"Paul Repacholi" wrote in message
...
Jim writes:

Still thinking about VNE and whether it is usually stated as a TAS
rather than an IAS (one must read the POH to be sure, of course).

I've gotten the notion, probably from comments I've not understood
very well, that the "coffin corner" is the intersection of stall
speed as an IAS indication on the airspeed indicator, and VNE
understood as a TAS and thus occurs at a decreasing IAS with
altitude.

I guess the consequence of this notion is that as aircraft altitude
goes up the stall speed TAS goes up to ultimately bump into the VNE
TAS. If VNE is published as an IAS, like stall speed, then stall
speed and VNE would never converge.

Or maybe it was the Manuevering TAS that could bump into the VNE
TAS.

IS this what is sometimes referred to as the "coffin corner"?

As you get higher, power drops off so you CAN'T go faster, or you get
Mach limited, and IAS drops so you get closer to stall. So, you can't
go faster, and you can't go slower or you stall. As soon as you have
the slightest load increase or slight turn, stall, and probably spin.

You do not have to go anywhere near Vne or Va, just get high enough.

There's a story in here
http://www.nationalgeographic.com/wave/index.html

Click the plus sign on the 747.

Frank Whiteley
Colorado