Q about stability with small fin area

Q about stability with small fin area

Post by AAFCf » Thu, 11 Feb 1999 04:00:00



I noticed that a Sat V has SMAAAALLL fin area. So where does the stability come
in? It seems as though, with its airframe profile, it could be flown without
fins since the fin area is so scant.
 
 
 

Q about stability with small fin area

Post by Kevin Drayso » Thu, 11 Feb 1999 04:00:00


Quote:

>I noticed that a Sat V has SMAAAALLL fin area. So where does the stability
come
>in? It seems as though, with its airframe profile, it could be flown
without
>fins since the fin area is so scant.

Actually, stability can be an issue with the Sat V, especially if built
heavily.  The fins are *very* necessary. In fact, some recommend adding some
nose weight, or slip-on clear plastic fins in order to increase the margin a
bit.

Kevin Drayson CAR #S369

http://personal.nbnet.nb.ca/kdrayson

 
 
 

Q about stability with small fin area

Post by Alan Jon » Fri, 12 Feb 1999 04:00:00



Quote:
>I noticed that a Sat V has SMAAAALLL fin area. So where does the stability come
>in? It seems as though, with its airframe profile, it could be flown without
>fins since the fin area is so scant.

The Saturn V was aerodynamicaly unstable and stability was achieved by
the gimbled engines.  The fins were ther to make the vehicle a little
less unstable so that in the case of failure, the crew emergency
escape system had time to opperate.  If you put the cg far enough
forward on a model you can get it staticaly stable.  I recommend using
clear slip on fins.

Alan Jones