In aviation there is not only one speed that is important. In this video I explain the most important speeds such as: Indicated Air Speed (IAS), Calibrated Air Speed (CAS), True Air Speed (TAS), Rotation Speed ( VR), Decision Speed (V1), Climb (Safety) Speed (V2), and there dependancies to the Critical Engine Failure Speed (VEF), Lift Off Speed (VLOF), Maximum Brake Energy Speed (VMBE), Minimum Control Speed Ground (VMCG) and Minimum Control Speed Air (VMCA). I also explain the correlations and prerequisites. Enjoy the video.