Couldn’t they ‘aim’ their a/c at the airliner and eject just a second or two before impact?...........
One would think you pull up behind and level, have your speed a bit faster than the airliner and then eject. The plane runs into the back of the plane and would easily do enough damage to down the plane.
The process of ejection removes considerable weight from the airplane, about 800 to 1,000 lbs and does it violently.
This changes the flight dynamics and center of gravity and the plane changes attitude. No guarantees of anything with respect to a predictable flight path.