spin characteristics of new racers

Bruce Greeff wrote in message ...


I understand that most modern European single seaters exhibit a violent
spin entry, progressing to an approximately vertical attitude with
airspeed approaching VNE on recovery in this configuration.

Some modern gliders may have violent spin entry but others do not. My
ASW-28 appears to be as benign as my old ASW 19.

There is a paradox though. If spins are prohibited with water ballast
how can a pilot know how the glider will behave. All my deliberate
spin attempts in the 19 and 28 were dry, but nearly all of my flying
is with ballast.


Andy

There is a paradox though. If spins are prohibited
with water ballast
how can a pilot know how the glider will behave. All
my deliberate
spin attempts in the 19 and 28 were dry, but nearly
all of my flying
is with ballast.


For my own sake, I generally go through a standard
general handling/stall/spin exercise for any new type
I fly. I tend also to get myself briefed/debriefed
with several other pilots opinions, who I know have
flown those types. When I did my conversion to flapped
gliders on the BGA DG, I specifically asked about spinning
flapped gliders, which was in itself an interesting
experience. When it came to flying the LS6, for which
I did the conversion for, I went through my usual routine,
with out water ballast. With my weigh I could fly it
fully tanked up, but to me common sence said that I
should not go and spin it in this configuration, rather
fly the thing at the correct speed all the time.

The reason I decided upon was simply to do with the
fact that ballast does load the glider further, it
increases the stresses on the airframe, it increases
the already impressive accelleration, so why would
I want to find out how it spins like when I know how
to prevent it from ever occuring in the first place.


Would you also want to practice landing a glider full
up with ballast as well?

I personally view my reasonably frequent stall/spin
exercises I give myself, not so much to prove I can
still instinctivly recover from them, but to remind
myself why I fly at the correct speed and attitude
for any given condition.

Pete Zeugma wrote in message ...

Would you also want to practice landing a glider full
up with ballast as well?

Possibly, but you'd better have plenty of runway and make sure your
wings are equal. You'll simply find that it lands more like a typical
light plane and flare angles are reduced and extended longitudinally.
No big deal.

In the experimental Sigma, modified by Dr. Marsden, then further
modified by myself, there's no choice. The 900 lb. wings are always
fully ballasted and 5/16" aluminum plate skins equate to 12.65 psf.

However, we are able to achieve a measured max CsubL of 2.4 and
therefore the landing speeds are moderate. Still quite an adventure to
land out, which I have done once, much to the chagrin of my friends...
well, some of them now ex-friends!

On the general thread of practicing for emergencies, I used to own
helicopters for personal transport in a business. In my Hughes 500D,
I always made it a point to practice an engine-out autorotational
landing on one of two legs of any round trip. As a result, I was
thorougly prepared and practiced when I was returning from a personal
trip with my wife and experienced a complete flame-out at minimum
downwind altitude after take-off. Contaminated jet fuel. Textbook
landing, with no damage to aircraft or us. Even so, FAA required
disasembly and trailering to regional service center for complete
inspection. Quite a hassle. Real damage was to my wife's psyche. Poor
thing.

Best Regards,
Gary Osoba

(Gary Osoba) wrote
In the experimental Sigma, modified by Dr. Marsden, then further
modified by myself, there's no choice. The 900 lb. wings are always
fully ballasted and 5/16" aluminum plate skins equate to 12.65 psf.

However, we are able to achieve a measured max CsubL of 2.4 and
therefore the landing speeds are moderate. Still quite an adventure to
land out, which I have done once, much to the chagrin of my friends...
well, some of them now ex-friends

No way, Gary! That wasn't near enough to make any of us into
ex-friends. If that was the goal, you are gonna have to try harder!
I had fun. Probably a lot more fun than the night you went out after
me because you knew that I must surely have landed out, as dark and
black as it was getting where I was. Only to find that I had some how
hung on and gotten out of the path of the storms and made it home.
Dang crew radios not working well enough, anyway!

