TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

A gyroscope that uses the property of gyroscopic rigidity to sense changes in altitude of a machine, such as an airplane; the spinning wheel or rotor is isolated from the airplane by gimbals; when the plane changes from level flight, the gyro remains vertical and gives the pilot an artificial horizon reference.  8, record 1, English, - free%20gyro

Record number: 1, Textual support number: 1 CONT

A free (unrestrained and not subject to any outside force) gyroscope is fixed to space... This means the centerline of the axle points to two points of absolute rest, 180 degrees apart, to the Universe or in the up and down direction.  3, record 1, English, - free%20gyro

Record number: 1, Textual support number: 1 OBS

... in order to be free of gravity, gyroscopes can be placed in a Cardan mount, which permits the gyroscopes to remain free of forces exerted on the systems of which they are a part. In the Cardan mount the shaft of a gyroscope wheel is mounted in a gimbal ring, which in turn is mounted in a larger gimbal ring along a diameter that is at right angles to the axis of the wheel.  6, record 1, English, - free%20gyro

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Gyroscope dont la suspension à la cardan est exempte de toute liaison.  3, record 1, French, - gyroscope%20libre

Record number: 1, Textual support number: 1 CONT

Le conservateur de cap, également appelé directionnel, est un gyroscope libre dont l'axe est orienté horizontalement selon la direction qui lui a été assignée lors de sa mise en rotation.  4, record 1, French, - gyroscope%20libre

Record number: 1, Textual support number: 1 OBS

Cardan : Système de suspension dans lequel le corps suspendu conserve une position invariable malgré les oscillations de son support.  5, record 1, French, - gyroscope%20libre

Record number: 1, Textual support number: 2 OBS

Cardan : Nom francisé du savant italien Cardano, 1501-1576.  5, record 1, French, - gyroscope%20libre

Record 1,  Textual support,  Spanish

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 CONT

Gyroscopes can be used as devices for direction finding, guidance, and control. If a gyroscope, mounted on its gimbal rings, is set spinning about a horizontal axis, and the outer gimbal ring is rotated in a horizontal plane, then the inner gimbal ring, carrying the flywheel, tilts up out of the horizontal plane in which it, too first lay. After a few oscillations, damped out by friction, the axis of spin of the gyroscope settles down along a vertical direction. Inertial guidance systems make use of very similar phenomena. Once a gyroscope has been set spinning about a chosen axis, any motion that would cause it to deviate from this direction calls into existence a torque that can be used as an error signal to control corrective maneuvers... Some of the most important applications of gyroscopic phenomena are in aircraft instruments. A free(perfectly balanced) gyroscope can give a constant indication of a chosen reference direction for checking the correct course, and a gravitationally loaded gyroscope can be used to identify the true vertical at all times and so define an artificial horizon against which the pilot can measure the angles of bank and climb.  2, record 2, English, - gyroscopic%20phenomenon

Record 2,  Textual support,  French

Record number: 2, Textual support number: 1 CONT

Le gyroscope construit par Foucault 1852 est un appareil qui dérive de son pendule. Comme lui, il met en évidence les effets de la rotation de la terre. Il est constitué d'une masse lourde, appelée rotor, en mouvement de rotation rapide autour d'un axe restant fixe dans un référentiel galiléen. Le gyroscope se caractérise par un moment cinétique élevé. Il existe des gyroscopes dont l'axe en rotation est lié à l'armature de l'appareil par deux axes et d'autres reliés à un seul axe. On retrouve le phénomène gyroscopique dans des jouets tels que les toupies. Il est utilisé dans des appareils appelés compas gyroscopiques servant au guidage des missiles, des avions et des satellites.  2, record 2, French, - ph%C3%A9nom%C3%A8ne%20gyroscopique

Record 2,  Textual support,  Spanish

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 CONT

In a skidding turn, the gyro precesses towards the inside of the turn. After return on the aircraft to straight and level flight, the instrument shows a turn in the direction of the skid. In a normal turn, the gyro precesses towards the inside of the turn. The precession error is quickly corrected by the erecting mechanism.  2, record 3, English, - erecting%20mechanism

Record number: 3, Textual support number: 2 CONT

The only really tricky part of the attitude indicator is its erecting mechanism. When power(vacuum) is first applied to the instrument, the mechanism quickly erects the gyro spindle to plumb-vertical in order to align the artificial horizon with the natural horizon. In flight, the erecting mechanism continually compensates the gyro for precession errors in order to keep it aligned throughout the course of a long flight. The design of the erecting mechanism is quite clever. In an air-driven attitude gyro, there are "pendulous vanes" suspended from pivots attached to the lower portion of the sealed gyro housing, one vane for each exhaust port. The vanes are positioned so that, when the gyro is erect, each vane half-covers its associated exhaust port. If the gyro tilts so that its axle is not plumb, the pendulous vanes shift so that one exhaust port is more-than-half-covered and the opposite exhaust port is less-than-half-covered. The resulting imbalance of discharge air exerts a force on the rotor housing at right angles to the direction of tilt, causing the gyro to precess to the erect position. As soon as the gyro is erect, the pendulous vanes return to a balanced condition to remove the precessing force. Pure magic! The erecting mechanism can erect the gyro quite quickly at initial power-up because the gyro doesn’t exhibit much gyroscopic rigidity at low rotor RPMs. Typically, the horizon bar becomes level within the first 10 or 15 seconds, and then its oscillations(caused by precessional nutation of the gyro) are damped out within a minute or so as the rotor comes up-to-speed.  3, record 3, English, - erecting%20mechanism

