Update on Minden tradegy

The remains of the Carat Motorglider have been placed
in its trailer and are awaiting the investigation by the NTSB
at Minden Airport.
I spoke to Larry Mansberger about the possibility of a wing
failure similar to those experienced by the Duo Discus and
the Discus CS a year or so ago. For those of you unfamiliar
to the Schempp-Hirth problems I will give you a little history.
The wings were manufactured in Eastern Europe and because
of quality assurance problems it was discovered that, after
a couple of wings disintegrated in the air, the glue used was
too thin and the parts that were expected to be glued together
had large voids where there should have been joined. This
weakened the wings causing in the air failures. Larry showed
me, using a boroscope, such defects in a Duo Discus wing
he was inspecting after the LBA and the FAA grounded
certain models of the Discus single and dual place gliders.
The Carat uses a modified std Discus wing. No problems
have ever been reported in the Carat wing. Larry helped
transport Alan's Carat back to the airport after the accident
and carefully checked to see if there were any similar
problems to those seen in the Duo's wings. There were non.
Mike More flew a Grob 103 with a student at the same time
Alan was in the air. They were also north of the airport. They
were flying above 14,000 feet, spoke of moderate turbulence,
but more importantly of the closure of layers of cloud below
them. Mike said to me that he had to be vigilant of the forming
and dissolving cloud layers and position himself so that there
was always a blue hole to get himself down in. A less
experienced pilot might not have been so aware of the dangers
of getting trapped in cloud.
Lets get the most out of this tragic accident. Lets learn and
in so doing become wiser. The wave can be a monster in more
than one sense. It can cause extreme rotor - read turbulence -
it can produce extreme lift greater than 1500 ft per minute; how
do you get down? You had better have a plan! Cloud layers can
form almost instantly - a big blue hole might disappear in
seconds. Most of the time wave is enjoyable and reasonably
safe, but it can so quickly turn into a monster. When it does
look out. Have a plan.
Copied below is an initial accident review from the US Carat
distributor.
Dave Bingham
---------------------

Date: Thu, 28 Oct 2004 04:23:53 -0000

Dear Saddened Carat Fans;

After a through investigation of the accident by AMS Flight d.o.o.,
Schempp-Hirth GmbH, Mansberger Aviation and AMS-USA it has been
determined that inflight structural failure was not the cause of this
accident.

On this flight, N418AP, went through an in flight envelope of
aproximately, a 15-20 positive G load, and an airspeed of 200+ knots.

The likely cause of the accident was a combination of high altitude
hypoxia and flying in IMC conditions, which lead to loss of control
of the aircraft and it exceeding its design limitations.

Oliver Dyer-Bennet
AMS-USA

Were the G numbers and speed found on a flight recorder?
Brian

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.

"nafod40" wrote in message
...
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.


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

For those of us flying with a PDA with GPS and TAS input, there are several
inexpensive software programs that derive bank from TAS and rate of change
in ground track and display it as an attitude indicator. It's not perfect
but it should get you out of a cloud.

Bill Daniels

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.

nafod40 wrote:

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.

Not very surprizing. Actually, the legal minimal instrumentation for
cloud flying in Switzerland is AI, Vario, Ball, Compass and Needle (and
radio). The glider instrument rating involves flying with those.

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

Why should it be lacking in a glider? It doesn't in ours.

Stefan

"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

Unfortunately Alan did not have a flight recorder.
Dave

Brian Iten wrote in message ...
Were the G numbers and speed found on a flight recorder?
Brian

Interesting. Two weeks ago, several of us contacted wave and managed a
beautiful climb up through a fairly small blue hole. Though there was never
any question about being able to get back through, it made me think about
the alternative routes to getting down if I were caught on top. I've tried
the benign spiral in several ships, ranging from a 1-34 to Grob 102 and an
LS4, and it seemed to work in all cases similar to Todd's description.

But, on this recent flight, I tried something different. I turned the
"gain" on my GPS display up to high (ie. shortest range) and used the Tracks
On feature to give me a reference to ground. I set an initial heading
using GPS display (not wet compass) and used the individual dots on the
Track as a sort of reverse CDI. I was curious to see if the response would
be sensitive and rapid enough to avoid major roll excursions. It SEEMED to
work. I was able to hold heading without reference to ground and used only
airspeed for pitch. I tried not to cheat, but since I don't routinely
bring my foggles along on glider flights and didn't have a safety pilot, I
didn't want to go too far heads down :-)) Now, I'm not advocating this,
but does anyone else see this as an option?

Erik Mann



"nafod40" wrote in message
...
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.

Papa3 wrote:


But, on this recent flight, I tried something different. I turned the
"gain" on my GPS display up to high (ie. shortest range) and used the Tracks
On feature to give me a reference to ground. I set an initial heading
using GPS display (not wet compass) and used the individual dots on the
Track as a sort of reverse CDI. I was curious to see if the response would
be sensitive and rapid enough to avoid major roll excursions. It SEEMED to
work. I was able to hold heading without reference to ground and used only
airspeed for pitch. I tried not to cheat, but since I don't routinely
bring my foggles along on glider flights and didn't have a safety pilot, I
didn't want to go too far heads down :-)) Now, I'm not advocating this,
but does anyone else see this as an option?

I've tried it under similar conditions, and it seems to work in smooth
air without much wind. In wave with 30+ knot wind, the heading was very
touchy going into the wind, and very insensitive going with the wind.

Throw in some turbulence, and? No idea. Not that I'm any good with
needle, ball, and airspeed in turbulence anyway.

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

Eric Greenwell
Washington State
USA