Before the second world war, airshows were associated with long distance air races, often lasting many days and covering thousands of miles. While the Reno Air Races keep this tradition alive, most airshows today primarily feature a series of aerial demos of short duration. Most airshows will feature warbirds, aerobatics, and demonstrations of modern military aircraft, and many airshows offer a variety of other aeronautical attractions as well, such as wing-walking, radio-controlled aircraft, water/slurry drops from firefighting aircraft, simulated helicopter rescues, etc. Specialist aerobatic aircraft have powerful piston engines, light weight and big control surfaces, making them capable of very high roll rates and accelerations.