KillKenny,
The short answer is no, and it isn't just because the equation is an approximation!
The problem is that rate of turn is related to TAS squared/Tangent of AOB, neither of which are linear functions. So you cannot simply extrapolate the original equation in a linear manner. The fact is that the equation you quote is simply a trick which happens to work for a rate one turn. But it works only for a rate one turn. One could however be devised for any rate of turn we might choose.
To demonstrate my point let's look at a rate 8.825 turn (whatever that is) Let's use 400 Kts as an arbitrary TAS.
We will then get:
AOB ((8.825 x 400)/10)+7 which = 360 degrees.
But this means that you can do a rate 8.825 turn at 400 kts with the wings level. Hummmmmm?
Worse still, a rate 8 turn turn requires 327 degrees AOB. This means that to do a rate 8 turn to the right we must bank 33 degrees to the left??? Even bigger Hummmmmmmmmmmm? (even I don't believe that).
Your e-mail address is not listed in your profile. If you send it to me I will send you a scan of a nomogram that enable you to wark out AOB for any combination of TAS and ROT up to rate 4.
[ 13 February 2002: Message edited by: Keith Williams. ]</p>