Military plans supersonic flights in Poland

The General Command of the RSZ says: “The sound barrier may be exceeded during the exercise. This phenomenon can origin an audible bang (so-called alleged sound thunder).’ This is simply a natural, audible effect of the flight, whose velocity is more than [speed of sound](https://pl.wikipedia.org/wiki/Pr%C4%99dko%C5%9B%C4%87_d%C5%BAwi%C4%99ku) - or about 1200 km/h (it is worth noting that with the increase in temperature, the velocity of the diffuse acoustic waves somewhat increases).