following posts are all
about low
altitude departures from controlled flight.

Nobody thinks he'll die on this flight but, if I was an insurance
underwriter,
I'd give lower premiums to those who commit to safe field landings over
those
who attempt low saves.

I have a hard time accepting "safety lectures" which espouse safely
pulling
your fat out of the fire rather than not letting it get there in the
first place.

Lordy. Are we reading the same posts?

*I'm* certainly not espousing safely pulling my - or anyone else's - fat
out of the fire (by attempting low saves in Russian roulette territory)
vs. "not going there in the first place".

Just to be clear, I think attempted thermalling at Russian roulette height
agl (and each pilot gets to determine what that height is for them) is
(choose what you'd like): asinine; foolish; irresponsible (at many
levels); playing with fire; etc., etc., etc.

That said, no "safety lecture" anyone thinks I may be indulging in applies
*only* to low thermalling. Minor messing about in the NTSB database,
paying attention to what one reads over the years, etc., reveals lots of
pattern-based, fatal, departures from controlled flight that may easily
have been avoidable had the pilots' involved not been "surprised".

Remember the Questair Venture? Designed by two highly experienced
professional aeronautical types, one of whom eventually died in a Venture
after a (very) high-altitude (meaning, lots of time to get things sorted
out and develop a plan) engine failure that resulted in a base-to-final
departure-from-controlled flight when they easily had the Des Moines
International Airport made.

That crunch merely springs to mind...there're lots more, including "benign
spam can" crunches.

Nor are pattern departure fatalities limited to power planes.

FWIW,
Bob W.

On Thursday, September 6, 2012 12:59:10 AM UTC-7, BruceGreeff wrote:
Hi Eric



Standard recovery is good - as long as the PIC knows the necessary

numbers, and has the presence of mind to apply it.



I have seen 2 fatalities where a spin recovery included the pilot

achieving a recovery attitude so steep that Vne was exceeded for the

flap setting.



Predictable results of flutter and catastrophic failure ensue quite rapidly.



In the one case the pilot achieved 2x Vne.



In my opinion the most important thing is to aviate first, as soon as

you are no longer spinning, fly the aeroplane. Don't follow a procedute

to it's end when you have achieved the object already, lest you make

things worse.



Most flapped gliders have multiple flap limiting speeds and accelerate

rapidly with nose down attitude. So - by the time you have gone flaps

neutral, you are probably already no longer stalled.



Bruce



On 2012/09/06 7:44 AM, Eric Greenwell wrote:

On 8/30/2012 1:13 PM, wrote:

The dumping of flaps seems to be well practiced in recovering from

this maneuver- I wonder who taught him this. Bruno seems more worried

about staying in the thermal than getting control of the glider.

Maybe these techniques were why he spun it so much. Luckily not at

low altitude.



From the flight manual spin recovery section for my ASH 26 E, which has

the same interconnected flap and aileron system as the ASW 20.



"Furthermore, spin recovery will be achieved more quickly if the flap

deflection is reduced. It is advisable to reduce circling flap to the

neutral flap setting."



I believe my ASW 20 B flight manual had similar advice. In any case, I

found reducing the flap deflection effective in the incipient or just

departed stage. I have not practiced spins beyond a quarter turn in

either the 20 or the 26.



Even though reducing flap deflection is effective, I always used the

standard recovery in addition, and I recommend Bruno learn to do that,

also. It is what gliders are certified to do, and the flap reduction

might not work well enough on all ships in all conditions, and certainly

won't work on a standard class glider.





--

Bruce Greeff

T59D #1771

Bruce, can you elaborate more on those accidents? I dont recall hearing about accidents attributed to exceeding VNE after spin recovery, in particular flap setting lower VNE. As far as I know the risk of exceeding flap VNE is flaps damage, not flutter, but I could be wrong.
I can imagine spin turning to spiral resulting in exceeding VNE, but normal recovery, even if pointing straight down, should not exceed VNE unless held too long, since the entry speed is low.

Ramy

On 9/6/2012 7:56 AM, Dan Marotta wrote:
I guess we were reading different posts, Bob, or, at least coming from
different mindsets. Having directly witnessed a low altitude departure and
the results, I'm just hard core about maintaining airspeed and NEVER getting
low enough that I need to claw my way out or crash.

Learn to recognize low airspeed by sound and control pressures and high AoA by
control feedback, buffeting, reversal, etc. Learn to extract the maximum from
your glider at altitude and learn to regain control with a simple flick of the
wrist at the first indication of a departure. Of course you should also know
how to recover from an incipient spin. You should learn none of these things
at low altitude because you most likely won't get the chance to try a second
time. That's my whole point - don't put yourself in a position to kill yourself.

