On Thursday we had the opportunity to visit Airbus at their Toulouse location. We were given a tour of their facilities and were guided through the process of construction and assembly at their factory. The Toulouse location does not deal specifically with the molding and construction of individual parts, but rather they deal with the final assembly, testing, and delivery of the aircraft to their clients. Overall, there were about 8 buildings on the Airbus campus, ranging in functions from testing structural and aerodynamics to construction of the A330, A350, and A380. Unfortunately, I do not have many pictures as we were all suspected spies for Boeing attempting to steal the secrets of the A380 aircraft, what can we do? I apologize in advance for the large amount of technical information in this article, but aim to condense the long and thorough process of developing an aircraft into a short, easy to understand article.
The day we arrived, there were already a few A330s on the assembly line. Outside, parts were coming in from all corners of the world, some parts arriving from China while others from the United States, using the Airbus Beluga aircraft. The aircraft was specifically designed by Airbus to transport fuselages and various parts. Even throughout the city, there is never a moment you won’t see a Beluga Aircraft in the air.
On the assembly line, Professor and Airbus Engineer, Jean-Fred Begue gave us a private tour of the A330’s under construction. When we arrived, they were in the process of attaching a wing section to the fuselage of the aircraft. This process is done very carefully as the two parts must come together precisely otherwise the wing would be compromised. They connect the two parts using a junction called Spliced Plates. It does have a high cost and can be difficult to remove for maintenance, but it is optimized for mass and incorporates redundancy for safety. The junction essentially consists of bringing the two parts together, placing a plate on top of and bellow the junction, and bolting through them. Overall, there are over 1000 bolts through the wing-fuselage junction. Professor Begue gave us a close-up perspective of the junction along with the connections for the engines and flap motors.
Today, engines are mounted on the wings using, at least, 4 points of contact, and are placed toward the front of the wing and as close to the wing as possible. This position is optimal due to the torque moment generated by the weight of the engine countering the moment generated by the lift from the airfoil, balancing the aircraft during flight. The engines are mounted using fail-safe pins that are meant to break upon extreme circumstances, such as a belly landing in which the landing gear fail, to ensure the engines do not spread fire to the aircraft.
During the visit, Professor Begue showed us both the interior of the wing and the interior of the fuselage. This view revealed the stringers and how they went uninterrupted by the frames of the aircraft through the interior of their structures as he discussed in class. The stringers are long metal beams that go the length of the aircraft that are meant to dissipate normal stresses that the airplane undergoes during takeoff, cruise, and landing. The stringers also help to maintain the skin’s stability by providing an anchoring point to attach to. Stringers are typically pretty thin, but are spaced close together – around one foot (30 centimeters) – so as to make up for the relatively low strength of the individual stringer.
In conjunction with the stringers, the skin is supported by frames which are circular supports spaced out a little more than the stringers and are meant to help prevent buckling while aiming to maintain the shape of the aircraft. During the visit, we were shown the interior of the fuselage before all the important insulation was in place which revealed the frames and stringers on the interior. The frames are made to allow the stringers to pass through them, but are connected via cleats to reduce the effective length of the stringers which reduces any moments generated on the stringers.
The facility we toured was assembling A330s. There were three different stations for the assembly. The first was to attach the wing to the fuselage as discussed earlier. The second process mounted the fuselage pieces together, attached the landing gear, and finished the majority of the exterior assembly. This process required a lot of heavy equipment and precision as it is imperative that everything is perfectly aligned. The third step of the process is to assemble the inside of the plane. Airbus has a tradition to paint the tail fin of the plane once the seller has been ascertained. Although it looks as if no one is doing anything on the outside, they are doing a lot of work on the inside to make sure that everything is perfect for the airline company.
All in all, the trip to Airbus was very revealing as you begin to think how hard it is to manufacture the first aircraft. This is because everything within the manufacturing plant and everything involved – the Beluga, the plants that manufacture the individual parts, and every other step in the process all play a small role in the large picture of the A330.