A method of aircraft fuel distribution includes selecting a longitudinal center of gravity and predicting a rate of change of the center of gravity during flight. Fuel is located in a tail fin tank of a vertical tail fin of the aircraft, and is transferred from the tail fin tank forward at a predetermined transfer rate to counteract the predicted rate of change thereby maintaining the selected center of gravity. An aircraft fuel distribution system includes a center main fuel tank, a tail fin tank and a tail fin fuel pump to pump fuel between the tail fin tank and the center main fuel tank. An electronic controller operates the tail fin fuel pump such that fuel is flowed between the tail fin tank and the center main fuel tank at a predetermined transfer rate to maintain automatically an optimal position of a longitudinal center of gravity of the aircraft.

A method of aircraft fuel distribution includes selecting a longitudinal center of gravity and predicting a rate of change of the center of gravity during flight. Fuel is located in a tail fin tank of a vertical tail fin of the aircraft, and is transferred from the tail fin tank forward at a predetermined transfer rate to counteract the predicted rate of change thereby maintaining the selected center of gravity. An aircraft fuel distribution system includes a center main fuel tank, a tail fin tank and a tail fin fuel pump to pump fuel between the tail fin tank and the center main fuel tank. An electronic controller operates the tail fin fuel pump such that fuel is flowed between the tail fin tank and the center main fuel tank at a predetermined transfer rate to maintain automatically an optimal position of a longitudinal center of gravity of the aircraft.

There is provided a center fuel tank assembly for an aircraft. The assembly includes a center fuel tank disposed in a central part of the aircraft. The assembly further includes one or more fuel barrier members partitioning the center fuel tank into two or more separate volume sections comprising two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank. The assembly further includes a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently. A sequential fuel burn of fuel in the two or more separate sub-tanks is made in a fore-to-aft sequence while the aircraft is in flight, to assist in shifting aftward a center of gravity (CG) of the aircraft, to reduce aircraft drag.

There is provided a center fuel tank assembly for an aircraft. The assembly includes a center fuel tank disposed in a central part of the aircraft. The assembly further includes one or more fuel barrier members partitioning the center fuel tank into two or more separate volume sections comprising two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank. The assembly further includes a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently. A sequential fuel burn of fuel in the two or more separate sub-tanks is made in a fore-to-aft sequence while the aircraft is in flight, to assist in shifting aftward a center of gravity (CG) of the aircraft, to reduce aircraft drag.

Two systems of a first pump unit and a third pump unit that supply fuel of a fuselage fuel tank, and a second pump unit and a fourth pump unit that supply fuel of fuel tanks in both right and left wings are provided corresponding to a left-wing engine and a right-wing engine, respectively. A supply source of the fuel to be supplied to the left-wing engine or the right-wing engine is switched by switching of the pump unit to be turned on.

Two systems of a first pump unit and a third pump unit that supply fuel of a fuselage fuel tank, and a second pump unit and a fourth pump unit that supply fuel of fuel tanks in both right and left wings are provided corresponding to a left-wing engine and a right-wing engine, respectively. A supply source of the fuel to be supplied to the left-wing engine or the right-wing engine is switched by switching of the pump unit to be turned on.

A method of controlling a magnitude of a sonic boom caused by off-design-condition operation of a supersonic aircraft at supersonic speeds includes, but is not limited to the step of operating the supersonic aircraft at supersonic speeds and at an off-design-condition. The supersonic aircraft has a pair of swept wings having a plurality of composite plies oriented at an angle such that an axis of greatest stiffness is non-parallel with respect to a rear spar of each wing of the pair of swept wings. The method further includes, but is not limited to the step of reducing wing twist caused by operation of the supersonic aircraft at supersonic speeds at the off-design condition with the composite plies. The method still further includes, but is not limited to, minimizing the magnitude of the sonic boom through reduction of wing twist.

A method of controlling a magnitude of a sonic boom caused by off-design-condition operation of a supersonic aircraft at supersonic speeds includes, but is not limited to the step of operating the supersonic aircraft at supersonic speeds and at an off-design-condition. The supersonic aircraft has a pair of swept wings having a plurality of composite plies oriented at an angle such that an axis of greatest stiffness is non-parallel with respect to a rear spar of each wing of the pair of swept wings. The method further includes, but is not limited to the step of reducing wing twist caused by operation of the supersonic aircraft at supersonic speeds at the off-design condition with the composite plies. The method still further includes, but is not limited to, minimizing the magnitude of the sonic boom through reduction of wing twist.

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.

A method for improving inflight fuel efficiency of an aircraft includes sensing aircraft fuel weight in the aircraft fuel tanks and reading the fuel weight by a flight management system during aircraft flight; calculating a current center of gravity position from the fuel weight; calculating an aircraft longitudinal trim drag factor from the current center of gravity; and adjusting a fuel burn prediction utilizing the longitudinal trim drag factor. A system for improving aircraft inflight fuel efficiency includes a flight management system programmed to calculate a current center of gravity position from a current aircraft fuel weight, calculate a longitudinal trim drag factor from the current center of gravity, adjust a fuel burn prediction, and display in the flight deck an adjusted fuel burn prediction for each leg of aircraft flight, which is used to adjust aircraft performance automatically by the flight control system or by the pilot.