Editing Flight instruments (section)

===Airspeed indicator===
{{main|Airspeed indicator}}
;[[Image:Airspeed indicator.svg|left|100px]]
The airspeed indicator shows the aircraft's speed relative to the surrounding air. [[knot (unit)|Knots]] is the currently most used unit, but kilometers per hour is sometimes used instead. The airspeed indicator works by measuring the ram-air pressure in the aircraft's [[pitot tube]] relative to the ambient static pressure. The [[indicated airspeed]] (IAS) must be corrected for nonstandard pressure and temperature in order to obtain the [[true airspeed]] (TAS). The instrument is color coded to indicate important airspeeds such as the stall speed, never-exceed airspeed, or safe [[Flap (aeronautics)|flap]] operation speeds.<ref name=faa/>{{rp|3-7 to 3-8}}