Simple string used as artificial horizon?

[Bruno[_2_]]

I had a very interesting conversation yesterday with a very
experienced pilot (older) who has spent a lot of time in some amazing
aircraft starting with the P51 Mustang and going up to jets including
the SR-71 blackbird and as we were looking over my glider we started
talking about the yaw string on the canopy.

He then mentioned that way back in the early days of flying they would
simply tape a string hanging from the ceiling to act as an artificial
horizon. I've never heard this one before! Next person who reads
this who goes up tape a string hanging from the inside of the canopy
and tell us how it works. Now you have another reason to take off
work and go soaring. ;)

Bruno -B4
http://www.youtube.com/user/bviv

[Andy[_1_]]

On Dec 29, 6:55*am, Bruno > wrote:
> I had a very interesting conversation yesterday with *a very
> experienced pilot (older) who has spent a lot of time in some amazing
> aircraft starting with the P51 Mustang and going up to jets including
> the SR-71 blackbird and as we were looking over my glider we started
> talking about the yaw string on the canopy.
>
> He then mentioned that way back in the early days of flying they would
> simply tape a string hanging from the ceiling to act as an artificial
> horizon. *I've never heard this one before! *Next person who reads
> this who goes up tape a string hanging from the inside of the canopy
> and tell us how it works. *Now you have another reason to take off
> work and go soaring. ;)
>
> Bruno -B4http://www.youtube.com/user/bviv


It's not April 1 already is it?

[T8]

On Dec 29, 9:24*am, Andy > wrote:
> On Dec 29, 6:55*am, Bruno > wrote:
>
> > I had a very interesting conversation yesterday with *a very
> > experienced pilot (older) who has spent a lot of time in some amazing
> > aircraft starting with the P51 Mustang and going up to jets including
> > the SR-71 blackbird and as we were looking over my glider we started
> > talking about the yaw string on the canopy.
>
> > He then mentioned that way back in the early days of flying they would
> > simply tape a string hanging from the ceiling to act as an artificial
> > horizon. *I've never heard this one before! *Next person who reads
> > this who goes up tape a string hanging from the inside of the canopy
> > and tell us how it works. *Now you have another reason to take off
> > work and go soaring. ;)
>
> > Bruno -B4http://www.youtube.com/user/bviv
>
> It's not April 1 already is it?

Just put a mark on your canopy and spit at it. If spit flies left of
target, you are turning right and vice versa.

-T8

[karen[_2_]]

T8 wrote:
> On Dec 29, 9:24*am, Andy > wrote:
> > On Dec 29, 6:55*am, Bruno > wrote:
> >
> > > I had a very interesting conversation yesterday with *a very
> > > experienced pilot (older) who has spent a lot of time in some amazing
> > > aircraft starting with the P51 Mustang and going up to jets including
> > > the SR-71 blackbird and as we were looking over my glider we started
> > > talking about the yaw string on the canopy.
> >
> > > He then mentioned that way back in the early days of flying they would
> > > simply tape a string hanging from the ceiling to act as an artificial
> > > horizon. *I've never heard this one before! *Next person who reads
> > > this who goes up tape a string hanging from the inside of the canopy
> > > and tell us how it works. *Now you have another reason to take off
> > > work and go soaring. ;)
> >
> > > Bruno -B4http://www.youtube.com/user/bviv
> >
> > It's not April 1 already is it?
>
> Just put a mark on your canopy and spit at it. If spit flies left of
> target, you are turning right and vice versa.
>
> -T8

Just slighly more accurate than spit, Bruce Miller taught me as a 13
year old at Black Forest to tie a string to the release knob (or
anywhere in your field of vision) with a light little weight on the
end)

Looks stupid and mainly created questions till one day I was stupid
enough to allow myself to be towed up through a hole in the stratus
layer by a dumber tow pilot.

You already guessed it. Released, climbed through 14K in wave @ 500
fpm. Hole in the layer quickly closed. Trapped VFR on top.

The tow pilot had flown far upwind in strong winds to get down. I
couldn't fly that far and stay out of the soup. The peak of 9,000 foot
Mount Stuart had now disappeared below and the and the airport down
there somewhere was reporting only 1,1000 foot cealings.

Within ten minutes, I did not know where I was. I think perhaps wo
things saved me.

Cindy Brickner's practice lesson a decade before returning from FL250.
Trim for a speed. Take your hands off the controls and let the
aircraft find a benign spiral down observing what the turbulence does
and how the glider always finds its left decending turn again.

The other reassuring thing was that stupid little string hanging there
told me what was straight up and down, when my senses said we were
banked and slipping or skidding. At higher speeds it was all over the
place. A breath above a stall, it was quite telling.

Happy ending that time. Broke through the bottom, way, way down wind
from where I had thought I was, a river to cross and lots of headwind
to barely make it back to the field without a pattern.

Went out the next day and bought a GPS. The string is still there. New
personal rule about cloud proximity.

Bruce and Cindy are two of my heros.

Michael

[Gary Boggs]

I am amazed that anyone with a pilots certificate would actually think
anything hanging in the cockpit would tell you anything about the
horizon!!!! Please tell me these aren't certified pilots!

Gary

[T8]

On Dec 29, 11:25*am, GARY BOGGS > wrote:
> I am amazed that anyone with a pilots certificate would actually think
> anything hanging in the cockpit would tell you anything about the
> horizon!!!! *Please tell me these aren't certified pilots!
>
> Gary

I'm with you there, Gary.

The spit bit, I may need to clarify, was intended as wry humor.

-T8

[mattm[_2_]]

On Dec 29, 11:45*am, T8 > wrote:
> On Dec 29, 11:25*am, GARY BOGGS > wrote:
>
> > I am amazed that anyone with a pilots certificate would actually think
> > anything hanging in the cockpit would tell you anything about the
> > horizon!!!! *Please tell me these aren't certified pilots!
>
> > Gary
>
> I'm with you there, Gary.
>
> The spit bit, I may need to clarify, was intended as wry humor.
>
> -T8

A number of years ago an article in The Atlantic magazine by William
Langewieche (son of
S&R author and current Vanity Fair chief editor) described an old
story that an airline pilot
had used a pocket watch as a turn indicator when his gyros failed. WL
tried it by flying out
over the open ocean, where the horizon disappears. He hung a pocket
watch from the ceiling
of the cockpit and used it as a pendulum. The pendulum DID work as a
crude turn indicator
but it tended to dampen out after a few swings. Nonetheless, if/when
ever stuck in the soup the
correct approach is the benign spiral. It does pay to try that
whenever you get checked out
in a new plane so you have confidence it will save your butt.