Whew! Color me mildly perplexed there, for a bit. :-)

I'm in 100% agreement with everything you say above, and it's not a recent
mindset. If I could find it - which I can't - I'd include a link to an old bit
on my soaring club's website from a pre-web newsletter proving my "not a
recent mindset" claim.

Back when Rick Kohler had recently started Sundance Aviation in Moriarty (a
glider FBO, for those unfamiliar with S.A., and, in the early '90s?), on the
drive down to attend a soaring camp, I'd been pondering various aspects of
landing-pattern-departure accidents then known to me. Sought (very experienced
CFIG) Rick's input/take on things, because I - generally a believer in "never
say 'never'" when it comes to airplane/pilot possibilities - had come to the
conclusion that Joe Pilot should NEVER put himself into the position of an
inadvertent departure from controlled flight in the landing pattern.

So I asked Rick, "What do you teach your students about pattern stalls?"

His reply was, "Don't DO them!" (He/we went on to elaborate, natch, but his
pithy point was immediately clear to any reasonably experienced pilot.)

Yeah, it's a "Duh!" conclusion...if a person has ever actively thought about
it. But no licensed pilot is born "wise in the ways of aviation"...

Bob - no harm no foul - W.

I tried a stall while thermalling, with a couple notches of positive flaps, in my last outing and find I am instinctively doing the same by moving flaps to neutral also, while moving stick forward to increase airspeed and re-attach flow. The main reason is because it is easier and requires less force to move the stick forward with the flaps moved forward to neutral at the same time. Since they are lightly mechanically coupled in my ship.

I was just discussing this thread with Rick this morning and we both agree
with what you say. I tow for Rick a couple of days a week (today being
one). It helps pay for my gliding.


"Bob Whelan" wrote in message
...
On 9/6/2012 7:56 AM, Dan Marotta wrote:
I guess we were reading different posts, Bob, or, at least coming from
different mindsets. Having directly witnessed a low altitude departure
and
the results, I'm just hard core about maintaining airspeed and NEVER
getting
low enough that I need to claw my way out or crash.

Learn to recognize low airspeed by sound and control pressures and high
AoA by
control feedback, buffeting, reversal, etc. Learn to extract the maximum
from
your glider at altitude and learn to regain control with a simple flick
of the
wrist at the first indication of a departure. Of course you should also
know
how to recover from an incipient spin. You should learn none of these
things
at low altitude because you most likely won't get the chance to try a
second
time. That's my whole point - don't put yourself in a position to kill
yourself.

Whew! Color me mildly perplexed there, for a bit. :-)

I'm in 100% agreement with everything you say above, and it's not a recent
mindset. If I could find it - which I can't - I'd include a link to an old
bit on my soaring club's website from a pre-web newsletter proving my "not
a recent mindset" claim.

Back when Rick Kohler had recently started Sundance Aviation in Moriarty
(a glider FBO, for those unfamiliar with S.A., and, in the early '90s?),
on the drive down to attend a soaring camp, I'd been pondering various
aspects of landing-pattern-departure accidents then known to me. Sought
(very experienced CFIG) Rick's input/take on things, because I - generally
a believer in "never say 'never'" when it comes to airplane/pilot
possibilities - had come to the conclusion that Joe Pilot should NEVER put
himself into the position of an inadvertent departure from controlled
flight in the landing pattern.

So I asked Rick, "What do you teach your students about pattern stalls?"

His reply was, "Don't DO them!" (He/we went on to elaborate, natch, but
his pithy point was immediately clear to any reasonably experienced
pilot.)

Yeah, it's a "Duh!" conclusion...if a person has ever actively thought
about it. But no licensed pilot is born "wise in the ways of aviation"...

Bob - no harm no foul - W.

Hi Bruce - I don't think I understand your points(s).

Are you suggesting the flap movement not be done, or the standard
recovery be done only if the flap movement doesn't stop the spin?

In other words, what would "aviate first" be for my ASH 26 E? My
understanding of the manual is the flap movement to a more negative
setting is initiated at the same time as the standard recovery. The
manual does not indicate you should follow the procedure to "it's end",
but to recover normally as soon as the spin is halted (in fact, I think
that is part of the standard procedure).

On 9/6/2012 12:59 AM, BruceGreeff wrote:
Hi Eric

Standard recovery is good - as long as the PIC knows the necessary
numbers, and has the presence of mind to apply it.

I have seen 2 fatalities where a spin recovery included the pilot
achieving a recovery attitude so steep that Vne was exceeded for the
flap setting.

Predictable results of flutter and catastrophic failure ensue quite
rapidly.

In the one case the pilot achieved 2x Vne.

In my opinion the most important thing is to aviate first, as soon as
you are no longer spinning, fly the aeroplane. Don't follow a procedute
to it's end when you have achieved the object already, lest you make
things worse.

