An airplane comprises a fuselage, two wings, engines, a rear tail unit comprising a horizontal tail provided with two tail ends, a first and a second set of fuel tanks, and a fuel transfer system configured to be able to transfer, at least in flight, fuel from one to the other of the first and second sets of fuel tanks, the tail ends being, in addition, mounted so as to be able to be pivoted, at least in flight, relative to the horizontal tail, the airplane thus having a configuration changeable in flight.