The Up Front Control Panel (UFC) of the F/A-18 could be quite difficult to grasp, because it deviates from a civilian A/P quite a bit.
The first thing to be noted is the UFC has basically two "levels" of operation. The "top" level is the COM mode. This is the mode the UFC is in by default, you know you are in this mode, because the indications will read:
This mode is simplified compared to the real one, since we don't obviously have the capability to encrypt ATC communications in FSX...So, the options about the Cypher or the frequency band will "act" like the real one, but will not have any impact on operation.
The most important controls in COM radios are the two channel selectors under the "1" and "2" Windows. These will control COM1 and COM2, respectively. Here we have another difference between real world F/A-18 and FSX. In the real one, those selectors can be rotated or pulled. Rotating the controls would select from a preset memory of 1 to 20 COM channels, while pulling would go into "Manual" mode, allowing for a direct COM frequency selection.
We have only implemented the Manual mode so, to select a COM frequency directly, pull the selector and the corresponding radio will go in Manual mode, showing an "M" in its Window, and the current COM frequency in the UFC Scratchpad.
Now, the COM radio is ready to accept input from the keypad. The input system is smart enough to allow to use shortcuts so, for example:
to select 128.375, dial 1-2-8-3-7-5-ENT on the keypad
to select 128.35, dial 1-2-8-3-5-ENT
to select 128.3, dial 1-2-8-3-ENT
to select 128.00, dial 1-2-8-ENT
Illegal input will be flagged with an "Error" flashing message, and you can correct an input by pressing the CLR button.
By using the two "VOL COMM1" and "VOL COMM2" knobs, you can select which COM you are transmitting to. The active COM is signaled by the "ON" indication on the UFC Scratchpad, when the frequency is displayed. Pulling again the Channel selector knobs, will return to normal operation.
Now, let's talk about the other modes, starting with the A/P. It's important to note that, apart for the "top" COM Mode, ALL the other modes are like sub-menus of the main COM mode. You "enter" a mode pressing the relevant mode key, and you "exit" from it, by pressing the same button again, thus returning to the top-level COM mode.
A/P Mode - Autopilot
Pressing the A/P button will enter into Autopilot mode. The Panel will now show:
It's important to note that, opposite to any civilian A/P, the F/A-18 A/P has been designed for speed of operation, not safety or passengers comfort. This means, there's no "preselection" of modes: when an A/P mode is selected, it will immediately engage and it will also turn on the A/P, if not already engaged. Of course, you can always manually turn on/off the A/P, by using the ON/OFF button when in Autopilot Mode.
To better learn autopilot modes, I suggest putting the left MFD screen on the ACL page, so you will be able to see all the Autopilot Annunciators, and the right MFD screen on HSI mode (should be default). To do this, press "MENU" on the left MFD, then press "ACL". On the right, press "MENU", then "HSI"
ATTH - is the Attitude Hold mode.
HSEL - Heading Select. It will mantain the Heading selected with the HDG selection bug. The HDG and CRS selection bugs are just under the Fuel selector. You can check the current selected heading on the HSI under the HSEL readout, and there's a bug displayed on the HSI as well. Note also, on the HSI, a "CPL HDG" readout will appear close to the airplane symbol.
BALT - Barometric Altitude Hold mode. This will set Altitude Hold mode at the CURRENT Altitude. There's no way to manually pre select a different altitude, Altitude mode here will always lock at your current altitude.
RALT - Radard Altitude Hold Mode. Not implemented
CPL - Coupled mode. This mode is a generic way to name all modes that are Coupled to something like a TACAN, and ILS or a WAYPOINT. What you are coupled to, depends on the mode that has been selected on the HSI screen. To change Coupling mode, select either "TCN", "ILS" or "WPT" on the HSI, to toggle between modes. NOTE: Of course, to use WPT mode, you first have to create a flight plan! Without a flight plan, the only modes available for coupling will be TCN and ILS.
Note the "CPL TCN" or "CPL ILS" on the airplane symbol. To select a Steering Course towards the station, use the CRS bug, and check the small "CSEL" readout on the HSI. By pressing the "CSEL" button on the HSI, instead, you can toggle on/off the visualization of the CRS indication for the HSI.
Pressing A/P button again, will exit from the Autopilot mode.