tail size!?

[Beginner!?]

hi friends

what is the best choice for a tail stabilizer for an indoor model?




what will hapen if the size of a tail become the same of the wings on a plane!?


thanks for any input

[Ollie]

From zero tail (flying wing) to wing first, to canard (tail first) could be best choice depending on the plane's purpose. You want plane's specific purposes? Duration? Cost? Size? Light weight? Stability? Etc,etc.

[Beginner!?]

my mean is what SIZE of tail is best for an indoor slow flyer?

[Andy W]

There is no single answer to your question. It depends on a lot of things, including those listed by Ollie, but many more complex factors.
..a

[Ollie]

What you mean by "best"? Until you mean "best" any size can be another type of tail design. V-tail? T-tail? Vert? Horz? No tail? Fore tail? Aft tail? Long wing? Stubby wing? Long fuselage? Short fuselage? Low power? High power?

http://www.djaerotech.com/dj_askjd/dj_questions/fuselength.html
http://www.djaerotech.com/dj_askjd/dj_questions/formula.html
http://www.djaerotech.com/dj_askjd/dj_questions/formula.html
http://www.djaerotech.com/dj_askjd/dj_questions/tailvolumn.html
http://www.djaerotech.com/dj_askjd/dj_questions/lifttail.html
http://www.djaerotech.com/dj_askjd/dj_questions/lifttail1.html
http://www.djaerotech.com/dj_askjd/dj_questions/tail_coef.html
http://www.djaerotech.com/dj_askjd/dj_questions/tail_surface.html
http://www.djaerotech.com/dj_askjd/dj_questions/vtail.html
http://www.djaerotech.com/dj_askjd/dj_questions/assym_vtail.html
Etc. etc.

[fhhuber506771]

what will hapen if the size of a tail become the same of the wings on a plane!?


When the horizontal stab area approaches the wing area.. you are approaching a "tandem wing" aircraft (example: the 1930's "Flying Flea")

Thee are some advantages to a tandem wing... there are also some serious disadvantages if it is done wrong.

As the others... but in other words... I'll say the "best" horizontal stabilizer (or rear tandem wing) is the one that is correct for the rest of the aircraft design.

[Beginner!?]

thanks for all helps

really i heard a thing about a T stabilizer with simply about 20% of the wing area but with these things you said i think i have some of problems with its design?

[Sparky Paul]

There's no set percentage of tail area to wing area.
The distance from the wing to the tail enters into the equation.. more distance, the area can be less.. and vice versa.
You also have to consider how important getting the smallest area is. Usually it's not that too important for a sport plane..
20% of the wing is adequate for most common designs, but not anything cast in concrete.
For T-tails, with the added mass above the fuselage, it pays to go as small as possible, considering a flying tail instead of a conventional stabilizer-elevator, for the increased effectiveness with the smaller area.

[BMatthews]

All they said. But here's some general observations.

If you want the model to fly as if it's a more or less normal airplane with good steep turns the odd maneuver and stuff like that then stick to a generic layout. With that the airfoil will be lower in camber and the tail will be roughly 20 to 25% assuming a trailing edge to stabilizer gap of about 1.5 to 2 chords.

For a slower floaty model with a highly undercambered airfoil then the stabilizer should be from 30 to 50% of the wing area. WIth a 2 chord tail gap this will let you move the CG back to about 50% of the wing chord and you'll get some lifting help from the tail area.

Tandem wings are a tricky design option. But done well it lets you have the CG just about half way between the front wing's trailing edge and the mid point of the gap between the wings.

But this is all highly generalized. The final CG will depend on the final design.

Some small balsa test gliders will teach you a LOT about stuff like this. 10 inch span with wings and tail surfaces from 1/32 sheet and a 1/8 x 1/2 stick for the fuselage. Takes all of 10 minutes to make and another 10 minutes to test fly but can answer a week's worth of questions. No camber needed, just flat wings and tails. Dihedral is nice but not a complete requirement unless you want to play...... er..... test them outside in more rigourous conditions.

[fhhuber506771]

thanks for all helps

really i heard a thing about a T stabilizer with simply about 20% of the wing area but with these things you said i think i have some of problems with its design?

A "T" Tail is not the same as a tandem wing... The T tail has the horizontal stab at or near the top of the vertical stab/rudder. (looks like a "T" from the front or rear)

"T" tails have some nice bennefits.. but have some problems with doing them properly and keeping the structure light. (again... great in some applications... rotten for others)

T tails are used on a lot of airliners. Gets the horizontal stab out of the turbulence from the wings and engines... makes the ride smoother.