SPEED DEVICES

The speed devices in the aviation uncorrected own speed, according to the uncorrected speed of the aircraft relative to the surrounding air mass ( IAS). The measurement is done by the IAS Staurohrs , Pitot tube. This provides the total pressure, resulting from the pressure of the current height (static pressure) and the dynamic pressure up. The display in the cockpit on the airspeed indicator, the difference between the total pressure and static pressure (the back pressure) on a scale speed. These uncorrected speed compared to the surrounding air is important for pilots, because it alone allows a direct inference on the current flight or the flight stability of an aircraft. In the early days of aviation has been slow aircraft tried to get the vane to measure the IAS (see anemometer). When an engine airplane is the own speed in the range of about 50 kt (90 km / h) at small propeller aircraft up to 350 kt (650km / h) for commercial aircraft. Limited, the IAS by the aircraft structure, regulations (for example, below 10,000 ft altitude only 250 kilotonnes) and no later than at cruise altitude by the Mach number - except of course überschallschnelle aircraft. Another limiting factor is the high state of buoyancy aids. Depending on how far the flaps are extended, threatening an aircraft below a certain IAS abzustürzen (currents demolition). When fully extended flaps but they can at a high IAS damaged. The self-speed of a glider can be between about 50 and 400 km / h (with some modern models only a short flight in the fall), that a balloon, however, is zero. It is only transported by the wind. Therefore, often in films shown at hair blowing balloon drivers nonsense

Actual speed over ground

The ground speed, GS around the wind corrected True air speed. It is the speed of an aircraft relative to the Earth's surface dar. Knowing the ground speed is important because it counterclaim or tailwind to a significant difference between the speed indicator in the cockpit and the actual speed may occur. To shorten the flight in a jet-stream due to the significantly higher ground speed the flying time considerably. Under special circumstances, a low ground speed combined with an excessive display in the cockpit to accidents like the crash of the Stardust on the Andes, or the Birgenair accident. You can speed over the ground by considering the Längskomponente of the wind through wind triangle on the basis of reports of aviation weather stations calculate today but also by modern on-board systems to measure (for example, inertial navigation system, Doppler) or navigation procedures such as GPS.