MASS DISTRIBUTION METHOD AND APPARATUS

Disclosed is a helicopter having a longitudinal axis, a lateral axis and a vertical axis, a helicopter centre of mass and a maximum gross mass of less than 5000 kg, the helicopter comprising a fuselage elongate along the longitudinal axis, the fuselage comprising an aerodynamically shaped shell defining a front, a rear, a top and a bottom of the fuselage and a passenger cabin therein having two forward-facing front seating positions for the pilot and a co-pilot or a passenger, and forward-facing rear seating positions for at least 2 passengers, optionally 3 passengers; a primary fuel cell mounted substantially behind the passenger cabin; the front seating position for the pilot having a centre of mass at a first location substantially in front of the rotor hub location, and the primary fuel cell having a centre of mass at a second location substantially behind the rotor hub location; a landing gear arrangement; a power plant mounted substantially above and behind the passenger cabin, wherein the primary fuel cell is arranged to provide fuel to the power plant; and a secondary fuel cell having a centre of mass at a nose location in front of the rotor hub location by at least 1500 mm.