Re: Data points for INAV submission?

From: Leo Pilachowski <leop_at_lyradev.com>
Date: Sun, 16 Dec 2012 05:08:52 -0000

Here is the formula I use to calculate the approximate flying speed of our models. I try to check actual flying speed which can vary greatly with the trim of the model. This fact is important to remember.

Speed in meters per second =
square root[(160 &#8727; weight in grams)/(wing area in sq.cm)]

This is for monoplanes. For biplanes, one cannot use double the wing area since the two wings do not act separately. I assume that a biplane flying speed is about 5% slower than the calculated speed for a the plane with just one wing (use the area of the larger wing). This seems to work out in practice at least for my observations.

One might also think that for planes with larger stab areas (tandems) that one should count the stab area, too. However, in practice it does not seem to make much difference as a plane is nearly always trimmed with more proportionate lift on the wing (cg moved forward of the neutral point) for pitch stability.

BTW, what speed do you use for an F1D?

Leo

--- In Indoor_Construction_at_yahoogroups.com, "mkirda@..." <mkirda@...> wrote:
>
> Also thinking that it might be useful to include an estimated flying speed for some various classes. However I have no idea what those might be outside of F1D.
>
> LPP/F1M
> A6
> Low Weight EZB
> F1L
> 35cm
> HLS - Probably very similar to F1D?
>
> Regards.
> Mike Kirda
>
Received on Sat Dec 15 2012 - 21:08:53 CET