Vne

I know that Vne can vary with altitude but does it also vary with aircraft weight?

At 18:49 09 November 2019, jp wrote:
I know that Vne can vary with altitude but does it also vary with
aircraft
weight?

Yes

At 18:49 09 November 2019, jp wrote:
I know that Vne can vary with altitude but does it also vary with
aircraft
weight?

Yes

Onlynif over max weight and with an engineering order. Within the certified weight range, it stays the same.

Charlie Quebec wrote on 11/9/2019 12:53 PM:
Onlynif over max weight and with an engineering order. Within the certified weight range, it stays the same.

It may depend on the glider, particularly gliders that carry ballast in the wings.
My guess is pilot weight would have such a small effect, it would not mentioned in
the operating handbook.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

I’ve never seen it vary by weight. Check your POH of course

Charles Longley wrote on 11/9/2019 6:22 PM:
I’ve never seen it vary by weight. Check your POH of course

Now I'm wondering if it's a regulatory requirement that the Vne be set that works
for all allowed weights.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Ehhhhhhh no. In our very sub supersonic world Vne is based on how fast the molecules actually go over the wing, which is the contributing factor to flutter. That's Vne, more specifically, it's given as a True Air Speed because that's the actual speed against molecules. Now what DOES change is the indicated speed for Vne, since IAS is a function more of HOW MANY molecules are getting rammed into the pitot tube. It's important to know those numbers as you descend out of wave. Vne as marked on the gauge red line is invalid up at the higher altitudes. Flying out west up high it may be more like 110kts indicated when the TAS is actually at redline.

Hmmm, I thought Vne Is basically a guess by the FAA that 10% below Vd is safer than 5% below Vd. Vne = 0.9 X Vd (FAR/JAR 23), dive speed Vd determined emperically and is a function of design cruising speed Vc.

Haven't read that, would be an interesting one though. I'd always been under the impression Vne is a flutter protection speed. That's why it's a TAS that doesn't change with weight like Va. Wouldn't be surprised if it was from some old math though.