Ah, the awkward old dance where two people try to walk through the doorway and end up mirroring each other's movements trying to get out of each other's way...
The aviation world actually solved this problem a long time ago. Everyone turns to their right. FAR 91.113:
> (e) Approaching head-on. When aircraft are approaching each other head-on, or nearly so, each pilot of each aircraft shall alter course to the right
(among other collision-avoidance regs in that section)
The planes talk to each other and run a common protocol that tells the pilots what to do to resolve the conflict. The problem is when one of the pilots doesn't listen to the nice robot voice yelling at him to DESCEND NOW!...
Yes, they do. Then the problem is when the 2 autopilots of the 2 planes take the same evasive manœuvre...