-- Matt

[Bob Whelan[_3_]]

(Someone) wrote:
> T8 wrote:
>> On Dec 29, 9:24 am, Andy > wrote:
>>> On Dec 29, 6:55 am, Bruno > wrote:
>>>
>>>> I had a very interesting conversation yesterday with a very
>>>> experienced pilot (older) who has spent a lot of time in some amazing
>>>> aircraft starting with the P51 Mustang and going up to jets including
>>>> the SR-71 blackbird and as we were looking over my glider we started
>>>> talking about the yaw string on the canopy.
>>>> He then mentioned that way back in the early days of flying they would
>>>> simply tape a string hanging from the ceiling to act as an artificial
>>>> horizon. I've never heard this one before! Next person who reads
>>>> this who goes up tape a string hanging from the inside of the canopy
>>>> and tell us how it works. Now you have another reason to take off
>>>> work and go soaring. ;)
>>>> Bruno -B4http://www.youtube.com/user/bviv
>>> It's not April 1 already is it?
>> Just put a mark on your canopy and spit at it. If spit flies left of
>> target, you are turning right and vice versa.
>>
>> -T8
>
> Just slighly more accurate than spit, Bruce Miller taught me as a 13
> year old at Black Forest to tie a string to the release knob (or
> anywhere in your field of vision) with a light little weight on the
> end)
>
> Looks stupid and mainly created questions till one day I was stupid
> enough to allow myself to be towed up through a hole in the stratus
> layer by a dumber tow pilot.
>
<Snip...>
>
> Went out the next day and bought a GPS. The string is still there. New
> personal rule about cloud proximity.
>
> Bruce and Cindy are two of my heros.
>
> Michael

Thanks for sharing that...but be prepared to be flayed by others in
hobnailed boots (rightly) pointing out a bob-weight in the cockpit
doesn't 'merely' react only to gravitational forces. IMVHO, the
'takeaway' point I suspect you're hoping others extract from your
sharing is that it was Cindy's and Bruce's *combined* tips that gave you
a fighting chance once above your sucker hole.

For those unfamiliar w. the general geography near Black Forest (in the
western/'pretty dry' U.S.), the 'real hills' (i.e. the wave-generating
ones) begin some miles west/upwind of the gliderport, so if a person can
descend while remaining below wing-pulling-off speeds to cloud base,
s/he's unlikely to die by hitting the ground beforehand. Youthful
ignorance aside, everybody raise their hands who'd rather have been
VFR-on-top in the above-mentioned conditions withOUT the two pieces of
information that worked in this instance...let's talk afterwards! :)

Bob - forces matter - W.

[Andy[_10_]]

On Dec 29, 8:02*am, karen > wrote:
>
> The other reassuring thing was that stupid little string hanging there
> told me what was straight up and down, when my senses said we were
> banked and slipping or skidding. At higher speeds it was all over the
> place. A breath above a stall, it was quite telling.

This is important as one's life potentially is a stake (unless you are
joking, in which case it's a dangerous joke to post).

Anything hanging in the cockpit like a pendulum (or any instruments
working on the same principle) DOES NOT tell you which way is up. At
best it tells you something about whether you are coordinated. All
aircraft fly in an accelerated reference frame - that is, the apparent
gravity vector is the sum of the earth's gravity vector and all the
other accelerations the glider is experiencing. The pendulum will
confirm all the incorrect senses you body is telling you - very
dangerous. To demonstrate this for yourself try a couple of
experiments:

- Hang a pendulum in the cockpit and do a straight-ahead negative-G
pushover. The pendulum will point straight up, apparently telling you
you are inverted when you are not.

- Look at the pendulum when you are in a 45-degree coordinated turn -
it will be pointing 45-degrees off vertical, right through the belly
of the glider, not straight down to the ground.

In the case you describe the real danger is getting into an
accelerated spiral dive where the speed and Gs build up until
something breaks. Through that entire process your little string will
point happily straight through the belly of the glider until the wings
come off. That's why the hands-free benign spiral is preferred - the
natural stability of the aircraft will keep you out of trouble far
better than your internal senses of up and down.

Stay safe out there.

9B

[Bruno[_2_]]

It is snowing here in Utah, soaring weather is a ways off and I was
thinking about an episode of Mythbusters: "airplane on a treadmill"
that created lots of interesting conversation over the internet. It
was amazing how many pilots got it wrong.

Obviously in a turn the centrifugal forces should pull a string to the
point that it would not be usable to help keeping things upright.
Just trying to start a fun discussion but now I am realizing that if
someone doesn't read far enough down the threads that they might not
see it doesn't work and might actually rely on it. Don't worry Gary.
Didn't think it would work. :)

Bruno


On Dec 29, 10:56*am, Andy > wrote:
> On Dec 29, 8:02*am, karen > wrote:
>
>
>
> > The other reassuring thing was that stupid little string hanging there
> > told me what was straight up and down, when my senses said we were
> > banked and slipping or skidding. At higher speeds it was all over the
> > place. A breath above a stall, it was quite telling.
>
> This is important as one's life potentially is a stake (unless you are
> joking, in which case it's a dangerous joke to post).
>
> Anything hanging in the cockpit like a pendulum (or any instruments
> working on the same principle) DOES NOT tell you which way is up. *At
> best it tells you something about whether you are coordinated. *All
> aircraft fly in an accelerated reference frame - that is, the apparent
> gravity vector is the sum of the earth's gravity vector and all the
> other accelerations the glider is experiencing. The pendulum will
> confirm all the incorrect senses you body is telling you - very
> dangerous. To demonstrate this for yourself try a couple of
> experiments:
>
> - Hang a pendulum in the cockpit and do a straight-ahead negative-G
> pushover. *The pendulum will point straight up, apparently telling you
> you are inverted when you are not.
>
> - Look at the pendulum when you are in a 45-degree coordinated turn -
> it will be pointing 45-degrees off vertical, right through the belly
> of the glider, not straight down to the ground.
>
> In the case you describe the real danger is getting into an
> accelerated spiral dive where the speed and Gs build up until
> something breaks. Through that entire process your little string will
> point happily straight through the belly of the glider until the wings
> come off. That's why the hands-free benign spiral is preferred - the
> natural stability of the aircraft will keep you out of trouble far
> better than your internal senses of up and down.
>
> Stay safe out there.
>
> 9B

[cfinn]

I think it's obvious that most pilots agree that none of these methods
work. As a military Standardization Instructor Pilot, I would
demonstrate a method that would keep your wings level and control your
descent with a complete gyro and altimeter failure. It would work in
many gliders. If your glider is equipped with a standard magnetic
compass, you can use it to maintain level flight. Powered pilots are
aware of the turning and acceleration errors of the compass. Glider
only pilots may not be as aware of the compass' actions.

Without going into all the technical reasons, when you are heading
North or South and bank the aircraft, the compass will indiate a rapid
turn. If you are heading North, a bank will initially indicate a turn
in the opposite direction or "lag" the turn. For example, Heading due
north and banking to the left to start a turn to the west, the compass
would initailly swing toward the east. If you are heading South, a
bank will initially indicate a rapid turn in the same direction or
"lead" the turn.

To keep the wings level, turn to 180 and keep the heading at 180. If
you bank slightly to the right, the compass will show a rapid turn to
the right, even before the aircraft starts a turn. If you bank
slightly to the left, the compass will show a rapid turn to the left,
again before the aircraft starts a turn. Although this method would
also work heading 360, you would need to always be correcting opposite
of the direction the compass indicated. For that reason, I suggest
using 180.

If your glider happens to be equipped with a free air temp gauge, you
can use it for rough altitude calculations. The standard lapse rate is
2 degrees centigrade or 3 1/2 degress farenheit. If you note your
altitude and free air temp when you have the system failure, you have
a reference. While descending if you note a temperature increase of 2
C, you have roughly descended 1,000 feet. If the temperature decreased
2C, you would have roughly climbed 1,000 feet.

FYI - I'm installing a Dynon D10 EFIS (Electronic Flight Information
System) and transponder in my glider and intend to do some glider IFR
flying. If you're not familiar with an EFIS, it basically is a glass
cockpit that combines gyro, flight, and nav instruments. I've talked
with Atlanta approach control and center and have worked out using
block altitude clearances. I'm ready for the season to start. Is
spring here yet?


Charlie

[bildan]

On Dec 29, 10:37*am, mattm > wrote:
> On Dec 29, 11:45*am, T8 > wrote:
>
> > On Dec 29, 11:25*am, GARY BOGGS > wrote:
>
> > > I am amazed that anyone with a pilots certificate would actually think
> > > anything hanging in the cockpit would tell you anything about the
> > > horizon!!!! *Please tell me these aren't certified pilots!
>
> > > Gary
>
> > I'm with you there, Gary.
>
> > The spit bit, I may need to clarify, was intended as wry humor.
>
> > -T8
>
> A number of years ago an article in The Atlantic magazine by William
> Langewieche (son of
> S&R author and current Vanity Fair chief editor) described an old
> story that an airline pilot
> had used a pocket watch as a turn indicator when his gyros failed. *WL
> tried it by flying out
> over the open ocean, where the horizon disappears. *He hung a pocket
> watch from the ceiling
> of the cockpit and used it as a pendulum. *The pendulum DID work as a
> crude turn indicator
> but it tended to dampen out after a few swings. *Nonetheless, if/when
> ever stuck in the soup the
> correct approach is the benign spiral. *It does pay to try that
> whenever you get checked out
> in a new plane so you have confidence it will save your butt.
>
> -- Matt

Nothing is quite as terrifying as pilots with zero "hood time"
discussing how to fly in clouds.

A weight on a string simply works as a poor ball bank by indicating
slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
or pitch. A ball or yaw string are far better instruments. A ball
will work even when a wet yaw string is stuck to the canopy.

If you think trying with this looks like fun, PLEASE find an old
school instrument instructor (CFII) and an old airplane with a "turn
and bank". Ask for some "partial panel" (Needle-Ball-Airspeed)
instruction. (Airplanes newer than ~1965 will have the cursed 'turn
coordinator' which indicates nothing but turbulence by wiggling.)

The killer is panic. Virtually every first timer will panic when his
gut sense and the instruments say different things - and they WILL be
different. The most basic instrument flying skill is to suppress what
you feel and concentrate on what the instruments are saying. That can
be VERY difficult.

[mattm[_2_]]

On Dec 29, 1:24*pm, bildan > wrote:
> On Dec 29, 10:37*am, mattm > wrote:
>
>
>
> > On Dec 29, 11:45*am, T8 > wrote:
>
> > > On Dec 29, 11:25*am, GARY BOGGS > wrote:
>
> > > > I am amazed that anyone with a pilots certificate would actually think
> > > > anything hanging in the cockpit would tell you anything about the
> > > > horizon!!!! *Please tell me these aren't certified pilots!
>
> > > > Gary
>
> > > I'm with you there, Gary.
>
> > > The spit bit, I may need to clarify, was intended as wry humor.
>
> > > -T8
>
> > A number of years ago an article in The Atlantic magazine by William
> > Langewieche (son of
> > S&R author and current Vanity Fair chief editor) described an old
> > story that an airline pilot
> > had used a pocket watch as a turn indicator when his gyros failed. *WL
> > tried it by flying out
> > over the open ocean, where the horizon disappears. *He hung a pocket
> > watch from the ceiling
> > of the cockpit and used it as a pendulum. *The pendulum DID work as a
> > crude turn indicator
> > but it tended to dampen out after a few swings. *Nonetheless, if/when
> > ever stuck in the soup the
> > correct approach is the benign spiral. *It does pay to try that
> > whenever you get checked out
> > in a new plane so you have confidence it will save your butt.
>
> > -- Matt
>
> Nothing is quite as terrifying as pilots with zero "hood time"
> discussing how to fly in clouds.
>
> A weight on a string simply works as a poor ball bank by indicating
> slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
> or pitch. *A ball or yaw string are far better instruments. *A ball
> will work even when a wet yaw string is stuck to the canopy.
>
> If you think trying with this looks like fun, PLEASE find an old
> school instrument instructor (CFII) and an old airplane with a "turn
> and bank". *Ask for some "partial panel" (Needle-Ball-Airspeed)
> instruction. *(Airplanes newer than ~1965 will have the cursed 'turn
> coordinator' which indicates nothing but turbulence by wiggling.)
>
> The killer is panic. *Virtually every first timer will panic when his
> gut sense and the instruments say different things - and they WILL be
> different. *The most basic instrument flying skill is to suppress what
> you feel and concentrate on what the instruments are saying. *That can
> be VERY difficult.

Actually I do have some instrument time, including partial panel. The
point
of the article is that the *swinging* pendulum will maintain its
orientation
in space, so you can use it as a very crude turn indicator. As a
matter of
fact, the turning of the earth is readily demonstrated by a large
pendulum
that will continue to swing for hours. The direction of the swing
will precess
as the earth turns under it. I was Not saying that a plumb line would
indicate
a turn -- I know perfectly well it will only show your coordination.

-- Matt

[Andy[_10_]]

On Dec 29, 10:44*am, mattm > wrote:
> On Dec 29, 1:24*pm, bildan > wrote:
>
>
>
>
>
> > On Dec 29, 10:37*am, mattm > wrote:
>
> > > On Dec 29, 11:45*am, T8 > wrote:
>
> > > > On Dec 29, 11:25*am, GARY BOGGS > wrote:
>
> > > > > I am amazed that anyone with a pilots certificate would actually think
> > > > > anything hanging in the cockpit would tell you anything about the
> > > > > horizon!!!! *Please tell me these aren't certified pilots!
>
> > > > > Gary
>
> > > > I'm with you there, Gary.
>
> > > > The spit bit, I may need to clarify, was intended as wry humor.
>
> > > > -T8
>
> > > A number of years ago an article in The Atlantic magazine by William
> > > Langewieche (son of
> > > S&R author and current Vanity Fair chief editor) described an old
> > > story that an airline pilot
> > > had used a pocket watch as a turn indicator when his gyros failed. *WL
> > > tried it by flying out
> > > over the open ocean, where the horizon disappears. *He hung a pocket
> > > watch from the ceiling
> > > of the cockpit and used it as a pendulum. *The pendulum DID work as a
> > > crude turn indicator
> > > but it tended to dampen out after a few swings. *Nonetheless, if/when
> > > ever stuck in the soup the
> > > correct approach is the benign spiral. *It does pay to try that
> > > whenever you get checked out
> > > in a new plane so you have confidence it will save your butt.
>
> > > -- Matt
>
> > Nothing is quite as terrifying as pilots with zero "hood time"
> > discussing how to fly in clouds.
>
> > A weight on a string simply works as a poor ball bank by indicating
> > slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
> > or pitch. *A ball or yaw string are far better instruments. *A ball
> > will work even when a wet yaw string is stuck to the canopy.
>
> > If you think trying with this looks like fun, PLEASE find an old
> > school instrument instructor (CFII) and an old airplane with a "turn
> > and bank". *Ask for some "partial panel" (Needle-Ball-Airspeed)
> > instruction. *(Airplanes newer than ~1965 will have the cursed 'turn
> > coordinator' which indicates nothing but turbulence by wiggling.)
>
> > The killer is panic. *Virtually every first timer will panic when his
> > gut sense and the instruments say different things - and they WILL be
> > different. *The most basic instrument flying skill is to suppress what
> > you feel and concentrate on what the instruments are saying. *That can
> > be VERY difficult.
>
> Actually I do have some instrument time, including partial panel. *The
> point
> of the article is that the *swinging* pendulum will maintain its
> orientation
> in space, so you can use it as a very crude turn indicator. *As a
> matter of
> fact, the turning of the earth is readily demonstrated by a large
> pendulum
> that will continue to swing for hours. *The direction of the swing
> will precess
> as the earth turns under it. *I was Not saying that a plumb line would
> indicate
> a turn -- I know perfectly well it will only show your coordination.
>
> -- Matt

Fair enough - as already mentioned you can also use the compass or
your GPS as a crude turn indicator - they just are severely limited as
devices to keep you straight and level for very long due to lags in
response or general imprecision. In turbulence (like a wave decent) I
expect you'd be best advised to try the heading technique only up to a
certain point then let go of the stick before you hurt yourself. I
expect a swinging pendulum would be totally useless in rough air.

I'm trying to imagine carrying a bob-weight, string and some tape as
part of my wave emergency kit.

9B

[Bruno[_2_]]

On Dec 29, 12:22*pm, Andy > wrote:
> On Dec 29, 10:44*am, mattm > wrote:
>
>
>
> > On Dec 29, 1:24*pm, bildan > wrote:
>
> > > On Dec 29, 10:37*am, mattm > wrote:
>
> > > > On Dec 29, 11:45*am, T8 > wrote:
>
> > > > > On Dec 29, 11:25*am, GARY BOGGS > wrote:
>
> > > > > > I am amazed that anyone with a pilots certificate would actually think
> > > > > > anything hanging in the cockpit would tell you anything about the
> > > > > > horizon!!!! *Please tell me these aren't certified pilots!
>
> > > > > > Gary
>
> > > > > I'm with you there, Gary.
>
> > > > > The spit bit, I may need to clarify, was intended as wry humor.
>
> > > > > -T8
>
> > > > A number of years ago an article in The Atlantic magazine by William
> > > > Langewieche (son of
> > > > S&R author and current Vanity Fair chief editor) described an old
> > > > story that an airline pilot
> > > > had used a pocket watch as a turn indicator when his gyros failed. *WL
> > > > tried it by flying out
> > > > over the open ocean, where the horizon disappears. *He hung a pocket
> > > > watch from the ceiling
> > > > of the cockpit and used it as a pendulum. *The pendulum DID work as a
> > > > crude turn indicator
> > > > but it tended to dampen out after a few swings. *Nonetheless, if/when
> > > > ever stuck in the soup the
> > > > correct approach is the benign spiral. *It does pay to try that
> > > > whenever you get checked out
> > > > in a new plane so you have confidence it will save your butt.
>
> > > > -- Matt
>
> > > Nothing is quite as terrifying as pilots with zero "hood time"
> > > discussing how to fly in clouds.
>
> > > A weight on a string simply works as a poor ball bank by indicating
> > > slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
> > > or pitch. *A ball or yaw string are far better instruments. *A ball
> > > will work even when a wet yaw string is stuck to the canopy.
>
> > > If you think trying with this looks like fun, PLEASE find an old
> > > school instrument instructor (CFII) and an old airplane with a "turn
> > > and bank". *Ask for some "partial panel" (Needle-Ball-Airspeed)
> > > instruction. *(Airplanes newer than ~1965 will have the cursed 'turn
> > > coordinator' which indicates nothing but turbulence by wiggling.)
>
> > > The killer is panic. *Virtually every first timer will panic when his
> > > gut sense and the instruments say different things - and they WILL be
> > > different. *The most basic instrument flying skill is to suppress what
> > > you feel and concentrate on what the instruments are saying. *That can
> > > be VERY difficult.
>
> > Actually I do have some instrument time, including partial panel. *The
> > point
> > of the article is that the *swinging* pendulum will maintain its
> > orientation
> > in space, so you can use it as a very crude turn indicator. *As a
> > matter of
> > fact, the turning of the earth is readily demonstrated by a large
> > pendulum
> > that will continue to swing for hours. *The direction of the swing
> > will precess
> > as the earth turns under it. *I was Not saying that a plumb line would
> > indicate
> > a turn -- I know perfectly well it will only show your coordination.
>
> > -- Matt
>
> Fair enough - as already mentioned you can also use the compass or
> your GPS as a crude turn indicator - they just are severely limited as
> devices to keep you straight and level for very long due to lags in
> response or general imprecision. In turbulence (like a wave decent) I
> expect you'd be best advised to try the heading technique only up to a
> certain point then let go of the stick before you hurt yourself. I
> expect a swinging pendulum would be totally useless in rough air.
>
> I'm trying to imagine carrying a bob-weight, string and some tape as
> part of my wave emergency kit.
>
> 9B

The thread started with only a taped string. No bob weight
required. ;)

Bruno

[Richard[_9_]]

On Dec 29, 5:55*am, Bruno > wrote:
> I had a very interesting conversation yesterday with *a very
> experienced pilot (older) who has spent a lot of time in some amazing
> aircraft starting with the P51 Mustang and going up to jets including
> the SR-71 blackbird and as we were looking over my glider we started
> talking about the yaw string on the canopy.
>
> He then mentioned that way back in the early days of flying they would
> simply tape a string hanging from the ceiling to act as an artificial
> horizon. *I've never heard this one before! *Next person who reads
> this who goes up tape a string hanging from the inside of the canopy
> and tell us how it works. *Now you have another reason to take off
> work and go soaring. ;)
>
> Bruno -B4http://www.youtube.com/user/bviv

Bruno,


I personally use the cat. Just throw it in the air every now and
then. A cat always lands on his feet and the purring can calm your
nerves.


Richard
www.craggyaero.com

[cfinn]

> I personally use the cat. *Just throw it in the air every now and
> then. *A cat always lands on his feet and the purring can calm your
> nerves.
>
> Richardwww.craggyaero.com

I hope he's de-clawed! Are you coming to the convention?

Charlie

[Richard[_9_]]

On Dec 29, 12:31*pm, cfinn > wrote:
> > I personally use the cat. *Just throw it in the air every now and
> > then. *A cat always lands on his feet and the purring can calm your
> > nerves.
>
> > Richardwww.craggyaero.com
>
> I hope he's de-clawed! Are you coming to the convention?
>
> Charlie

Charlie,

The claws keep you on top of your game.
I will be at the convention Booth 18 & 19

Richard
www.craggyaero.com

[bildan]

> Actually I do have some instrument time, including partial panel. *The
> point
> of the article is that the *swinging* pendulum will maintain its
> orientation
> in space, so you can use it as a very crude turn indicator. *

Yes, that's how Coriolis vibratory gyros work. However, they're a LOT
more sophisticated than a string and weight.

[Bruno[_2_]]

On Dec 29, 1:38*pm, Richard > wrote:
> On Dec 29, 12:31*pm, cfinn > wrote:
>
> > > I personally use the cat. *Just throw it in the air every now and
> > > then. *A cat always lands on his feet and the purring can calm your
> > > nerves.
>
> > > Richardwww.craggyaero.com
>
> > I hope he's de-clawed! Are you coming to the convention?
>
> > Charlie
>
> Charlie,
>
> The claws keep you on top of your game.
> I will be at the convention Booth 18 & 19
>
> Richardwww.craggyaero.com

I am very excited to try the cat idea. I was thinking of actually
using some toilet paper hanging from the ceiling to start but decided
toilet paper is only good for detecting the center of thermals. ;)
See you at the convention Richard. Maybe we can hit dinner together
one of the nights.

Bruno - B4

[Brian Whatcott]

T8 wrote:
>
>>> He then mentioned that way back in the early days of flying they would
>>> simply tape a string hanging from the ceiling to act as an artificial
>>> horizon.

>> It's not April 1 already is it?
>
> Just put a mark on your canopy and spit at it. If spit flies left of
> target, you are turning right and vice versa.
>
> -T8

NOW you're talking.
There was a D-I_Y autopilot design which used a blower tube streaming
air onto four thermistors arranged pairwise-differentially. This gave
pitch rate and yaw rate, or if mounted skew, inputs on all three axes.
These days, a three axis acceleraometer goes for $25 and rate sensors
for a little more... One well known Arduino project ["ArduPilot"]
offers the guts of an autopilot suitable for driving R/C servoes, which
will easily fit in a medium size model plane. I expect this could easliy
fit in a homebuilt...

Brian W

[Brian Whatcott]

karen wrote:
/snip/
> The other reassuring thing was that stupid little string hanging there
> told me what was straight up and down, when my senses said we were
> banked and slipping or skidding./snip/
> Michael

....but now you realise that it would have stayed straight up and down
even in a steep balanced turn, of course....

Brian W

[BT]

Ever watch Bob Hoover video of him pouring a glass of ice tea.. or was it
lemonade.. with one hand while rolling his AeroCommander with his other
hand. He had a ball on a string below the board that held his glass. The
board was mounted to his glare shield. He kept the ball centered below the
glass through the entire roll 1G roll. You can see the real horizon through
the front windshield as he rolled.

Strings in cockpits are only slip skid indicators, as someone else also
posted.

BT

"bildan" > wrote in message
...
On Dec 29, 10:37 am, mattm > wrote:
> On Dec 29, 11:45 am, T8 > wrote:
>
> > On Dec 29, 11:25 am, GARY BOGGS > wrote:
>
> > > I am amazed that anyone with a pilots certificate would actually think
> > > anything hanging in the cockpit would tell you anything about the
> > > horizon!!!! Please tell me these aren't certified pilots!
>
> > > Gary
>
> > I'm with you there, Gary.
>
> > The spit bit, I may need to clarify, was intended as wry humor.
>
> > -T8
>
> A number of years ago an article in The Atlantic magazine by William
> Langewieche (son of
> S&R author and current Vanity Fair chief editor) described an old
> story that an airline pilot
> had used a pocket watch as a turn indicator when his gyros failed. WL
> tried it by flying out
> over the open ocean, where the horizon disappears. He hung a pocket
> watch from the ceiling
> of the cockpit and used it as a pendulum. The pendulum DID work as a
> crude turn indicator
> but it tended to dampen out after a few swings. Nonetheless, if/when
> ever stuck in the soup the
> correct approach is the benign spiral. It does pay to try that
> whenever you get checked out
> in a new plane so you have confidence it will save your butt.
>
> -- Matt

Nothing is quite as terrifying as pilots with zero "hood time"
discussing how to fly in clouds.

A weight on a string simply works as a poor ball bank by indicating
slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
or pitch. A ball or yaw string are far better instruments. A ball
will work even when a wet yaw string is stuck to the canopy.

If you think trying with this looks like fun, PLEASE find an old
school instrument instructor (CFII) and an old airplane with a "turn
and bank". Ask for some "partial panel" (Needle-Ball-Airspeed)
instruction. (Airplanes newer than ~1965 will have the cursed 'turn
coordinator' which indicates nothing but turbulence by wiggling.)

The killer is panic. Virtually every first timer will panic when his
gut sense and the instruments say different things - and they WILL be
different. The most basic instrument flying skill is to suppress what
you feel and concentrate on what the instruments are saying. That can
be VERY difficult.

[Brian Whatcott]

Andy wrote:

> Anything hanging in the cockpit like a pendulum (or any instruments
> working on the same principle) DOES NOT tell you which way is up./snip/

> 9B

If you are going to take on the school master role, you had better be
right. Current solid state angular rate sensors act like a mini pendulum
or tuning fork - when turned, the pendulum retains spatial inertia.
Foucault, an' all that. Remember?

Brian W

[Brian Whatcott]

bildan wrote:

>> A number of years ago an article in The Atlantic magazine by William
>> Langewieche (son of
>> S&R author and current Vanity Fair chief editor) described an old
>> story that an airline pilot
>> had used a pocket watch as a turn indicator when his gyros failed. WL
>> tried it by flying out
>> over the open ocean, where the horizon disappears. He hung a pocket
>> watch from the ceiling
>> of the cockpit and used it as a pendulum. /snip/
>> -- Matt
>
> Nothing is quite as terrifying as pilots with zero "hood time"
> discussing how to fly in clouds.
>
> A weight on a string simply works as a poor ball bank by indicating
> slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
> or pitch.

Ho hum: there is ONE thing more terrifying than pilots with zero hood
time giving advice - and that's pilots with or without hood time who
don't think twice before speaking once.

A pendulum is NOT a plumb bob.

Brian W

[Capt. Geoffrey Thorpe]

"Bruno" > wrote in message
...
>I had a very interesting conversation yesterday with a very
> experienced pilot (older) who has spent a lot of time in some amazing
> aircraft starting with the P51 Mustang and going up to jets including
> the SR-71 blackbird and as we were looking over my glider we started
> talking about the yaw string on the canopy.
>
> He then mentioned that way back in the early days of flying they would
> simply tape a string hanging from the ceiling to act as an artificial
> horizon. I've never heard this one before! Next person who reads
> this who goes up tape a string hanging from the inside of the canopy
> and tell us how it works. Now you have another reason to take off
> work and go soaring. ;)
>
> Bruno -B4
> http://www.youtube.com/user/bviv

Watch the white ball on the end of the string in this video starting at
about 2:00 (but do yourself a favor and watch the whole thing):

http://www.alexisparkinn.com/photogallery/Videos/2006-3-11_bob_hoover.avi

Question answered?

