Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D15/00—De-icing or preventing icing on exterior surfaces of aircraft
  • B64D15/16—De-icing or preventing icing on exterior surfaces of aircraft by mechanical means, e.g. pulsating mats or shoes attached to, or built into, surface
  • B64D15/166—De-icing or preventing icing on exterior surfaces of aircraft by mechanical means, e.g. pulsating mats or shoes attached to, or built into, surface using pneumatic boots

Definitions

• the present invention relates to a device for checking the function of a de-icing means, consisting of at least one elongated container, which is arranged to reversibly increase its volume under the effect of a gas brought to the internal cavity of the container with a pressure superceding that of the surrounding atmosphere, the container being attached with a at least partly elastic wall to the external wall of an aircraft wing or horizontal tail, the interior of the wing or horizontal tail standing in gas pressure levelling connection with the surrounding atmosphere.
• Ice formation on aircraft is a problem that has been much noted, particularly in connection with accidents where it is presumed that ice formation has been the cause. It is especially common, that ice is formed on the leading edge of wings and horizontal tails during weather conditions that favour ice formation.
• aircraft are provided with containers of the kind mentioned above. They are called “boots” and are arranged in groups of several such containers parallelly on the leading edge of wings and horizontal tails. They are manufactured from combinations of synthetic rubber and raw rubber and fabric that is more or less elastic.
• the object of the present invention is therefore to provide a device of the kind mentioned in the introduction, which is simple and inexpensive, and gives great reliability when checking the correct functioning of the de-icing means.
• such a device is primarily characterized by an opening in said external wall, covered by an elastic part of said wall of the container, at which opening a sensor is arranged to sense occurring pressure difference between the internal cavity of the container and the interior of the wing and the horizontal tail, respectively, and to emit a corresponding signal.
• a pressure difference of adequate size for example 150 kPa
• the sensor is of course connected with an indication instrument or the like inside cockpit, so that the pilot will receive a direct acknowledgement of his action to increase the pressure in the de-icing means.
• the above-mentioned elastic part of the wall of the conatiner needs only be so elastic that a sensor can indicate a convexity.
• said sensor consists of a relatively stiff but flexible plate carrying a strain gauge, the plate being fixed relative to said external wall, arranged to be mechanically acted upon by the elastic wall of the de ⁇ icing means that is located over said opening, the strain gauge being arranged to emit a signal in dependence on occurring pressure difference between the internal cavity of the container and the interior of the wing and the horizontal tail, respectively.
• Fig. 1 schematically shows an aircraft in perspective, with markings of the parts of the wings and horizontal tails that are exposed to ice formation;
• Fig 2 schematically and in perspective shows a part of a de-icing means on a leading edge of wing, with a number of containers, i.e. "boots";
• Fig 3 schematically and in perspective shows a part of a container on the external wall of a wing with an opening for mounting a plate with strain gauge; wheras
• Fig 4 schematically shows a longitudinal section through the external wall of a wing with opening and the elastic wall of a de-icing means on one side and a plate with strain gauge on the other side.
• FIG. 1 an aircraft is shown with wings 1 and horizontal tails 3,
• de-icing means 2 On the leading edges of the wings de-icing means 2 are arranged, and on the horizontal tails the de-icing means 5. These consists, as is evident from Figure 2, of a number of elongated containers, so-called
• the plate 10 stands in rigid connection with the external wall of the wing.
• an overpressure for example in the order of 150 kPa
• a container to the degree this overpressure is brought unhindered to the container, there appears a pressure difference between the internal cavity 13 of the container and the interior 14 of the wing, which is. marked with arrows in Figure 4.
• the strain gauge 11 is acted upon, as the plate 10 is exposed to a certain, if small, bending, and a signal is emitted to the instrument 12, showing that an overpressure exists in the container, which is a certain indication that the internal cavity of the container 6 has been exposed to overpressure and that ice is cracked away frcm the leading edge of wing, or as the case may be the leading edge of a horizontal tail.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Measuring Fluid Pressure (AREA)
• Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20388688

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (4)

• 1993
  • 1993-01-28 SE SE9300258A patent/SE500464C2/sv unknown
• 1994
  • 1994-01-25 WO PCT/SE1994/000049 patent/WO1994016944A1/en active Application Filing

Patent Citations (4)

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