no instrument flight

Derek Copeland wrote:
I have had an ASI failure in flight. A few hundred
feet up on an aerotow launch, I glanced at the instruments
and noticed that the ASI was reading 20 knots and slowly
falling. Realising that neither the tug nor the glider
were capable of flying at this speed, although they
were clearly doing so quite happily, I knew that it
had to be an instrument failure.

snip story

I know of at least two other occasions where pilots
have suffered instrument failures and have managed
to cope with it.

My first flight in a 1-34 had an ASI failure. I radioed the tow pilot
to fly along next to me at a reasonable pattern speed to get a feel for
the proper attitude to fly the pattern. Seemed to help. Did a few
stalls to see how far up the nose needed to be before I got into
trouble. I also recalled Tom Knauf's comment about how very few gliders
will stall under normal flight conditions (i.e. not accelerated stalls)
with the nose below the horizon. Probably landed a little hot, but
all's well...

Shawn

Why are we talking about this as an emergency practice? Its really not,
maybe I should have bailed out of my Nimbus 3 because I lost all
instruments and the yaw string, then proceeded to go XC! This is
standard practice in training, at least it should be. If a student is
chasing an airspeed indicator, they don't get it anymore. If they
call off an altitude without looking outside they don't get an
altimeter anymore. I fly 2-33's and I don't have instruments in the
back, no big deal, can't see the front with an "average" male
American sitting in the front seat anyway.

The local club has a Blanik that they would approach at Mach 1, because
the ASI said 55knts!!! It didn't even dawn on them that it may be off.
A leak in the pitot system was found. But everyone was too interested
in what the needle pointed to vs. where the nose was pointed. After my
first pattern tow I bet a club member it was off, but they weren't
foolish enough to take it.

Yaw sting....if you cant feel your body sliding left or right when your
uncoordinated, you should probably relax some, because you are way too
uptight. But then again one of my coaches said I was too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and my Nimbus 3
doesn't have one either, and I probably won't get it "fixed" before the
Opens. I fly in the mountains and I don't feel that it is hazardous.
Plus that sting is way too much drag.

If your "eye ball gauge" is getting rusty, maybe you should take
the time with your flight instructor on your next flight review to work
on it, perhaps even earlier. But then again we could always just wing
it and let it get worse over time.

I flew without a yaw string once in a two-place ship
that the owner thought the mechanical T+B was better.
Thermalling and the such were okay, but I certainly
missed not having it as an input in the pattern. If
everything was going according to plan...I could live
without it. In a tight situation I would want information
from it.

At 06:42 08 July 2006, G L I D E R S T U D wrote:

Yaw sting....if you cant feel your body sliding left
or right when your
uncoordinated, you should probably relax some, because
you are way too
uptight. But then again one of my coaches said I was
too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and
my Nimbus 3
doesn't have one either, and I probably won't get it
'fixed' before the
Opens. I fly in the mountains and I don't feel that
it is hazardous.
Plus that sting is way too much drag.

I defy anyone to 'feel' the tiny amount of yaw that
a yaw string will indicate. The drag created by even
the largest piece of wool will be very small compared
to even a small amout of yaw in straight and level
flight. A 'T&S' ball is just not sensitive enough and
the yaw string has the advantage of being in your eye
line, you don't have to go heads down to see it. To
fly efficiently in a big winged glider is is even more
essential as even tiny amoutns of control differences
are magnified with the addition leverage of long wings.

"Don Johnstone" wrote in message
...
At 06:42 08 July 2006, G L I D E R S T U D wrote:

Yaw sting....if you cant feel your body sliding left
or right when your
uncoordinated, you should probably relax some, because
you are way too
uptight. But then again one of my coaches said I was
too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and
my Nimbus 3
doesn't have one either, and I probably won't get it
'fixed' before the
Opens. I fly in the mountains and I don't feel that
it is hazardous.
Plus that sting is way too much drag.

I defy anyone to 'feel' the tiny amount of yaw that
a yaw string will indicate. The drag created by even
the largest piece of wool will be very small compared
to even a small amout of yaw in straight and level
flight. A 'T&S' ball is just not sensitive enough and
the yaw string has the advantage of being in your eye
line, you don't have to go heads down to see it. To
fly efficiently in a big winged glider is is even more
essential as even tiny amoutns of control differences
are magnified with the addition leverage of long wings.


