The 747-8 passenger model’s 3,300 gal. tailplane fuel tank was de-activated before the first aircraft entered service after analysis indicated that, under certain fuel load circumstances, the tail tank could induce flutter.
Re-activation of the tail fuel tank will provide added range and improve the aircraft’s performance, says Lufthansa’s Boje. The extra weight of the fuel in the aft of the aircraft can be used to assist in trimming the 747-8 to lower cruise drag. The 747-8’s fuselage extension “tends to be nose heavy so we might gain performance,” he adds.
Lufthansa also plans to ask Boeing to study minor software changes to the fuel transfer system which would extend the length of time the fuel remains in the aft tank, which would increase the trim benefit.