> The A380's wings are sized for a maximum takeoff weight (MTOW) over 650 tonnes to accommodate these [larger] future versions, albeit with some internal strengthening required on the A380F freighter. The optimal wingspan for this weight is about 90 m (300 ft), but airport restrictions have limited it to less than 80 m (260 ft), thereby lowering the aspect ratio to 7.8 which reduces fuel efficiency by about 10% and increases operating costs a few percent, given that fuel costs constitute about 50% of the cost of long-haul aeroplane operation.