New answers tagged stability
4
It depends on general geometry of the aeroplane:
The vertical position of the main wing and the horizontal tail.
If the aeroplane even has a horizontal tail.
The sweep angle.
The angle of incidence in the landing flare.
When a wing enters ground effect, its lift coefficient rises: the wing creates more lift at a given speed and Angle of Attack. A wing is ...
3
Ground effect makes the airplane more longitudinally stable for two reasons:
Ground effect increases the lift curve slope ($\frac{\partial{C_{L_t}}}{\partial{\alpha_t}}$) of the tailplane due to vortex reduction. An increase in tail lift curve slope is equivalent to increasing the effective tail volume.
Ground effect decreases the downwash of the wing on ...
2
If the pivot (suspension point) of a pendulum is inside a plane, for example in the ceiling of the cockpit, it does not matter were, it will have a random acceleration and in consequence it will move like in the animation you can see below. The demonstration can be found here. The pendulum never aligns to the vertical and so it is useless as a reference able ...
2
Based on all comments the question received, I will try to formulate a clear answer illustrated with a picture.
The vane V will always tend to stay in the same plane as the axis XX' no matter what the glider does: climbs, descends or flies horizontally. If the vane goes toward the upper or lower wing then automatically it will drive the mechanism that ...
3
The free dictionary is correct: Damping results from rotation.
Since all rigid-body rotations of a flying aircraft will occur around its center of gravity (this is a consequence of the conservation of momentum), that rotation will cause a vertical movement of parts which have a distance to the axis of rotation. This vertical movement changes the local angle ...
0
Damping is a force that opposes motion, and is a function of velocity. It is an important factor in responses of equilibrium distortions - the classical way to explain this is to consider a spring/damper combination, as described here. Damping provides energy loss, so that the oscillation stops.
If an aeroplane is trimmed and stable, it can be flown hands-...
5
The link you provided has a poor choice of words: "restoring moment".
Damping forces are not restorative, i.e. they do not attempt to return the body to equilibrium, but rather oppose its movement. That is an important nuance.
Imagine a classic spring and dashpot vehicle suspension: the spring tries to restore the vehicle to its regular position, while the ...
1
No, I don't see how this would work as a controller for maintaining flight level. The angle of attack on any part of the airplane during a steady-state climb is identical to that of level flight, so there is no additional "relative wind" for the mechanism to work with.
However, a proportional feedback in angle of attack is a valid stability augmentation ...
8
Yes, this vane-based stabilizer really did work. In fact the pendulum system for direction control also worked as it was used to sense yaw in a slip, just like the ball in a turn and bank indicator.
The entire system worked so well that Orville Wright received the 1913 Collier Trophy "For development of the automatic stabilizer" after demonstrating it for ...
1
This appears to be a mechanical version of the modern computer driven Angle of Attack vane / Stabilator pitch control system. The catch is it is based on relative wind. A plane can do an entire loop without changing its AOA with a very good pilot using throttle and gravity.
So, back in 1908, to maintain altitude, one might try a balloon mounted in a ...
Top 50 recent answers are included
