Battle of Britain remake of PSS game CodeSVN

Soem research on turnaroud times (rearm+refuel). 25 minutes seems best for now.

Added maximum fuel amount (capacity of plane's fuel tanks)

Just some research (comments added) about game mechanics (based on original emulated game)

Some notes on turn around time of squadrons

Trying to add more info to airfield menu. Just resized it to be higher. It looks not pretty now. Will fix it later.

Bingo fuel: doesn't allow to select target other than airfield when on bingo fuel. Also minor bugs fixes with searching for closest available airfield.

Bingo fuel: doesn't allow to select airfield that is too far away to fly to

Bingo fuel: doesn't allow to select airfield that is too far away to fly to

Checks for bingo fuel properly. Automatically sets destination to home airfield if bingo fuel is reached. If fuel amount is less than bingo fuel, seeks closest airfield. Doesn't allow to manually change destination by player if squadron has been set to return to airfield because of lack of fuel.

Unstable.
Added checking for bingo fuel and automatix return to home base (or any other base in range if home base is too far away). Need some testing and adjustments, though.