RCU Forums - View Single Post - Continuation of rational of trimming
Thread: Continuation of rational of trimming
View Single Post
Old 02-15-2011 | 03:48 AM
  #26  
DagTheElder
 
Joined: Dec 2008
Posts: 214
Received 2 Likes on 2 Posts
From: Sande, NORWAY
Default RE: Continuation of rational of trimming
ORIGINAL: BMatthews

But a 25% stability margin is a GROSS amount. Even trainer designs only use about 10 to 12% stability margin. Sport and competition aerobatic models use more like 0 to 5%.
I have been looking into this figures and the following has been found:
1 A SM of 20% will need a stab that is app 11.25-11.5 half span. Gives a TVC of 0,61
2 A SM of app 5% will need a stab that is only 5 inches half span. Gives a TVC of 0,265
Both calc at 25% CG

I would suggest if one want to push CG aft, i would re-design stab to maintain a level of stability.

Best Regards
The stabs measures as in previous posts. The figure above is for illustrations only.
DagTheElder is offline  
Reply Like