Aerial Mounted Archery

All right, so, I'm running into a bit of a quandary.

I'm designing an air-based mounted archer, and I'm unsure of what feats I need or what feats my companion needs.

I pose this:

1) My Pegasus initiates a Flyby Attack.
2) When my pegasus reaches the enemy and attacks, I want to attack it at the point when both my pegasus and I are within the pegasus's melee range.
3) My pegasus continues its movement.

For #2, I'm at a loss. Would I only get one attack? From various rules on mounted combat, a mounted archer can use the move action of its mount to move the mounted team, while the archer gets to use his/her turn for a full-round attack.

Now, does Flyby Attack make it so I only receive one attack?
Or is it still using the actions of my mount, so I get a full-attack option?

Would I need Flyby Attack to make this work? Or do I need Shot on the Run?

I'm sort of the guinea pig in my Pathfinder group as far as mounted combat goes. We've never really had to deal with it.

Alternatively, for #2, could I just, oh, say, wait until my Pegasus ends its movement with Flyby Attack and let loose the arrows? This seems like the easiest way to deal with this without getting.. I don't know, complicated?

You don't need any feats for mounted archery. Provided you limit your mounts movement to a single move you get o make a full-attack without penalty (aside from any penalties you incur from firing into melee or at foes with cover relative to you - assuming you don't have feats to mitigate those penalties).

The part about the Pegasus getting their attacks I'm not sure about (will need to re-read). One thing to consider is if you are asking your Ranged attacks in a threatened area (while your mount attacks) you will provoke if you don't have PBM.

You can make all your attacks with a ranged weapon while your mount moves. You take a penalty if it double moves or runs (which it won't be if using flyby attack, so no worries there). What could be worrying is that generally, you make your ranged attacks when your mount has moved half the distance it will be going for the round. Which, with Flyby Attack, could very easily be when you're within an enemy's threatened area.

Not to mention the movement from Fly-by provokes, so unless your mount has more reach than the enemy (Lunge feat is your friend here), you will BOTH be moving out of its reach and thus provoke AoOs.

I don't think there yet exists any feat or option to change when during your mount's move you're able to make your ranged attacks. Seems like something that would be easy enough to houserule as a feat, mounted archers just don't get much consideration by the designers of PF *or* D&D 3E, so nothing official I know of.

You will need your Pegasus to actually have the Flyby Attack feat for this to work It won't do anything for you to have it. Also note, ranged attacks while mounted have to be taken when your mount has completed half its movement. So your mount could Flyby Attack and you could make a full attack with your bow, but whether or not those attacks happen at the same point in the movement is dependent on how far you move and how far away your enemy is.

Those are good points StreamOfTheSky; I hadn't seen that rule yet about half its movement.

I really appreciate the replies. Your help is going a long way to make the rules more refined and for our gaming group to finally, perhaps, incorporate a long-overlooked form of combat.

The Pegasus has a reach of 5 feet. Lunge is definitely an option. I do have a lot of routes open to me, since this is a level 20 Pathfinder Gestalt campaign (let's just say that my DM, and I quote, said "let's get crazy").

Thank you! Perhaps we can houserule something. I'll post it here if we can come up with something.