I'm with LRBS; unsure where they got the idea that overpowering an autopilot would actually damage an FCC.  Also, there's not really such a thing as an "engine anti ice OVERPRESSURE warning".  The only applicable caution is a "cowl anti ice" caution; this will be tripped by an overpressure, but anyone looking for an "overpressure warning" will be looking for a while 😉.

PMDG's systems modeling is pretty good.  It's not perfect, but for a video game, pretty darn good.  Their documentation is maybe a step below the actual modeling, but given so many devs don't include anything these days, it's definitely a nice touch.

The autopilot FCC is an electrical component with no mechanical input, electrical position and force signals transferred from CC/CW to FCC A/B. The meaning of the sentense seems to be: if due to overforce and shear off the mechanically system the position and force signals as FCC inputs are invalid, no further calculation of these signals will be made inside the FCC, meaning the AP channel is inoperative and could not be restored during flight since it is sheared off = mechanically damaged.

The first PMDG product, the handbook for Hardys 747 PS1 Precision Simulator was also used as login precedure and state of the art for the time beeing. Best regards

10 hours ago, DavidP said:

The original manual was for the original Aerowinx Precision 747 around 1997 or so.

Their first move into aircraft modelling was the 757 for the ill-fated "Fly!" simulator. 

I owned them all.

Fascinating bits of PMDG history, David…before my time in the hobby…🙂…

I know them closely since they published the 737-600 for FS9. I believe they had stuff also in FS98.

I still recall well my first PMDG lift-off with the -600, an a/c I am passionate about, to this day…had deluded myself thoroughly thinking I’d instantly become a real 737 pilot, and told my better-half so, who, of course, didn’t think so…🙂…

A little learning is a dangerous thing, as they say.

Good memories, though.

Edited February 4Feb 4 by P_7878

 

Default FS9 737 (Classic) vs PMDG (NG)

https://www.youtube.com/watch?v=SROhwNHMGwA

https://www.youtube.com/watch?v=_J65Qqv4wn8

 

1 hour ago, flyingscampi said:

 

Default FS9 737 (Classic) vs PMDG (NG)

https://www.youtube.com/watch?v=SROhwNHMGwA

https://www.youtube.com/watch?v=_J65Qqv4wn8

 

Yes, those are the ones…

After umpteen hours in the stock 737-400 flying with 50 or so airlines…I mean repaints…🙂…, I’d thought I was now well-qualified to tackle the PMDG 737-600.

What excitement it was to push the Saitek throttles on that first PMDG NG, and let it rumble down the runway…it had felt so uniquely different from the stock one…

Thanks for sharing these videos…!

9 hours ago, cseu said:

The meaning of the sentense seems to be: if due to overforce and shear off the mechanically system the position and force signals as FCC inputs are invalid, no further calculation of these signals will be made inside the FCC, meaning the AP channel is inoperative and could not be restored during flight since it is sheared off = mechanically damaged.

Yes, but it's an important distinction as the FCCs do an awful lot more than just drive the autopilot, and these functions are not impaired just because you shear an autopilot servo.  The flight control computer isn't being damaged at all, just the autopilot.  It reads as if someone was just trying to make it sound as complex as possible, so they wrote something incorrect because they thought it sounded better.

yes, it sounds dramatically, but speaking for the B737 family the FCC's are relative "old fashioned" they have the FD and AP functions as well as Mach Trim with AP on and Speed Trim with AP off, Autothrottle has it's own computer, same for the Yaw Damping. There was no basically change between the Classic and the NG, for the Max they introduced an additional Stall Managagement Yaw Damper Computer and included the AT functions into FCC's. Of course they all have Bits and BITE and internal logics to compare and protect, connect, disengage, indicate and so on, but this is valid for all the Boeing FCC's, from the classic B757/767 3-FCC architecture to the B744 and 748 - here the AT functions are incuded in the FMC's then B777 with a new idea of Autoflight Director Computer, Actuator Control Electronics and Primary Flight Computers and finally the card architecture of the B787's or the two FCC each with two independant chanel architecture of the MD11 from Douglas, not speaking about Airbus, since it's a PMDG thread... It's an interesting chapter of different methods but after all they do the same: controlling the plane. Best regards

On 2/4/2026 at 9:52 PM, Stearmandriver said:

It reads as if someone was just trying to make it sound as complex as possible, so they wrote something incorrect because they thought it sounded better.

That's exactly what I thought.

Standard MSFS logic determines that if you make excessive control inputs with the AP on, it will disconnect.

...and that gets spun into something that sounds fantastically customized and super specific 😄

A few of the items on the OPs list are like that.   Word spin, for something pretty standard.

34 minutes ago, JYW said:

Word spin, for something pretty standard.

Maybe, but there is a whole lot more in the docs and just moving around the cockpit and cabin ... however, when I click the pen Robert didn't respond!

Where is the documentation folder located for the 738 for MSFS 2024 purchased in the Marketplace in WIndows 10?

I have a folder in c:\XBoxGames\Microsoft Flight SImulator 2024 and there's only one folder in it called Content.  The Content folder has a folder called Packages but I don't see anything that may contain PMDG or "documentation".

Edit:
I just checked this folder:
C:\User\admin\AppData\Local\Packages\Microsoft.Limitless_8wekyb3d8bbwe\LocalCache\Packages\Official2024\OneStore

It doesn't contain anything.

Edited February 6Feb 6 by Matt Sdeel

9 hours ago, cseu said:

There was no basically change between the Classic and the NG, for the Max they introduced an additional Stall Managagement Yaw Damper Computer and included the AT functions into FCC's.

There was significant change in FCC performance between the classics and the NGs, though it wouldn't necessarily be obvious unless you did a lot of .10 RNP approaches.  The flight director / auto flight performance was significantly tuned on the NG with an eye towards smoothness and precision on these procedures, and it was very noticeable when we flew them both.  Our -400s were the testbed aircraft that created RNP(AR) procedures and they were certified down to .10 RNP, but they needed babysitting at that level in a way that the NGs and now the Maxs do not.

Also, don't forget that the Max spoilers are now fly by wire.  They're controlled by a dedicated unit but it does communicate with the FCCs.

Interesting systems minutia, but the overall point remains: overpowering an autopilot won't damage an FCC; that would seem to be a statement made by someone at PMDG who doesn't quite understand this.