Production side: I would agree. However statistical differential equations? SAS is good for predefined "statistical analysis", not for solving partial differential equations. Almost all mechanical problems in aerospace (read fluids, solids, thermal, electro) are expressed as partial differential equations. solutions of these (baring a few special cases) require numerical methods. The most common of these methods are finite element, finite difference and finite volume.
And each one of these has it numerous "schemes" for solving a particular class of PDE. The choice of scheme/method depends on the problem at hand. You can use a prepackaged tool like Fluent/Gambit. But that limits you to the limitations of those packages. Need anything cutting edge, or applicable to a special case, you need to program it yourself (c/c++/fortran). Most design houses have tons of legacy code that they build upon and add modules to deal with their specific problem. A lot of these run on linux clusters or unix big irons. I don't think they use gcc though. For performance sake most use proprietary compilers (eg pgc, icc etc). But no SAS.
Now, on the control systems side, most researchers use matlab, but most of the implementation is done using imbeded C or ADA.
As for SAS, they do now support freeware aka Linux.
I have personally notice a sense of unease when SAS employees are asked about R. They are quick to dismiss it claiming the usual FUD and then change the topic. It is quite amusing actually. Happens everytime.