Steve Leonard
Spinner of Soaring Lore since the late 1970s.
Nutritional Label for Soaring Lore
Soaring Lore is made up of Fact (Less than 2%) and "Enhanced" Fact.

I would never dream of spinning a ballasted wing intenionally - especially
if you have water bags instead of tanks.
There is no reason whatsoever that the bags should resist to the water
rushing into the wingtip section, and when they burst you are in deep ****.

--
Bert Willing

ASW20 "TW"


"Andy Durbin" a écrit dans le message de
om...
Bruce Greeff wrote in message
...


I understand that most modern European single seaters exhibit a violent
spin entry, progressing to an approximately vertical attitude with
airspeed approaching VNE on recovery in this configuration.

Some modern gliders may have violent spin entry but others do not. My
ASW-28 appears to be as benign as my old ASW 19.

There is a paradox though. If spins are prohibited with water ballast
how can a pilot know how the glider will behave. All my deliberate
spin attempts in the 19 and 28 were dry, but nearly all of my flying
is with ballast.


Andy

Bert Willing wrote:
I would never dream of spinning a ballasted wing intenionally - especially
if you have water bags instead of tanks.
There is no reason whatsoever that the bags should resist to the water
rushing into the wingtip section, and when they burst you are in deep ****.

The ballast greatly increases the glider's rotational inertia, which
probably has a bad effect on spin recovery. Partially full bags or tanks
could yiedl interesting results, too.
--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Andy Durbin wrote:
Bruce Greeff wrote in message ...

There is a paradox though. If spins are prohibited with water ballast
how can a pilot know how the glider will behave. All my deliberate
spin attempts in the 19 and 28 were dry, but nearly all of my flying
is with ballast.

An excellent point. Has anyone practiced spins with water ballast?
With just one tank full? In a Nimbus DM? With the pylon extended?
In a Cirrus?

I think one could, with enough money and altitude and good chutes
and maybe a small tail drogue chute, but the insurance
companies might catch on after a while...

Until then, I'll just try not to stall ANY part of the glider...

Good. We all agree not to intentionally spin a ballasted glider.
But if it should happen, does the correct response change in any way?
As all of our training is in unballasted ships AND we tend to sink to the
level of our training rather than rise to the occaision, I suspect most of
us would do what we've been taught to do in unballasted ships. Would this
be the right response?

Yes, recovery is the same for water ballast. It will require
significantly more altitude, and speed at the bottom of the dive will
be higher. Most manuals add 40% greater altitude loss and 25% greater
speed. Partial ballast should not affect recovery early in the spin,
but it would be inadvisable to continue a spin through several
rotations with 1/2 full ballast tanks.

If you have uneven water ballast (result of a frozen dump valve or
leak), you must avoid stalling altogether.


"303pilot" brentUNDERSCOREsullivanATbmcDOTcom wrote in message ...
Good. We all agree not to intentionally spin a ballasted glider.
But if it should happen, does the correct response change in any way?
As all of our training is in unballasted ships AND we tend to sink to the
level of our training rather than rise to the occaision, I suspect most of
us would do what we've been taught to do in unballasted ships. Would this
be the right response?

On 29 Jan 2004 10:08:20 -0700, (Mark James Boyd)
wrote:


There is a paradox though. If spins are prohibited with water ballast
how can a pilot know how the glider will behave. All my deliberate
spin attempts in the 19 and 28 were dry, but nearly all of my flying
is with ballast.

An excellent point. Has anyone practiced spins with water ballast?
With just one tank full? In a Nimbus DM? With the pylon extended?


Ask Martin Heide, the current Schleicher chief designer.
His first task at Schleicher was the spin-testing of the first ASW-22.

When he did what you described (spin with only one full water tank),
the first 22 prototype broke apart inflight.

Hereupon this test was removed from the German LBA certification
requirement.

BTW: Martin was convinced that the 22 would break up in this kiind of
test.
Bye
Andreas