Can planes fly faster than sound?

Federal Army

When it has to be done quickly

In the context of airspace surveillance, it may be necessary for the Eurofighter pilots of the Federal Armed Forces to accelerate their interceptors to supersonic speed. This enables them to reach unidentified intruders in the shortest possible time and ensure security in Austrian airspace.

Training for emergencies: two Eurofighters from the German Armed Forces escort an Austrian Airlines scheduled aircraft.

Only possible with appropriate training

Appropriate training is a prerequisite for a supersonic deployment. Because flying at extreme speeds requires close cooperation between pilots, radar control officers and civil air traffic control. Exercises on the simulator are not enough for this, among other things because the flight and body loads for the pilots cannot be represented.

The sonic boom

Flying at supersonic means that the airspeed is greater than the speed of sound. This is the case at around 1,200 kilometers per hour and is known as "Mach 1". If a Eurofighter approaches this speed, shock waves occur on various parts of the aircraft. As a result, the aerodynamic resistance increases considerably until this limit, pictorially known as the "sound barrier", is overcome. The sonic boom is the audible effect of this shock wave. In individual cases it can happen that this can be heard on the ground.

Supersonic flights are mainly carried out over alpine, uninhabited areas.

Minimal noise pollution

In order to keep noise pollution for people and animals as low as possible, the armed forces also adhere to the following guidelines:

  • The acceleration phases of the Eurofighters are kept as short as possible.
  • The noise distribution is continuously documented in order to avoid multiple exposure of areas.
  • There are no supersonic flights between 11:30 a.m. and 1:30 p.m. and on Saturdays and Sundays.

Flights over sparsely populated areas

Most of the flights are in the sparsely populated Alpine core area of ‚Äč‚ÄčAustria. There is no training over metropolitan areas, the federal capital or Vorarlberg. The exact flight areas are determined depending on the civil air traffic in cooperation with the civil air traffic control. In order to keep the noise level as low as possible, the flights are also completed between 12,500 to 15,200 meters and only take place on weekdays.

In order to reduce noise pollution, the machines fly at great heights.