Stall speed

[Mojave9240]

I know, a very stupid question. Is there a easy way to figure out the stall speed of pistions,turboprops,jets at 5,000 on up to 40,000 feet? thanx very much!!!!!!

 

[Mr. Cole]

Do you mean the indicated stall speed or true stall speed? Indicated stall speed should remain the same no matter what altitude, only the true stall speed would change with altitude. But I could be wrong.

Dave

 

[Mojave9240]

True airspeed stall speed.thanx

 

[midlifeflyer]

Approved Flight Manual?

 

[Tinstaafl]

Convert the manual's Vs in IAS to the TAS for the Density Altitude using a whiz wheel

Why would you want TAS Vs?

 

[Donsa320]

Pinnacle found out the hard way recently, I believe, that indicated stall speed certainly does not remain the same as you climb.

~DC

 

[Folding_Expert]

Approved Flight Manual?

Thar ya go.

 

[lawfly]

Stall Speed

Might want to throw in some calculations for load factor, weight, aircraft configuration.

 

[Stby One]

Both the indicated and true stall speed will increase. Its only slowflying airplane at low altitude that has a nearly constant indicated stall speed with altitude (c172 and so on). A commercial jet will have an increasing indicated stall speed due to compressibility. First of all there is an instrumet error due to compressibility which makes the airspeed indicator overread hence the indicated speed will be higher.
The second compressibility effect is the decreased coefficient of lift on the wings due to shock wave formation.

When climbing your indicated stall speed (and TAS stall speed) increases. At the same time your maximum indicated speed decreases and at a certain altitude they will be the same, ie coffin corner.

The compressibility effect on airspeed indicators can easily be corrected for but the effect of compressibility on the wings is more complex. So there is no general rule for the increase in stall speed. You would have to examine each aircraft to see what the effect will be.

 

[midlifeflyer]

Sbty One,

You mention slow airplane and low altitude. Are both speed and altitude factors? Whether together or apart, at what altitude and/or at what airspeed does this become a factor?