This topic has been just driven into the ground. Might be worth a search to see teh terrain already covered...
In brief, opposing pilots DO NOT see the exact same thing on their computers. You are fighting a time delayed image from your enemy's computer, while YOUR moves are immediate. So, if he's made a move in the last 1/2 to 1 second, you dont know it.
Meanwhile, HIS image of your plane is 1/2 to 1 sec behind what you've "really done".
Together that means that there can be 2 seconds difference in position, whcih is an eternity when measuring yards of separation at 300 mph.
The only way to solve the time delays built into the internet, while still ahving a massively multiplayer simulation, is to have the "game" played on YOUR front end computer, with status reposrts being fed to the server.
THE ONLY COLLISIONS THAT HAPPEN ARE THE ONES YOU CAUSE BY FLYING TOO CLOSE. YOUR ENEMY CANNOT HIT YOU ON YOUR COMPUTER -- ONLY YOU CAN HIT HIM.
IRL, enemies did unexpected things, so you couldnt expect to be safe as you roar under their belly -- they might nose down. Same thing in AH: If you fly