On Tuesday, June 12, 2018 at 2:30:07 PM UTC-4, Michael Opitz wrote:
At 17:57 12 June 2018, resigler wrote:
On Tuesday, June 12, 2018 at 10:44:01 AM UTC-5, Tom Kelley
#711 wrote:

https://www.onlinecontest.org/olc-3....ightinfo.html?
dsId=6514812

Flight details
Points for the flight 279.92
scoring distance 783.79 km
Speed 313.51 km/h
Duration 02:30:00
Scoring class double
Scoring start 23:56:30
Scoring end 02:56:45
Index: 116.0
Club Perlan Project
Date of claim 10.06.2018 03:26:24

Best. Tom #711.

So how did they get around the plane's VNE of 280 km/h? Can't
be a
tailwind because the trace shows speeds of up to 380 km/h going
both
Northbound and Southbound.


True airspeed goes up with altitude at a rate of ~2% per 1000'.
So, in wave at 20,000' the true airspeed is ~40% higher than
the indicated airspeed... 280 km/h indicated = ~ 392 km/h in
true airspeed at 20k ft.....

RO

But doesn't Vne (as indicated) go down with altitude? That's since for some speed limiting issues (such as flutter) it's the true airspeed that counts. Is it "true" to say that Vne as TAS is constant with altitude? Perhaps only approximately. This has been debated here before, e.g.:
https://groups.google.com/forum/#!to...ng/p_sj7hCKC5o