Stability

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One definition of stability in regard to aircraft is:

The quality of an aircraft in flight which causes it to return to a condition of equilibrium when meeting a disturbance.[1]

There were efforts to make aircraft more stable in the air, and so this is a technological category for patents and publications.

Lawrence Hargrave made a useful finding that box kites were more stable than flat kites in the wind, and this led to the development of biplanes.

Some inventors focused on designing self-correcting systems, in which a tilt in one direction would predictably cause a compensatory corrective force.

Maxim, 1909, Artificial and Natural Flight, p. 92:

A ship at sea has only to be steered in a horizontal direction; the water in which it is floated assures its stability in a vertical direction; but when a flying machine is once launched in the air, it has to be steered in two directions—that is, the vertical and the horizontal. Moreover, it is constantly encountering air currents that are moving with a much higher velocity than any water currents that have ever to be encountered. It is, therefore, evident that, as far as vertical steering is concerned, it should be automatic.

(He recommends the gyroscope as the only acceptable means for accomplishing this type of stability.)

Stability versus control

Stability is closely related to the issue of how the pilot can control the aircraft (navigation or piloting), as the pilot may be able to accomplish through directed control the object of restoring the aircraft to a stable course. According to aviation historian Charles Harvard Gibbs-Smith, the European engineers of the first decade in the twentieth century were wedded to the "inherent stability" model, while the Wright Brothers had chosen to develop control systems.[2]

Crouch, 1981, p. 36, writes on the same subject:

Most experimenters chose simply to ignore the possibility of active pilot control in roll. Following the lead of French experimenter Alphonse Pénaud, they sought to perfect a mechanism that would guarantee absolute inherent lateral stability. This would mean that a flaying machine would proceed on a straight and level course, with the pilot intervening only when changing direction or altitude. Thus, a simple mechanism such as building dihedral into the wings, which would provide some measure of stability in roll, was substituted for an active control system. The rudder alone would be used to swing the aircraft around in a slow, flat turn, perhaps assisted by some device that could increase air resistance on the pivoting wing.

A number of factors explain this emphasis on automatic stability. Many students of the atmosphere were so convinced that upper-air gusts and currents shifted so rapidly as to defeat human reflexes. They believed that a mechanism that could "sense" these changes and automatically maintain the craft on an even keel was required. [...]

Just as important, however, is the fact that few experimenters really sought to develop a finished aircraft, complete with adequate controls. Most felt that the first task was to demonstrate a simple straight-line flight with a man on board. Once this had been accomplished, they argued, full attention could be given to control.

Other techtypes related to stability: ballonet, CPC B64C17/00, CPC B64C17/02, CPC B64C17/06, CPC B64C5/00, CPC B64C5/02, CPC B64D27/023, CPC F42B10/12, CPC F42B10/26, CPC F42B10/30, cybernetics, fighter airplane, Pratt truss, USPC 244/3.1, USPC 244/3.12, USPC 244/3.21, USPC 244/3.23, USPC 244/3.24, USPC 244/3.26, USPC 244/3.27, USPC 244/3.28, USPC 244/3.29, USPC 244/3.3, USPC 244/76, USPC 244/80, USPC 244/91

Enclosing categories simple tech terms
Subcategories gyroscope, pendulum, aileron
Keywords USPC 244/91, CPC B64C17/00, airfoil
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References

  1. Aircraft Year Book, 1919, "Nomenclature for Aeronautics", Compiled from Report No. 9 of the National Advisory Committee for Aeronautics, pp. 366–371.
  2. Gibbs-Smith, Aviation, 1970, pp. 111–112.

Other techtypes related to Stability: ballonet, CPC B64C17/00, CPC B64C17/02, CPC B64C17/06, CPC B64C5/00, CPC B64C5/02, CPC B64D27/023, CPC F42B10/12, CPC F42B10/26, CPC F42B10/30, cybernetics, fighter airplane, Pratt truss, USPC 244/3.1, USPC 244/3.12, USPC 244/3.21, USPC 244/3.23, USPC 244/3.24, USPC 244/3.26, USPC 244/3.27, USPC 244/3.28, USPC 244/3.29, USPC 244/3.3, USPC 244/76, USPC 244/80, USPC 244/91

Patents in category Stability

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