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Seems like 6 of one, 1/2 dozen of another?



 
 
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  #11  
Old August 28th 09, 08:06 PM posted to rec.aviation.homebuilt
jerry wass
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Posts: 180
Default Seems like 6 of one, 1/2 dozen of another?

Dan wrote:
BobR wrote:
On Aug 28, 3:13 am, Oliver Arend wrote:
Regardless of what is fact and what is fiction, most of what has been
said about composite canard pushers vs. metal classic tractors is
comparing apples to oranges (IIRC, in Germany we usually compare
apples to pears). Advantages and disadvantes have been pointed out,
but do not relate to the original pusher-vs.-tractor question. The
Cessna Skymaster example in the original text suits it much better.

Apart from the problem of aft CG and hence the difficulty to make a
single-engine pusher in a classical wing layout, there are two
opposing factors:

1. The tractor engine works more efficiently since the prop is in an
undisturbed air stream. The slipstream may be able to increase maximum
lift on parts of the wing, but can induce a rolling moment. The
turbulence created creates more drag, especially on the fuselage.
Also, putting the engine up front makes it less likely to have an
aerodynamically optimized fuselage.

2. The pusher engine works less efficiently since the prop sits in an
airstream that has already passed fuselage and wing. OTOH, the
fuselage can be shape-optimized more easily and sees an undisturbed,
laminar airflow. Maximum lift is likely to be a little lower.

Now, which of these effects is the dominant one? Also, if you have a
twin engine airplane, the fuselage is out of the equation, so the
final result may be different!?

Oliver


So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.


On the other hand..... there are more fingers.

Dan, U.S. Air Force, retired

Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot
  #12  
Old August 28th 09, 08:36 PM posted to rec.aviation.homebuilt
cavelamb[_2_]
external usenet poster
 
Posts: 257
Default Seems like 6 of one, 1/2 dozen of another?

Jerry Wass wrote:
Dan wrote:
BobR wrote:
On Aug 28, 3:13 am, Oliver Arend wrote:
Regardless of what is fact and what is fiction, most of what has been
said about composite canard pushers vs. metal classic tractors is
comparing apples to oranges (IIRC, in Germany we usually compare
apples to pears). Advantages and disadvantes have been pointed out,
but do not relate to the original pusher-vs.-tractor question. The
Cessna Skymaster example in the original text suits it much better.

Apart from the problem of aft CG and hence the difficulty to make a
single-engine pusher in a classical wing layout, there are two
opposing factors:

1. The tractor engine works more efficiently since the prop is in an
undisturbed air stream. The slipstream may be able to increase maximum
lift on parts of the wing, but can induce a rolling moment. The
turbulence created creates more drag, especially on the fuselage.
Also, putting the engine up front makes it less likely to have an
aerodynamically optimized fuselage.

2. The pusher engine works less efficiently since the prop sits in an
airstream that has already passed fuselage and wing. OTOH, the
fuselage can be shape-optimized more easily and sees an undisturbed,
laminar airflow. Maximum lift is likely to be a little lower.

Now, which of these effects is the dominant one? Also, if you have a
twin engine airplane, the fuselage is out of the equation, so the
final result may be different!?

Oliver

So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.


On the other hand..... there are more fingers.

Dan, U.S. Air Force, retired

Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot



starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?
  #13  
Old August 28th 09, 08:48 PM posted to rec.aviation.homebuilt
BobR
external usenet poster
 
Posts: 356
Default Seems like 6 of one, 1/2 dozen of another?

On Aug 28, 2:36*pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:
On Aug 28, 3:13 am, Oliver Arend wrote:
Regardless of what is fact and what is fiction, most of what has been
said about composite canard pushers vs. metal classic tractors is
comparing apples to oranges (IIRC, in Germany we usually compare
apples to pears). Advantages and disadvantes have been pointed out,
but do not relate to the original pusher-vs.-tractor question. The
Cessna Skymaster example in the original text suits it much better.


Apart from the problem of aft CG and hence the difficulty to make a
single-engine pusher in a classical wing layout, there are two
opposing factors:


1. The tractor engine works more efficiently since the prop is in an
undisturbed air stream. The slipstream may be able to increase maximum
lift on parts of the wing, but can induce a rolling moment. The
turbulence created creates more drag, especially on the fuselage.
Also, putting the engine up front makes it less likely to have an
aerodynamically optimized fuselage.


2. The pusher engine works less efficiently since the prop sits in an
airstream that has already passed fuselage and wing. OTOH, the
fuselage can be shape-optimized more easily and sees an undisturbed,
laminar airflow. Maximum lift is likely to be a little lower.


Now, which of these effects is the dominant one? Also, if you have a
twin engine airplane, the fuselage is out of the equation, so the
final result may be different!?


Oliver


So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.


* On the other hand..... there are more fingers.


Dan, U.S. Air Force, retired

Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot


starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted text -


There you go again using that educated government math.
  #14  
Old August 28th 09, 11:52 PM posted to rec.aviation.homebuilt
Dan[_12_]
external usenet poster
 
Posts: 451
Default Seems like 6 of one, 1/2 dozen of another?

