Another stall spin

On Sunday, August 26, 2012 12:11:45 AM UTC-4, Jp Stewart wrote:
From TA's Dansville contest write-up:

"Unfortunately, we were also saddened to hear of yet another apparent stall-spin fatality; Jim Rizzo, Finger Lakes club president and FAA Designated Examiner for the area was killed when his glider crashed into a farmer’s field not far from the Dansville airport. Jim was not part of the contest and was just flying locally when the accident occurred. All we know is what the farmer said (and this is 3rd hand to me) that apparently Jim was trying to thermal away from a low altitude and spun in (sound familiar? – it should – this is the 3rd almost identical fatality this season here on the east coast)."

http://soaringcafe.com/2012/08/day-6...ille-region-3/



JP

You all seem to "assume" that Jim was intentionally trying to execute controlled flight at a low altitude. He may,.... have experienced an extreme crisis, ie heart attack.
JG

On 8/28/2012 11:08 AM, John Cochrane wrote:

One point not reiterated yet here -- the atmosphere down low is very
different from what you're used to at 2000 feet and above.
Snip...

A short list of what's different down low: The atmosphere is much more
turbulent. Thermals, such as they are are much smaller. In this layer,
many small punchy thermals will start. Many will die. The ones we use
up higher consist of many little parcels of hot air that have
coalesced. Most thermals are either short lived, or basically
unworkable to a modern glider. You're in the boundary layer where wind
is being affected by the ground, so there is wind-induced turbulence.
Punches of strong lift/gust followed by sink when you make a half turn
will be the norm.

The ground picture will be totally different to the pilot. If you turn
downwind at altitude, you don't notice that much. If you turn downwind
at 300 feet, all of a sudden the ground will rush by and, this being a
high stress moment, you may pull back. Just as the gust you turned in
fades, or the thermal turns to sink. And when the canopy fills with
trees going by at 70 mph, the urge to pull back will be really strong.
You may push forward to recover at altitude, but it's really really
hard to do with the ground coming up fast.

So, just because you've never unintentionally spun at altitude does
not mean your chances at 300 feet are the same.
Snip...

John Cochrane

Science now can create movies & pictures of the accuracy/reality of what John
asserts above. Roughly 10 years ago I attended a presentation that included
LIDAR movies and pictures of thermals from ground to ~1500' agl. I expect
atmospheric imaging technology has significantly advanced since then.

Any "somewhat experienced" glider pilot would instantly recognize the 1,500'
images as being a thermal. However, in the absence of previous exposure to the
presentation, it required an explanation of what one was looking at, before
Joe Average Glider Pilot might recognize the rising air patterns from ground
level to the base of "a recognizable thermal" as being a coalescing thermal.
(For doubting-Thomas readers, there were multiple thermal examples, so we
weren't looking at the notorious "sample of one".)

Aficionados of tornado photographs might have a glimmer, because the closest
visual wavelength pictures I've seen that kinda-sorta mimic what the LIDAR
imagery showed, have been tornadoes with multitudes of thin, ropy,
mini-twisters feeding into the main funnel well above ground level.
Near-ground-level organization of some "multiple rope twister" photos I've
seen is scanty to non-existent. It doesn't take too much imagination to equate
"plenty of low-altitude garbage" I - and probably many RAS readers - have
tussled with striving for a low-altitude save, with what LIDAR and tornado
photos suggest (to me, anyway) isn't uncommon low-level thermal organization.
"Dynamic" is a pale descriptor of what goes on between ground level and the
agl level a modern sailplane can effectively use.

Unless your ship has the thermaling radius of an insect or a small bird, "what
John C. said" is likely to be in your low-level future. Is it worth betting
your life on?

For the record, the lowest I ever thermaled away from was 650' agl (Dalhart,
TX) on a day with 15-20 knot ground winds (not uncommon there). Yeah, right
above the launch airport. It took me 20 minutes and multiple low points, and
despite being both on vacation and on top of my game at the time, I was
sufficiently wrung out by the process that it also required some decompression
time once I'd established myself, before I could talk myself into heading out
on-course. The save was right after launching, when I was fresh.

