Get rid of tail heavy physics

[Chalenge]

Yes, but I'm saying loosing part of a wing won't affect speed in and of itself with the exception of drag created by the jaged edges. The rest of that stuff will cause a reduce in airspeed, and is required due to the loss of part of a wing, but loosing part of a wing in and of itself won't have a negative effect on airspeed.

The F8F Bearcat was designed (attempted anyway) so that catastrophic loss of both wing outer sections would increase speed and decrease turn radius. In AH if you lose a wing tip your plane will speed up (or at least has in the past).

[Dream Child]

     I  can understand why this effect could bother someone, but seriously, if your
tail is gone, the fight's pretty much over. 

I did mention that an FM-2 can go around in circles with the stabilizers gone, right?

[Rino]

     Well that doesn't seem very well modeled 

[Dream Child]

     Well that doesn't seem very well modeled 

I found this out in the DA. Needless to say, there were several protests on open channel after that one...

[Nemisis]

     Well that doesn't seem very well modeled 

Question. What is a stabalizer, and how does it function?

[Wedge1126]

In short, no. To demonstrate this, pick up a broom by the end of the handle and hold it parallel to the ground. The center of gravity is somewhere in the middle of the broom. All the lift is at one end. You could do the same thing with the wings, though it would be a very innefficient system to be that far from the center of gravity.

In your broom example, I would also be applying torque.

In my example, the tail and wings would generate a net force equal to and opposed to gravity. Where is the torque coming from?

Edit: I think from your argument, the torque would be from the downforce generated by the tail. I'm looking for the explanation from the opposing argument where both the wing and tail generate positive lift.

[Baumer]

In short, no. To demonstrate this, pick up a broom by the end of the handle and hold it parallel to the ground. The center of gravity is somewhere in the middle of the broom. All the lift is at one end. You could do the same thing with the wings, though it would be a very innefficient system to be that far from the center of gravity.

Dream Child, I believe there is an error in your analogy that might help explain the various forces that have been discussed in this thread so we can all understand it better.

First let me restate Wedges question with a slight rewording;

In level flight (with no other acceleration forces, i.e. stable in all 3 axis), the net force of tail and wing should be at the same point as CG. Otherwise, there will be a pitching motion, right?

From my education the answer is yes, the vector for lift and weight are exactly equal and in the opposite direction from one another, as are the vectors for thrust and drag.

Or another why to look at your analogy is this. Your hand is the wing (for the broom) the CG is aft of your hand, and the bristle end is where the horizontal stabilizer should be.  But since it's been shot-off I ask you this. Which direction is the part in your hand trying to move up or down?

I'm not trying to stir the pot but I think there are some fundamental terms that we (or at least me) should all be clear on to properly discuss this topic. As Wedges question stated he was asking about net lift not just the wing lift component.

 

[Dream Child]

Question. What is a stabalizer, and how does it function?

For the purposes of this discussion, a stabilizer is the non-moving part of the tail that holds the elevator. The elevator controls pitch (up/down).

[Dream Child]

In your broom example, I would also be applying torque.

In my example, the tail and wings would generate a net force equal to and opposed to gravity. Where is the torque coming from?

Edit: I think from your argument, the torque would be from the downforce generated by the tail. I'm looking for the explanation from the opposing argument where both the wing and tail generate positive lift.

Looking at the question again, yes, the net force at the CG has to be zero to keep from changing pitch. Didn't do a good job reading the question first time.

[Kweassa]

I've seen a footage of an air-race midair collision in which a rear approaching plane collided with another plane flying in front of it. I took particular interest in the result, since it almost exactly replicated what happened in AH.

The plane behind smashed into the tail of the plane in front, and removed the whole rear fuselage - the horizontal, vertical stabs were gone in an instant. Obviously, the pilot of the plane behind tried to avoid the collision, and most of the damage was done by the props which just simply chopped off the rear end of the plane flying in front of it.

It was exactly the same thing as seen in AH when a plane fires at the target and blows off either the whole aft fuselage, or the two horizontal stabs.

... and what ultimately followed, was again, the same thing as seen in AH.

The plane which suddenly lost its tail, flipped upwards nose-high. The only difference was that in AH, the planes flips nose-high and then falls downwards in that state, whereas in real life, the plane flips upwards nose-high, and then the momentum of the flipping goes on and ultimately tumbles the wreckage, and it falls down to the ground tumbling and spinning in all directions.

At that moment, I was impressed by how AH got it right.

Obviously, in real life, things happen in the way how AH describes it, Dream Child, not in the way you think it might.

[PJ_Godzilla]

Only if you consider the force acting on the H-stab is acting in a downward motion.  Its not.  Unless there's some down-wash or relative wind issue I'm not considering, the lift vector of the H-stab is up, in the same direction of the lift vector of the wing.

Again, answer why we de-camber the H-stab (by pulling back on the yoke/stick, which induces an upward deflection of the elevator and decambers the airfoil of the H-stab) and reduce lift to make the plane pitch up?  Why do we increase the lift vector of the H-stab to make the plane pitch down?

NO, no, and no...

The H-stab is most definitely producing downforce when you're flying level at constant speed. What you call decambering is actually a camber increase (viewed upside down) and increases that negative lift. That's the force that causes the pitch moment and it very definitely points down.

Believe me on this. I got my MSE Aero from Stanford and worked in windtunnels at NASA ARC for years.

[PJ_Godzilla]

In short, no. To demonstrate this, pick up a broom by the end of the handle and hold it parallel to the ground. The center of gravity is somewhere in the middle of the broom. All the lift is at one end. You could do the same thing with the wings, though it would be a very innefficient system to be that far from the center of gravity.

Actually, you can do this with a flying wing. There is such a thing as a statically stable flying wing but, as you've surmised, you need it creating some downforce aft to counteract the pitch moment caused by the lifting surface. You can think of it, if you like, like a compound wing that serves the same purpose as the wing plus h-stab on a conventional tailed aircraft.

You've also surmised, but for the wrong reason, that using an h-stab, or compounded wing, to create an aft downforce is somehat inefficient. This is generally true - creating downforce at some distance from the cg increases induced drag - both from the surface creating the negative lift (the h-stab) and from the wing itself - which has to create lift to counter the grav force PLUS that negative lift from the h-stab aforementioned.

This is a good time to introduce THE CANARD, whose forward h-stab lifts UP to counter the pitch caused by the wing which lifts aft of the CG.

Active stability is another story altogether - but is primarily done for maneuverability and efficiency and does away with pesky control surfaces making (usually) unnecessary forces.

[Ex-jazz]

Question

Is the Scale 1 showing the CG weight figure OR less/more?

[hitech]

Question

Is the Scale 1 showing the CG weight figure OR less/more?

(Image removed from quote.)

Ooow Ooow Ooww mista cata mista cata.

HiTech

[Baumer]

LOL hitech back in the day!



My answer would be, it depends on if the aircraft is a taildragger or not!