Update on Minden tradegy

I could never get my ASW-20B to do a benign spiral. I tried many times
over a period of sixteen years and 2000 hours with flaps, spoilers,
gear, trim and CG in various positions. My technique was to set up the
configuration, then upset the attitude a bit the way rotor cloud
turbulence would, and then hands and feet off. It always would begin
with small "zoomies" which got bigger and bigger until I was forced to
take control to save my life.

My '20 was also the only glider (or throttled back power plane) that I
ever flew which was uncontrollable with the stick against the aft
stop. With every type but the '20 I could very slowly ease the stick
aft until it hit the stop and then control it indefinitely with coarse
use of aileron and rudder as it waffled downwards. Not the '20. Very
quickly it would tell me that I better push forward or it was going to
self destruct. The exception was in a very steep bank, 50 or 60
degrees, doing 10 second circles and pulling about 2 g's.

I loved my '20 - a wonderful airplane. There must be other types out
there with the same characteristics but I never came across one. This
winter while I'm floating around the skies in Florida I'll try out my
'27 and see what it does.

Walter

Walter Weir wrote:

My '20 was also the only glider (or throttled back power plane) that I
ever flew which was uncontrollable with the stick against the aft
stop. With every type but the '20 I could very slowly ease the stick
aft until it hit the stop and then control it indefinitely with coarse
use of aileron and rudder as it waffled downwards.

I would think "coarse use" of the ailerons would be exactly the wrong
thing to do with the stick full aft.

Rudder is often the best, and sometimes the only, way to do high AOA
maneuvering in fixed-wing types I have flown.

In what types have you found coarse use of aileron to be of benefit at
high AOA?



Jack

"Ben Flewett" wrote in message
...
At 15:54 02 November 2004, Stefan wrote:

There is no such thing as 'trapped' by a layer if you
act
as you should.


Sounds like you haven't done much cross country wave
flying.

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud. Sometimes
you are forced to fly part of your task above 8/8 where
we fly. Other times the cloud can close quickly and
you get caught.

We were trained to position approx 1km downwind of
a known landing point using GPS (depending on terrain),
set the glider up in a stable position and open the
airbrakes at 70kts. Not desirable by any stretch of
the imagination but sometimes a required technique.


I have to agree with Ben.

I got caught above a cloud deck in wave once. It wasn't that the deck
'moved in" below me, it just formed very quickly. One moment there was a
scattered lenticular deck at 22,000 and the next there was a solid deck
below me at 12,000. There was never an option to escape VFR.

Having neither radio nor gyros, I was in no hurry to try a descent either by
benign spiral or in a stable spin so I just sat there and maintained my
position in the wave. The cloud tops marked the wave nicely. After about
an hour, the patch of moisture moved off downwind and a foehn gap appeared
in the cloud deck below. Descending through the gap meant fighting my way
down through the strong lift with full spoilers in a dive. It took almost
an hour.

I'm a believer. Sooner or later, you'll need the ability to make a blind
descent.

Bill Daniels

Ben Flewett wrote:
At 15:54 02 November 2004, Stefan wrote:

There is no such thing as 'trapped' by a layer if you
act
as you should.



Sounds like you haven't done much cross country wave
flying.

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud. Sometimes
you are forced to fly part of your task above 8/8 where
we fly. Other times the cloud can close quickly and
you get caught.

We were trained to position approx 1km downwind of
a known landing point using GPS (depending on terrain),
set the glider up in a stable position and open the
airbrakes at 70kts. Not desirable by any stretch of
the imagination but sometimes a required technique.



Why downwind?

I too learned to fly clouds, in the UK on Turn and Ball; those old gliders did
at least have speed limiting dve brakes which I never had to use.
When I graduated to the Oly with a German WWII artificail horizon
cloud flying was the proverbial piece of cake. When my AH failed
(low battery) about 12000 ft in Yugo '72, I was glad that I had those hours
Of time using T and B.
I was told that a skilled pilot with a Bohli freely gimballed compass
could adequately cloud fly and Bohlis were banned from World comps.
I did prove to my limited satisfaction that with great care and circumspection
one could maintain a controlled trun using the COOK vertcal bearing compass
but I do not think I would try it now.
In closing, always have a backup, if you go IFR; the offical report of a
sad accident to a single engine transatlantic delivery happened on final
IFR approach to Reyavik , when the pilot reported AH failure! (no T and B)
That is pegging your life to one unkown instrument.
Don't do it.
John Firth
Old, no longer bold pilot.

Ian
Strachan ) writes:
In article , Todd Pattist
writes

I've also had some pilots tell me they were trained years
ago to use a standard compass

That is, an old fashioned one with pendulous suspension of the magnet
assembly. This type of compass has acceleration errors on east and west
and turning errors on north and south. What may be an "error" in terms
of registering an accurate instantaneous heading, might be turned to
advantage in a case of total failure of gyro instruments. With great
caution, of course, and IMHO not the best answer, see below.

