Hmmmm ...

You shouldn't need any software to design a light airplane except for
maybe an FEA program. However whether of not you need an FEA program
depends on the type of structure you are designing. For instance if
you are designing a tin airplane then there is little need for FEA
(unless you really know what you are doing you will just get trash out
because, for example, the FEA does not account for skin buckling). If
you are designing a composite airplane then a FEA package is strongly
recommended (but not essential) but it needs to laminated composite
element.

Generally you can calculate all the loads and do all the stressing
manually using relatively simple techniques and only moderately
advanced maths.

I get nervous when amateur designers start asking about software as
though it is an essential design tool. Usually this means that it is
being used as a black box to fill in a fundamental lack of engineering
knowledge with little understanding of what is actually going on
inside the code or any ability to interprete what the results are
telling them. That is dangerous. My suggestion is to invest your money
in a copy of Bruhn's "Analysis and Design of Flight Vehicle
Structures" and Stintons "Design of the Airplane" to name a couple of
good texts instead of software. Read them and understand what they are
saying and then decide if you still need software. If you can't
understand the texts then you are not sufficiently qualified to start
using design software ... period. In fact if you can't understand them
then you should seriously consider buying a set of plans for an
established design.

Yeah I know .... half of the group is going to rubbish what I have
just written but I have been around long enough to see how danagerous
non professional designers are with software that they don't
understand. (I earn a living designing and modifying all sorts of
airplanes - certified and homebuilt).

The safest way for a homebuilder to design an airplane is to produce
an evolutionary design that is based on an existing sound design and
do most of the design work by comparison to other aircraft designs.
The best design tool if you are using this approach is a cupboard full
of plans for a range of aircraft.





"Brad Mallard" wrote in message
...
I am still in the design phase of my future plane. I would like to hear
opinions on design software, and even buy software that someone doesn't
use
anymore.

Brad





"Brad Mallard" wrote in message ...
I am still in the design phase of my future plane. I would like to hear
opinions on design software, and even buy software that someone doesn't use
anymore.

Brad