To Don Johnstone - Yep!

The weather is doing something it hasn't done in quite a while - raining -
therefore, I'm spending the weekend indoors. This has led me to research a
few ideas that I had set aside. One of them is an angle of attack indicator
for gliders.

Any reading of accident reports will quickly lead one to the conclusion that
pilots don't pay enough attention to AOA. No matter how hard AOA is
hammered into a students brain, a few months after their checkride, they
just watch the ASI. Some of them are involved in stall/spin accidents.

AOA indicators have long been essential to the safe operation of large
aircraft so, now that electronics are cheap, why not gliders too? Gliders
spend a lot of time flying near the stall AOA so we shoud be especially
interested in an AOA indicator.

So, how do we measure AOA? The traditional nose boom pitch vane is too
fragile for gliders but there is another way to get AOA data. Companies
like Masi make a simple AOA probes. See:
http://www.cgmasi.com/aviation/index.html

The Masi probe computes AOA from the pressure difference between two
pressure ports at 45 degrees to the airflow. Could the same be done with
pressure ports located on upper and lower nose? I think so. An inexpensive
differential pressure sensor and a bit of electronics driving an LED
lightbar plus a calibration proceedure would do it.

The calilbration procedure would be simple since we are only interested in
three AOA's - Stall, Minimum sink, and Best L/D. These would be very
helpful when flying gliders with a wide range of wing loadings. The min
sink AOA would be particularly helpful when flying at steep bank angles.

Gliders with flaps would have to repeat the calibration procedure for each
flap setting of interest - those being approach flaps and thermalling flaps.
Flap setting would have to be sent to the AOA conputer.

Any gadgeteers out there interested in making a few bucks awhile maybe
saving a few lives?

Bill Daniels

The last thing I want is another instrument. I enjoy gliding because I
can fly by visual references and only use the instruments to glance at
occasionally.


Bill Daniels wrote:
"Don Johnstone" wrote in message
...
At 06:42 08 July 2006, G L I D E R S T U D wrote:

Yaw sting....if you cant feel your body sliding left
or right when your
uncoordinated, you should probably relax some, because
you are way too
uptight. But then again one of my coaches said I was
too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and
my Nimbus 3
doesn't have one either, and I probably won't get it
'fixed' before the
Opens. I fly in the mountains and I don't feel that
it is hazardous.
Plus that sting is way too much drag.

I defy anyone to 'feel' the tiny amount of yaw that
a yaw string will indicate. The drag created by even
the largest piece of wool will be very small compared
to even a small amout of yaw in straight and level
flight. A 'T&S' ball is just not sensitive enough and
the yaw string has the advantage of being in your eye
line, you don't have to go heads down to see it. To
fly efficiently in a big winged glider is is even more
essential as even tiny amoutns of control differences
are magnified with the addition leverage of long wings.


To Don Johnstone - Yep!

The weather is doing something it hasn't done in quite a while - raining -
therefore, I'm spending the weekend indoors. This has led me to research a
few ideas that I had set aside. One of them is an angle of attack indicator
for gliders.

Any reading of accident reports will quickly lead one to the conclusion that
pilots don't pay enough attention to AOA. No matter how hard AOA is
hammered into a students brain, a few months after their checkride, they
just watch the ASI. Some of them are involved in stall/spin accidents.

AOA indicators have long been essential to the safe operation of large
aircraft so, now that electronics are cheap, why not gliders too? Gliders
spend a lot of time flying near the stall AOA so we shoud be especially
interested in an AOA indicator.

So, how do we measure AOA? The traditional nose boom pitch vane is too
fragile for gliders but there is another way to get AOA data. Companies
like Masi make a simple AOA probes. See:
http://www.cgmasi.com/aviation/index.html

The Masi probe computes AOA from the pressure difference between two
pressure ports at 45 degrees to the airflow. Could the same be done with
pressure ports located on upper and lower nose? I think so. An inexpensive
differential pressure sensor and a bit of electronics driving an LED
lightbar plus a calibration proceedure would do it.

