Flight Management Computer/FMS

Can anyone give me a simple explanation about the acronyms FMS (Flight Management System) and FMC (Flight Management Computer)? Are they the same thing?

Am I right in thinking that a FMS/FMC is a tool which gives you an indication about navigation and controls in an aircraft and that FS9 doesn't come automatically equpped with this - apart from GPS, that is?

And how does the acronym RNAV tie up in this? Is that also something which gives you precision flying?

I need to more precise in navigation, specifically plotting courses from intersections to intersections which DON'T lie on any VOR radial and I'm getting fed up flying WAY off course trying to achieve this. Flying between VOR/NDBs etc of course is no problem.

In RL do pilots rely on a FMC (not GPS) to do this. And how doI get this in FS9? Payware download?

So many questions, sorry. Hope someone can give me advice.

Thanks in advance!

Here's an overview of what FMC (flight mangement computer) is for

http://www.b737.org.uk/fmc.htm

Hope it helps!

FMS and FMC are the same thing.
FMS- Flight Management System
FMC- Flight Management Computer


You are correct, the FMS/FMC is a navigation tool that integrates navigation sensor information. It can also help to compute aircraft weight and balance(pilot input required), V speeds and vertical navigation. It is not included in default FS9. The FMS/FMC can use different sensors to determine it's position. This could be the signals from VORs, an internal navigation sensor(IRU) or GPS. Pilots of jets do rely on the FMS for navigation, almost to much. If you want to upset an airline pilot, tell him that his FMC is inoperative. He can fly without it but he doesn't want to.

RNAV is an old term that stands for Random navigation. It was developed in the 1960s. It used a small computer to electronically manipulate the navigational information from VOR stations so that you could travel point to point instead of going from VOR to VOR. It's also known as Area navigation. Any navigation that does not go directly to or from ground based navigational aids is RNAV.
http://en.wikipedia.org/wiki/RNAV

There are payware such a PMDG or PSS but there are a few freeware aircraft that feature FMC/FMS.
http://www.precisionmanuals.com/
http://www.phoenix-simulation.co.uk/default.asp?pss=moreinfo&ID=97

Free aircraft with FMC
http://flyawaysimulation.com/downloads/files/2790/fs2004-ifly-boeing-747-400/

Thank you both of you.! Exactly the info I needed.
Greatly appreciated.