Bob W.

Bill D On Saturday [in part]

...If you look carefully at Bruno's video of the inadvertent, incipient spin, you will see a moment where the stick is moving progressively left even as the glider accelerates its roll to the right. That's the instant he departed from controlled flight - the glider was not 'answering' his aileron input. It should set off all the alarms in your head as it did in his. For me, it's like an electric shock.
Bruno's recovery was not textbook but it worked extremely well. He unloaded the wing by moving the stick forward unstalling the wing and reentering the realm of controlled flight where his ailerons worked normally. Even his narration indicated he didn't apply opposite rudder in a timely manner as the text books call for. Actually, I think he did the right thing - first unload the wing then, after it unstalls, fly the glider normally.

Bill makes several good points. However, Bruno's response to the
incipient right-hand spin as viewed on his tape (
http://www.youtube.com/watch?v=PpJA5...feature=relmfu ) and
narrated in his YouTube comments is not what happens. He does have the
stick biased to the left, but then after he enters the spin and his
reaction is to jam more opposite aileron in. Also, I do not see him
unload the wing and the stick never appears to move forward, at least
by much. His rudder input is what appears to unstall the glider. To
quote from his 70K viewed video. " I instinctively moved the stick
left after the wing dropped to the right and started spinning. It
didn't cause the spin entry because I did it after the spin started.
You are completely right though that I should have moved the stick
back to neutral or even into the turn. I thought I had at the time the
video proved I didn't.  Can't argue with video. -Bruno"

On Tuesday, August 28, 2012 7:43:23 PM UTC-6, Duster wrote:
Bill D On Saturday [in part]



...If you look carefully at Bruno's video of the inadvertent, incipient spin, you will see a moment where the stick is moving progressively left even as the glider accelerates its roll to the right. That's the instant he departed from controlled flight - the glider was not 'answering' his aileron input. It should set off all the alarms in your head as it did in his. For me, it's like an electric shock.

Bruno's recovery was not textbook but it worked extremely well. He unloaded the wing by moving the stick forward unstalling the wing and reentering the realm of controlled flight where his ailerons worked normally. Even his narration indicated he didn't apply opposite rudder in a timely manner as the text books call for. Actually, I think he did the right thing - first unload the wing then, after it unstalls, fly the glider normally.



Bill makes several good points. However, Bruno's response to the

incipient right-hand spin as viewed on his tape (

http://www.youtube.com/watch?v=PpJA5...feature=relmfu ) and

narrated in his YouTube comments is not what happens. He does have the

stick biased to the left, but then after he enters the spin and his

reaction is to jam more opposite aileron in. Also, I do not see him

unload the wing and the stick never appears to move forward, at least

by much. His rudder input is what appears to unstall the glider. To

quote from his 70K viewed video. " I instinctively moved the stick

left after the wing dropped to the right and started spinning. It

didn't cause the spin entry because I did it after the spin started.

You are completely right though that I should have moved the stick

back to neutral or even into the turn. I thought I had at the time the

video proved I didn't.  Can't argue with video. -Bruno"

The stick doesn't have to move forward much - 3/4 of an inch will do it. I thought I saw that much. The main thing is to "feel" the ailerons start "answering the helm" again - then add some airspeed and don't do it again.

On Tuesday, August 28, 2012 8:53:10 PM UTC-6, Bill D wrote:
On Tuesday, August 28, 2012 7:43:23 PM UTC-6, Duster wrote:

Bill D On Saturday [in part]







...If you look carefully at Bruno's video of the inadvertent, incipient spin, you will see a moment where the stick is moving progressively left even as the glider accelerates its roll to the right. That's the instant he departed from controlled flight - the glider was not 'answering' his aileron input. It should set off all the alarms in your head as it did in his. For me, it's like an electric shock.



Bruno's recovery was not textbook but it worked extremely well. He unloaded the wing by moving the stick forward unstalling the wing and reentering the realm of controlled flight where his ailerons worked normally. Even his narration indicated he didn't apply opposite rudder in a timely manner as the text books call for. Actually, I think he did the right thing - first unload the wing then, after it unstalls, fly the glider normally.