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[bildan]

On Dec 29, 5:19*pm, brian whatcott > wrote:
> T8 wrote:
>
> >>> He then mentioned that way back in the early days of flying they would
> >>> simply tape a string hanging from the ceiling to act as an artificial
> >>> horizon.
> >> It's not April 1 already is it?
>
> > Just put a mark on your canopy and spit at it. *If spit flies left of
> > target, you are turning right and vice versa.
>
> > -T8
>
> NOW you're talking.
> There was a D-I_Y autopilot design which used a blower tube streaming
> air onto four thermistors arranged pairwise-differentially. This gave
> pitch rate and yaw rate, or if mounted skew, inputs on all three axes.
> These days, a three axis acceleraometer goes for $25 and rate sensors
> for a little more... * One well known Arduino project ["ArduPilot"]
> offers the guts of an autopilot suitable for driving R/C servoes, which
> will easily fit in a medium size model plane. I expect this could easliy
> fit in a homebuilt...
>
> Brian W

One thing I think would work is pitot tubes on each wing tip connected
to a Winter type variometer with the vario rotated so the needle
pointed up. Air would flow from the faster wing tip to the slower one
through the vario which would show rate of turn. It's the only "non-
gyro" rate of turn instrument I can think of.

[Matt Herron Jr.]

On Dec 29, 4:34*pm, brian whatcott > wrote:
> bildan wrote:
> >> A number of years ago an article in The Atlantic magazine by William
> >> Langewieche (son of
> >> S&R author and current Vanity Fair chief editor) described an old
> >> story that an airline pilot
> >> had used a pocket watch as a turn indicator when his gyros failed. *WL
> >> tried it by flying out
> >> over the open ocean, where the horizon disappears. *He hung a pocket
> >> watch from the ceiling
> >> of the cockpit and used it as a pendulum. /snip/
> >> -- Matt
>
> > Nothing is quite as terrifying as pilots with zero "hood time"
> > discussing how to fly in clouds.
>
> > A weight on a string simply works as a poor ball bank by indicating
> > slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
> > or pitch.
>
> Ho hum: there is ONE thing more terrifying than pilots with zero hood
> time giving advice - and that's pilots with or without hood time who
> don't think twice before speaking once.
>
> A pendulum is NOT a plumb bob.
>
> Brian W

Such an energetic conversation! And the list had ben such a quiet
place... In this case I think you are both right. Yes a pendulum is
not a plumb bob. But it will also not tell you which was is up- which
is what Andy stated. I might be a viable rate and direction of turn
indicator in a pinch. I would imagine if you tried to start swinging
it once you had entered a turn, it would only go in circles or
ellipses, but...

I rather like the idea! I can imagine a little square of velcro on
the inside of the canopy where the yaw string is taped down, so it
didn't cut out visibility during normal flight. Then maybe a short (8
inch?) piano wire with a fishing weight at one end and a loop at the
other that goes through one of those cable tie pads with mating
velcro. All stashed in the side pocket.

Now the cloud layer closes below me and I must make an emergency
decent through an IFR layer. I velcro my pendulum to the canopy, head
into the wind, start it swinging fore and aft, and pull the spoilers.
Nothing to it.

Please someone try this right away (without the clouds!) and report
back to the list. I want one.

Matt

[Morgans[_2_]]

"GARY BOGGS" > wrote in message
...
>
> I am amazed that anyone with a pilots certificate would actually think
> anything hanging in the cockpit would tell you anything about the
> horizon!!!! Please tell me these aren't certified pilots!

Amen. It is completely possible to have the string pointed at the floor in
a 90 degree bank, or even upside-down.
--
Jim in NC

[cfinn]

OK guys, why not just install a relatively inexpensive turn and bank?
We flew actual instruments with them for years. They spin up fairly
fast and don't need to be on all the time. If you want to keep it
seperate from the main electrical system, you could install a small 2
AH battery that would power it for a long time.

[Jim Logajan]

"Morgans" > wrote:
> "GARY BOGGS" > wrote in message
> .
> ..
>>
>> I am amazed that anyone with a pilots certificate would actually
>> think anything hanging in the cockpit would tell you anything about
>> the horizon!!!! Please tell me these aren't certified pilots!
>
> Amen. It is completely possible to have the string pointed at the
> floor in a 90 degree bank, or even upside-down.

I believe it is impossible for a force vector of weight (always at 0
degrees; indicating down) added to a centrifugal force (at 90 degrees in
your example) to yield a resultant that is also at 90 degrees. Unless maybe
you're pulling infinite gees in those turns!

Since there is a structural limit to how much one can bank a plane or
glider and keep the resultant force vector directly through the floor,
there is a moderately large range of bank angles around 90 degrees where
you shouldn't be able to get the string pointed through the floor.

If you hadn't chosen a 90 degree bank as one of your examples I wouldn't
have been able to contest your post. Your statement appears to be true for
all other bank angles. :-)

[Eric Greenwell]

Bob Whelan wrote:
> Youthful ignorance aside, everybody raise their hands who'd rather
> have been VFR-on-top in the above-mentioned conditions withOUT the two
> pieces of information that worked in this instance...let's talk
> afterwards! :)
>
> Bob - forces matter - W.
Can I do without that information as long as I promise to power up the
T&B when I'm VFR on top?

Regardless of what technique or device you want to use in that
situation, please practice with it at least a few times a year.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

[Jim Logajan]

Jim Logajan > wrote:
> "Morgans" > wrote:
>> Amen. It is completely possible to have the string pointed at the
>> floor in a 90 degree bank, or even upside-down.
>
> I believe it is impossible for a force vector of weight (always at 0
> degrees; indicating down) added to a centrifugal force (at 90 degrees
> in your example) to yield a resultant that is also at 90 degrees.
> Unless maybe you're pulling infinite gees in those turns!

Correcting myself - I was assuming that level flight was being maintained
or attempted during the turn. Take away that assumption and it is no
problem having the string point through the floor in a 90 degree bank.

So never mind!

[Darryl Ramm]

On Dec 29, 4:28*pm, brian whatcott > wrote:
> Andy wrote:
> > Anything hanging in the cockpit like a pendulum (or any instruments
> > working on the same principle) DOES NOT tell you which way is up./snip/
> > 9B
>
> If you are going to take on the school master role, you had better be
> right. Current solid state angular rate sensors act like a mini pendulum
> or tuning fork - when *turned, the pendulum retains spatial inertia.
> Foucault, an' all that. Remember?
>
> Brian W

That has zero practical relevance. I'll leave the school master stuff
to Andy (and here I was thinking he's a management consultant with a
masters in aeronautical engineering), anyhow I managed to waste part
of my life working on precision sensors for general relativity physics
experiments. MEMS rate based devices like tuning fork designs etc.
vibrate many orders of magnitude above the signal frequency. Hanging a
weight on an about a foot long string will give a resonant period of
about one second. For movement of the aircraft that happen of order
~seconds the mass on a string is essentially a plumb-bob and the
"pendulum" will be perturbed. Again a focualt pendulum is oscillating
in it's inertial frame with a resonant frequency orders of magnitude
above above any signal frequency (the earth's rotation).

---

The pendulum in the cockpit is one of the most goofball things I've
heard in a while. On the other hand the cat idea has promise. The cat
also has the benefit of being an amusing companion in the event of a
landout, or a nutritious food source in the event of a more serious
survival situation. But unfortunately until I I can overcome my cat
allergy it's a plain old (non-edible) T&B backup for me.

---

As others have pointed out, the important thing is to go try this and
practice, with an instructor if needed. The advice from some others
about the benign spiral, always needs a caveat - whether your ship
will benign spiral or not is glider design and possibly W&B dependent.
My ASH-26E at my normal W&B will not benign spiral. So I carry a
pictorial T&B for backup just in case, and I've spent enough time
under a hood to remind me I really don't want to go there.

Darryl

[jimboffin]

On 30 Dec, 05:59, Darryl Ramm > wrote:

> As others have pointed out, the important thing is to go try this and
> practice, with an instructor if needed. The advice from some others
> about the benign spiral, always needs a caveat - whether your ship
> will benign spiral or not is glider design and possibly W&B dependent.
> My ASH-26E at my normal W&B will not benign spiral. So I carry a
> pictorial T&B for backup just in case, and I've spent enough time
> under a hood to remind me I really don't want to go there.
>
> Darryl

At last...my Discus would do a benign spiral without going VNE with
wheel down, brakes out, and hands off. My ASW27 won't and will fall to
bits. I suggest everyone try hanging everything out and taking hands
off to see what happens. If speed goes through rough air, pull out.
You will then know whether you can safely use this technique or not.

I have practised using string for slip, ears for speed, and gps for
turn. I reckon that I could descend without my horizon through cloud
most times without spinning or over speeding. Failing that I guess it
is, pull the wings off then pull the chute!

Jim

[Brian Whatcott]

bildan wrote:

>
> One thing I think would work is pitot tubes on each wing tip connected
> to a Winter type variometer with the vario rotated so the needle
> pointed up. Air would flow from the faster wing tip to the slower one
> through the vario which would show rate of turn. It's the only "non-
> gyro" rate of turn instrument I can think of.

Yes, I see that. Reminds me that some folk have played with a GPS on
each wingtip and some decode software - not very fast on its feet
though, I don't think - even at 5 frames a second...

Brian W

[Brian Whatcott]

Jim Logajan wrote:

> I believe it is impossible for a force vector of weight (always at 0
> degrees; indicating down) added to a centrifugal force (at 90 degrees in
> your example) to yield a resultant that is also at 90 degrees. Unless maybe
> you're pulling infinite gees in those turns!

Actually, in this hypothetical, the bank angle was 90 degrees.
To place a bob towards the floor, it is necessary to induce some slip
too....

Brian W (The impossible takes a little longer)

[Brian Whatcott]

Darryl Ramm wrote:
> /snip/
>> If you are going to take on the school master role, you had better be
>> right. /snip/
>> Brian W
>
> That has zero practical relevance. I'll leave the school master stuff
> to Andy (and here I was thinking he's a management consultant with a
> masters in aeronautical engineering), anyhow I managed to waste part
> of my life working on precision sensors for general relativity physics
> experiments. /snip/
> Darryl
>

For a person who appreciates practical relevance, can I suggest you
actually DO the experiment?
Swing a bob on a foot long string in your right hand.
Turn at a reasonable rate in place.
Notice what happens to the pendulum's plane of rotation?

Regards
Brian W
p.s. I can usually detect someone with physics background: no matter how
much they have forgotten, they always retain that 'physics' attitude :-)

[Brian Whatcott]

jimboffin wrote:
> On 30 Dec, 05:59, Darryl Ramm > wrote:
>
>> As others have pointed out, the important thing is to go try this and
>> practice, with an instructor if needed. The advice from some others
>> about the benign spiral, always needs a caveat - whether your ship
>> will benign spiral or not is glider design and possibly W&B dependent.
>> My ASH-26E at my normal W&B will not benign spiral. So I carry a
>> pictorial T&B for backup just in case, and I've spent enough time
>> under a hood to remind me I really don't want to go there.
>>
>> Darryl
>
> At last...my Discus would do a benign spiral without going VNE with
> wheel down, brakes out, and hands off. My ASW27 won't and will fall to
> bits. I suggest everyone try hanging everything out and taking hands
> off to see what happens. If speed goes through rough air, pull out.
> You will then know whether you can safely use this technique or not.
>
> I have practised using string for slip, ears for speed, and gps for
> turn. I reckon that I could descend without my horizon through cloud
> most times without spinning or over speeding. Failing that I guess it
> is, pull the wings off then pull the chute!
>
> Jim


Now THERE'S a post worth repeating: students are not taught about
'the fatal spiral' for nothing....

Brian W

[Paul Remde]

The cat theory may have merit.
http://www.youtube.com/watch?v=wvRzWYCZ2e0


"Darryl Ramm" > wrote in message
...
On Dec 29, 4:28 pm, brian whatcott > wrote:
> Andy wrote:
> > Anything hanging in the cockpit like a pendulum (or any instruments
> > working on the same principle) DOES NOT tell you which way is up./snip/
> > 9B
>
> If you are going to take on the school master role, you had better be
> right. Current solid state angular rate sensors act like a mini pendulum
> or tuning fork - when turned, the pendulum retains spatial inertia.
> Foucault, an' all that. Remember?
>
> Brian W

That has zero practical relevance. I'll leave the school master stuff
to Andy (and here I was thinking he's a management consultant with a
masters in aeronautical engineering), anyhow I managed to waste part
of my life working on precision sensors for general relativity physics
experiments. MEMS rate based devices like tuning fork designs etc.
vibrate many orders of magnitude above the signal frequency. Hanging a
weight on an about a foot long string will give a resonant period of
about one second. For movement of the aircraft that happen of order
~seconds the mass on a string is essentially a plumb-bob and the
"pendulum" will be perturbed. Again a focualt pendulum is oscillating
in it's inertial frame with a resonant frequency orders of magnitude
above above any signal frequency (the earth's rotation).

---

The pendulum in the cockpit is one of the most goofball things I've
heard in a while. On the other hand the cat idea has promise. The cat
also has the benefit of being an amusing companion in the event of a
landout, or a nutritious food source in the event of a more serious
survival situation. But unfortunately until I I can overcome my cat
allergy it's a plain old (non-edible) T&B backup for me.

---

As others have pointed out, the important thing is to go try this and
practice, with an instructor if needed. The advice from some others
about the benign spiral, always needs a caveat - whether your ship
will benign spiral or not is glider design and possibly W&B dependent.
My ASH-26E at my normal W&B will not benign spiral. So I carry a
pictorial T&B for backup just in case, and I've spent enough time
under a hood to remind me I really don't want to go there.

