Why the T-Tail?

On 27 Oct 2004 15:30:43 GMT, Jim Vincent wrote:

snip
Then again, with a T-tail, the elevator is no longer essentially in rotation,
but also in translation, so there that to consider too...

Jim Vincent
N483SZ
illspam

Jim,
Why does the elevator have more translation on a T-Tail than on a
conventional one please ? (I presume you are referring to translation
in a direction normal to the tailplane surface)
Bemused John G.

The 'T' configuration gets the tail out of the way
of crops when field landing and consequently helps
to be prevent it from being ripped off! I should imagine
that this would be a rather expensive mistake?!

It also provides an end plate for fin and so potentially
reduces drag, although I'm not sure by how much.


At 11:06 26 October 2004, Stefan wrote:

Pro T-tail: It's in the clean air.
Contra T-tail: Huge torque forces.

The torque forces are more easily mastered when the
planes are small.
There are biz jets and turboprops with T-tails. On
the other hand, all
serious acro planes, gliders included, have 'conventional'
tails.

Stefan

On Tue, 26 Oct 2004 11:46:18 +0200, Marian Aldenhövel
wrote:


I have noticed that most if not all modern gliders are built with a
T-Tail (not sure about the term, I am talking about the elevator being
located at the top of the tailfin). While most power-aircraft I know
right up to the airliners have it at the bottom.

What are the aerodynamic or constructive reasons for that?

A T-Tail has significantly less interference drag
(Interferenzwiderstand) than a conventional one. Since its weight is
located on top of the vertical stabilizer (Seitenflosse), fuselage
structure needs to be stronger, but the additional weight is
acceptable for a glider that needs to have as little drag as possible.


Bye
Andreas

What about the pilatus B4 then?

Rgds,

Derrick Steed

"Derrick Steed" wrote in message
...
What about the pilatus B4 then?

Rgds,

Derrick Steed

Whats your point the B4 is a T Tail, I fly one

Peter.

"Peter Seddon" wrote in message
...

"Derrick Steed" wrote in message
...
What about the pilatus B4 then?

Rgds,

Derrick Steed

Whats your point the B4 is a T Tail, I fly one

Peter.
Oh you mean modern, well it is of sorts.

Peter.

Additionally the T-Tail acts like a large Winglet on the end of the
vertical stab and improves the effectiveness of the vertical Stab and
Rudder. Also it only has 2 intersections as opposed to 4 on a
conventional tail. Plus it is easier to mount a one piece removable
stab on top rather than in the middle of the vertical stab.

Brian


Marian Aldenhövel wrote in message ...
Hi,

I have noticed that most if not all modern gliders are built with a
T-Tail (not sure about the term, I am talking about the elevator being
located at the top of the tailfin). While most power-aircraft I know
right up to the airliners have it at the bottom.

What are the aerodynamic or constructive reasons for that?

Ciao, MM

Or even the Salto


At 12:48 26 October 2004, Derrick Steed wrote:
What about the pilatus B4 then?

Rgds,

Derrick Steed

What about the pilatus B4 then?

It has a T-tail too;-)

Seriously, every design is a trade off between structural weight and
performance issues such as wetted area and configuration.

The B-4 is an aerobatic glider with very good glider performance, about 35:1.
It has a shorter distance from wing to tail compared to most gliders and a
larger cross section. That allows the structure to handle the torsional forced
induced by the T-tail. In fact there are two models, one for limited
aerobatics, the other for full. The main difference is a stiffening plate at
the tail.

Jim Vincent
N483SZ
illspam

"Jim Vincent" wrote in message
...
What about the pilatus B4 then?

It has a T-tail too;-)

Seriously, every design is a trade off between structural weight and
performance issues such as wetted area and configuration.

The B-4 is an aerobatic glider with very good glider performance, about
35:1.
It has a shorter distance from wing to tail compared to most gliders and a
larger cross section. That allows the structure to handle the torsional
forced
induced by the T-tail. In fact there are two models, one for limited
aerobatics, the other for full. The main difference is a stiffening plate
at
the tail.

Jim Vincent
N483SZ
illspam

There are actually 3 variants 4 if you count the fixed U/C one
they are
B4 PC11
B4 PC11A
B4 PC11AF

Peter.