Turbo prop question

Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of some
show
about rich people and their planes. Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between the
prop and engine. How can that be?


I didn't catch the name of the plane. but as I remember, there were 4
seats in the passenger area, and it was pretty roomy. The only other
distinctive thing I can remember is it had a fairly large cargo door
with a power assist to close it because it was so far over head when
it
was open.




It's a free turbine. Most modern turboprops use that system. There's a
seperate turbine that runs the prop geabox. He's technically incorrect
since that turbine is part of the engine...


Bertie


Rich people. More money than brains.

On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of some
show
about rich people and their planes. *Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between the
prop and engine. *How can that be?

It's a free turbine. Most modern turboprops use that system. There's a
seperate turbine that runs the prop geabox. He's technically incorrect
since that turbine is part of the engine...

Bertie

Rich people. *More money than brains.- Hide quoted text -


I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml


http://www.britannica.com/eb/topic-1...c-transmission
http://en.wikipedia.org/wiki/Diesel-electric

http://www.fpweb.com/200/FPE/Hydraul...450/Hydraulics

wrote in news:de5298d4-778b-475f-9321-
:

On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of
some
show
about rich people and their planes. *Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between
the
prop and engine. *How can that be?

It's a free turbine. Most modern turboprops use that system.
There's a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...

Bertie

Rich people. *More money than brains.- Hide quoted text -


I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.



Nah, not on a turbine.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml



Yeah, almost all modern turboprops use this system. Some of the older
ones, like the RR Dart or the Allisons were gear driven off the main
turbine, but this is all but abandoned these days. In fact, even "jets"
are really just ducted fan turboprops with the fan driven by a turbine
in the exhaust.


Bertie

On Apr 25, 4:37 am, Bertie the Bunyip wrote:
wrote in news:de5298d4-778b-475f-9321-
:





On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of
some
show
about rich people and their planes. Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between
the
prop and engine. How can that be?

It's a free turbine. Most modern turboprops use that system.
There's a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...

Bertie

Rich people. More money than brains.- Hide quoted text -

I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.

Nah, not on a turbine.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml

Yeah, almost all modern turboprops use this system. Some of the older
ones, like the RR Dart or the Allisons were gear driven off the main
turbine, but this is all but abandoned these days. In fact, even "jets"
are really just ducted fan turboprops with the fan driven by a turbine
in the exhaust.

Bertie

The Garrett TPE 331 is still a fixed turboprop. Lots of those
flying, especially on some upscale kitplanes. Isn't the Swearingen
Merlin powered by those, too?
http://www.aircraftenginedesign.com/pictures/TPE331.gif

Dan

wrote in news:e508d435-db20-4b21-9c9b-
:

On Apr 25, 4:37 am, Bertie the Bunyip wrote:
wrote in news:de5298d4-778b-475f-9321-
:





On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of
some
show
about rich people and their planes. Anyway the pilot of this
one
single
engine turbo prop said there was no mechanical connection
between
the
prop and engine. How can that be?

It's a free turbine. Most modern turboprops use that system.
There's a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...

Bertie

Rich people. More money than brains.- Hide quoted text -

I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.

Nah, not on a turbine.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml

Yeah, almost all modern turboprops use this system. Some of the older
ones, like the RR Dart or the Allisons were gear driven off the main
turbine, but this is all but abandoned these days. In fact, even
"jets"
are really just ducted fan turboprops with the fan driven by a
turbine
in the exhaust.

Bertie

The Garrett TPE 331 is still a fixed turboprop. Lots of those
flying, especially on some upscale kitplanes. Isn't the Swearingen
Merlin powered by those, too?
http://www.aircraftenginedesign.com/pictures/TPE331.gif

Dan


Yeah, Garret are one of the holdouts. They're on alot of airplanes. the
Metro, the turbine commanders. I think there's a Walter that's in th
esame class being used on quite a few airplanes as well. The Pratts are
all free turbines, AFAIK. The older ones are centrifugal engines with a
revese flow, that is, the intake is on the back and they exhaust in
front, which is why the PT6 's have those stovepipes just behind the
prop, and the newer 120 and newers are axial with the air coming in the
front and the fire going out the back. The 120 has a prop brake with
which you can stop the prop while the engine is running ( on the ground)
and use the engine for an APU.


