ORIGINAL: Jim Thomerson
How are people figuring scale speed? I might think of it in terms of airplane lengths traveled per second. Is that reasonable?
No Jim, it is nonsense. There is no such a thing as scale speed.
Yes, I suppose that a model covering its own length in the same time as the full size could be regarded as scale speed, but ONLY in a straight line and in zero wind. How long does that last?
In manoeuvres (turns loops etc) it would look stupidly slow and floaty, and of course it would stop in a wind. That's even before you approach any of the other aerodynamic considerations mentioned.
I wrote a series of 4 articles in RC Model World (June to September 2009) detailing what is wrong with the concept of Scale Speed and how we can reach a practical compromise. It culminated in a Spreadsheet that runs in Excel, and you can download it (and the instructions to use it) from
http://www20.brinkster.com/gvmac/
look on the Alasdair's Aerodynamic page