The calilbration procedure would be simple since we are only interested in
three AOA's - Stall, Minimum sink, and Best L/D. These would be very
helpful when flying gliders with a wide range of wing loadings. The min
sink AOA would be particularly helpful when flying at steep bank angles.

Gliders with flaps would have to repeat the calibration procedure for each
flap setting of interest - those being approach flaps and thermalling flaps.
Flap setting would have to be sent to the AOA conputer.

Any gadgeteers out there interested in making a few bucks awhile maybe
saving a few lives?

Bill Daniels

On 7/9/06 11:27 AM, in article ,
"Bill Daniels" bildan@comcast-dot-net wrote:


"Don Johnstone" wrote in message
...
At 06:42 08 July 2006, G L I D E R S T U D wrote:

Yaw sting....if you cant feel your body sliding left
or right when your
uncoordinated, you should probably relax some, because
you are way too
uptight. But then again one of my coaches said I was
too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and
my Nimbus 3
doesn't have one either, and I probably won't get it
'fixed' before the
Opens. I fly in the mountains and I don't feel that
it is hazardous.
Plus that sting is way too much drag.

I defy anyone to 'feel' the tiny amount of yaw that
a yaw string will indicate. The drag created by even
the largest piece of wool will be very small compared
to even a small amout of yaw in straight and level
flight. A 'T&S' ball is just not sensitive enough and
the yaw string has the advantage of being in your eye
line, you don't have to go heads down to see it. To
fly efficiently in a big winged glider is is even more
essential as even tiny amoutns of control differences
are magnified with the addition leverage of long wings.


To Don Johnstone - Yep!

The weather is doing something it hasn't done in quite a while - raining -
therefore, I'm spending the weekend indoors. This has led me to research a
few ideas that I had set aside. One of them is an angle of attack indicator
for gliders.

Any reading of accident reports will quickly lead one to the conclusion that
pilots don't pay enough attention to AOA. No matter how hard AOA is
hammered into a students brain, a few months after their checkride, they
just watch the ASI. Some of them are involved in stall/spin accidents.

AOA indicators have long been essential to the safe operation of large
aircraft so, now that electronics are cheap, why not gliders too? Gliders
spend a lot of time flying near the stall AOA so we shoud be especially
interested in an AOA indicator.

So, how do we measure AOA? The traditional nose boom pitch vane is too
fragile for gliders but there is another way to get AOA data. Companies
like Masi make a simple AOA probes. See:
http://www.cgmasi.com/aviation/index.html

The Masi probe computes AOA from the pressure difference between two
pressure ports at 45 degrees to the airflow. Could the same be done with
pressure ports located on upper and lower nose? I think so. An inexpensive
differential pressure sensor and a bit of electronics driving an LED
lightbar plus a calibration proceedure would do it.

The calilbration procedure would be simple since we are only interested in
three AOA's - Stall, Minimum sink, and Best L/D. These would be very
helpful when flying gliders with a wide range of wing loadings. The min
sink AOA would be particularly helpful when flying at steep bank angles.

Gliders with flaps would have to repeat the calibration procedure for each
flap setting of interest - those being approach flaps and thermalling flaps.
Flap setting would have to be sent to the AOA conputer.

Any gadgeteers out there interested in making a few bucks awhile maybe
saving a few lives?

Bill Daniels


Bill,

Two or three pilots at Black Forest have very inexpensive AOA indicators
installed. They have yawstrings taped to the canopy way down the sides,
adjacent to their thighs, basically at the junction of the canopy and the
frame.

They then make marks with grease pencil at the crucial airspeeds, and report
being happy as clams with it.

Haven't tried it myself. YMMV.

Bullwinkle

"Bullwinkle" wrote in message
...
On 7/9/06 11:27 AM, in article
,
"Bill Daniels" bildan@comcast-dot-net wrote:


"Don Johnstone" wrote in message
...
At 06:42 08 July 2006, G L I D E R S T U D wrote:

Yaw sting....if you cant feel your body sliding left
or right when your
uncoordinated, you should probably relax some, because
you are way too
uptight. But then again one of my coaches said I was
too relaxed. On
that note my Discus 2ax didn't have a yaw sting, and
my Nimbus 3
doesn't have one either, and I probably won't get it
'fixed' before the
Opens. I fly in the mountains and I don't feel that
it is hazardous.
Plus that sting is way too much drag.

