Jet engine design shifts significantly between supersonic and subsonic aircraft. Aerodynamic heating is a concern for supersonic and hypersonic aircraft. These regimes are subsonic, transonic, supersonic, hypersonic, and hypervelocity flow. Transonic, supersonic, and hypersonic flows are all compressible flows. Aircraft designed to operate at transonic or supersonic speeds will incorporate a machmeter. The hypersonic regime is a subset of the supersonic regime. Its operation relies on the different properties of gases flowing at subsonic and supersonic speeds. The aircraft had many advantages over expensive supersonic jets. It also sees use in supersonic jet engines. Turbojets can be highly efficient for supersonic aircraft. The ramjet was predicted to be able to fly at supersonic speeds for months. Air is heated considerably when compressed by the passage of an aircraft at supersonic speeds. A common analogy is the sonic boom of a supersonic aircraft. Concorde flew long distances at supersonic speeds. The F-5 became the first military plane in Venezuela capable of flying at supersonic speeds.