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Es/Velocidad de la aeronave

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Speed combines two factors, the distance travelled in a certain amount of time. In aviation speed is most often expressed in knots (kt). One knot is one nautical mile per hour. In aircraft the speed is "measured" with a pitot tube, the result is not the speed of the aircraft, it is the speed of the air flowing around the aircraft, the airspeed.

Velocidad combina dos factores, la distancia' viajó en una cierta cantidad de tiempo'. En la aviación velocidad se expresa con más frecuencia en 'nudos (kt). Un nudo es una milla náutica por hora. En los aviones, la velocidad se "mide" con un tubo pitot, el resultado no es la velocidad de la aeronave, es la velocidad del aire que fluye alrededor de la aeronave, la http://en [.wikipedia.org / wiki / Airspeed 'velocidad].

In older planes, notably German WW II fighter planes, the airspeed is indicated in kilometres per hour (km/h), which is still used in present-day European glider planes. The conversion factor is 1.852, i.e. you can roughly divide a reading in km/h by two in order to get the value in knot.

En los antiguos aviones, sobre todo alemanes de WW II aviones de combate, la velocidad se indica en kilómetros por hora (km / h), que todavía se utiliza hoy en día en los aviones planeadores europeos. El factor de conversión es de 1,852, es decir, que más o menos se puede dividir la lectura en km / h por dos para obtener el valor en el nudo.

If the speed is indicated in knot, sometimes a 'K' is put before the acronym, so KEAS stands for 'equivalent airspeed in knot'.

Si la velocidad se indica en el nudo, a veces una 'K' se presenta ante el acrónimo, por lo KEAS significa "velocidad equivalente en el nudo.

For (near-)supersonic planes the speed can be expressed in Mach. Para (cerca-) aviones supersónicos la velocidad se puede expresar en Mach.

Expresiones de velocidad

Velocidad respecto a tierra

  • Ground speed (GS) is the horizontal speed in which the aircraft moves relative to a fixed point on the ground.
  • Ground velocidad (GS) es la velocidad horizontal en la que la aeronave se mueve con respecto a un punto fijo en el suelo. La velocidad de avance.

One needs to know the GS in order to see how long a flight from A to B actually takes. Nowadays GS can be directly measured using a GPS system, and some aircraft equipped with such a system have a GS indicator. The GS can be calculated from TAS by correcting it for the prevailing wind at altitude or by measuring the time between passing two points on the ground radio beacons with a known distance, but in Flightgear you can always cheat and get it from the property browser under velocities/groundspeed-kt.

Uno necesita saber la GS con el fin de ver cuánto tiempo un vuelo desde A hasta B en realidad se necesita. Hoy en día GS puede ser medido directamente usando un sistema GPS, y algunos de los aviones equipados con un sistema de tener un indicador de GS. El GS se puede calcular a partir de TAS corrigiendo por el viento predominante en la altura o midiendo el tiempo que pasa entre dos puntos de la tierra radio balizas con una distancia conocida, pero en Flightgear siempre se puede engañar y conseguir que a partir de el explorador de propiedades bajo velocidades velocidad respecto a tierra-kt .

GS is the velocity in the horizontal direction of the aircraft. I.e. in a steep dive, the aircraft can move very fast, but because the motion is chiefly vertical, the ground-speed can be very small at the same time. This is where the GS differs from the ground-speed of a car.

GS es la velocidad en la dirección horizontal de la aeronave. Es decir en una picada, el avión puede moverse muy rápido, pero debido a que el movimiento es principalmente vertical, la velocidad de tierra puede ser muy pequeño al mismo tiempo. Aquí es donde la GS se diferencia de la tierra-velocidad de un automóvil.

Velocidad verdadera

The difference between TAS and GS is that the air itself may move with respect to the ground (that's wind), and dependent on course relative to the wind direction a discrepancy between TAS and GS is induced. TAS can't really be measured directly but needs to be calculated, unless standing still on the ground where the TAS can be "seen" with the windbag.

La diferencia entre TAS y GS es que el aire mismo se puede mover con respecto a la tierra (que es el viento), y depende de la trayectoria en relación con la dirección del viento una discrepancia entre TAS y GS es inducida. TAS no se puede medir directamente, pero tiene que ser calculada, a menos que inmóvil en el suelo, donde el TAS se puede "ver" con el charlatán manga chivato de viento.

Knowing TAS during flight is surprisingly useless - for navigation, ground speed is needed, and aerodynamic limits do not depend on TAS but rather IAS. The chief value of TAS is as a measure of aircraft performance and in pre-flight planning before the wind effect is taken into account.

Sabiendo TAS durante el vuelo es sorprendentemente inútil - para la navegación, la velocidad de avance que se necesita, y límites aerodinámicos no dependen de la TAS, sino más bien la IAS. El principal valor de TAS es una medida de la performance de las aeronaves y de planificación previa al vuelo antes de que el efecto del viento es tomada en cuenta.

The TAS can be calculated from CAS, air temperature and pressure altitude and is the second step to calculate the GS from IAS for navigation.