, head south

It is true that a pendulous compass has turning errors on South, and
could be used a sort of turn indicator on that heading.

and steer with
rudders.

No! A good way to get disorientated, IMHO. What is wrong with turning
in the normal way, application of (in this case) small amounts of bank
where necessary. Fly gently, don't get used to coarse use of
unnecessary control inputs. Particularly boots of rudder un-coordinated
with aileron, unless you wish to spin or do aerobatics, of course!.

However, to stay alive in instrument flying, particularly in turbulence,
there is no substitute for proper aircraft-designed gyro instruments.

I taught and examined on what we used to call "limited panel" for many
years, AND IT WORKS, with a bit of practice. That is, instrument flight
using a good old Sperry turn gyro presented through a needle display
("needle, ball, airspeed ... needle, ball, airspeed"). Turn gyros take
little power and normally run on DC, so are well suited to glider use.

People say that instrument flight using only a turn needle is difficult,
But at least it is designed for the job, unlike pendulous compasses, GPS
presentations etc. And what is difficult is limited-panel accurate
pattern turns, approaches etc., with an examiner breathing down your
neck!

Merely keeping the wings about level so as not to enter a spiral dive,
is not difficult. On a safe heading, of course, that is away from known
high ground. Try it in a two-seater with a safety pilot, but make sure
that you are really "under the hood" and are not peeping out to see the
horizon, otherwise you are not really getting proper training that might
get you out of trouble later.

The dear old Link Trainer was pretty good for this training also, but
there aren't many about now except in museums!

Of course even better if your glider has a gyro-driven Artificial
Horizon as well as that rate-gyro. Makes instrument flight for those
not in practice, including me nowadays, reasonably straightforward.

--
Ian Strachan
Lasham Gliding Centre, UK

Shawn wrote in message ...
Ben Flewett wrote:
At 15:54 02 November 2004, Stefan wrote:

There is no such thing as 'trapped' by a layer if you
act
as you should.



Sounds like you haven't done much cross country wave
flying.

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud. Sometimes
you are forced to fly part of your task above 8/8 where
we fly. Other times the cloud can close quickly and
you get caught.

We were trained to position approx 1km downwind of
a known landing point using GPS (depending on terrain),
set the glider up in a stable position and open the
airbrakes at 70kts. Not desirable by any stretch of
the imagination but sometimes a required technique.



Why downwind?

Am I missing something here? If I were caught above a cloud layer, I
would go to into a spin before trying a "benign spiral". A spin is a
controlled maneuver where a spiral seems more likely to get out of
control.

Am I missing something here? If I were caught above a cloud layer, I
would go to into a spin before trying a "benign spiral". A spin is a
controlled maneuver where a spiral seems more likely to get out of
control.

Flight handbook reads: "Intentional spins are prohibited"

Ian

clay thomas wrote:

Am I missing something here? If I were caught above a cloud layer, I
would go to into a spin before trying a "benign spiral". A spin is a
controlled maneuver where a spiral seems more likely to get out of
control.

You are missing that many gliders won't stay in the spin but rather go
into a spiral after a few turns.

Stefan

Todd Pattist wrote:

And even if they will stay in a spin, U.S. certification
standards do not require that the spin be recoverable after
extended spinning (6 turns or 3 seconds) .

JAA standards require a recovery with the standard procedure after 5
turns. I wouldn't assume that the factories build an extra line of
gliders for the USA that won't recover, just to please the FAA. (I'm
talking of modern gliders here, Schweitzer's milage may vary.)

Stefan

Stefan wrote:
Todd Pattist wrote:

And even if they will stay in a spin, U.S. certification
standards do not require that the spin be recoverable after
extended spinning (6 turns or 3 seconds) .


JAA standards require a recovery with the standard procedure after 5
turns. I wouldn't assume that the factories build an extra line of
gliders for the USA that won't recover, just to please the FAA. (I'm
talking of modern gliders here, Schweitzer's milage may vary.)

Five turns, six turns - not a very comforting margin if you are spinning
down through a cloud when you might need many more than that. I don't
want to be a test pilot when I really need to descend through a cloud;
in fact, I don't want to be a test pilot determining how many times the
glider can spin before it won't recover!

At least, the benign spiral can be safely tested before you need it.
Regardless of the technique (T&B, AH, GPS or compass heading, spinning,
benign spiral) a pilot chooses to rely on when descending through clouds
in wave conditions, the pilot should practice it in those conditions
before it's needed. And, I think, include some turbulence if your waves
have it.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA