Why is the turn coordinator so popular? I find the presentation similar to
the artificial horizon is poor. The good old turn needle never leads to any
confusion. If the silly little airplane was replaced by a needle and dog
houses, I think I'd like it better. The 4 minute needle gives superior turn
rate information so you can more easily make standard of half standard rate
turns. The Turn Coordinator's ability to sense both yaw and roll doesn't
seem to be of much value to me. Overhaul Prices are higher for the TC.



While I'm at it, how about venturi tube suction. Put a heater on them so
they won't ice up and you no longer have to worry about a failing vacuum
pump. Add one as an emergency vacuum source.



Grump. Grump.



Oh well. Both are being replaced by Electronic Primary Flight Display
(Though I'll never be able to afford them)

john hawkins wrote:
> Why is the turn coordinator so popular? I find the presentation similar to
> the artificial horizon is poor. The good old turn needle never leads to any
> confusion. If the silly little airplane was replaced by a needle and dog
> houses, I think I'd like it better. The 4 minute needle gives superior turn
> rate information so you can more easily make standard of half standard rate
> turns. The Turn Coordinator's ability to sense both yaw and roll doesn't
> seem to be of much value to me. Overhaul Prices are higher for the TC.
>

There's a difference: a needle-in-the-doghouse indicator
feels turn rate only, but a turn coordinator senses
additionally some of the roll rate to respond quicker.



> While I'm at it, how about venturi tube suction. Put a heater on them so
> they won't ice up and you no longer have to worry about a failing vacuum
> pump. Add one as an emergency vacuum source.
>
>
>
> Grump. Grump.
>
>
>
> Oh well. Both are being replaced by Electronic Primary Flight Display
> (Though I'll never be able to afford them)

Me too - but would like to.

--

Tauno Voipio (PA28RT201T, OH-PYM)
tauno voipio (at) iki fi

The TC will run a wing leveler autopilot.



"john hawkins" > wrote in message
hlink.net...
| Why is the turn coordinator so popular? I find the
presentation similar to
| the artificial horizon is poor. The good old turn needle
never leads to any
| confusion. If the silly little airplane was replaced by a
needle and dog
| houses, I think I'd like it better. The 4 minute needle
gives superior turn
| rate information so you can more easily make standard of
half standard rate
| turns. The Turn Coordinator's ability to sense both yaw
and roll doesn't
| seem to be of much value to me. Overhaul Prices are higher
for the TC.
|
|
|
| While I'm at it, how about venturi tube suction. Put a
heater on them so
| they won't ice up and you no longer have to worry about a
failing vacuum
| pump. Add one as an emergency vacuum source.
|
|
|
| Grump. Grump.
|
|
|
| Oh well. Both are being replaced by Electronic Primary
Flight Display
| (Though I'll never be able to afford them)
|
|

Jim Macklin wrote:
> The TC will run a wing leveler autopilot.

Which is the only reason I have one. I had a needle-ball
gauge until I put in the STEC autopilot. I think the TC
was just one of those things that people thought were a
cool idea in the 70's that turned out not to be all it was
cracked up to be.

IIRC they were invented by Brittain (sp?) specifically to provide an input to
their wing levelers and, I suppose, autopilots.

On 2/4/2007 6:11 PM, Ron Natalie wrote the following:
> Jim Macklin wrote:
>> The TC will run a wing leveler autopilot.
>
> Which is the only reason I have one. I had a needle-ball
> gauge until I put in the STEC autopilot. I think the TC
> was just one of those things that people thought were a
> cool idea in the 70's that turned out not to be all it was
> cracked up to be.

Ron Natalie wrote:
> Jim Macklin wrote:
>
>> The TC will run a wing leveler autopilot.
>
>
> Which is the only reason I have one. I had a needle-ball
> gauge until I put in the STEC autopilot. I think the TC
> was just one of those things that people thought were a
> cool idea in the 70's that turned out not to be all it was
> cracked up to be.

That would be my assessment.

Alas, some airlines hated to maintain anything they didn't absolutely
have to, so carrier TWx had their turn-and-bank indicators removed from
their 727s once they gained federal approval. There was a tiny ball
under the attidue indicator that was supposed to be "good enough" for
engine failures.

