What are the typical static margins used for deltas and low AR flying wings? Am I correct in thinking between 10-15%?

Thx

MJD

One message would have been easier..

- or am I getting those numbers from a rule of thumb of 10-15% of MAC back from the LE @ MAC?

You mean this Centre of gravity at deltawing?

Jens Eirik

Yes - what I was looking for was a recommended CG position for delta wings or low aspect ratio flying wings. A reference I found yesterday recommended 10% of mean aerodynamic chord ahead of the aerodynamic center - which is a typical setting for a conventional aircraft too, where 10-15% is recommended for normal control responsiveness.

MJD

I think it is a matter of preference. I would probably start with a stable 10%, the start a cycle of small changes in static margin followed by a flight check of handling qualities and stop when i was comfortable with the performance. I assume that this is a pure delta, so you are not worrying about sizing a tail surface, is that correct?

Yup. I am drawing up some slightly different versions of the same basic aircraft, basically something that looks a bit like a Multiplex Pico Jet or Twin Jet (roughly) with a short nose, rear exhaust engine, tractor config, with enclosed pipe, etc. Designed as a fast sport flier. So the design iterations hover between a higher aspect ratio delta to a low aspect ratio flying wing with a touch of sweep. Thanks.

MJD