soaring flight, while unpowered gliders will have to land out, away from the home airfield, requiring retrieval by road using the glider's trailer. Aerobatic competitions World and European Aerobatic competitions are held regularly. In this type of competition, the pilots fly a program of maneuvers (such as inverted flight, loop, roll, and various combinations). Each maneuver has a rating called the "K-Factor". Maximum points are given for the maneuver if it is flown perfectly; otherwise, points are deducted. Efficient maneuvers also enable the whole program to be completed with the height available. The winner is the pilot with the most points. Hazards Unlike hang gliders and paragliders, gliders surround the pilots with strong structures and have undercarriages to absorb impacts when landing. These features prevent injuries from otherwise minor incidents, but there are some hazards. Although training and safe procedures are central to the ethos of the sport, a few fatal accidents occur every year, almost all caused by pilot error. In particular there is a risk of mid-air collisions between gliders, because two pilots might choose to fly to the same area of lift and so might collide. To avoid other gliders and general aviation traffic, pilots must comply with the Rules of the Air and keep a good lookout. They also usually wear parachutes. In several European countries and Australia, the FLARM warning system is used to help avoid mid-air collisions between gliders. A few modern gliders have a ballistic emergency parachute to stabilize the aircraft after a collision. Training and regulation In addition to national laws controlling aviation, the sport in many countries is regulated through national gliding associations and then through local gliding clubs. Much of the regulation concerns safety and training. Many clubs provide training for new pilots. The student flies with an instructor in a two-seat glider fitted with dual controls. The instructor performs the first launches and landings, typically from the back seat, but otherwise the student manages the controls until the student is deemed to have the skill and the airmanship necessary to fly solo. Simulators are also beginning to be used in training, especially during poor weather. After the first solo flights glider pilots are required to stay within gliding range of their home airfield. In addition to solo flying, further flights are made with an instructor until the student is capable of taking a glider cross-country and of handling more