|Quoting Ptrjong (Reply 3):|
How could the cockpit noise differ from that in a civil 767, and how could that not meet military requirements?
Well, the fact that theres a boom several meters long trailing behind the plane definitely induces some extra aerodynamic noice... In fact for the 767 it seems it is even adding a LOT of extra noice, possibly caused from unexpectedly large interference between boom and tail section of the plane.
The requirement to have only a certain noice level in the cockpit is understandable from several points of view: first of all, that of fatigue: tankers often go on very long missions and noice is known to be a very big contributing factor to fatigue, but also the fact that crew communication ight be impaired has to be considered. After all, contrary to a 767F, a KC
-767 sees much more crew communication during a high workload mission and you definitely don't want to the crew to be screeming for 10 hours long!
It's increadible indeed that Boeing missed this pretty simple target by such a large margin! Remember we're not talking about a linear scale, so the difference between 75 and 79dB is HUGE! Its actually DOUBLE!