Update on Minden tradegy

At 20:06 29 October 2004, Nafod40 wrote:
Todd Pattist wrote:

I had my doubts about using this technique in a slippery
glass ship, but I found it to work fairly well, except
I use
trim back. I have tried this in my Ventus C, once
for a
total of 10,000' descent, once for 8,000' descent
and once
for 5,000' (a real waste of altitude, but each was
after a
wave flight and I was cold). I found that trim back
(thermal setting), flaps at -1 (one notch negative
- zero
and positive flap settings are limited to 80 knots),
wheel
out and brakes full open worked best. The 10,000'
and
5,000' descents were entered level, became a gentle
stable
turn and remained fairly stable with some phugoid
speed
oscillation. The turn would sometimes steepen, sometimes
shallow or even reverse.

When flying in the military, we used to play games
and see what we could
fail and still fly the plane IMC. I found I could get
by with a turn
needle, an AOA gauge, a balance ball (or a balance
string) and an ASI.
The turn needle coupled with the balance string could
be used to
maintain wings level. Basically use rudder to keep
the turn needle
centered, and wing to balance flight.

The AOA with the airspeed, oddly enough, worked fine
for pitch once you
got used to it. The AOA responded instantly to pitch
inputs, and let you
immediately correct them. From a controls standpoint,
it gave great
derivative information. The airspeed then let you dampen
the slow pitch
deviations. It was a great integrator. One could replicate
an AOA
indicator by a string on the side of a cockpit.

I could fly a PAR to mins using this technique. Tiring,
but doable.

So the turn needle is the only thing seriously lacking
in a glider.


Speak for yourself, I have a turn and slip AND a horizon
in my panel and consider them minimum equipment for
wave soaring on cloudy days in a slippery glider.

kernel.dll has caused a general protection fault, please
wait while your instrument panel reboots, would you
like to send a fault report to Microsoft?

Spinning gyro's might be passe but they don't rely
on Bill Gates flaky operating systems. I personally
don't trust Billy Boy for final glide or navigation
(I have two backups for both) never mind saving my
neck descending through cloud.

At 21:12 29 October 2004, Bill Daniels wrote:

'nafod40' wrote in message
...
Bill Daniels wrote:


You can fly with just the turn needle and ASI if
you learn to control
airspeed trends.

I'm being flip here a little bit, but I wonder if
you couldn't
manufacture an 'emergency gyro' that would be spun
up like a top by
battery, and would spin for enough minutes to hold
an attitude. Clamp it
onto the dash and start descending.


Spinning gyros are passe.
Look at: http://www.pcflightsystems.com/egyro.html
or: http://www.icarusinstruments.com/microEFIS.html

Bill Daniels

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

In article ,
Ian Strachan wrote:

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.

It's amazing how hard it is to get *true* no-visual-reference conditions
in IMC.

I've done some flying with a commercial pilot friend doing night freight
runs in small turboprops. Even in the clouds in the middle of nowhere
in NZ you can almost always see some speck of light out of the corner of
your eye, whether a farmhouse or a star, and that gives you roll
information even when you're not looking at the AH. You don't realize
how much this helps until the first time there really *is* nothing out
there.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

In article , Bruce
Hoult writes

It's amazing how hard it is to get *true* no-visual-reference conditions
in IMC.

I've done some flying with a commercial pilot friend doing night freight
runs in small turboprops. Even in the clouds in the middle of nowhere
in NZ you can almost always see some speck of light out of the corner of
your eye, whether a farmhouse or a star, and that gives you roll
information even when you're not looking at the AH. You don't realize
how much this helps until the first time there really *is* nothing out
there.

A reference if you are rolling but for a controlled descent you do not
want to be rolling. More important, what about horizon reference? I
have often seen "false horizons" in cloud layers and at night. They can
be very disorientating. For instance, I got severe "leans" once when
coming off a tanker at night when the lit tanker was in a turn. And
several times when between slanting cloud layers.

Not a glider case, of course, but "beware the false horizon" and
"believe the turn needle" would appear to be good guidance!

Incidentally the title of this thread uses the word "benign". An
accelerating spiral in a slick glider can be anything but benign. It is
not difficult, I imagine, to literally pull the wings off in an attempt
to recover. The rule on "limited panel" unusual attitude recoveries was
"don't pull until you have the turn needle within about Rate 1 of the
centre of the instrument.

--
Ian Strachan

Bentworth Hall West
Tel: +44 1420 564 195 Bentworth, Alton
Fax: +44 1420 563 140 Hampshire GU34 5LA, ENGLAND

Bruce Hoult wrote:

It's amazing how hard it is to get *true* no-visual-reference conditions
in IMC.

I've done some flying with a commercial pilot friend doing night freight
runs in small turboprops. Even in the clouds in the middle of nowhere
in NZ you can almost always see some speck of light out of the corner of
your eye, whether a farmhouse or a star, and that gives you roll
information even when you're not looking at the AH. You don't realize
how much this helps until the first time there really *is* nothing out
there.

There have been an amazing number of Navy pilots that have flown into
the water as they mistaked boat lights for either stars or an aircraft
they were joining on. I know, not pertinent to gliders, but the optical
illusions of sort of IMC/VMC can be intense and almost more disorienting.

nafod40 wrote:

There have been an amazing number of Navy pilots that have flown into
the water as they mistaked boat lights for either stars or an aircraft

There are libraries full of books about wrong visual clues: Houses on a
hill taken for stars, a street taken for a shore line, wrong
perspectives, wrong distances, wrong altitude, etc. etc. etc. I'm always
amazed that there would still be pilots who believe they are smarter
than those who contributed to this knowledge with their blood.

If in IMC or at night, believe your instruments and nothing else. If
your aircraft (glider) is not adequately equipped, avoid clouds. This
can be done! There is no such thing as "trapped" by a layer if you act
as you should. If you feel like cloud flying, equip your glider
accordingly and learn how to use the gauges.

Stefan

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.

Ben Flewett wrote:

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud.

I do not agree. Know the weather. Allow yourself enough time to build
experience. Keep sharp on the development of the weather. Never, never,
never fly above a lenticularis. Keep your föhn gap in sight. Be sure
your glider can penetrate against the wind. And if in doubt, don't go.
But you knew all this before.

If you insist that getting trapped by cloud can't be avoided, then, by
all means, install at least a needle and get some training on it. You
simply can't control a slippery glass glider in cloud without a gyro.

Stefan

Right. If you run the risk to get involved into this kind of scenario, plain
common sense tells that you better have at least one gyro needle on board
(that's what I do although I prefer not to get into a trap in the first
place). Anything else would be fairly irresponsible.

--
Bert Willing

ASW20 "TW"


"Todd Pattist" a écrit dans le message de
news: ...
Stefan wrote:

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

I know two pilots who admit to having to descend through a
wave cloud deck in a glider. There is not much to be gained
by telling them that they didn't act as they should, or that
there's no such thing as what happened to them.

In a strong wind setting up a wave, it's not that hard to
make a mistake, get swept downwind into the sink and be
unable to penetrate upwind across a lenticular below. While
it would be nice to never make a mistake, some do. It's a
good idea to think about the options before you get into a
situation that you wouldn't be in if you'd acted "as you
should."


Todd Pattist - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)