Necessary Tail

It seems we humans stick to what we know works. It took a new war for us to go over to monoplanes. The unstallable canard design is far superior (from a safety pov) than the standard arrangement yet light aircraft continue to be designed as per the known arrangement.

This is not an example of Commercial Aviation but the concept has been around for some time (passengers in the wings). It does, however, prove that an aircraft does not need a an ‘Empennage’ (tail feathers) to fly, and fly with pitch stability without computer aids.

Enjoy

http://www.youtube.com/watch?v=to3_zToZrLA&feature=player_embedded#!

Which needs a lot of computers to fly it. It’s still unstable. If one or two computers fail, the Pilots either punch out or check out.

But the same layout was used in the pre-computer age with thesmall Northrop proof of concept twin, XB-35 and YB-49.
Both bombers were unstable, but they flew well enough to get a small order (which was cancelled).

So it’s not just computers that make flying wings possible.

Which needs a lot of computers to fly it. It’s still unstable. If one or two computers fail, the Pilots either punch out or check out.

A wing on it’s own is unstable in pitch.

Well, apart from highly advanced designs like the B-2B blended wing design 😉

Thank you all so much, it makes sense! You guys are very informative.

Regarding fin and rudder – fin obviously will provide a returning torque against yawing into sideslip.

Is it needed?

Is Taube dangerously yawing?

Taube could turn by banking via aileron application (actually wing warping, but the control effects are equivalent).

What is a rudder for? For “coordinated” turns.

What is the problem with uncoordinated turns by ailerons alone – with rudder either idle or nonexistent?

A wing on it’s own is unstable in pitch.

Let’s say at a certain angle of attack you balance it with the C.G. in the same place as the centre of lift – it balances so no tailplane required. But if you increase the angle of attack, the centre of pressure (lift) moves forward which then creates an out of balance moment which tends to pitch the wing up MORE. The reverse happens for decreasing angle of attack – the centre of pressure moves back tending to pitch the wing further down. The tailplane is there in part to provide a large corrective moment and prevent this effect.

Not quite sure about the fin either – Etrich Taube certainly has no fin whatsoever.

But does have horizontal stabilizer.

Now, what is the use of the horizontal stabilizer? Concorde does without.

The use is stabilizing the plane against pitching.

The angle of attack must decrease backwards. Accordingly, a tailplane must have smaller angle of attack than main wing, whereas a canard must have bigger angle of attack.

When a plane with tailplane pitches up so far as to stall the main wing, the wing falls – but the tailplane at lower angle of attack is as yet unstalled, keeps the tail up and therefore drops nose, releasing the main wing from stall;
when a plane with canards pitches up, the canard having higher angle of attack stalls first, drops nose and thus prevents main wing from stalling.

So either way the stabilizer prevents sustained stalls – and also changes of pitch short of stall.

Then how does Concorde fly without any horizontal stabilizer at all?

Note how big the wing chord is.

You can move the tailplane closer to main wing and still keep the plane stable – if the tailplane is made bigger on account of the smaller leverage.

Accordingly, a plane with big chord could completely merge the stabilizer into the trailing edge of the main wing.

With some obvious disadvantages.