Hi Luiz,
thanks for your response. You are right, I actually do use my HP-41. Although I have to confess that I'm not nearly old enough to have witnessed the times when it came out, I'm nevertheless absolutely fascinated by this little machine and its abilities.
I'm not only interested in aerospace, I work as an aeronautical engineer. We develop, document and certify all sorts of fligth experiments, so my main jobs are engineering computations and the 41 does a great job on these. Besides, the look of colleagues when you get it out during a discussion for a quick calculation is just priceless...
However, once things start to get too intense regarding the math required to solve a problem I usually switch over to tools like Scilab (mainly because the results are much easier to document). So a HP50 would indeed by nice, but I doubt that I would use it to its full capabilities. A HP-41 serves both, my computational needs as well as my nostalgic interest in engineering history (I even put out my fathers slide rule from time to time, just to remind myself how complex things were in his early active years...)
By the way, thanks for the links, they sure look interesting! I will study them soon.
Best regards from Germany,
Timo