The FAQ was correct, the formula for falling distance in Earth-like gravity (acceleration = -32 ft/s2, negative because gravity pulls down, and in the general reference frame, up and right are +, while down and left are -) is:
D = 0.5*a*t^2 + Vi*t + Di
D= distance (in feet) fallen
a= acceleration (gravity in this case, which is -32 ft/s2)
t= time (in seconds)
Vi= Downward Initial Velocity (for a free fall like we are discussing, you assume no initial downward velocity, just like dropping an object, rather than throwing it down, so Vi = 0)
Di= Initial height of the object. This is relative, and so we can assume a reference height of 0 which means are D values will be negative, indicating the object is falling to a height lower (below) than our reference of 0. It makes D give the distance fallen which is what we want.
So for a 6 second fall, assuming no wind resistance, you get:
D = (0.5)*(-32)*(6)^2 + (0)*(6) + (0)
D = -576 feet
For 12 seconds (2 rounds):
D = (0.5)*(-32)*(12)^2
D = -2,304 feet
For 18 seconds (3 rounds):
D = (0.5)*(-32)*(18)^2
D = -5,184 feet (5,280 feet = 1 mile, so you fall about 1 mile in 3 rounds assuming no wind resistance)
As for house rules, since I love aerial combat, I have used the following:
Aerial House Rules
1) Changing Altitude: (no more free altitude changes as per 4E rules)
a) Ascending (non-hover) - You may only increase your altitude by 1 square for every square of movement you spend toward doing so.
b) Ascending (hover) - If you have the (hover) trait, you can increase your altitude by 1 square for free for each square you move horizontally; but if you choose to move vertically, you do not get a free square of altitude increase in this manner.
c) Descending (all) - You may decrease your altitude for free by 1 square for every square of movement you make. If you move down, you can effectively decrease your altitude by 2 squares for each square down you move.
2) Aerial Prone (all): You are considered Prone just like you would be if on the ground. You can only "crawl" but in an aerial version, moving half your speed just like if grounded, cannot Shift, and still suffer a -2 attack penalty. You can end being Prone by spending a Move Action to "stand up" just as if on the ground. While Prone in the air, apply the following differences:
a) (non-hover) - You Grant Combat Advantage to all creatures while you are Prone in the air.
b) (hover) - If you have the (hover) trait, you only Grant CA to Melee attacks as per normal ground rules for Prone.
c) (all) - Ranged Attacks do not take a -2 penalty against you while you are Prone in the air.
3) Forced Movement: As per normal 4E rules
a) (non-hover) - Creatures without (hover) do not fall while stunned, instead they can make a Save and if they succeed they do not change altitude that Round due to being stunned, otherwise, if they fail, they lose 6 squares of altitude as they struggle to "tread air". If they start their turn stunned, they make this Save at the start of their turn to see if they maintain their altitude. If they fail the Save, they lose 6 squares of altitude that Round for being stunned. If this altitude loss causes their altitude to become 0, they suffer falling damage as if they fell the distance from where they were before they lost those 6 squares (so at most suffering a 6 square fall or 30 feet = 3d10 damage).
b) (hover) - As per normal 4E rules (which means stunned does not change their altitude)
5) Hover: In addition to the normal 4E benefits related to being stunned, and those in the house rules above (regarding altitude changes and being prone), hover fliers also gain the same benefit as a creature with the aquatic trait while fighting underwater against those without it. Creatures with (hover) gain a +2 bonus to Attack Rolls against other creatures without (hover) if those other creatures are airborne.
Mounted Combat feat
: In addition to its normal benefits, it also grants:
1) Proficiency with all weapons that have the Mounted keyword (currently only the Lance in 4E)
2) You are considered to have the (hover) trait if you are mounted on a creature with that trait
3) When you make an Athletics, Acrobatics, Endurance or Stealth check while mounted, whether you use your own skill or that of the mount, make the check as if both you and the mount were trained in that skill (this gives no additional benefit if you and/or the mount were already trained in the skill)
4) You may make a Quick Mount. When you Move or Shift, you can Move or Shift into the same space as your mount and are then considered to be mounted. Doing so, however, costs 1 extra point of movement/shifting and you may spur your mount into motion, allowing it to move a distance equal to its speed less the number of squares of movement/shifting you used during the action that allowed you to Move or Shift. If this value is 0 or less, the mount cannot be spurred into motion, but you are still mounted.
5) You may make a Quick Dismount. When you Move or Shift while mounted, you can use part of that Move or Shift to move/shift into any open square adjacent to your mount and are then considered to be dismounted. Doing so costs 1 extra point of movement/shifting. You may continue moving once dismounted up to a distance equal to your speed less the number of squares of movement/shifting you used during the the action that allowed you to Move or Shift. If this value is 0 or less, you cannot make any additional movement, but you are still dismounted.
Example of Quick Mount:
Your mount has a speed of fly 6, you have a speed of 8. You take a move action to use a power than lets you Shift your speed +1 (9 squares). You shift 3 squares adjacent to your mount, and spend 2 more to shift into the mount's space (this costs 1 square normally and 1 extra for using the Quick Mount feature) and are now considered mounted. You have 4 squares of shifting left (having spend 5 so far to shift up and mount), so you want to spur your mount into motion. Your mount has a speed of 6, you used 5 squares of shifting so far during this action, so your mount can move (not shift, even though you were shifting, you mount can only move normally) a distance equal to its speed less the number of squares of movement/shifting you used during the the action, which is 6 - 5 = 1 square. So your mount can fly 1 square (with you now riding it) at which point your movement ends.
Example of Quick Dismount:
Your mount has a speed of fly 12, you have a speed of 8. You take a Move action to fly (while mounted), and fly 4 squares to the ground, where you spend 2 more to quick dismount into a square adjacent to your mount (this costs 1 square to move out of your mount's space and into an adjacent square and 1 extra for using the Quick Dismount feature, a total of 2 squares of movement used up) and are now considered dismounted. You have 6 squares of movement left (having spend 6 so far to fly down (4) and then dismount (2) onto the ground), so you want to continue moving. You used 6 squares so far during this action, so you can move (not shift/fly, even though you were flying during this movement initially, you can only move normally for the rest of this movement, unless one of your normal movement modes happens to be fly, then you could use this extra movement to fly) a distance equal to your speed less the number of squares of movement/shifting you used during the the action, which is 8 - 6 = 2 squares. So you can move 2 squares at which point your movement ends.
1) Aerial Saddle: this saddle straps the rider in. While strapped in, the rider cannot be knocked Prone. The saddle constrains the rider and imposes an additional -2 Check penalty to the same skills as Armor or Heavy Shields would. If the rider does not have the Mounted Combat feat, it is not considered to be proficient in the use of this saddle, and suffers a -2 to Attack Rolls as well while using it. While the saddle is usually designed for use on aerial mounts, it can also be used for other mounts, such as war horses.
It takes a Standard Action for the rider to unstrap himself before he can attempt a dismount. While strapped in, the rider must go where the mount goes, and the mount must move with the rider if the rider is forced to move. If the mount is Prone, so is the rider.