Aerobatics is an activity that involves flying techniques using aircraft altitudes which are normally not used in a flight. It is performed in gliders and airplanes for training purposes, entertainment, recreation and as a sport.
Aerobatic flying is based on piloting skills of a broader range. In this the aircraft is exposed to higher stress than in a normal flight Sometime the pilot is supposed to wear a parachute while performing aerobatics.
The aircrafts used for aerobatics are of two types – aerobatic capable and specialist aerobatic. The specialist design like the Extra 200 and 300, the Pitts Special, the Sukhoi Su-26M, Sukhoi Su- 29 etc, are all used for their aerobatic performance. But this comes at the cost of general purposes like touring and the ease of landing. Aerobatic capable aircrafts like the Cessna 152 Aerobat model can be of dual purposes and used to carry passengers or luggage and also capable for some basic aerobatic figures.
The competition begins at Primary (graduate) level and then goes on to complex stages like the Sportsman, the Intermediate and the Advanced stage, the Unlimited stage being the high end of the competition. The g levels varies among the pilots, experienced pilots pull up to +/- 5g for smaller periods and unlimited pilots who are more experienced have g levels of +8/-6g. Because of the limited ability to pool blood for positive g, the limits of positive g is more than that of negative g. +9g for if held for a few seconds or more can lead to unconsciousness.