Monk3y found out a way you need to program your own in c# or C++. Start up a custom game with a friend make sure you are on opposite teams.
Make sure its AB then what you will need to do is a little bit of math. you have to have him fly level and calculate how far the aim indicator is away from the plane.
Given that bit of into you can calculate something as a holder like so.
Plane() <- enemy info
Indicator() <- this is your holder
Indicator that bit will be tied to the plane so you have to get a draw function
drawI() <- will pull form indicator to print a indicator on screen.