Bill makes several good points. However, Bruno's response to the



incipient right-hand spin as viewed on his tape (



http://www.youtube.com/watch?v=PpJA5...feature=relmfu ) and



narrated in his YouTube comments is not what happens. He does have the



stick biased to the left, but then after he enters the spin and his



reaction is to jam more opposite aileron in. Also, I do not see him



unload the wing and the stick never appears to move forward, at least



by much. His rudder input is what appears to unstall the glider. To



quote from his 70K viewed video. " I instinctively moved the stick



left after the wing dropped to the right and started spinning. It



didn't cause the spin entry because I did it after the spin started.



You are completely right though that I should have moved the stick



back to neutral or even into the turn. I thought I had at the time the



video proved I didn't.  Can't argue with video. -Bruno"



The stick doesn't have to move forward much - 3/4 of an inch will do it. I thought I saw that much. The main thing is to "feel" the ailerons start "answering the helm" again - then add some airspeed and don't do it again.

I am extremely saddened to hear of Jim's accident and passing. My heart goes out to his family and close friends. In the soaring community we all are close friends and family.

I don't have a clue what happened to Jim and still don't understand why ships will spin close to the ground when they don't normally up high - other than the new to me points made by John C.

My video that has been referenced before can be a good learning tool but there are some facts that need to be known. I was flying in an ASW-20BL that had some major known flight and stability issues. The ship would try to spin on me at least 10 times every flight while thermalling! As you can see in the video I was able to get out of it and still stay centered in the thermal. Spinning is always a surprise but I had actually gotten used to it.

PLEASE NOTE that what got me out of the spin was that I immediately and instinctively went into negative flap. I didn't have time to press the rudder before it was already out of the spin and recovering. Yes, I reactively moved the ailerons in the wrong direction because I instinctively didn't want to turn the way the ship was turning/entering into spin. I think if most unexpected spins were caught on video you would also see the reflexive pull of the stick in the wrong direction as the nose drops and aircraft dip to the side unexpectedly. It was the moving of the flaps to negative that would always get me out of the spin before I had time and presence of mind to do the 3 right things we are all taught with unloading the sailplane, opposite rudder and neutralizing the ailerons. I had trained myself to instantly throw the flaps forward as soon as the sailplane broke and you can see that little altitude was lost.

Please note that we fixed this particular 20's spin tendency with those crazy wonderful winglets and it never tried to spin on my again. I have not had a single spin either since getting a 27. My thoughts are with Jim and his loved ones and hope and pray we don't have any more of these terrible events.

Warm wishes,
Bruno - B4

On Tuesday, August 28, 2012 8:26:37 PM UTC-7, wrote:
My video that has been referenced before can be a good learning tool but
there are some facts that need to be known. I was flying in an ASW-20BL
that had some major known flight and stability issues. The ship would try
to spin on me at least 10 times every flight while thermalling! As you can
see in the video I was able to get out of it and still stay centered in the
thermal. Spinning is always a surprise but I had actually gotten used to it.

Really? I believe I was one of the past owners of that ship, and it was the nicest handling glider I ever owned, and I never once had a problem with an inadvertent spin entry (I did do 90% of my flying with the 16.6M tips, though). What the heck did you guys do to it out in Utah? ;^)

Marc

Le mercredi 29 août 2012 03:00:11 UTC+2, John Cochrane a écrit*:
On Aug 28, 4:39*pm, Brian wrote:



It's easy technically. Add sua files that prescribe minimum MSL

altitudes over the task area. RIdges and mountains stick out; areas

near known ridge routes that need less than 500 feet can be

specifically exempted. Then flight computers will tell you when you

get close, and give an airspace intrusion noise when you've violated

it.


For most flatland sites a single MSL altitude will work over most of

the contest area and it's easy.

[...]



John Cochrane

Well, it's not that easy. I live in one of the flattest regions in Europe (there is even a song in French about "this flat land that is mine"), but only 50 miles out the ground has already risen 1000 ft. There are programs, of course, with relief maps that seem to be the answer. But when using See You, for example, to analyse a flight, I'm always made aware that these maps are still too inaccurate to really implement the proposed rule.


