Welcome Guest. Sign in or Signup

2 Answers

How does CAS, IAS, TAS stall speed changes?

Asked by: 4097 views Aerodynamics, Private Pilot

I recently read an article stating that one of two type of stall speed(IAS, CAS, TAS) will never change with altitude.

From my understanding,  as we go up, there are lesser air molecules so when you exceed the critical angle of attack, the registered IAS is lesser than that of lower altitude.

Could anyone offer an scientific idea on how each type of airspeed readings change ?

Thanks.

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

2 Answers

  1. Best Answer


    David George on Oct 05, 2017

    Think of IAS as purely dynamic pressure (the aerodynamic equivalent of kinetic energy). A plane stalls at the same IAS because it is just a reference of dynamic pressure acting upon the airfoil. TAS stall speed will of course therefore increase with altitude.

    +1 Votes Thumb up 1 Votes Thumb down 0 Votes



  2. Actuator on Oct 07, 2017

    could you give me more explanation with what dynamic pressure means over the wing and what it has to do with readings on ASI?

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.