Jets commonly use a micro-turbine or ducted fan to power them. Most airframes are constructed from fiberglass and carbon fiber.  Inside the aircraft, wooden spars reinforce the body to make a rigid airframe. They also have Kevlar fuel tanks for the Jet A fuel that they run on. Most micro turbines start with propane and burn for a few seconds before introducing the jet fuel by solenoid. These aircraft can often reach speeds over 320 km/h (200 mph).