Equivalent Airspeed?

[Smurfjet]

Is there such a thing?

Just came back from ground school (in french :)) and I didn't get the chance to ask the instructor about it...

From what I understood its for high performance/Altitude Ops...?

Cheers

[Johnman]

Equivalent airspeed" means the calibrated airspeed of an aircraft corrected
for adiabatic compressible flow for the particular altitude.

[Johnman]

EQUIVALENT AIRSPEED (EAS)

Equivalent airspeed is the true airspeed at sea level on a standard day that produces the same dynamic pressure
as the total flight condition
EAS is found by correcting the calibrated airspeed for compressibility error

[NIMBUS]

Smurfjet,
4 types of airspeed:
INDICATED- what the A/s indicator says.
CALIBRATED- indicated corrected for installation error. (Airflow disturbed by a wing strut, probe, etc, can cause minor errors depending on where the pitot tube is located. POH will normally have a chart/graph showing expected error at different speeds)
TRUE- calibrated corrected for non-standard pressure/temperature.(As altitude or temperature increases, air density decreases. For any given IAS, TAS will increase with altitude)
EQUIVALENT-calibrated corrected for compression/temperature errors.

EAS only needs to be considered at high speeds, around 190 kts+.
At those speeds, the airspeed probe compresses the air in front of, and in, the probe itself (pitot tube!) This 'compacting' changes the air density and temperature, and must be corrected to yield an accurate airspeed. (Simplified version!)

[Smurfjet]

Yep, thanks for the heads up! :)

Cheers

[This message has been edited by Smurfjet (edited 17 January 2001).]