There are a few settings that you don't need for the first few tries, but you should know them afterwards.

Munition Type

You select the ammunition type to match the type of ammunition loaded: MK-50 or PGU-28.
Leave it as it is when in doubt.
This setting is available in both A/G and A/A mode.

Rate of Fire

The firing rate is set to 6,000 or 4,000 rounds per minute with HI or LO.
Try both settings a little.
This setting is available in both A/G and A/A mode.

Wing Span

In the air-to-air mode of the aircraft cannon the size of the tunnel is set as default to a wing span of 40 ft.
This is approximately the span of a fighter. If you want to attack a larger target, you can set the wingspan of the target.
The following steps are necessary for this:

1. On the SMS page, activate the UFC.
   UFC is boxed and the first UFC option button is labeled WSPN for Wingspan.
2. Press the option button WSPN.
   The option is activated, recognisable by the colon on the left of the label (:WSPN).
3. Now add the desired span in feet.
   In the example below the span of the Su-25 = 47 ft.
4. Confirm the entry with the key ENT.
   At the top right of the SMS, XXX disappears and the new span is displayed next to WSPN.