Bertie

"Bertie the Bunyip" wrote in message
.. .
wrote in news:e508d435-db20-4b21-9c9b-
:

On Apr 25, 4:37 am, Bertie the Bunyip wrote:
wrote in news:de5298d4-778b-475f-9321-
:





On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of
some
show
about rich people and their planes. Anyway the pilot of this
one
single
engine turbo prop said there was no mechanical connection
between
the
prop and engine. How can that be?

It's a free turbine. Most modern turboprops use that system.
There's a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...

Bertie

Rich people. More money than brains.- Hide quoted text -

I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.

Nah, not on a turbine.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml

Yeah, almost all modern turboprops use this system. Some of the older
ones, like the RR Dart or the Allisons were gear driven off the main
turbine, but this is all but abandoned these days. In fact, even
"jets"
are really just ducted fan turboprops with the fan driven by a
turbine
in the exhaust.

Bertie

The Garrett TPE 331 is still a fixed turboprop. Lots of those
flying, especially on some upscale kitplanes. Isn't the Swearingen
Merlin powered by those, too?
http://www.aircraftenginedesign.com/pictures/TPE331.gif

Dan


Yeah, Garret are one of the holdouts. They're on alot of airplanes. the
Metro, the turbine commanders. I think there's a Walter that's in th
esame class being used on quite a few airplanes as well. The Pratts are
all free turbines, AFAIK. The older ones are centrifugal engines with a
revese flow, that is, the intake is on the back and they exhaust in
front, which is why the PT6 's have those stovepipes just behind the
prop, and the newer 120 and newers are axial with the air coming in the
front and the fire going out the back. The 120 has a prop brake with
which you can stop the prop while the engine is running ( on the ground)
and use the engine for an APU.


Bertie

Amazing how after a while you can tell the difference between the Pratts and
the Garretts from the ground while the plane is at 13,500 ft above you. Many
times we had a Twin Otter with Pratts and a Casa 212 with Garretts flying on
the same day and you could tell which was on jump run just by the sound. I
just assumed it was because of the different methods of coupling the props
to the powerplant.

TonyP.

"muff528" wrote in
news:krtRj.968$lc6.775@trnddc04:


"Bertie the Bunyip" wrote in message
.. .
wrote in news:e508d435-db20-4b21-9c9b-
:

On Apr 25, 4:37 am, Bertie the Bunyip wrote:
wrote in news:de5298d4-778b-475f-9321-
:





On 25 Apr, 11:53, Frank Olson
wrote:
Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end
of
some
show
about rich people and their planes. Anyway the pilot of this
one
single
engine turbo prop said there was no mechanical connection
between
the
prop and engine. How can that be?

It's a free turbine. Most modern turboprops use that system.
There's a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...

Bertie

Rich people. More money than brains.- Hide quoted text -

I'm not in disagreement with Bertie, wouldn't dare, but it
"could be" electric drive, hydraulic drive.

Nah, not on a turbine.

These are used in other vehicles. Most cars in the US
use an automatic transmission that includes a
torque convertor for example.

I am sure that it is in this case a free turbine - gas drive -
that connects to a propellor - gas-gas drive.

http://www.gasgas.com/index.shtml

Yeah, almost all modern turboprops use this system. Some of the
older ones, like the RR Dart or the Allisons were gear driven off
the main turbine, but this is all but abandoned these days. In
fact, even
"jets"
are really just ducted fan turboprops with the fan driven by a
turbine
in the exhaust.