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 CONT

Dans un virage dérapé, le gyroscope «précesse» du côté du virage. Une fois l'avion revenu au vol rectiligne en palier, l'instrument indique un virage dans la direction du dérapage. Dans un virage normal, le gyroscope «précesse» du côté du virage. Le mécanisme de redressement du gyroscope corrige rapidement l'erreur de précession.  1, record 3, French, - m%C3%A9canisme%20de%20redressement

Record number: 3, Textual support number: 2 CONT

Description d'un Épervier [drone] [...] d. Le gyroscope vertical: Dans ce cas, les deux axes, ROLL et PITCH sont terminés par les potentiomètres qui détectent les écarts de positions angulaires du corps par rapport aux horizons roll et pitch. Les mécanismes d'érection ne sont prévus que pour maintenir la verticalité parfaite de la masse en rotation.  6, record 3, French, - m%C3%A9canisme%20de%20redressement

Record number: 3, Textual support number: 1 OBS

Horizon gyroscopique [...] La verticalité de l'axe de toupie [delta] est approximativement assurée par un érecteur (mécanique, électro-mécanique, pneumatique) produisant une raideur en quadrature de signe convenable.  7, record 3, French, - m%C3%A9canisme%20de%20redressement

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

Record number: 4, Textual support number: 1 CONT

The attitude indicator (also called the artificial horizon or the gyro horizon) provides the pilot with an artificial horizon as a means of reference when the natural horizon cannot be seen because of cloud, fog, rain or other obstructions to visibility... The natural horizon is represented by a horizon bar on the face of the instrument.  4, record 4, English, - natural%20horizon

Record number: 4, Textual support number: 2 CONT

The attitude indicator relies on the principle of gyroscopic rigidity in space--the rapidly-spinning rotor disk resists any attempt to disturb its orientation. Thus, the gyro provides a stable horizontal reference against which the pitch and roll attitudes of the aircraft can be measured. The "artificial horizon bar" on the face of the attitude indicator is mechanically coupled to the gyro inside, so it remains parallel to the natural horizon. The instrument's little "symbolic airplane" is fixed to the instrument case, however, so it follows the roll and pitch movements of the real airplane. Consequently, the relationship of the horizon bar to the symbolic airplane is the same as the relationship between the natural horizon and the real airplane.  5, record 4, English, - natural%20horizon

Record number: 4, Textual support number: 3 CONT

The attitude indicator and heading indicator are based on a gyro’s rigidity in space. Because a gyro resists being tipped over, it can provide a stable reference to the real horizon or to a specific direction.  2, record 4, English, - natural%20horizon

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 CONT

Horizon artificiel. Cet instrument gyroscopique indique au pilote la position des ailes et du nez de l'avion par rapport à l'horizon terrestre lorsque l'horizon naturel n'est pas visible en raison des nuages, du brouillard, de la pluie.  2, record 4, French, - horizon%20naturel

Record number: 4, Textual support number: 2 CONT

En cas de perte des références extérieures, (rentrer dans un nuage, forte dégradation de la visibilité par brume ou pluie...), le pilote ne disposera plus que d'une vision réduite de son environnement par l'intermédiaire de l'horizon artificiel. Cet instrument sera - au même titre que l'horizon naturel en pilotage à vue - sa référence principale.  4, record 4, French, - horizon%20naturel

Record number: 4, Textual support number: 3 CONT

L'horizon artificiel dont se servent les pilotes d'avion est produit par un gyroscope en mouvement. Cet instrument est extrêmement important pour les pilotes puisqu'il leur indique la position de l'avion par rapport à l'horizon vrai.  3, record 4, French, - horizon%20naturel

Record number: 4, Textual support number: 1 OBS

Les termes «horizon terrestre» et «horizon naturel» ne sont pas de parfaits synonymes mais, en contexte de pilotage avion, on peut penser que les deux termes se confondent.  5, record 4, French, - horizon%20naturel

Record 4,  Textual support,  Spanish

Record 5,  Textual support,  English

Record number: 5, Textual support number: 1 DEF

The mode of operation of a vertical gyro in which the gyro is being erected or slaved initially.  2, record 5, English, - initial%20erection

Record number: 5, Textual support number: 1 CONT

Gyroscopic instruments... Once the artificial horizon line is aligned with the natural horizon of the earth during initial erection, the artificial horizon is kept horizontal by the gyro on which it is mounted. An erection mechanism automatically rights the gyro when precession occurs due to maneuvers or friction. When the older-type gyro tumbles as a result of extreme attitude changes, the rotor normally precesses slowly back to the horizontal plane. Even an attitude indicator in perfect condition can give slight erroneous readings. Small errors due to acceleration and deceleration are not significant because the erection device corrects them promptly; nonetheless, the pilot should be aware of them...  3, record 5, English, - initial%20erection

Record number: 5, Textual support number: 1 OBS

The initial erection rate is usually relatively high.  4, record 5, English, - initial%20erection

Record 5,  Textual support,  French

Record 5,  Textual support,  Spanish