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Is it quiet in the cockpit when flying faster than the speed of sound or is the noise from air resistance just too loud?

Similar question: is it quieter at the front of an airliner flying faster than the speed of sound because the engines are behind you (comparing to the rear of the plane)?

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  • $\begingroup$ There may also be an answer to your question here, but as an aside, if you're at all interested in anything about the Concorde: omegataupodcast.net/2015/02/166-flying-the-concorde $\endgroup$ – Greg Hewgill Jul 20 '15 at 21:47
  • $\begingroup$ It is indeed quieter in the forward part of the cabin, but already at subsonic speeds, because the boundary layer is thinner and produces less noise. This is audible in subsonic jets; supersonic jets have too loud engines to let you pick up such subtleties. $\endgroup$ – Peter Kämpf Jul 21 '15 at 16:21
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No, for two reasons:

  • Speed of sound is always relative to the material the sound propagates in; it moves faster through denser media, such as the aluminum structure of the aircraft itself. The aircraft's structure moves with the aircraft, so the vibrations of the jet engines will be transmitted to the cockpit/cabin at the same speed as when the airplane were flying subsonic.

  • The air inside the cockpit is still, and so sound within this local bubble is unaffected by the speed of the bubble itself (and so sound can travel faster than sound). If this weren't true then radios and other cockpit sound sources like alarms would be inaudible at supersonic speeds, which would be a major safety hazard and tactical disadvantage to supersonic flight.

You actually don't even have any significant aural cues inside the cockpit that you've exceeded Mach 1; you have to rely on your airspeed gauge to tell you.

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The jet sounds the same inside the cockpit at M .98 as it does at M 1.3 . The sound is still the same relative to your ears - everything is still in the same proximity to you.

I have flown at 1.3 and what does change is the airflow around the aircraft, changing the flight characteristics of the jet. The handling of the jet becomes much more stable. If your jet could aileron roll at 360 degrees per second subsonic, it now lumbers through a roll at perhaps 120 degrees per second. Your only real indicators of going supersonic are seeing your pressure instruments (airspeed/Mach indicator and VVI) momentarily jumping as you pass M 1 and the fact that your shiny little rocket now flies like a 172, albeit considerably faster, higher and cooler.

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