From ST to XL: defining the differences between Airbus’ two generations of Beluga aircraft

While Airbus’ new-generation Beluga XL oversized airlifter may resemble its Beluga ST predecessor, several key physical changes will bring additional capabilities to the movement of major aircraft sections and components within the company’s production network. 
The Beluga XL, which is based on today’s A330 jetliner, has its enlarged fuselage “bubble” section that is six metres longer and one metre wider than on the Beluga ST – an aircraft derived from Airbus’ earlier-production A300-600.  
With this bigger “bubble,” the Beluga XL will be able to carry larger sections of Airbus aircraft between European production sites and to the final assembly lines in Toulouse, France and Hamburg, Germany – including a full wing-set for the A350 XWB’s latest A350-1000 version. 
"Payload was the big driver for us,” explained Jean-Marc Passuello – leader of a cross-functional Airbus delivery team responsible for the development of major component assemblies. “We knew what the Beluga XL had to be able to carry, and that meant making some changes.” 
“Among the physical differences between the Beluga ST and XL versions is the dorsal fin that connects to the vertical tailplane” added Olivier Maillard, delivery  team leader for rear fuselage and dorsal fin. On the Beluga ST, this component is triangular and manufactured as a single part – but to ensure stability for the larger Beluga XL, it was increased in size and produced in three parts with a distinctive “kink” in the diagonal. 
According to delivery team leader Guillaume Pages, the need for stability also led to an updated horizontal tailplane. "We had to add a metre to each side using what we call extension boxes, and the auxiliary fins on the outside of the horizontal tailplane are a metre higher than those on the Beluga ST," he said. 
Pages’ team also added ventral fins as a completely new feature of the Beluga XL. Located along the bottom of the aft fuselage, they have the same stabilising function as the dorsal fin.