I'm sorry, but that's bull regarding the "integrated" FMS.
I've seen and continue to work on -8's that use 'old' Garmin GPS 165's.(https://buy.garmin.c...?pID=27&ra=true
) This thing hardly provides the same functionality as the other popular solution, a Universal UNS-1 (and all it's associated WAAS/Non-WAAS/IFR/Not-IFR/Terrian/other gimmick models). It's a cost-sensitive capable unit with IFR Approach capability that makes many operators scratch thier heads when it comes to the prices being quoted for Universal equipped a/c.
In Rob's defense they were probably looking into modelling the -200's, which "feature" the UNS-1 on certain S/N A/C. It even is described as a "integrated" navigation management system. The book states "The system is supplied with navigation data from the DME, VHF navigation, AHRS, air data system and fuel flow data. The navigation data is shown on a control display unit (CDU) and is supplied as steering signal to the pilot’s EHSI and auto flight system." Personally, I don't see much difference between this and what the JS41 FMS already does...with the exception of VHF and DME provided position information....
Again in Rob's defense the autopilot system in the -8 is a bit more complex than the JS41, but's it's certainly not something they havn't done before.
Really they could save themselves a lot of time if they toned down some of the FMS stuff (VHF/DME position updating, reciever autonomous integrity monitoring, some COMM/NAV radio tuning integration), and even more time if they stuck with older Electro-Mechanical insturmentation...although simmers would probably cry foul at that.
The real challenge they are going to find with the -8 is correctly modelling a free-turbine and the kinda tricky powerplant behaivour with the PW's. Things like quiet taxi, how the ECU and stuff works...still kinda confusing to me as well.