I currently have a dilemma. I currently do structural FEA analysis (mechanics/vibrations) in the gas turbine industry. This has mainly been my specialty as I have had little experience in other areas of gas turbines. However, I have always been fascinated on a personal level with the aerodynamics/combustion processes involved. As I continue my career I see two paths. 1. Continue pursuing my field and specialize in other aspects of it (ie. thermal stresses, heat transfer, etc). Although these are slightly different disciplines, they are all linked to structures and FEA and hence I can easily pursue those areas without making a huge career change. 2. Completely change my discipline and pursue aerodynamics/combustion. This however would mean that I would be essentially starting from scratch and learning everything new methods (ie. CFD) which I have no current proficiency in. 3. Stay in my current discipline and become highly proficient in mechanics/vibrations and focus on various parts of gas turbines. The second option would make me more versatile in the field as I would be exploring more. However, I'm afraid it would slow down my career progress and should I want to switch to another company I would be seen as inexperienced in the discipline. I plan on staying in my current discipline for a total of 5 years before making any switch. My main reason for wanting to switch disciplines is because I want to explore new things which I have not explored before and I have always wanted to be a well rounded engineer. I fear though that I would be spreading myself thin, and I would be more valuable by mastering one discipline. It all comes down to versatility versus job security as I have been progressing well in my current discipline. Are there any thoughts on this? Would spending five years in my discipline just to switch hurt my career in any way? Has anyone made a huge career change and if so what were the benefits/consequences?