A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Glider down near Reno - pilot OK



 
 
Thread Tools Display Modes
  #31  
Old November 9th 05, 12:18 AM
bagmaker bagmaker is offline
Senior Member
 
First recorded activity by AviationBanter: Aug 2005
Location: Melbourne Australia
Posts: 167
Default

pardon my newbie ignorance, but -why not check a compass? If not turning and still flying, decending safely shouldnt be out of the question.
Having said that, we in Oz arent permitted cloud flying (bless the lucky poms, though) and although I have ventured into what looked, sounded, felt and smelt like cloud, it wasnt, because that would be illegal here! I was VERY nervous doing it, with that simple lack of vision, and can understand how easily the accident would occur if the pilot was also at the extremes of speed & altitude already.
Is it possible to get a first hand account from the lucky guy and post it for us?

Damn the gravity, Wayne
  #32  
Old November 9th 05, 04:46 AM
Guy Acheson
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK

I have some experience with the benign spiral mode.
My previous sailplane was a Grob 104, Speed Astir.
The benign spiral mode was in the pilot's handbook.
It saved my bacon two times where clouds just reached
out and grabbed me. Very scarey when you can't see
anything and your inner ear is giving you all kinds
of bizare information. Very, very hard to keep my
hands and feet off of the controls.

My current sailplane is an LS8 and I can tell you that
the benign spiral mode does not exist. This aircraft
will overspeed and overbank no matter how it is trimmed
if you keep your hands and feet off of the controls.

My message is that you must practice this manuever
many times in various configurations with your particular
aircraft before you should even consider it as a possibility.

For those of you who do not understand how the Tru-trak
would allow you to recover from a death spiral, please
get some partial panel IFR training. The recovery
is the same in all aircraft I have trained in; level
the wings FIRST (this is what the Tru-trak will allow
you to do quickly) and then reduce the airspeed. If
you try to pull the nose up while in a bank you will
only increase the G loads very rapidly and put yourself
in an accelerated stall if you don't break the plane
first.

This is my two cents.

Guy Acheson, 'DDS'
At 16:48 08 November 2005, Raphael Warshaw wrote:
Todd:

Cindy and Marty at Caracole have demonstrated the benign
spiral to me in
both the K-21 and the Duo-Discus. It works in my LAK-17
(15m) at zero flap
with the trim 1/3 aft (wheel in or out) although, like
you, I've never tried
it from near redline or from a spiral dive. It needs
to be practiced, both
to see that it works in your airplane and, recurrently,
so that you really
do (hopefully) stay off the controls in an actual emergency.

Caracole routinely performs the benign spiral as a
training exercise, so
that their students and BFR candidates can experience
it. Perhaps either
Cindy or Marty could be enticed into joining this thread
as they know much
more about this and wave flying in general than I do
and have given
considerable thought to emergency procedures. They
provide serious mountain
wave training BTW, IMHO a VERY good idea before venturing
into the awesome
world of the wave.

Raphael Warshaw
1LK




'T o d d P a t t i s t' wrote in message
.. .
wrote:

Don't delude yourself by thinking that going IFC at
red line in the
Sierra Wave with just a turn and bank is anything like
a Microsoft
flight simulator with a partial panel or an instrument
flight in a
small plane with a partial panel and an instructor.


About once or twice a year, I find myself in the happy
situation of being at the end of a flight and having
10,000'
or more to kill off before landing. About 5 times
I have
used this altitude to try the benign spiral mode in
my
Ventus. Full trim back, full negative flaps, brakes
fully
open and hands and feet off the controls seems to
be
reasonably balanced. I've entered at speeds up to
90 knots,
and have always lost 8,000 or more before having to
take
control for landing. I've never seen excess G's, but
I've
never been in extreme wave conditions during these
tests and
I've never tried this by entering from extreme high
speeds
as one might be experiencing attempting to move out
from IMC
wave conditions. I have seen some 1/2- 1.5 g excursions,
but bank has always remained within 45 degrees.

I wonder if anyone else has tried this in a modern
glider
and wants to report their experience.
--
T o d d P a t t i s t - 'WH' Ventus C
(Remove DONTSPAMME from address to email reply.)







  #33  
Old November 9th 05, 05:56 AM
bumper
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK

It went into an unstable phugoid oscillation with each dive being steeper
than the previous. I chickened out and stopped the "test" early on after my
ears got pinned back - - and I was in a closed cockpit (g).

I did not have spoilers or gear out.

bumper
"T o d d P a t t i s t" wrote in message
...
"bumper" wrote:

I'd not want to rely on a benign spiral or spinning to exit IMC.


I agree with the spin comment, but I'm five for five on the
benign spiral.

