25:
229:
620:
455:
319:
804:
378:
851:
860:
The above formula is accurate within 1% up to Mach 1.2 and useful with acceptable error up to Mach 1.5. The 4th order Mach term can be neglected for speeds below Mach 0.85.
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161:(TAS) and altitude at which the aircraft is flying. In low-speed flight, it is the speed which would be shown by an
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646:(TAS). At any other altitude, EAS may be obtained from CAS by correcting for compressibility error.
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with zero error. It is useful for predicting aircraft handling, aerodynamic loads, stalling etc.
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224:{\displaystyle \mathrm {EAS} =\mathrm {TAS} \times {\sqrt {\frac {\rho }{\rho _{0}}}}}
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are airspeeds and can be measured in knots, km/h, mph or any other appropriate unit.
643:
158:
488:
Combining the above with the expression for Mach number gives EAS as a function of
468:
is 1,225 km/h (661.45 kn) (the standard speed of sound at 15 °C),
383:
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24:
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615:{\displaystyle \mathrm {EAS} =a_{0}{\sqrt {{\frac {5P}{P_{0}}}\left}}}
649:
The following simplified formula allows calculation of CAS from EAS:
876:
16:
Airspeed corrected for the compressibility of air at high speeds
450:{\displaystyle \mathrm {EAS} ={a_{0}}M{\sqrt {P \over P_{0}}}}
314:{\displaystyle \mathrm {EAS} ={\sqrt {\frac {2q}{\rho _{0}}}}}
18:
799:{\displaystyle \mathrm {CAS} ={\mathrm {EAS} \times \left}}
993:, Section 3.4 (4th edition), McGraw-Hill, New York USA.
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969:, Section 2.3.3, Butterworth-Heinemann, Oxford UK.
49:. Unsourced material may be challenged and removed.
949:, p.215 (4th edition), McGraw-Hill, New York USA.
929:, Section 3.8, Pitman Publishing Limited, London.
845:
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372:
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373:{\displaystyle q={\tfrac {1}{2}}\,\rho \,v^{2}.}
492:and static pressure (valid for subsonic flow):
485:is standard sea level pressure (1013.25 hPa).
8:
1005:"Measurement of Aircraft Speed and Altitude"
846:{\displaystyle \delta ={\tfrac {P}{P_{0}}},}
965:Houghton, E.L. and Carpenter, P.W. (1993),
382:EAS can also be obtained from the aircraft
157:is the same as the dynamic pressure at the
638:At standard sea level, EAS is the same as
1014:(11 MB), NASA Reference Publication 1046.
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109:Learn how and when to remove this message
918:
871:Acronyms and abbreviations in avionics
254:(1.225 kg/m or 0.00237 slug/ft).
967:Aerodynamics for Engineering Students
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47:adding citations to reliable sources
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1025:Equivalent airspeed calculator
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991:Fundamentals of Aerodynamics
947:Fundamentals of Aerodynamics
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989:Anderson, John D. (2007),
945:Anderson, John D. (2007),
891:Global Positioning System
808:where the pressure ratio
1003:Gracey, William (1980),
476:is static pressure, and
327:is the dynamic pressure
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58:"Equivalent airspeed"
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149:at sea level in the
43:improve this article
881:Calibrated airspeed
640:calibrated airspeed
135:calibrated airspeed
127:equivalent airspeed
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896:Indicated airspeed
886:Flight instruments
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163:airspeed indicator
145:. It is also the
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906:True airspeed
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60: –
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54:Find sources:
48:
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32:This article
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21:
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990:
984:Bibliography
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927:Aerodynamics
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99:January 2009
96:
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41:Please help
36:verification
33:
384:Mach number
239:air density
143:Mach number
913:References
642:(CAS) and
237:is actual
69:newspapers
816:δ
769:δ
759:δ
753:−
718:δ
715:−
685:×
600:−
354:ρ
300:ρ
210:ρ
206:ρ
200:×
1040:Airspeed
1034:Category
1008:Archived
864:See also
855:CAS, EAS
147:airspeed
123:aviation
83:scholar
997:
973:
953:
933:
624:where
459:where
323:where
244:ρ
235:ρ
233:where
85:
78:
71:
64:
56:
133:) is
90:JSTOR
76:books
995:ISBN
971:ISBN
951:ISBN
931:ISBN
853:and
386:and
241:and
62:news
742:640
631:is
258:EAS
131:EAS
121:In
45:by
1036::
756:10
635:.
390:.
264::
125:,
841:,
833:0
829:P
825:P
819:=
792:]
786:4
782:M
778:)
773:2
765:9
762:+
750:1
747:(
739:3
734:+
729:2
725:M
721:)
712:1
709:(
704:8
701:1
696:+
693:1
689:[
681:S
678:A
675:E
670:=
666:S
663:A
660:C
628:c
626:q
607:]
603:1
594:7
591:2
585:)
581:1
578:+
573:P
568:c
564:q
557:(
551:[
543:0
539:P
534:P
531:5
521:0
517:a
513:=
509:S
506:A
503:E
482:0
479:P
474:P
470:M
465:0
462:a
440:0
436:P
432:P
426:M
420:0
416:a
411:=
407:S
404:A
401:E
368:.
363:2
359:v
347:2
344:1
338:=
335:q
325:q
304:0
295:q
292:2
285:=
281:S
278:A
275:E
247:0
214:0
196:S
193:A
190:T
186:=
182:S
179:A
176:E
129:(
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
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