Hello All,
I've used COMPUTERS since the early days, but have no experience with how operating systems work.
This may WELL be like asking whether I can run my car on hay instead of petrol, but nothing ventured, nothing gained.
I would be happy to migrate most of my computer operations to non-MS programmes, but I am a keen flight simmer, and do not want to lose access to this hobby.

So the question is; Is there a way of running MS Flight Sim on anything other than an MS OS, please?

Thanks, Mike
Yes, with limitations.
https://www.youtube.com/watch?v=KkjP0MHA9eo
The above Video uses a program called Wine.
Thanks Mr G!
Watched that link
I see that there's no reply to the complaint about the awful fps, and if one has to pilot by mouse rather than Yoke & Pedals, it wouldn't suit me.
I NOTE your comment about "with limitations"
Cheers for now.Glad to help.
BTW, do you own a legit copy of Windows FS?
If so, you can install a dual boot setup on your Linux PC and play FS by doing a reboot and SELECT windows. **
For a limited time, MS will let you run Windows without a license on a trail basis. But that is only for the OS, not other products, like FS.
Here is a link about a trial version of windows.

How to run Windows 8.1 for free for 90 days

** forgot to mention, it is better to install Windows before Linux.

Install Ubuntu 14.04 alongside Windows 8.1