You're welcome
There is no special thing about acrobatic planes. Acrobatic planes and jets usually a built having symmetrical wings because they don't carry much load, like cargo planes.
On how they fly, their pilots a well trained, and know how to maneuver the plane in such a way that the angle of attack is maintained. This is usually done by slightly tilting the nose of the plane upwards, this helps the plane continue its creation of down lift.
An assignment: watch a video of an acrobatic plane flying. You'll see that from the nose they are directed upwards. What I simply mean is, they seldomly fly horizontally when upside-down.
SyNick
Very smart! Thanks for the explanation :)