• # question_answer Inside the airplane flying at a high altitude: A)  The pressure is the same as that outside B)  Normal atmospheric pressure is maintained by the use of air pumps C)  The normal humidity and partial vacuum are maintained D)  The pressure inside is less than the pressure outside

[b] Modern airplane with jet propulsion flies at a cruise altitude between 8000 and 11000 m. At that altitude the pressure is about 1/3 than at sea level and the temperature is about $-\,40{}^\circ C.$ These conditions inside the cabin and cockpit the life for passengers and crew not possible. To solve that problem air is spilled out from engine and conditioned to allow living.