Conceptual design of a flying boom for air-to-air refueling of passenger aircraft

This paper describes the conceptual development of a flying boom for air-to-air refuelingof passenger aircraft. This operational concept is currently evaluated within the EC project RECREATE as a possible means to achieve significant increase in overall fuel efficiency. While in military aviation aerial refueling is performed with the tankerflyingahead and above the receiver aircraft, in case of passenger aircraft, safety, cost and comfort criteria suggest to invert the set up. This unconventional configuration would require a different refueling boom, able to extend from the tanker towards the cruiser, against wind and gravity. Amultidisciplinary design optimization framework was set up to size and compare various boom design solutions free of structural divergence and sufficientlycontrollable and with minimum values of weight and drag. Oneconcept, based on an innovative kinematic mechanism, was selected for its ability to meet all design constraints, with weight and drag values comparable to conventional boom designs.