El TAS se puede calcular a partir de CAS, la temperatura del aire y del altitud de presión y es el segundo paso para el cálculo de la SG de la NIC para la navegación.

Often TAS and GS are assumed (confused) to be the same, they are not. A menudo TAS y GS se supone (confundido) a ser el mismo, no lo son.

Velocidad indicada

Airspeed is usually measured with a #Pitot tube at the front of the aircraft. The IAS can be the CAS. The IAS is not the TAS since the pressure differs greatly with altitude (more specific the density of the air). The higher the altitude the lower the IAS while flying the same TAS.

Airspeed se mide normalmente con un Tubo Pitote en la parte delantera de la aeronave. El IAS puede ser el CAS. La IAS no es el TAS puesto que la presión difiere en gran medida con la altitud (más específico de la densidad del aire). Cuanto mayor sea la altitud menor será la IAS aunque se vuele con el mismo TAS.

In spite of this dependence on altitude, IAS is a very useful quantity in flight. Many aerodynamical properties, for example drag, lift, the stress on the airframe, stall speed or the forces on control surfaces depend on the dynamic pressure generated by the airstream, not on the actual aircraft speed. The stall speed of an aircraft at sea level is very different from the stall speed (in TAS) at 30.000 ft - but they correspond to the same IAS reading.

A pesar de esta dependencia de altura, la NIC es una cantidad muy útil en vuelo. Muchas de las propiedades aerodinámicas, para arrastrar ejemplo, levantar, la presión sobre la velocidad de fuselaje establo, o las fuerzas sobre las superficies de control dependen de la presión dinámica generada por la corriente de aire, no en la velocidad real de la aeronave. La velocidad de pérdida de un avión a nivel del mar es muy diferente de la velocidad de pérdida (en TAS) a 30,000 ft - pero que corresponden a la misma lectura de la NIC.

At sea level, a IAS of 400 knot roughly corresponds to 400 knot TAS. At 80.000 feet (the cruising altitude of a SR-71), the IAS of 400 knot corresponds to a TAS in excess of 1600 knot (..that corresponds with about Mach 3 at that altitude).

A nivel del mar, un SAI de 400 nudos corresponde aproximadamente a 400 nudos TAS. A 80,000 pies (la altitud de crucero de un SR-71), la NIC de 400 corresponde a un nudo TAS en exceso de 1600 nudo (.. que se corresponde con aproximadamente Mach 3 a esa altitud).

Velocidad calibrada

Modern equipment can most often can indicate the CAS. For navigation the CAS is the first step to calculate the GS.

Los equipos modernos pueden mayoría de las veces puede indicar la CAS. Para navegar el CAS es el primer paso para el cálculo de la GS.

Velocidad equivalente

At high altitude, the compressibility of air changes, so even CAS becomes more and more unreliable. For the SR-71 Blackbird with a ceiling of 85.000 feet, the CAS becomes very unreliable and the plane has to be flown based on a EAS. For more conventional aircraft, EAS is not used. Thus, EAS is what a perfect dynamic pressure sensor would show when properly calibrated for the air compressibility at the current altitude. The EAS is the calculated result from the ram pressure (measured by the #Pitot tube) and the static pressure (measured by the altimeter).

A grandes altitudes, la compresibilidad del aire cambia, por lo que incluso CAS se vuelve cada vez más fiable. Para el SR-71 Mirlo con un techo de 85,000 pies, el CAS se hace muy poco fiable y el avión tiene que volar sobre la base de una EAS. Para las aeronaves más convencional, EAS no se utiliza. Por lo tanto, EAS es lo que un sensor perfecto presión dinámica se muestran cuando está debidamente calibrado para la compresibilidad del aire en la altura actual. El EAS es el resultado calculado de la presión del ariete (medida por el # de tubo Pitot) y la presión estática (medida por el altímetro).

Número Mach

  • The Mach number (M) is the speed of the aircraft divided by the speed of sound (at that altitude). It is a calculated number without a unit.
  • El 'número de Mach' (M) es la velocidad de la aeronave dividido por la velocidad del sonido (a esa altitud). Se trata de un número que se calcula sin una unidad.

The aircraft's behaviour at Mach 1 at sea level is about the same as the behaviour of the aircraft at an altitude of 60000 feet. A Mach number below 1 means that the plane moves subsonic. A Mach number above 1 indicates supersonic flight. The Mach number is critical because a number of phenomena take place just around Mach 1 (transonic speed), for example a sudden increase in drag induced by shock-wave generation (sonic-boom). Aircraft that are not designed to fly supersonic will break up at Mach 1. The shape of the aircraft can cause parts of the aircraft being at or above Mach 1 while the fuselage is subsonic. Flying near Mach 1 can be quite dangerous, for most fast (but subsonic) aircraft Mach 0.83 is the limit. High flying aircraft, like passenger aircraft, can reach that limit easy while descending.