Most flapped gliders have multiple flap limiting speeds and accelerate
rapidly with nose down attitude. So - by the time you have gone flaps
neutral, you are probably already no longer stalled.

Bruce

On 2012/09/06 7:44 AM, Eric Greenwell wrote:
On 8/30/2012 1:13 PM, wrote:
The dumping of flaps seems to be well practiced in recovering from
this maneuver- I wonder who taught him this. Bruno seems more worried
about staying in the thermal than getting control of the glider.
Maybe these techniques were why he spun it so much. Luckily not at
low altitude.

From the flight manual spin recovery section for my ASH 26 E, which has
the same interconnected flap and aileron system as the ASW 20.

"Furthermore, spin recovery will be achieved more quickly if the flap
deflection is reduced. It is advisable to reduce circling flap to the
neutral flap setting."

I believe my ASW 20 B flight manual had similar advice. In any case, I
found reducing the flap deflection effective in the incipient or just
departed stage. I have not practiced spins beyond a quarter turn in
either the 20 or the 26.

Even though reducing flap deflection is effective, I always used the
standard recovery in addition, and I recommend Bruno learn to do that,
also. It is what gliders are certified to do, and the flap reduction
might not work well enough on all ships in all conditions, and certainly
won't work on a standard class glider.




--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

On 8/30/2012 1:15 PM, Bob Whelan wrote:
Indeed, assuming no other changes/inputs, reducing flap deflection
reduces lift, the glider will settle (increasing the AoA, as - thanks
to gravity and trim forces - the plane/wing tries to regenerate the
lost lift and return to a non-changing-acceleration state), and the
stall speed (assuming no change in G load) increases. Kinda makes for
a strong argument to not put oneself in the position of NEEDing to
dump flaps (reducing the wing's camber and effective AoA) to prevent
a spin when close to the ground, eh?

"Settling" is more of an issue at 50 feet on final, than at spin
starting at pattern altitude.

When thermalling or on final, I can change from positive to neutral or
some negative flap, and the settling is minimal. Because it is
effective, quick to do, and loses less altitude, I think doing near the
ground is safer than the standard procedure.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

I see the sailplane spin recovery procedure in the EASA
certification specs is

ailerons neutral
full opposite rudder
stick forward until rotation stops
centralise rudder and ease out of the dive

I'd guess any flap change that manufacturers recommend is more
in preparation for the likely high speeds in the dive.

http://www.easa.europa.eu/agency-mea...certification-
specifications/CS-22/Consolidated%20version%20CS-
22%20Amdt%202.pdf





At 02:54 10 September 2012, Eric Greenwell wrote:
On 8/30/2012 1:15 PM, Bob Whelan wrote:
Indeed, assuming no other changes/inputs, reducing flap
deflection
reduces lift, the glider will settle (increasing the AoA, as -
thanks
to gravity and trim forces - the plane/wing tries to regenerate
the
lost lift and return to a non-changing-acceleration state), and
the
stall speed (assuming no change in G load) increases. Kinda
makes for
a strong argument to not put oneself in the position of NEEDing
to
dump flaps (reducing the wing's camber and effective AoA) to
prevent
a spin when close to the ground, eh?

"Settling" is more of an issue at 50 feet on final, than at spin
starting at pattern altitude.

When thermalling or on final, I can change from positive to
neutral or
some negative flap, and the settling is minimal. Because it is
effective, quick to do, and loses less altitude, I think doing near
the
ground is safer than the standard procedure.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us"
to
email me)

On 9/4/2012 6:49 PM, Greg Arnold wrote:
What glider were you flying?: We tried that with an Blanik L13, and
couldn't get it to spin without using the normal highly exaggerated
control inputs - stick all the way back and full rudder.

Our Blanik would depart and spin from a smoothly flown, coordinated
turn. I'd have the student do a shallow (10-15 degrees) turn, keeping
the yaw string centered, and have them slowly reduce speed. At some
point, the inner wing would fall and begin a spin.

A common response was out-spin aileron, even though I'd briefed them and
demonstrated the maneuver earlier. With one student (the lightest one),
the out-spin aileron was enough to maintain the spin, even though the
stick was a bit forward of neutral.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On 9/9/2012 8:18 PM, Andrew wrote:
I see the sailplane spin recovery procedure in the EASA
certification specs is

ailerons neutral
full opposite rudder
stick forward until rotation stops
centralise rudder and ease out of the dive

I'd guess any flap change that manufacturers recommend is more
in preparation for the likely high speeds in the dive.

No need to guess, as the flight manual for my ASH 26 E (and my ASW 20 B
before) is clear:

"Furthermore, spin recovery will be achieved more quickly if the flap
deflection is reduced. It is advisable to reduce circling flap to the
neutral flap setting."

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)