Darryl

[Uncle Fuzzy]

On Dec 29, 6:48*am, T8 > wrote:
> On Dec 29, 9:24*am, Andy > wrote:
>
>
>
>
>
> > On Dec 29, 6:55*am, Bruno > wrote:
>
> > > I had a very interesting conversation yesterday with *a very
> > > experienced pilot (older) who has spent a lot of time in some amazing
> > > aircraft starting with the P51 Mustang and going up to jets including
> > > the SR-71 blackbird and as we were looking over my glider we started
> > > talking about the yaw string on the canopy.
>
> > > He then mentioned that way back in the early days of flying they would
> > > simply tape a string hanging from the ceiling to act as an artificial
> > > horizon. *I've never heard this one before! *Next person who reads
> > > this who goes up tape a string hanging from the inside of the canopy
> > > and tell us how it works. *Now you have another reason to take off
> > > work and go soaring. ;)
>
> > > Bruno -B4http://www.youtube.com/user/bviv
>
> > It's not April 1 already is it?
>
> Just put a mark on your canopy and spit at it. *If spit flies left of
> target, you are turning right and vice versa.
>
> -T8- Hide quoted text -
>
> - Show quoted text -

That'd work, except for one thing: If I'm in a situation requiring
that trick, my mouth is probably going to be too dry to spit!

[Andy[_10_]]

On Dec 29, 9:59*pm, Darryl Ramm > wrote:
> On Dec 29, 4:28*pm, brian whatcott > wrote:
>
> > Andy wrote:
> > > Anything hanging in the cockpit like a pendulum (or any instruments
> > > working on the same principle) DOES NOT tell you which way is up./snip/
> > > 9B
>
> > If you are going to take on the school master role, you had better be
> > right. Current solid state angular rate sensors act like a mini pendulum
> > or tuning fork - when *turned, the pendulum retains spatial inertia.
> > Foucault, an' all that. Remember?
>
> > Brian W
>
> That has zero practical relevance. I'll leave the school master stuff
> to Andy (and here I was thinking he's a management consultant with a
> masters in aeronautical engineering), anyhow I managed to waste part
> of my life working on precision sensors for general relativity physics
> experiments. MEMS rate based devices like tuning fork designs etc.
> vibrate many orders of magnitude above the signal frequency. Hanging a
> weight on an about a foot long string will give a resonant period of
> about one second. For movement of the aircraft that happen of order
> ~seconds the mass on a string is essentially a plumb-bob and the
> "pendulum" will be perturbed. Again a focualt pendulum is oscillating
> in it's inertial frame with a resonant frequency orders of magnitude
> above above any signal frequency (the earth's rotation).
>
> ---
>
> The pendulum in the cockpit is one of the most goofball things I've
> heard in a while. On the other hand the cat idea has promise. The cat
> also has the benefit of being an amusing companion in the event of a
> landout, or a nutritious food source in the event of a more serious
> survival situation. But unfortunately until I I can overcome my cat
> allergy it's a plain old (non-edible) T&B backup for me.
>

I stand by my original statement. Sorry if it sounded like a school
master. Even if you had a pendulum at a high frequency - tuning fork
style - I don't believe it would be able to tell you anything about
whether you are right side up. It would only tell you about your
angular rotation about the axis along the "string" line. You could do
a roll to inverted and it wouldn't indicate anything different (ok,
the string would go limp I guess if you weren't pulling Gs).

To determine definitively an aircraft's attitude you need to be able
to measure or estimate the three Euler angles that define the
rotations about all three axes. To do this with a tuning fork/pendulum
thingy you need to measure all three angular rates and integrate (in a
calculus sense) them over time from a known, generally non-rotating,
starting point. Over time, depending on the precision of the
instrument, the integrated values will drift off of the actual angles
- this is why inertial reference platforms need to be aligned prior to
flight.

Again, the string without a weight on it will tell you zip about
aircraft attitude. The swinging pendulum might, in calm air, be able
to pick up some gradual heading changes, but so will a compass or a
GPS and I'd trust both of those a lot better than a string.

I will give the jellied cat a try. I have not tried the benign spiral
in my -27B, sounds like I should try that too. I have tried about
everything else:

http://www.youtube.com/watch?v=9aDJLDQ-5QU

9B

[Brian Whatcott]

Andy wrote:
> /snip/ Even if you had a pendulum at a high frequency - tuning fork
> style - I don't believe it would be able to tell you anything about
> whether you are right side up. /snip/


I need first to ask you to look for some observable change in a swinging
half second pendulum when you hold it at waist level and turn in place.
See it?

Then suppose one concedes that a swinging pendulum can act like a
rubbish single gyroscope: do you think that pilots have maintained their
composure with a turn and slip in clouds at all?
They certainly used to do something of the kind with what was called a
'limited panel'.

If you find this somewhat plausible so far, then tell me: how many gyros
are there in a turn and slip?

(It's so much fun argued against what everybody KNOWS ain't so!)

OK if you are still finding this slightly plausible, then perhaps you
can give a little more credit to a great name in aviation, as I do....

Regards

Brian W

[bildan]

Most have probably heard this before but an instrument rating will
significantly improve your flying even if you never use it to fly in
clouds.

I think it really benefits a soaring pilot because the instrument
student must learn a REALLY precise flying technique while learning to
form a mental picture of his surroundings without using his vision -
that really helps centering thermals. He must also learn and
understand exactly how pitch and bank relate to airspeed and rate of
turn. Beyond flying technique, you'll learn the air traffic system
which in itself can be a lifesaver.

An instrument rating isn't inexpensive or easy to get. It's not even
possible to train in a glider - it has to be earned in an airplane.
Once you have the rating, it can be used in a glider. Then, a turn
and bank will get you down through an undercast.

Even if a PP SEL Instrument rating doesn't interest you, even a few
hours with a CFII learning attitude control in a light plane will help.

[Andy[_10_]]

On Dec 30, 9:58*am, brian whatcott > wrote:
> Andy wrote:
> > /snip/ *Even if you had a pendulum at a high frequency - tuning fork
> > style - I don't believe it would be able to tell you anything about
> > whether you are right side up. /snip/
>
> I need first to ask you to look for some observable change in a swinging
> half second pendulum when you hold it at waist level and turn in place.
> See it?
>
> Then suppose one concedes that a swinging pendulum can act like a
> rubbish single gyroscope: do you think that pilots have maintained their
> composure with a turn and slip in clouds at all?
> They certainly used to do something of the kind with what was called a
> 'limited panel'.
>
> If you find this somewhat plausible so far, then tell me: how many gyros
> are there in a turn and slip?
>
> (It's so much fun argued against what everybody KNOWS ain't so!)
>
> OK if you are still finding this slightly plausible, then perhaps you
> can give a little more credit to a great name in aviation, as I do....
>
> Regards
>
> Brian W

Sorry, you lost me at the first syllable - and the other syllables
didn't help.

9B