At present there aren't any spotting rules; all of the games we've played have started with all aircraft in contact. Spotting allows some aircraft to get the drop on the enemy.
It's simple enough. All aircraft start the game unaware of any enemy aircraft. At the end of each turn an aircraft or a formation can attempt to spot one enemy aircraft. Roll 2D6 and score 9+ to do so. Modify as follows:
+1 - Veteran Crew
-1 - Inexperienced Crew
+1 - If in formation of three or more aircraft (see below)
-1 - Target is lone aircraft (not in formation)
+2 - Range is up to 6"
+1 - Range is up to 12"
-1 - Range is over 18"
For a single-seater:
+1 if spotting into Nose Arc
-1 if spotting into Tail Arc
(I am working on different modifiers for other types of planes).
Formations - A formation is a group of two or more aircraft that have not yet spotted an enemy. Each aircraft in the formation must remain within 3" of at least one other aircraft in the formation at all times. When spotting only one aircraft in the formation rolls, but if it spots an enemy then all planes in the formation become aware.
If an aircraft or formation has not spotted an enemy aircraft then it moves at 3" per turn and each plane can make up to one 45 degree turn (you do not have to roll do do this however). Once an enemy aircraft is spotted then the plane or formation becomes aware of all enemy aircraft and can move normally.
Initiative will still be a single D6 roll per plane, but with a +1 for Veteran crew and -1 for Inexperienced. The Maximum score will be 6 and the minimum 1; this allows a dice to be placed next to each plane with their initiative score on it. Planes move in order of initiative from lowest to highest.
I am looking at swapping the tie-breaks so that the plane's agility is used first, then the crew's experience. In addition, some planes will have a '+' appended to their agility - so B+ instead of just B. They maneuver the same, but in the event of a tie-break against a plane with the same agility, a plane with a + moves after one without. So, for example, an SE5a has Agility B, whilst a Fokker DVII has Agility B+. If they both tie for initiative, the SE5a must moves first, as the Fokker has a 'better' agility. When a plane goes down an agility class because of damage it keeps the + (so agility C+ downgrades to agility D+). From looking at plane stats only A, B and C agility planes really need to be split up in this way.
As simple adjustment here; if the number of dice a plane gets for firing is equal to zero then they can roll one red dice, but it always needs a '6' to score a hit.
Hopefully the next time I update the rules I should have a more comprehensive list of aircraft stats as well; I have been slowly adding planes into a spreadsheet and have a good, varied collection.
And finally ... the obligatory photo. I'm questioning my own sanity because, at some point, I thought it would be a good idea to try and scratchbuild 1/600th scale DH2s. These still need the undercarriages putting on them, but they may work (the models are fragile, though - I will probably give them a good coat of watered-down PVA to hold them together before painting):
|Those are 1cm squares on the board ...|