On Saturday, April 11, 2015 at 6:15:16 PM UTC-7, jfitch wrote:
On Saturday, April 11, 2015 at 2:31:02 PM UTC-7, Martin Gregorie wrote:
On Sat, 11 Apr 2015 11:34:01 -0700, Bob Pasker wrote:

On Saturday, April 11, 2015 at 12:02:23 AM UTC-4,
wrote:
"Its also worth mentioning that Vne is not based on load factor, like
Va, but on flutter, which is why its True and not Indicated. "

Actually flutter is dependent on equivalent airspeed not true airspeed.

VD is defined based on EAS (eg FAR 23.335), and Vne is defined based on
VD (23.1505).

But EAS doesn't take into account air density, which is primarily a
function of altitude (and a some temp thrown in). So Vne has to be
corrected for air density, which is the TAS.

Are you sure about that?

This reference says that EAS is a measure of dynamic pressure and gives
several formulae for it that all use either air density or air pressu

https://en.wikipedia.org/wiki/Equivalent_airspeed

Yes, I know about Wikipedia's dodgy treatment some social facts, but IME
its pretty good on this sort of stuff.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

I always thought IAS (or EAS minus instrument error) was just an indication of dynamic pressure, in fact that is how the instruments are constructed: to measure dynamic pressure. It is proportional to rho, air density.

Here is the reference I think I was remembering. Can't seem to access it now without money, but the abstract pretty much says it. I think Schleicher at least believes this, or they would not have bothered to put mention and tables in their manuals.

http://journals.sfu.ca/ts/index.php/ts/article/view/216