Where do you study? http://bcsystems.pl/changes-in-the-land-cliff-notes.pdf ask research paper already done weather socket Boeing's chief 787 engineer, Mike Sinnett, told Reuters that the humidity controller on the 787, made by CTT Systems AB of Sweden, is designed to "dry out the crown" or upper fuselage, of the aircraft, and prevent moisture from accumulating. Without the system "we would wind up having that water stay in the insulation."