Why is Toothless the only one with tailfins?

[buckmana]

I started to wonder about this.

All the other dragons don't have tailfins and fly just fine without them.

Meatlug is the most significant example, since her tail is just a round ball, which doesn't help anything in flight.

So why is Toothless incapable of flying just because he loses one of his tailfins when all the other dragons don't need them?

[timberjack]

May 12, 2013 1:47:21 GMT -5 buckmana said:

I started to wonder about this.

All the other dragons don't have tailfins and fly just fine without them.

Meatlug is the most significant example, since her tail is just a round ball, which doesn't help anything in flight.

So why is Toothless incapable of flying just because he loses one of his tailfins when all the other dragons don't need them?

Their weight is probably distributed differently. You could ask why hawks need tail feathers and bats dont.

[buckmana]

Actually, bats have an tail much like a bird does, although not as pronounced.

And according to this article:
www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0032074
The tail of a bat is as important to them during flight as the tail of a bird is.

[TheCube]

I think Toothless's inability to fly without the left tailfin is due to it creating a difference in the amount of lift generated in the left side and the right side of his body. There is some lift lost when he loses that tailfin (it's small but a tailfin is still an airfoil) and that destroys the balance of lift forces between the two sides of his body. Lift is an upward force, yes, but it is also a collection of tiny little forces being applied to each point on his wings. Since any lift force away form his center of gravity would also generate torque, there has to be equal forces on each side to make net torque 0 in order to prevent his body from uncontrollably spinning. But we already know that the lift forces on the two sides aren't equal, so Toothless spins and falls. There are cases where pilots were able to compensate for a damaged or missing wing/tail using ailerons, but I think this doesn't apply to low-speed flight.

But can't you get rid of the other tailfin? Well, doesn't seem like it, at least looking at real-life airplanes. Airplanes with tailplanes (or stabilizers) have them because with just the traditional wings (similar to Toothless's wings?) the center of lift is not even close to the center of gravity of the plane. In this situation, the total lift generated would be applied to the center of lift, which would be behind the center of gravity. This causes the plane to pitch forward (or roll towards its head), and that would NOT be a fun thing. In these traditional planes, the tailfin serves to counteract the imbalance and also give the pilot more control. Toothless's wings are placed much closer to his head, but I would guess that the tailfin has a similar function, which means that without tailfins flight would be much more unstable.

Sources: Wikipedia articles on tailplane and tailless aircraft, and example of low-speed flight causing roll in damaged planes. PHYSICS!!!!

Now, for only Toothless having tailfins... I got nothin'.

[buckmana]

I have noticed that Thornado seems to have a similar fin setup to Toothless, although they're in different places.

His tailfins are closer to the main wings, directly behind them and over his hind legs.

Maybe in the world of How to Train Your Dragon, 4 limbed dragons need the tailfins for extra stability.

However, this doesn't explain Barf and Belch, Meatlug and the Green Death, who all have 4 limbs, but no tailfins.

[Sunny]

i know that for the movie, the animators spent a very long time studying the flight of animals and birds. the dragons themselves all have very different designs and anatomy so i think its safe to assume that they all have very different flight patterns and techniques.

as thecube pointed out, there are lots of complex factors which come into play which may not be obvious. if you really want to find out what the exact reasons are for tail fins then i cant be of any help so my apologies there.

[Abbigail]

May 18, 2013 16:21:14 GMT -5 TheCube said:

I think Toothless's inability to fly without the left tailfin is due to it creating a difference in the amount of lift generated in the left side and the right side of his body. There is some lift lost when he loses that tailfin (it's small but a tailfin is still an airfoil) and that destroys the balance of lift forces between the two sides of his body. Lift is an upward force, yes, but it is also a collection of tiny little forces being applied to each point on his wings. Since any lift force away form his center of gravity would also generate torque, there has to be equal forces on each side to make net torque 0 in order to prevent his body from uncontrollably spinning. But we already know that the lift forces on the two sides aren't equal, so Toothless spins and falls. There are cases where pilots were able to compensate for a damaged or missing wing/tail using ailerons, but I think this doesn't apply to low-speed flight.

But can't you get rid of the other tailfin? Well, doesn't seem like it, at least looking at real-life airplanes. Airplanes with tailplanes (or stabilizers) have them because with just the traditional wings (similar to Toothless's wings?) the center of lift is not even close to the center of gravity of the plane. In this situation, the total lift generated would be applied to the center of lift, which would be behind the center of gravity. This causes the plane to pitch forward (or roll towards its head), and that would NOT be a fun thing. In these traditional planes, the tailfin serves to counteract the imbalance and also give the pilot more control. Toothless's wings are placed much closer to his head, but I would guess that the tailfin has a similar function, which means that without tailfins flight would be much more unstable.

Sources: Wikipedia articles on tailplane and tailless aircraft, and example of low-speed flight causing roll in damaged planes. PHYSICS!!!!

Now, for only Toothless having tailfins... I got nothin'.

Can you maybe...dumb it down for me? I don't understand what you were saying. At all.

[yourMom]

I'm pretty sure that Night Furies aren't the only dragons with tailfins. Stormcutters like Cloudjumper have tailfins, Stormcutters having 3 of them. When Cloudjumper's tailfin was shot and covered in ice by a Bewilderbeast in the 2nd movie, he couldn't fly, similar to Toothless.

[Adz77sharp]

I wondered about this for a while as toothless also has fins behind his wings so the tail fin shouldn’t make a difference. But then I realised it’s an animated dragon and it works for the story lol