I'd hate to rely on a benign spiral if there was anything but glass smooth
air. The few times I've tried a benign spiral, it didn't stay benign for
long.


How did it go bad? Did you go too fast, too steep a bank or
did it want to loop/stall? I have to admit on some
excursions, I was awfully tempted to touch the controls, but
it always made it just fine until I'd lost at least 8,000'.
--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)



  #34  
Old November 9th 05, 07:05 AM
Bruce Hoult
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK

In article , "bumper"
wrote:

It went into an unstable phugoid oscillation with each dive being steeper
than the previous. I chickened out and stopped the "test" early on after my
ears got pinned back - - and I was in a closed cockpit (g).

I did not have spoilers or gear out.


That's the problem. The more drag you can put out the more stable it is.

Here's why.

First of all, more drag limits speed buildup when the nose is down,
giving time for the extra lift from increased speed to raise the nose
before the speed is such that you're going to go way nose up.

Second, you are never going to have a roll rate of precisely zero. It's
only manual corrections that keep the wings level (or at constant bank),
wich you can't do when you can't see. Given enough time, even a tiny
roll rate will tip you over. BUT, when you're gliding (losing altitude
comparred to the air) a portion of the roll rate goes directly into
changing your heading. The steeper your glide angle the greater that
coupling is. If you're 90 degrees nose down (which gliders with really
good airbrakes can do at a safe speed) then *all* the roll rate goes
into changing your heading, and none of it into tipping you over. If
you're 45 degrees nose down (which all cerrtified gliders can do) then
70% of the roll rate goes into changing your heading. Even at 1:7
(which certified gliders must be able to acheive at approach speed), 15%
of the roll rate goes straight into changing your heading. At 40:1 only
2.5% does.

Anyway. The point is that even if you have quite a large roll rate, if
your nose is well down, with the speed stabilised with drag, then the
roll rate just makes you turn faster instead of tipping you over, and
your bank angle will stabilize at almost certainly no more than 45 - 60
degrees, and quite probably only 30 degrees.


Every aircraft is different. But drag is the key to the whole thing.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------
  #35  
Old November 9th 05, 07:34 AM
Jack
external usenet poster
 
Posts: n/a
Default Benign spirals, etc. [was Glider down near Reno - pilot OK]

bumper wrote:
It went into an unstable phugoid oscillation with each dive being steeper
than the previous. I chickened out and stopped the "test" early on after my
ears got pinned back - - and I was in a closed cockpit (g).

I did not have spoilers or gear out.


I thought certified aircraft were supposed to demonstrate diminishing
phugoids. No?


Jack
  #36  
Old November 9th 05, 08:07 AM
Bruce
external usenet poster
 
Posts: n/a
Default Benign spirals, etc. [was Glider down near Reno - pilot OK]

Jack wrote:
bumper wrote:

It went into an unstable phugoid oscillation with each dive being
steeper than the previous. I chickened out and stopped the "test"
early on after my ears got pinned back - - and I was in a closed
cockpit (g).

I did not have spoilers or gear out.



I thought certified aircraft were supposed to demonstrate diminishing
phugoids. No?


Jack

In all of the above - "certified glider" appears to apply to a JAR22 - EASA
certified glider.

Don't expect an older "certified" design to have the airbrake efficiency, or
pitch stability. Theory is my Cirrus will stay below Vne at 45%, hands off I
would hate to bet my life on it...

The Cirrus' phugoid amplitude seems to increase rather than decrease at the CG
positions I can achieve. Leave it long enough and it might just get exciting.
Might just be specific to my 35 year old mistress, but I think not.

Bruce

--
Bruce Greeff
Std Cirrus #57
I'm no-T at the address above.
  #37  
Old November 9th 05, 10:46 AM
Jancsika
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK

bagmaker wrote:
pardon my newbie ignorance, but -why not check a compass? If not turning
and still flying, decending safely shouldnt be out of the question.


Compass is almost useless for instrument flying. It will just roll
left to right and back again with serious delays in most cases. If you
can maintain a 1 or 2 minute calm turn than it could help you to find
the desired path but won't tell you if you are turning or not.
Turn and bank indicator, vario, speed indicator, sound. You have to
use all of them simultaneously to keep the glider in the required
position. It's frustrating task... There is huge difference between a
turn with 90 or 110 km/h (VNE?).

/jancsika
  #38  
Old November 9th 05, 04:08 PM
bumper
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK


"T o d d P a t t i s t" wrote I have yet to
try the "hold a magnetic compass heading of
south with rudder only" method or the "fly constant GPS
heading" method to compare. The latter two are difficult to
practice realistically in a single seat aircraft without
being contaminated/influenced by the visual horizon.
--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)



I used to think the GPS, and especially Garmin's excellent "panel page",
would be adequate to prevent pulling the wings off - - this assumes adequate
instrument training of course (I'm instrument rated, though not current).

