So what is an autopilot any way? My first autopilot was one piece of hardware that was connected to the flight controls at one end and a simple flight director at the other. And that is still basically true.
In the GVII, the flight director is essentially the higher brain function of the autopilot to do high level things, like takeoff, climb, intercept a course, descend, fly an approach, and land. Most of our interaction with this Flight Director is through the Flight Guidance Panel. The Flight Control Computers provide the inner brain function, the stick and rudder required to do what the higher brain directs. That is the basic autopilot itself.
Most of your interface with the flight director is through the Flight Guidance Panel, though inputs are also made from the Touch Screen Controllers. But for our purposes here, let's get to know the Flight Guidance Panel.
Everything here is from the references shown below, with a few comments in an alternate color.
Photo: Flight guidance panel: speed, Symmetry, §2b-21-40, fig. 1
Click photo for a larger image
[Symmetry, §2b-21-40] The guidance panel contains two independent channels. Each channel communicates with one FGC channel. When a FD mode is armed or engaged, the annunciator on the appropriate button on the GP is lit. The annunciation of the mode and the AP engage status is provided on the PFD and SFD.
The guidance panel interfaces using the following switches:
The guidance panel interfaces with the following systems:
The flight director provides guidance for the Flight Control Computers and displays information to the pilots for takeoff, climb, cruise, descent, approach, and landing. It does this by using information from air data sensors, position sensors, the flight management system, and pilot inputs through the touch screen controllers and the flight guidance panel.
As with previous Gulfstreams, after a while most of the Flight Guidance Panel becomes second nature, with the more obscure functions causing confusion now and then. Even with years of experience, you might need a refresher now and then. With that in mind, I'll simply present the uses for each part of the panel from left to right.
[Symmetry, §2b-21-40, ¶1]
Automatic speeds are derived by the FMS as follows:
If below the speed limit altitude (250 knots/10,000 feet), the climb, cruise, and descent speeds are set to minimum with the speed/altitude limit.
The automatic speed target is set based on the speed mode.
If in a holding pattern, then the speed is max endurance.
Limit speeds are applied as follows:
[Symmetry, §2b-21-40, ¶2]
In greater detail: Lateral Flight Director Modes.
[Symmetry, §2b-21-40, ¶3]
Until Block 1, if FLCH mode is active below 2,000 feet AGL or AAL (whichever occurs first) with FLCH mode active, you will get an amber FLCH Inhibit Altitude CAS Message, the FPA vertical mode will take over, and the autothrottles will automatically engage. If you press the FLCH mode button below 2,000 feet AGL or AAL (whichever occurs first), you will get a cyan FLCH Inhibit Altitude advisory CAS message and the vertical mode will not be selected.
[Symmetry, §2b-21-40, ¶4]
[Symmetry, §2b-21-40, ¶5]
NOTE: Pushing the PFD SRC button when the autopilot is engaged changes the lateral flight director mode to ROL and the vertical mode to FPA , but does not disengage the autopilot.
Gulfstream GVII-G500 Production Aircraft Systems, Revision 1, Oct 1, 2018
Gulfstream Symmetry Flight Deck for the G500 Aircraft Pilot's Guide, April 10/19.
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