Bertie

The Garrett TPE 331 is still a fixed turboprop. Lots of
those
flying, especially on some upscale kitplanes. Isn't the Swearingen
Merlin powered by those, too?
http://www.aircraftenginedesign.com/pictures/TPE331.gif

Dan


Yeah, Garret are one of the holdouts. They're on alot of airplanes.
the Metro, the turbine commanders. I think there's a Walter that's in
th esame class being used on quite a few airplanes as well. The
Pratts are all free turbines, AFAIK. The older ones are centrifugal
engines with a revese flow, that is, the intake is on the back and
they exhaust in front, which is why the PT6 's have those stovepipes
just behind the prop, and the newer 120 and newers are axial with the
air coming in the front and the fire going out the back. The 120 has
a prop brake with which you can stop the prop while the engine is
running ( on the ground) and use the engine for an APU.


Bertie

Amazing how after a while you can tell the difference between the
Pratts and the Garretts from the ground while the plane is at 13,500
ft above you. Many times we had a Twin Otter with Pratts and a Casa
212 with Garretts flying on the same day and you could tell which was
on jump run just by the sound. I just assumed it was because of the
different methods of coupling the props to the powerplant.

!!! I don't think I could except by seeing the airplane. Yeah, you get
tuned in to any engine you're familiar with, though, don't you?


Bertie

Frank Olson wrote in
news:0ShQj.90501$rd2.26964@pd7urf3no:

Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of some
show
about rich people and their planes. Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between
the
prop and engine. How can that be?


I didn't catch the name of the plane. but as I remember, there were
4
seats in the passenger area, and it was pretty roomy. The only
other
distinctive thing I can remember is it had a fairly large cargo door
with a power assist to close it because it was so far over head
when
it
was open.




It's a free turbine. Most modern turboprops use that system. There's
a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...


Bertie


Rich people. More money than brains.


Well, what he maenas is the prop isn;t connected to the main drive of
the engine. You can actually stop the prop on a free turbine while the
engine is running and it will run just fine. He's not wrong but he's not
right if you know what I mean.

Bertie

"Bertie the Bunyip" wrote in message
.. .
Frank Olson wrote in
news:0ShQj.90501$rd2.26964@pd7urf3no:

Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of some
show
about rich people and their planes. Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between
the
prop and engine. How can that be?


I didn't catch the name of the plane. but as I remember, there were
4
seats in the passenger area, and it was pretty roomy. The only
other
distinctive thing I can remember is it had a fairly large cargo door
with a power assist to close it because it was so far over head
when
it
was open.




It's a free turbine. Most modern turboprops use that system. There's
a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...


Bertie


Rich people. More money than brains.


Well, what he maenas is the prop isn;t connected to the main drive of
the engine. You can actually stop the prop on a free turbine while the
engine is running and it will run just fine. He's not wrong but he's not
right if you know what I mean.

Bertie

Wannnboi, you don't know what you maena.

"Maxwell" luv2^fly99@cox.^net wrote in news:%5kQj.67977$y05.64004
@newsfe22.lga:


"Bertie the Bunyip" wrote in message
.. .
Frank Olson wrote in
news:0ShQj.90501$rd2.26964@pd7urf3no:

Bertie the Bunyip wrote:
Chris W wrote in news:74gQj.67968$y05.19485
@newsfe22.lga:

I was channel surfing the other day and caught the tail end of
some
show
about rich people and their planes. Anyway the pilot of this one
single
engine turbo prop said there was no mechanical connection between
the
prop and engine. How can that be?


I didn't catch the name of the plane. but as I remember, there
were
4
seats in the passenger area, and it was pretty roomy. The only
other
distinctive thing I can remember is it had a fairly large cargo
door
with a power assist to close it because it was so far over head
when
it
was open.




It's a free turbine. Most modern turboprops use that system.
There's
a
seperate turbine that runs the prop geabox. He's technically
incorrect
since that turbine is part of the engine...


Bertie


Rich people. More money than brains.


Well, what he maenas is the prop isn;t connected to the main drive of
the engine. You can actually stop the prop on a free turbine while
the
engine is running and it will run just fine. He's not wrong but he's
not
right if you know what I mean.

Bertie

Wannnboi, you don't know what you maena.



snort!


Bertie