Engage in air combat with a big beefy UFO and rather than running away at some point . . . instead it decides its going to CHARGE you and shoot down your interceptor.
No more sitting there for what seems like days plugging away at battleships, terror ships, and supply ships. They know they're tough, and you're not. And they're going to prove it, by chasing you down and eliminating your pestulant flying toys.
So there you have it.
* If enabled for an enemy ship, and its maximum speed is greater than yours, after a certain period of time it will force "Aggressive" air combat mode and lock you out from being able to fly away. And its a fight to the death.
* If more than one interceptor is present as a valid target, it can only charge one of them at a time, but unless it is close to being shot down (lower than 60% max damage remaining) the alien ship will continue down the list after each one of your interceptors is shot down.
I suppose there could also be a interception AI mode where one of these ships that detects one of your ships close to it will change course, intercept you, and do all of the above.
* * * For those of us who like our Games as Hard as our Liquor.