El comportamiento del avión a Mach 1 a nivel del mar es aproximadamente el mismo que el comportamiento del avión a una altitud de 60000 pies. Un número de Mach por debajo de 1 significa que el avión se desplaza subsónico. Un número de Mach superior a 1 indica el vuelo supersónico. El número de Mach es crítica porque una serie de fenómenos tienen lugar sólo alrededor de Mach 1 (velocidad transónica), por ejemplo, un repentino aumento en la resistencia inducida por la generación de ondas de choque (sonic-boom). Las aeronaves que no están diseñadas para volar supersónico se romperá a Mach 1. La forma de la aeronave puede causar que las partes de la aeronave que está siendo igual o superior a Mach 1, mientras que el fuselaje es subsónico. Avión cerca de Mach 1 puede ser muy peligroso, por más rápido (pero subsónico) aviones Mach 0,83 es el límite. Alta aviones volando, como aviones de pasajeros, puede llegar a ese límite fácil al descender.

The speed of sound changes with the compressibility (and hence temperature) of air, the Mach number is dependent on altitude (as the air temperature drops at higher altitudes). This implies that Mach 2 at sea level corresponds to a faster TAS than Mach 2 at 30.000 ft. The precise relation between TAS, Mach number and altitude is a complicated formulae and depends in essence on the local weather pattern determining the pressure and temperature gradients in the atmosphere. The Mach number is measured/calculated from the same information as the EAS (#Pitot tube and altimeter)

La velocidad del sonido cambia con la compresibilidad (y por lo tanto la temperatura) del aire, el número de Mach es dependiente de altura (como la temperatura del aire disminuye a mayores altitudes). Esto implica que Mach 2 a nivel del mar corresponde a un más rápido TAS de Mach 2 a 30,000 pies La relación precisa entre TAS, del número de Mach y la altitud es una fórmulas complicado y depende en esencia en el patrón de tiempo local para determinar los gradientes de presión y temperatura en la atmósfera. El número Mach es medido / calculado a partir de la misma información que el EAS (# Tubo Pitot y altímetro)

Velocidades V

For the complete V speed "definitions" list please visit Wikipedia. Here a small abstract. Note that V speed definitions can depend of local Flight rules. Most V speeds depend on the aircraft configuration (how much it weights etc.) so must be calculated forehand and must be included in the flight-plan. V speeds are used to compare aircraft performance and will be mentioned in the aircraft flight manual (AFM).

  • M speeds are expressed in Mach.
V1 Take-off decision speed & Critical engine failure recognition speed.

During take-off the speed at which the aircraft safely can take-off even when one (of more) engine fails ("eats a bird"). The co-pilot (FO) will call out V1 during take-off, the pilot will check if all engines are running and decides to continue or abort take-off.

VR Nose-wheel take off speed.

The speed at which the nose-wheel leaves (should leave) the ground. As the speed increases the yokes will be pulled at Vr. It is also the speed at which the aircraft still can be stopped if there is a critical failure. The co-pilot (FO) will call out "rotate" during take off. VR is very similar to VROT and VREF.

V2 Take-off safety speed.
V3 Flap retraction speed.
VA Design manoeuvring speed. Above this speed it is a bad idea to make sudden manoeuvres.
VLO Maximum landing gear operating speed.
VLE Maximum landing gear extended speed.
VFE Maximum flap extended speed.
VC Design cruising speed, also known as the optimum cruise speed, is the most efficient speed in terms of distance, speed and fuel usage.
VS Stall speed or minimum steady flight speed for which the aircraft is still controllable.
VS0 Stall speed or minimum flight speed in landing configuration.
VRef Landing reference speed or threshold crossing speed.
VMO Maximum operating limit speed.
VNE Never exceed speed.
VNO Maximum structural cruising speed or maximum speed for normal operations.
  • Not knowing the (complete list of) V speeds has caused dramatic accidents. It has occurred that the pilot and co-pilot were not aware of the minimal speed of an aircraft during landing with one engine damaged causing loss of control just before touch-down (the pilot gave full throttle hoping to gain speed expecting to get back control causing the left-over engine push the aircraft to one side).

Tubos Pitote

The pitot tube is the tool to measure the airspeed. It is a tube directed forwards, exposed to the airstream. The air is being pushed inwards (rammed) by the motion of the aircraft and the (ram) pressure is measured. The measured pressure is corrected indicating the airspeed. The ram pressure is also called the dynamic pressure opposite the static pressure that us used to indicate altitude. Bigger aircraft have two pitot tubes and the indicator displays the average of the two. However, most often only one pitot tube is used to control the autopilot, even when the indicator is connected with two.

The pitot tube can be blocked easy, once blocked, or worse, partially blocked the IAS will have no relation with the speed of the aircraft. This situation is enhanced if the pitot tube controlling the autopilot is blocked.

Ice is a known cause of blockage of the pitot tube hence there are pitot heaters that should prevent forming of ice. Another known cause of blockage are insects. Blockage of pitot tubes is a known cause of some very dramatic accidents and every pilot should learn how to deal with strange behaving speed indicators and autopilots.

Información Adicional