Kitty Hawk reveals its secret project, Heaviside

When they led with “100x quieter than a helicopter,” my first reaction was a skeptical “well sure, decibels are logarithmic!” But 40dB from 600ft away is impressive, and within the range of what I would consider acceptable for residential flyover (though not takeoff and landing) in a medium-density area.

It is pretty quiet and very impressive. I wonder how many flyovers I would be ok with. 4 per hour sounds ok, but what if they route a highway above my house?

40dB at 600ft is impressive, especially if it is carrying a payload equal to that of a passenger, and is maintaining altitude. That 100x quote, however, has a whiff of an intent to deceive people who are not familiar with the technicalities of loudness measurement.

100x quieter than a helicopter, with a few thousand people using them, is louder than a helicopter. A glance at any urban interstate would suggest that mass adoption would be loud...

Oh sure because the air roads are going to be packed as densely as the ground roads with planes flying tail to tail in multiple lanes. /S