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Garmin 3000 Autopilot

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I thought it might be helpful to some to point out a few things about the autopilot in the G3000.

When the Garmin G3000 autopilot (AP) is ON the a/c will always be in AP controlled modes with respect to both the lateral (roll) and vertical (pitch) axes.  This is similar to other Garmin autopilots like GFC 600 and in the G1000. This means, for example, unlike some other autopilots where the lateral and vertical modes are independent, you cannot have the autopilot in HDG mode or NAV mode but still control altitude manually, or vice versa.

To see this, if you put the TBM 930 in a bank of say 20 degs and pitch attitude of 10 degs up, when you turn the AP on the a/c will roll level and maintain the 10 degs of pitch up  even though you have not selected any AP mode (pushed any of the other AP buttons). And on the top of the PFD you will see ROL (Roll) and PIT(Pitch) on the mode annunciator. Similarly, if you are in HDG or NAV mode and you turn that mode off, the AP will go to ROL wings level mode (The G1000 indicates LVL mode). ROL and PIT are the G3000 default AP modes if nothing else has been selected for those respective axes. So if the AP is in NAV and ALT hold mode while you are in cruise and you want to change your altitude by 1000ft, for example, you can't just turn off ALT Hold and expect to be able to manually pitch the a/c as needed to gain the new altitude as you can do with some APs. You either have to turn off the AP and hand fly, or use one of the AP vertical modes such as VS or FLC (or you could turn the AP off, pitch the a/c up as needed, and then turn the AP on to maintain the pitch with wings level in roll). Or for another example, to buy a little time on takeoff, once you have established a trimmed climb rate, you can simply turn on the AP and the a/c will stay wings level in roll and continue climbing at your pitch up setting while you sort things out if necessary.

Al

 

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Thank you!  I've fought that word not allowed thing too many times to count (you'd think I'd have found out what was up on my own...) and now I know why.  Not knowing that will get you in a bad way quick.  Much appreciated.

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I forgot to say a few words above about the overall AFCS  (Automated Flight Control System) above. I have found it useful to think of the G3000 AFCS (actually most AFCS systems) as composed of a Flight Director (FD) and an Autopilot (AP). Based on the flight plan and aircraft's position, attitude, airspeed, etc, the FD system develops steering commands needed to guide the aircraft to where it needs to go and sends these commands to the AP system. So the FD commands the AP, it is not the other way around.The AP then converts the FD commands into signals to the servos connected to the flight control surfaces. If the AP is not on, however, the FD will send the steering commands to you, the pilot, through the FD display (command bars) on the PDF. In this case the pilot is simply replacing the AP flight control servos. So you can 'hand fly' that ILS approach with the AP off but still get guidance from the FD system by turning on the FD PDF display.

So in simplistic summary, the FD system figures out what is needed to guide the a/c according to the flight plan, and either passes that info on to the AP if the AP is on (whether or not the FD display is also on), or if the AP is off provides the information to the pilot if the FD command bars are being displayed on the PFD.

Al

 

Edited by ark

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1 hour ago, ark said:

So in simplistic summary, the FD system figures out what is needed to guide the a/c according to the flight plan, and either passes that info on to the AP if the AP is on (whether or not the FD display is also on), or if the AP is off provides the information to the pilot if the FD command bars are being displayed on the PFD.

As best I know, there is no such thing as AP on with FD off..  On a typical system, turning off the FD will also turn off the AP.


Bert

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You're making things way too complicated and confusing. 

It's not rocket science:

1) Arm FD, Nav, VS on the ground. Dial in a rate of climb (I use 2,000 fpm). Set flaps to take off. 

2) Rotate smoothly, point the aircraft where you need it to be, watching your speed and pitch. Trim as necessary. 

3) Retract flaps at 115

3) YD on.

4) AP on. 

Enjoy your flight. 😀

 

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39 minutes ago, Bert Pieke said:

As best I know, there is no such thing as AP on with FD off..  On a typical system, turning off the FD will also turn off the AP.

I generally agree with that, but noticed that you could have the FD display off in the TMB 930 G3000 with the AP on as in the pic below. So I don't know for sure if this is just another MSFS bug (likely, sigh) or if that is allowed in case the FD command bar display itself is bad for some reason which could be very disconcerting and confusing in flight.

Al

 

1d9fee4c77.png

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Just now, ark said:

So I don't know for sure if this is just another MSFS bug

Looks like a bug to me..


Bert

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1 hour ago, Bert Pieke said:

Looks like a bug to me..

Agree. Found the following in the Garmin G3000 Reference Guide which implies the FD command bars should display when the AP is turned on:

"The FD Key is dis­abled when the autopilot is engaged".

Al

Edited by ark

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