First off -- you need a squadron (just 2 planes will do) for rearming/reloading to be available. Mainly needed for mission that you need to rearm in order to complete the mission. (e.g. destroying ships)

It works by commanding the A.I. the reload command, as you deplete the aircrafts' ammo you exchange aircraft with the A.I. to head back to base to rearm/reload because you can't do it yourself.

When the A.I. returns you would "usually" exchange aircraft again to continue with the mission until accomplished... or let the A.I. continue the mission (unlikely) or let the A.I. reload again (usually a reload is enough - depends on mission and/or aircraft ammo type/capacity).

Controller Setup Screen (*Accessible via settings while in mission > Press ESC > CONTROLS (look below right -- scroll wheel down when needed)

* Updated game version 1.5 added control set-up in mainmenu settings


Note: KEYBOARD / MOUSE columns: are the game default bindings.
CONTROLLER column: for this game I use Logitech Extreme 3D Pro

Note that when the icon is green it means that the A.I. aircraft will follow what you commanded.
(ACTIVE) means you control that aircraft.

Press L (default key bind for Plane List) to enter "Squadron Commands".

Example 1: This airplane (FW 190) is damaged and must return to base to avoid loss.
Will certainly needs repair when you get back. (Note: this return to base is A.I. initiated... but, you can initiate it if you like or deem necessary)

Example 2: This one (J2M) needs to reload cannon ammo.
In this example I just used up all the cannon ammo so I change plane and will send this plane to reload, when it returns, I'll take control again and use the crafts cannon for the mission or you could just give orders to the A.I. to carry out.
Click the "Gray Icon" to initiate reload (Note: this icon will only show when reloading is really needed).

Flying back to base and rearming takes time...

...heading back to mission also takes time. after its return you can commandeer the aircraft or give commands.

Return to mission area in xx sec.
When the timer runs out your aircraft will explode and your mission will fail.

This guide is still a W.I.P.

Will be refining this guide if needed.

And please don't forget to comment, constructive or otherwise + a ThumbsUp Rating & Favorite, will be greatly appreciated!!! Tnx.
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^ btw, don't use these button image, use the one located near the top.