Arnold Pieper wrote:

Thank you Simon,

Exaclty like I said in a previous message :
The table below confirms it, It is NOT simply the VNE corrected as TAS.

Go ahead and check this table if you will :
100Kt IAS @ 26000ft is LEGAL, ALLOWED and SAFE as per the manual.
That's because table shows 111Kt IAS as being the limit at this altitude.

Now calculate your TAS for this condition (100Kt IAS @ 26000ft), with
various range of temperatures.
Here's what you will get as TAS for the various temperatures :
163Kt @ -45 Celsius (way below Standard),
167Kt @ -35 Celsius (aprox. std temperature for this altitude)
170Kt @ -25 Celsius (above Standard)

All of these TAS are higher than the original Low-altitude IAS VNE of
146Kt, painted on the ASI.
Which confirms what I said : the VNE is NOT simply to be corrected as a TAS
figure.

This limitation in IAS with Altitudes are "NEW" values for VNE, due to
flutter or whatever the reason with altitude.
But the resulting TAS at these conditions will be higher than the original
VNE.

Perhaps you missed this post:

Quoting from the manual for my Schleicher ASH 26 E:

"4.5.8 High altitude flight

Flutter tests were carried out at about 2000 m msl. As the ASI
under-reads at increasing altitude, but since flutter limits for light
aircraft are determined by the true air speed, the following limitations
apply to high altitude flights:

[table of IAS at Vne for altitudes to 13000m follows]

If above airspeed limits given as IAS are regarded the true air speed
above 3000 m altitude will remain constant at 300 km/h = 162 knots."

So for this glider, the Vne in TAS does increase to 10,000', then
remains at a constant 162 knots TAS. They are quite explicit about the
Vne depending on TAS.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA