Partly the lesson here is that nothing is really a tabula rasa ur-source, not even Original D&D. On the contrary, one of the ways that OD&D is so commendable is precisely in how it makes its mechanical predecessors explicit, in a fashion that was mostly wiped out in later editions. For example:
- In the OD&D "Recommended Equipment" section you're supposed to have a copy of the Outdoor Survival game by Avalon Hill (coming even before suggestions for dice and Chainmail [Vol-1, p. 5]), and it gets used & referenced as the basis for D&D's Wilderness movement and adventuring rules [Vol-3, p. 14-17].
- The OD&D section on "Aerial Combat" begins with a reference to another work, as well -- "Many of the most interesting battles take place in the air, so we offer you 'Battle in the Skies' or 'BITS' (with no apologies to Mike Carr, creator of Fight in the Skies)" [Vol-3, p. 25]
- In the OD&D section on Naval Combat, the situation is somewhat more obscured, but the suggested scale for action exactly matches Gygax & Arneson's earlier work, Don't Give Up the Ship! -- "For movement purposes 1:1200 scale models can be used, so a playing area about the size recommended for aerial combat will suffice." [Vol-3, p. 30]
Now, never once in all my years of playing D&D have I actually made use of the flying rules in any way. But one interesting thing -- In Gygax's works of OD&D and AD&D , the Aerial Combat section actually appears before Naval Combat. (As opposed to how you'd intuit the presentation would run, starting from the mundane and proceeding to the more-exotic: presumably standard wilderness, then land combat, naval combat, aerial combat, possibly extra-planar, etc.) So this, combined with the line above on the "most interesting battles", suggests that Gygax was more personally intrigued and invested in Aerial action rules than even something presumably more common like Ships. Therefore, it's a case especially worth considering.
OD&D has a very nice and fully-developed mini-game for aerial combat (presumably inspired in some way by the Mike Carr game, as we see above). It suggests either miniatures or paper counters on a hex-grid specifically at least 48×48 inches (or 6' square for miniatures), with written orders from each side per turn. There are specific move rules for Climbing, Diving, Crashing (including the 1-die-per-1" falling rule, "i.e., a crash from 12" means twelve dice"), Bombing, Melee, Air-to-Air, and Ground-to-Air Fire (specifying catapults with a load of small stones acting as a "shotgun effect"). Here's the table for turning (presumably with "moves" technically in rounds and "turns" [pivots] in number of hex-sides, i.e., 60-degrees each):
(Note that Dragons are in a separate category from "Giant Reptile" at the end of that table -- representing a flying dinosaur, I suppose?) And here's a specialized system for "Critical Hits" on flyers, by which a partly-damaged aerial combatant might be forced to crash or land:
One critique here: Note that the chance to critical-hit a flyer out of the game doesn't account for individual toughness in any way. A single sling-stone is just as likely to take down a dragon as a hawk!
As usual, the word-count in AD&D expands greatly, and here you get long passages on training, feeding, and resting different types of aerial mounts in the campaign; issues of thrust and balance on different types of creatures; seating and restraints for mounted fighters, etc. Each separate flyer type now gets a separate entry with a few lines on individual powers & tactics in the air. The specialized "Critical Hits" system is stripped out here, and replaced with a more abstract rule of "Any winged creature which sustains damage greater than 50% of its hit points will be unable to maintain flight and must land" [DMG, p. 53]. The Bombing system is missing, but we are introduced to new rules for diving attacks (double damage), and under the levitation/flying notes, a special accumulating penalty for firing missiles without a stable platform (OD&D just said: "Missile Fire, Air-to-Air: Treat as normal missile fire..." [Vol-3, p. 27]). But the core of changes is to systematize flyer maneuverability into new lettered classes A through E, which looks like this:
Class A: Creature can turn 180° per round, and requires 1 segment to reach full airspeed. Creature requires 1 segment to come to a full stop in the air, and can hover in place. Class A creatures have total and almost instantaneous control of their movements in the air. Examples: diinn, air elementals, aerial servants, couatl.
Class B: Creature can turn 120° per round, and requires 6 segments to reach full airspeed. Creature requires 5 segments to come to a full stop in the air, and can hover in place. Examples: fly spell, sprites, sylphs, giant wasps, ki-rin.
