sterile cockpit
n.— «Her ears were stuffed up, and at one point in the flight to Buffalo she asked if the plane could descend early so she would be more comfortable. With the plane flying well under 10,000 feet, a time when the crew was supposed to maintain a “sterile cockpit” with no non-pertinent conversation, Captain Renslow asked, “How’s the ears?”» —“Pilots Chatted in Moments Before Buffalo Crash” by Matthew L. Wald New York Times May 12, 2009. (source: Double-Tongued Dictionary)