About low saves: we once had a relatively well known international competitor doing a speech about competition flights, and claiming he succeeded in thermaling away from treetop height with his big Nimbus. What he didn't tell on that occasion was that he'd crashed another Nimbus by trying to fly a 180° to land when failing to get his "turbo" started after a car launch with only 650 ft of rope (that story was published by one of his friends who was doing the same sort of thing: they both were touring Australia with their gliders). I think he was very lucky to be able to tell his story... but he certainly gave the wrong signal to his audience!

Hi All, I think two things have not been mentioned about your practice
spins...

We have all tried spinning from S+L flight, even by quickly raising the
nose and maybe kicking in a bit of rudder, but have you tried replicating
the circumstances of the crash...
i.e. Entering a 45deg angle of bank orbit, reducing the speed, then
kicking in a boot-full of pro rudder. This is soooo much different to
the S+L entry.

The second point I would like to make is that several posts refer to flying
at the (IAS.) stall speed. This again is going to be different with the
wings at a banked angle... typically add 7 knotts at 45 deg and 16 knotts
at 60 deg AOB. (to take account of the increased G loading.) and make sure
it is your inner wing tip is doing that speed.

Pete

At 00:41 29 August 2012, BobW wrote:
On 8/28/2012 5:25 PM, jfitch wrote:
On Tuesday, August 28, 2012 2:13:48 PM UTC-7,
wrote:
On Tuesday, August 28, 2012 10:16:31 AM UTC-7, kirk.stant wrote:



Bob, I'm not quite sure what your point is. In fact, you seem at
first
to suggest that practicing unusual attitude recoveries is a bad
thing!



I agree with Kirk. Just because practicing spin entry/recovery at
altitude isn't identical to spin entry/recovery at 300' doesn't mean
that
practice at altitude isn't worthwhile - and it's definitely a lot
easier
on the nerves than practicing at 300'. There are other things we can
do
to try to become aware of the different atmospheric, geometric and
mindset issues down low and under pressure, but the basic airmanship
of
knowing how your glider spins/recovers is a universal good in my
estimation.

On Tuesday, August 28, 2012 6:25:32 PM UTC-5, jfitch wrote:

I think for most pilots, recovering from a spin initiated at 300 ft would scare the hell out of them. You should really not be intentionally putting yourself in a position where the hell can be scared out of you. If you are engaging in an activity that cannot be safely practiced, how then can it be safely done without practice?

The point of practicing recognition and recovery from departures (incipient spins) at altitude is to learn to recognize the symptoms and the immediate recovery procedures that apply to your glider. If you never really slow your glider down and actually recover - or not - from a departure, then your minimum altitude had better include enough to learn - which is probably a lot more than 1000'!

This is similar to the fiasco the FAA in the US went through with twin-engine VMC training long ago (60s?): FAA required single engine VMC demonstration at low altitude, and of course lost a bunch due to loss of control too low to recover. Dumb and totally unnecessary, of course, and was quickly changed to allow the demonstration at a high enough altitude to allow recovery if VMC became spin recovery. But the training for control at VMC is still required.

(VMC: minimum controllable speed on one engine - below that you run out of rudder & aileron to maintain control and depart into a spin, aggravated by the good engine running at full power - not fun at any altitude but deadly down low.)

Kirk

OK, I guess my reading skills were not functioning very well when I read your first post (need more practice at altitude). We pretty much agree.

On Tuesday, August 28, 2012 7:41:20 PM UTC-5, BobW wrote:

Re-reading my earlier post, I can't find where I even *hinted* "practicing

unusual attitude recoveries is a bad thing!"



But since it was implicitly asked what my point was, I'll try and be succinct.

(Warning! There was more than one point.) In no particular order...

- skills practice is good;

- practicing some skills (e.g. departures from controlled flight at low

altitudes) is like practicing Russian roulette;

- skill won't help if your margins are too thin;

- certain margins (e.g. "safe spinning height") are inherently unquantifiable

if life-continuing precision is one's goal.



Bob - wimpoid - W.