I like the needle better too. Kept it in my grumman in spite of all the
advice to remove it.

john hawkins wrote:
> Why is the turn coordinator so popular? I find the presentation similar to
> the artificial horizon is poor. The good old turn needle never leads to any
> confusion. If the silly little airplane was replaced by a needle and dog
> houses, I think I'd like it better. The 4 minute needle gives superior turn
> rate information so you can more easily make standard of half standard rate
> turns. The Turn Coordinator's ability to sense both yaw and roll doesn't
> seem to be of much value to me. Overhaul Prices are higher for the TC.
>
>
>
> While I'm at it, how about venturi tube suction. Put a heater on them so
> they won't ice up and you no longer have to worry about a failing vacuum
> pump. Add one as an emergency vacuum source.
>
>
>
> Grump. Grump.
>
>
>
> Oh well. Both are being replaced by Electronic Primary Flight Display
> (Though I'll never be able to afford them)
>
>

On Feb 4, 6:11 pm, Ron Natalie > wrote:
> I think the TC
> was just one of those things that people thought were a
> cool idea in the 70's that turned out not to be all it was
> cracked up to be.

Try flying a slippery, fast, not-terribly-roll-stable airplane in
turbulent IMC on a T&S, and you will quickly change your mind. The TC
is a good idea. Not as good as a backup AI, and there is now an AC
that allows you to remove the TC (or T&S) from your airplane if you
replace it with a second AI powered from a different system than the
primary AI.

I seem to recall you fly a Navion. I've flown one. They're VERY
stable. You can keep the wings level in turbulent IMC with a T&S in a
Navion. I suspect you could probably do it with just a compass. I
know it can be done in the TriPacer on just a compass.

It's nearly impossible to keep the wings level in turbulent IMC in
something like a Bonanza, a late model Mooney, or my Twin Comanche if
all you have is a T&S. That's why your autopilot doesn't use one. By
the time you have started to actually turn (developed a yaw rate, the
only thing the T&S can sense) you already have too much roll rate
going. The TC will respond to roll rate, and that makes all the
difference.

Having actually lost my attitude gyro in turnulent night IMC in my
Twin Comanche, I am really glad I had the TC and not a T&S.

A good rule of thumb for determining if your plane really needs a TC
rather than a T&S - if, when doing partial panel work with a wet
compass and no moving map, you find you miss the HI more than the AI,
you don't need the T&S. Your plane is stable enough. If you miss the
AI more, you need a TC.

Michael

On Feb 6, 9:20 am, "Michael" >
wrote:
>... and there is now an AC
> that allows you to remove the TC (or T&S) from your airplane if you
> replace it with a second AI powered from a different system than the
> primary AI.
>
> Michael

Even knowing this, when the DE asked for required equipment for IFR
flight, I still included the TC (second R in grabcard).

ak.

Michael > wrote:

> It's nearly impossible to keep the wings level in turbulent IMC in
> something like a Bonanza, a late model Mooney, or my Twin Comanche if
> all you have is a T&S. That's why your autopilot doesn't use one. By
> the time you have started to actually turn (developed a yaw rate, the
> only thing the T&S can sense) you already have too much roll rate
> going. The TC will respond to roll rate, and that makes all the
> difference.

I own a Bonanza. I fly the Oregon/Washington Cascade mountains on a
regular basis, especially in the summer. It has a T&S. I'm not God's
gift to aviation, but the T&S does fine for me.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

On Feb 6, 9:47 pm, Frank Stutzman > wrote:
> I own a Bonanza. I fly the Oregon/Washington Cascade mountains on a
> regular basis, especially in the summer. It has a T&S. I'm not God's
> gift to aviation, but the T&S does fine for me.

Maybe it does. If you have actually had a total attitude gyro failure
in turbulent IMC and actually had to complete an IFR-in-IMC instrument
approach in turbulent IMC with just the T&S, then I believe you - and
you're a better man than I am.

If this has not actually happened, I think you are kidding yourself.
It's a whole lot easier under the hood.

Michael