Class C: Creature can turn 90° per round, and requires 1 round to reach full airspeed. Examples: carpet or wings of flying, gargoyles, harpies, pegasi, lammasu, shedu.
Class D: Creature can turn 60° per round, and requires 2 rounds to reach full airspeed. Examples: pteranodons, sphinxes, mounted pegasi.
Class E: Creature can turn 30° per round, and requires 4 rounds to reach full airspeed. Examples: dragons, rocs, wyverns. [DMG, p. 50-51]
Holy smoke -- look at how much maneuverability was reduced between OD&D and AD&D! As one example: In OD&D, Dragons could make 3×60° = 180° turns each round (that is, wheel around in one half-circle). Here, reduced to a 30° pivot each round, it would now take 6 rounds to make the same turnabout (i.e., 6 minutes in AD&D alleged 1 round=1 minute time scale). The same can be said for all the rest -- the OD&D range was from 120° to 360° per round; in AD&D it's 30° to 180° (generally halved or quartered). However, the minimum-spaces-between-turns rule from OD&D is now gone.
The next place that aerial combat shows up is in Dave Cook's D&D Expert Rulebook (in the 1980 B/X line, the follow-up to Moldvay D&D Basic). What you get here is a clearly cut-down version (24 lines total), emphasizing shortened versions of the new AD&D rules. You get mechanics for: Surprise (diving/swoop for double damage), Spell Casting (stable platform or no spells: a harsh new restriction!), Missile Fire (stable platform or -4 to hit), but we also reach back to OD&D for the delightful Bombing rules. What's been sliced out are any of the other rules, in particular all of the rules for maneuverability and critical hit-locations (as seen in the tables above). These considerations are, perhaps quite reasonably (again, I never used them, so arguably they're a waste of space), punted off to the DM:
The DM should feel free to add to these guidelines as needed; for example, rules for climbing, diving, turns, crashing, and so on can be added. [D&D Expert, p. X25]
The other place I thought to look (granted my particular interest in their use for a mass-combat game), was in Doug Niles' Battlesystem rules. In the first edition (Battlesystem Fantasy Combat Supplement, 1985), Niles explicitly refers back to the AD&D text, using the exact same Maneuverability Class ratings and rules as seen above (which is maybe a bit sketchy, since the mass time scale has converted to 1 turn=3 rounds):
Basic rules on flying movement and combat for the AD&D game are listed in the DMG, p. 49-53. Those rules apply in the BATTLESYSTEM game except as specifically noted below. For the D&D game, use the rules given below only. [Battlesystem FCS, p. 29]
One thing that Niles does here is to abstract altitude (in previous system, recorded as inches in paper, counters, or with a dowel) to simply 3 categories: Low, Medium, and High. Other than that, he hews pretty closely to AD&D, presenting conversions for the Aerial Fire (stable platform or penalty), Forced Landing (flying creature takes partial damage), and again the Bombing rules, as seen above.
In the later edition, however (Battlesystem Miniatures Rules, 1989), Niles allows his ruleset to evolve into something beyond the original basis. He keeps the same maneuverability classes (A to E), but wisely multiplies the turns allowed for his mass-combat game (A has no limit, B is 360 degrees/turn, etc., down to E at 60 degrees/turn). The abstracted height categories are gone, and altitude is recorded by a d20 placed next to a unit, showing height in actual inches. There are specialized rules for Changing Altitude, Ground Attack, Pass-By Attack, Vertical Envelopment, Dogfighting, Setting Spears/Pikes Against Flying Creatures, Falling Damage, Flying Units and Missile Combat (negate wall bonuses), Range Effects (shortcut rule for triangulating height & ground distance), and Morale and Flying Units (aerial units suffer morale penalties and are harder to rally). What's out are: the Dive bonus to attack, Hits forcing flyers to the ground, and the Bombing rule. Largely this puts this system in a different class than what has come before.
Here's a summary table of notable Aerial Combat mechanics throughout the different editions of classic D&D:
Which of these rules do you prefer in your own D&D games? Do you think it's preferable to let Dragons and similar creatures turnabout in the air within 1 round, after 6 rounds, or some number in between?