Now, after some recent incidents and tragic accidents, I've concluded that I
was wrong. The GPS will be of little to no help in strong and varying wave
conditions such as we experience at Minden.

Since the GPS data displayed is base entirely on ground track, strong winds
will skew those results. Consider crabbing into a 70+ knot wind. A change in
wind speed, and thus ground track, will be displays as a roll on the Garmin
panel page - - not so good if one is trying to survive some moments in IMC.

Still, the Garmin panel page is useful and would work in lesser conditions.
I'm counting on it as my back up if the TruTrac fails. A benign spiral or
other aerodynamic tricks will remain a last resort options.

bumper


  #39  
Old November 9th 05, 04:59 PM
Bill Daniels
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK


"T o d d P a t t i s t" wrote in message
...
"bumper" wrote:

It went into an unstable phugoid oscillation with each dive being steeper
than the previous. I chickened out and stopped the "test" early on after

my
ears got pinned back - - and I was in a closed cockpit (g).

I did not have spoilers or gear out.


I have always done this with the brakes out. It's always
entered phugoid oscillations, but not so bad that I felt the
aircraft was in any danger. I must admit that sometimes,
they seemed to be getting more severe, but in the 8 -
10,000' I've had to play with, I've always been limited by
the need to land, not by the need to protect the glider from
itself. I'm reasonably confident that with 8,000' or less
of cloud to descend through, it would protect itself better
than I could.


Any high performance glider will have an undamped phugoid - they're just too
good at converting airspeed into altitude and vice versa. Opening the
spoilers and lowering the gear with help with damping. Experiments with any
particular glider are recomended.


I have yet to try the "hold a magnetic compass heading of
south with rudder only" method or the "fly constant GPS
heading" method to compare. The latter two are difficult to
practice realistically in a single seat aircraft without
being contaminated/influenced by the visual horizon.
--

I've practiced the south compass heading trick from the back seat of a Duo
Discus and it works surprisingly well particularly when combined with GPS
ground track data. I just used smooth, coordinated control inputs to hold
the south heading. However, I've had a LOT of IFR experience in single
engine light aircraft. Even so, I'd still want at least a T&B if I had to
try it in IMC.

Bill Daniels

  #40  
Old November 10th 05, 06:27 AM
M B
external usenet poster
 
Posts: n/a
Default Glider down near Reno - pilot OK

I've wondered, how about ejecting the canopy? It must
be an effective airbrake, lots of drag, right?''

And then if you have to bail, that's one less thing
to do, which is good...

I'm not saying this is realistic. I would be surprised
to find a pilot who would do this even if it would
save his life. Holding a spin all the way through
the lenticular is probably safer too, but it isn't
realistic to think anyone could actually accomplish
such a feat of willpower.

But both are worth a looksie from the armchair...

At 15:24 09 November 2005, T O D D P A T T I S T wrote:
'bumper' wrote:

It went into an unstable phugoid oscillation with each
dive being steeper
than the previous. I chickened out and stopped the
'test' early on after my
ears got pinned back - - and I was in a closed cockpit
(g).

I did not have spoilers or gear out.


I have always done this with the brakes out. It's
always
entered phugoid oscillations, but not so bad that I
felt the
aircraft was in any danger. I must admit that sometimes,
they seemed to be getting more severe, but in the 8
-
10,000' I've had to play with, I've always been limited
by
the need to land, not by the need to protect the glider
from
itself. I'm reasonably confident that with 8,000'
or less
of cloud to descend through, it would protect itself
better
than I could.

I have yet to try the 'hold a magnetic compass heading
of
south with rudder only' method or the 'fly constant
GPS
heading' method to compare. The latter two are difficult
to
practice realistically in a single seat aircraft without
being contaminated/influenced by the visual horizon.
--
T o d d P a t t i s t - 'WH' Ventus C
(Remove DONTSPAMME from address to email reply.)

Mark J. Boyd


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AOPA Stall/Spin Study -- Stowell's Review (8,000 words) Rich Stowell Aerobatics 28 January 2nd 09 02:26 PM
Can a Private Pilot tow gliders and get paid? BTIZ Soaring 1 October 17th 04 01:35 AM
Elder Statesman/Most Senior Glider Pilot? - Otto Zauner Mike Fadden Soaring 15 October 5th 04 04:25 PM
Toronto Area Glider Pilot Ground School Starts Thu. March 25, 2004 Ulf Soaring 0 March 3rd 04 05:02 PM
USAF = US Amphetamine Fools RT Military Aviation 104 September 25th 03 03:17 PM


All times are GMT +1. The time now is 10:04 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.