Indicated airspeed (IAS) is the airspeed read directly from the airspeed indicator on an aircraft, driven by the pitot-static system. IAS is directly related to calibrated airspeed (CAS), but includes instrument errors and position error. This article contains information that has not been verified and thus might not be reliable. ... Airspeed Indicator in a light aircraft The airspeed indicator or airspeed gauge is an instrument used in an aircraft to display the crafts airspeed, typically in knots, to the pilot. ... A pitot-static system is an avionics component which directs ram air pressure and static air pressure lines into the appropriate flight instruments. ... Calibrated airspeed (CAS) is indicated airspeed, corrected for instrument error and position error. ... This article belongs in one or more categories. ...

An aircraft's indicated airspeed in knots is typically abbreviated KIAS for "Knots-Indicated Air Speed" (vs. KCAS for calibrated airspeed and KTAS for true airspeed). A knot is a unit of speed abbreviated kt or kn. ... Calibrated airspeed (CAS) is indicated airspeed, corrected for instrument error and position error. ... True airspeed (TAS) is the speed of an aircraft relative to the airmass in which it flies, i. ...

IAS and V speeds

Unless an aircraft is at a sufficent sea level under International Standard Atmosphere conditions (15°C, 1013 hPa, 0% humidity) and no wind, the IAS bears little relation to how fast an aircraft is moving in reference to the ground; however, because the air pressure and density affect IAS/CAS and an aircraft's flight characteristics in exactly the same way, IAS and CAS are extremely useful for controlling an aircraft, and the critical V speeds are usually given as IAS. The pascal (symbol: Pa) is the SI unit of pressure. ... V speeds are speeds that define certain performance and limiting characteristics of an aircraft. ...

In aneroid instruments the indicated airspeed drops-off with increasing altitude as air pressure decreases, and this leads to an apparent falling-off of airspeed at higher altitudes. For this reason never exceed speeds (abbreviated V_NE) are often given at several differing altitudes in the aircraft's operating manual, the V_NE IAS figure falling as height is increased, as shown in the sample table below. An aircrafts Vne is the velocity that should never be exceeded. ...

Ref: Pilot's Notes for Tempest V Sabre IIA Engine - Air Ministry A.P.2458C-PN Miles per hour is a unit of speed, expressing the number of international miles covered per hour. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Hawker Tempest II, RAF Museum, Hendon The Hawker Tempest was a Royal Air Force (RAF) fighter aircraft of World War II, an improved derivative of the Hawker Typhoon, and one of the most powerful fighters used in the war. ... The Sabre was a 24-cylinder sleeve valve piston aircraft engine designed by Major Frank Halford and built by Napier & Son during WWII. It was one of the most powerful piston aircraft engines in the world, especially for inline designs, developing over 3,500 horsepower (2,200 kW) in its... The Air Ministry was formerly a department of the United Kingdom Government, established in 1918 with the responsibility of managing the affairs of the (then newly formed) Royal Air Force. ...

IAS and navigation

For navigation, it is necessary to convert IAS to ground speed (GS) using several steps: Ground speed is the speed of an aircraft compared to the ground without factoring in the wind or other weather conditions. ...

• correct IAS to calibrated airspeed (CAS) using an aircraft-specific correction table;
• convert CAS to equivalent airspeed (EAS) by allowing for compressibility effects (not necessary at slow speed or low altitude);
• convert EAS to true airspeed (TAS) by allowing for differences in density altitude; and
• convert TAS to ground speed (GS) by allowing for the effect of wind.

With the advent of GPS receivers and other advanced navigation equipment that allows pilots to read ground speed (and often, TAS) directly, these complex calculations are becoming unnecessary. Calibrated airspeed (CAS) is indicated airspeed, corrected for instrument error and position error. ... Equivalent airspeed (EAS) is the airspeed which represents the same dynamic pressure at altitude that would be generated by flying at the corresponding true airspeed (TAS) at sea level. ... True airspeed (TAS) is the speed of an aircraft relative to the airmass in which it flies, i. ... Density altitude is the altitude in the International Standard Atmosphere at which the air density would be equal to the actual air density at the place of observation. ... Ground speed is the speed of an aircraft compared to the ground without factoring in the wind or other weather conditions. ... For other uses, see Wind (disambiguation). ... GPS redirects here. ...