I defy anyone to 'feel' the tiny amount of yaw that
a yaw string will indicate. The drag created by even
the largest piece of wool will be very small compared
to even a small amout of yaw in straight and level
flight. A 'T&S' ball is just not sensitive enough and
the yaw string has the advantage of being in your eye
line, you don't have to go heads down to see it. To
fly efficiently in a big winged glider is is even more
essential as even tiny amoutns of control differences
are magnified with the addition leverage of long wings.


To Don Johnstone - Yep!

The weather is doing something it hasn't done in quite a while -
raining -
therefore, I'm spending the weekend indoors. This has led me to research
a
few ideas that I had set aside. One of them is an angle of attack
indicator
for gliders.

Any reading of accident reports will quickly lead one to the conclusion
that
pilots don't pay enough attention to AOA. No matter how hard AOA is
hammered into a students brain, a few months after their checkride, they
just watch the ASI. Some of them are involved in stall/spin accidents.

AOA indicators have long been essential to the safe operation of large
aircraft so, now that electronics are cheap, why not gliders too?
Gliders
spend a lot of time flying near the stall AOA so we shoud be especially
interested in an AOA indicator.

So, how do we measure AOA? The traditional nose boom pitch vane is too
fragile for gliders but there is another way to get AOA data. Companies
like Masi make a simple AOA probes. See:
http://www.cgmasi.com/aviation/index.html

The Masi probe computes AOA from the pressure difference between two
pressure ports at 45 degrees to the airflow. Could the same be done with
pressure ports located on upper and lower nose? I think so. An
inexpensive
differential pressure sensor and a bit of electronics driving an LED
lightbar plus a calibration proceedure would do it.

The calilbration procedure would be simple since we are only interested
in
three AOA's - Stall, Minimum sink, and Best L/D. These would be very
helpful when flying gliders with a wide range of wing loadings. The min
sink AOA would be particularly helpful when flying at steep bank angles.

Gliders with flaps would have to repeat the calibration procedure for
each
flap setting of interest - those being approach flaps and thermalling
flaps.
Flap setting would have to be sent to the AOA conputer.

Any gadgeteers out there interested in making a few bucks awhile maybe
saving a few lives?

Bill Daniels


Bill,

Two or three pilots at Black Forest have very inexpensive AOA indicators
installed. They have yawstrings taped to the canopy way down the sides,
adjacent to their thighs, basically at the junction of the canopy and the
frame.

They then make marks with grease pencil at the crucial airspeeds, and
report
being happy as clams with it.

Haven't tried it myself. YMMV.

Bullwinkle


I've done that going back several years. It works fine but those darn
strings keep getting caught under the canopy frame when you close it and
some gliders don't have canopies that allow proper placement of the strings.
Also, it only works at a zero slip angle. An electronic AOA system shouldn't
cost much but, of course, it'll cost more than strings.

bildan

Bill Daniels wrote:
I've done that going back several years. It works fine but those darn
strings keep getting caught under the canopy frame when you close it and
some gliders don't have canopies that allow proper placement of the strings.
Also, it only works at a zero slip angle. An electronic AOA system shouldn't
cost much but, of course, it'll cost more than strings.

I suspect that surface ports on the top and bottom of the nose will also
only work at zero slip/skid angle. My DG-600 was factory equipped with
an AoA meter, using two cross-connected sets of surface ports on the
fuselage just above the wing roots. One set is just aft of the leading
edge, another set is about 60% aft. The meter is a modified electronic
variometer. I've never had the meter in my panel, so I don't know how
well it works. One of these days, I'm going to connect a low pressure
differential transducer between the two sets of ports, and see if I can
get any usable data.

Marc

"Marc Ramsey" wrote in message
. com...

I suspect that surface ports on the top and bottom of the nose will also
only work at zero slip/skid angle. Marc

Why would that be?

If both top and bottom ports are on the center line they should be equally
influenced by slip/skid induced crossflow. You'd just be measuring the
pressure difference between the ports not the absolute pressure.

BTW, the guys at Black Forrest with pitch strings report they give advanced
warning of lift so zooms can start a few seconds sooner. An electronic AOA
indicator should do the same. Seems an AOA indicator is both a safety
device and a performance boon.

Bill Daniels