Speeds where only some parts of the air around an object -LRB- such as the ends of rotor blades -RRB- reach supersonic speeds are labeled transonic -LRB- typically somewhere between Mach NUMBER@1 and Mach NUMBER@2 -RRB- .

Speeds where only some parts of the air around an object -LRB- such as the ends of rotor blades -RRB- reach supersonic speeds are called transonic -LRB- typically somewhere between Mach NUMBER@1 and Mach NUMBER@2 -RRB- .
