Re: How will the number of fins affect a rocket's flight path?

Dear User,

Let us assume that we are working with a simple-minded, straight-nozzle 
rocket, of the type that is sold by Estes. We should also assume that we 
are talking about absolutely equal fins - uniform in size, shape and 
weight. 

In such case, the minimal number of fins necessary for straight flight is 
3. It is obvious why two fins is not enough - they will not stabilize 
flight in the direction perpendicular to their plane.

Though three fins is sufficient, it is often more convenient to use four 
because arranging four fins in a cross-wise manner is easier than arranging 
three fins with perfect 120 degree angle between their axes.

I hope this answers your question.

Sincerely,

A.G.E.