Definition
The aircraft's airspeed in knots as shown directly on the airspeed indicator, before any corrections for instrument error, installation error, air density, or compressibility. It reflects the dynamic pressure sensed by the pitot-static system at the moment of reading.
Plain English
It's the speed number you actually see on the airspeed dial, expressed in knots. Nothing has been adjusted or corrected — it's the raw reading.
Context Anchor
Seen in instrument procedures, aircraft operating limits, and speed instructions where the pilot is expected to fly a specific indicated speed.
Derivation
Knots' comes from the old sailing practice of trailing a knotted rope behind a ship and counting how many knots passed through a sailor's hands in a set time — one knot equals one nautical mile per hour. 'Indicated' simply means 'as shown by the instrument.' Together, KIAS means 'the speed the instrument is showing you, in knots.'
Why Pilots Care
KIAS is the reference pilots use for stall speeds, flap settings, and procedure turn speeds because it matches the instrument markings and published limitations.
Grounding Statement
When the airspeed indicator shows 100 knots, the airplane is flying at 100 KIAS even if wind makes its speed across the ground higher or lower.
Intuition Check
Do not read KIAS as the airplane’s actual speed over the ground. KIAS is the speed indicated on the cockpit airspeed instrument, in knots.
Example Sentence 1
The procedure turn must be flown at or below 200 KIAS.
Example Sentence 2
The published approach speed for this aircraft is 85 KIAS.