Sextant Avionique

Thomson-csf

Thales

Thales Avionics S.a.

Joel Choisnet

Henri Leblond

Jacques Mandle

Jean-Marc Breda

Lionel Collot

Nicolas Hanson

Monique Naim

Gregoire Dodel

The invention relates to a probe for aerodynamic measurement of an airflow. The probe comprises a plate rotating about an axis, a transmitter for transmitting a sound wave and a receiver responsive to the sound wave, the transmitter and the receiver forming two elements which are integrally connected to the plate and are placed at separate positions on the plate, the probe furthermore comprising means for delivering information representing a time of flight of the sound wave between the two elements and a temporal variation of the information. In the case of using the probe on board a helicopter, the rotating plate is advantageously placed at the centre of the rotor of the helicopter while being integrally connected to it. This type of probe makes it possible to carry out aerodynamic measurements even at low airspeeds of the helicopter.

Aerodynamic measurement probe and helicopter equipped with the probe

The invention pertains to a process for determining aerodynamic parameters of an airflow surrounding an aircraft. On the basis of at least two probes situated on the skin of the aircraft, each probe comprising means for measuring the local angle of attack (&#x3b1;, &#x3b1;), the process consists in determining the angle of attack (&#x3b1;) and/or sideslip (&#x3b2;) of the aircraft, as a function of the local angle of attack of each probe and of the aerodynamic field of the aircraft. The invention also pertains to a process for detecting a fault with a probe used to determine the aerodynamic parameters of the airflow surrounding an aircraft. This fault detection process consists in:

Method for determining aerodynamic parameters and method for detecting failure of a probe used for determining aerodynamic parameters

A fixed multifunction probe, e.g., for aircraft and configured to measure air flow parameters near an airplane. The probe includes a body closed by a rounded cap, at least three pressure taps situated at specified positions of the body, a pressure measurement mechanism for measuring at least as many pressures as pressure taps, and a calculation device for calculating the air flow parameters.

Fixed multifunction probe for aircraft

An optical device on board an aircraft for detecting icing conditions including an optical beam emitter to create at least one illuminated external volume of measurement through which there circulates a flow of air charged with water particles; a collector optical system for the collection of at least a part of the light beam back-scattered by the water particles (the external volume of measurement being located on the optical axis of said collector optical system); a photodetector for detecting back-scattered optical beams; a signal processor for processing the signal delivered by the photodetector to compute the severity of the icing conditions; an information provider for providing information on the calculated severity of the icing conditions. Advantageously, the optical means for the differentiation of device includes a differentiation for differentiating between liquid water particles and solid water particles, based on analysis of the polarization.

Optical device for the detection of icing conditions on aircraft

A method and apparatus for determining the severity of icing conditions for an aircraft in flight. A mobile probe projecting from a surface of the aircraft is heated to a predetermined range of temperatures, and the total power required for the heating is measured. The measured total power is divided into a basic power corresponding to the thermal exchange in dry air having the same flow parameters as those measured and a complimentary power corresponding to the evaporating of drops of water contained in the actual air. A parameter representative of the speed at which the thickness of ice increases at the surface of the aircraft is computed from the complementary power.

Procedure and devices to determine the severity of icing conditions for

The present invention relates to an incidence probe, in particular for an aircraft, comprising at least two pressure inlets. To this end, it comprises a least one flowmeter (1) and a pneumatic restriction (4) arranged in series between two pressure inlets.

Incidence probe with multiple pressure inlets

An apparatus for the detection of the icing-up of an aircraft rotor. The apparatus has a sensor (10) for the tractive force and a sensor (11) for torque; for measuring respectively the axial force and the torque exerted on the shaft of the rotor. A device (12) calculates the ratio between these two quantities. A determination is also made, as a function of the flying conditions, of what should be the nominal value of this ratio in the absence of icing-up. Finally a device (12) compares the calculated ratio with the nominal ratio.

Apparatus for the detection of the icing-up of the blades of an aircraft

Disclosed are capacitive sensors designed to measure the very low-amplitude displacements of two zones with respect to each other. It comprises a capacitive element formed by two elements that are fitted to each other by a shrink-on method, and respectively having two facing cylindrical surfaces, the longitudinal axes of which are parallel to one and the same given direction, these surfaces bearing electrodes, at least some of which have limits parallel to the given direction. These two supports are respectively rigidly connected to the two zones, so much so that the capacitance of the capacitors formed by the electrodes of the facing surfaces varies as a function of the relative displacements of the two zones perpendicularly to the given direction. Thus the measurement of the displacements perpendicularly to this given direction is done by a measurement of variation in capacitance.

Capacitive sensor of displacement and twist angle sensor including at

The disclosed sensor has a sleeve which forms a section of an engine shaft. Pairs of plane electrodes, parallel to the axis of the shaft, are arranged in the sleeve. The two electrodes of one and the same pair are respectivley soldily joined to the ends of the sleeve, and form a capacitor the inter-electrode space of which varies when an engine torque causes a torsion of the sleeve. The variations in the capacitances of the capacitors are measured by an electronic circuit borne by a plane internal to the sleeve of the sensor. A rotating transformer provides for the supply to the electronic circuit and the transfer of output signals from this circuit to an operating device external the sensor. The disclosed device can be applied to the measurement of torque transmitted bya helicopter engine shaft.

Torsion angle capacitive sensor and torque measuring

A device for measuring the ratio between a first capacitor and a second capacitor in which first and second switches are provided for selectively conducting a signal, therethrough based on a control signal. A capacity switching device receives the two capacitors, and includes a third switch for switching between these two capacitors. A control device controls the first and second switches to conduct in phase opposition to one another, and the third switch to connect the first and second capacitors separately and successively between the first and second switches. An integrator is connected to the output of the capacity switching device to integrate the output signal, and a capacity ratio measuring circuit is provided to detect the capacity ratio. In this way, detection of capacity ratio can be performed independent of the switching currents for the switches, the biasing current for the integrating amplifier, and any other biasing currents.

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La Frette Sur Seine, France

Joel Choisnet