BobR wrote:
On Aug 28, 2:36 pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:
On Aug 28, 3:13 am, Oliver Arend wrote:
Regardless of what is fact and what is fiction, most of what has been
said about composite canard pushers vs. metal classic tractors is
comparing apples to oranges (IIRC, in Germany we usually compare
apples to pears). Advantages and disadvantes have been pointed out,
but do not relate to the original pusher-vs.-tractor question. The
Cessna Skymaster example in the original text suits it much better.
Apart from the problem of aft CG and hence the difficulty to make a
single-engine pusher in a classical wing layout, there are two
opposing factors:
1. The tractor engine works more efficiently since the prop is in an
undisturbed air stream. The slipstream may be able to increase maximum
lift on parts of the wing, but can induce a rolling moment. The
turbulence created creates more drag, especially on the fuselage.
Also, putting the engine up front makes it less likely to have an
aerodynamically optimized fuselage.
2. The pusher engine works less efficiently since the prop sits in an
airstream that has already passed fuselage and wing. OTOH, the
fuselage can be shape-optimized more easily and sees an undisturbed,
laminar airflow. Maximum lift is likely to be a little lower.
Now, which of these effects is the dominant one? Also, if you have a
twin engine airplane, the fuselage is out of the equation, so the
final result may be different!?
Oliver
So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.
On the other hand..... there are more fingers.
Dan, U.S. Air Force, retired
Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot

starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted text -


There you go again using that educated government math.


It could be worse, he could be using algebra. That's when you stop
counting on your fingers and start using your toes.

Higher level math usually requires illegal substances.

Dan, U.S. Air Force, retired



  #15  
Old August 29th 09, 12:03 AM posted to rec.aviation.homebuilt
Mark
external usenet poster
 
Posts: 815
Default Seems like 6 of one, 1/2 dozen of another?

On Aug 28, 3:36*pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:
On Aug 28, 3:13 am, Oliver Arend wrote:
Regardless of what is fact and what is fiction, most of what has been
said about composite canard pushers vs. metal classic tractors is
comparing apples to oranges (IIRC, in Germany we usually compare
apples to pears). Advantages and disadvantes have been pointed out,
but do not relate to the original pusher-vs.-tractor question. The
Cessna Skymaster example in the original text suits it much better.


Apart from the problem of aft CG and hence the difficulty to make a
single-engine pusher in a classical wing layout, there are two
opposing factors:


1. The tractor engine works more efficiently since the prop is in an
undisturbed air stream. The slipstream may be able to increase maximum
lift on parts of the wing, but can induce a rolling moment. The
turbulence created creates more drag, especially on the fuselage.
Also, putting the engine up front makes it less likely to have an
aerodynamically optimized fuselage.


2. The pusher engine works less efficiently since the prop sits in an
airstream that has already passed fuselage and wing. OTOH, the
fuselage can be shape-optimized more easily and sees an undisturbed,
laminar airflow. Maximum lift is likely to be a little lower.


Now, which of these effects is the dominant one? Also, if you have a
twin engine airplane, the fuselage is out of the equation, so the
final result may be different!?


Oliver


So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.


* On the other hand..... there are more fingers.


Dan, U.S. Air Force, retired

Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot


starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted text -

- Show quoted text -


When you put your plane in reverse do the
backup lights come on?
  #16  
Old August 29th 09, 01:13 AM posted to rec.aviation.homebuilt
Steve Hix
external usenet poster
 
Posts: 340
Default Seems like 6 of one, 1/2 dozen of another?

In article
,
Mark wrote:

On Aug 28, 3:36*pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:


So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.


* On the other hand..... there are more fingers.


Dan, U.S. Air Force, retired
Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot


starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted text -


When you put your plane in reverse do the
backup lights come on?


Watched an MU-2 backing into a parking spot at Rawlings, WY years ago.

I wondered about it then. Once I'd picked up my teeth from the ramp.
  #17  
Old August 29th 09, 03:25 AM posted to rec.aviation.homebuilt
Peter Dohm
external usenet poster
 
Posts: 1,754
Default Seems like 6 of one, 1/2 dozen of another?

"Steve Hix" wrote in message
...
In article
,
Mark wrote:

On Aug 28, 3:36 pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:

So let me sum it up thusly.... 6 of one, 1/2 dozen of the other.

On the other hand..... there are more fingers.

Dan, U.S. Air Force, retired
Are we speaking of 6 fingered hands??--that would broaden the subject
sumwhot

starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted text -


When you put your plane in reverse do the
backup lights come on?


Watched an MU-2 backing into a parking spot at Rawlings, WY years ago.

I wondered about it then. Once I'd picked up my teeth from the ramp.


It looks just as strange to see a Cessna Caravan do it.



  #18  
Old August 29th 09, 03:07 PM posted to rec.aviation.homebuilt
Anyolmouse
external usenet poster
 
Posts: 138
Default Seems like 6 of one, 1/2 dozen of another?


"Peter Dohm" wrote in message
...
"Steve Hix" wrote in message
...
In article
,
Mark wrote:

On Aug 28, 3:36 pm, cavelamb wrote:
Jerry Wass wrote:
Dan wrote:
BobR wrote:

So let me sum it up thusly.... 6 of one, 1/2 dozen of the

other.

On the other hand..... there are more fingers.

Dan, U.S. Air Force, retired
Are we speaking of 6 fingered hands??--that would broaden the

subject
sumwhot

starting from ten on this hand we have - 10, 9, 8, 7, and 6.
Plus five on the other hand would be = eleven?- Hide quoted

text -

When you put your plane in reverse do the
backup lights come on?


Watched an MU-2 backing into a parking spot at Rawlings, WY years

ago.

I wondered about it then. Once I'd picked up my teeth from the ramp.


It looks just as strange to see a Cessna Caravan do it.




Or a turbo Thrush G

--
A man is known by the company he keeps- Unknown

Anyolmouse

 




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