See An Airbus A320 Towed Out of a Hangar It's Too Big For
When a large commercial aircraft enters what's known as final assembly — the joining of key aircraft sections including the wings, vertical tail plane, and the main fuselage — it comes together in stages, entering the final assembly line (FAL) in pieces and leaving at the end almost ready to fly. That's what Boeing and Airbus do, for example, getting the components from various suppliers around the world and joining them together at one of their several production sites around the world. (Boeing assembles its jets at three facilities in Seattle and Charleston; Airbus has four, in Europe, the US and China.)
On a recent visit to Airbus headquarters in Toulouse, France, I got a chance to look at the final assembly line for the Airbus single-aisle family — the A319, A320 and A321. And that also meant a look at something that most passengers won't see their airplane do: Being towed ingeniously out of a hangar it is too big for.
That is what happened with this almost-finished A320, number 7,846 off the assembly line. The tail was already painted in the colors of the customer, Aeroflot Russian Airlines. Ordinarily this jet would have just come out of the assembly building through the giant doors at the end of the line, which are big enough to let an A320 through.
Sometimes the aircraft at the front of the final assembly line isn't quite ready to exit yet, but the aircraft behind it is. Keeping the airplane that's ready for delivery in the hangar while the one in front is finished would be a giant waste of money; these are after all machines that a customer pays $100 million for. Keeping them idle on the ground is not a good idea. Number 7,846 was ready to leave the assembly hangar ad move to another one for the final touches before delivery, but blocked by an unfinished jet in front.
This is where the "side door" trick comes in handy: You just open the side of the hangar and wheel the aircraft out. Except there's a problem: The 12-meter (38 feet) tail. It's too big to go through.
With the aircraft turned to face the exit, Airbus engineers resort to a neat solution: a hydraulic tow bar attached to the nose gear, lifting the aircraft, almost as if it were taking off. That lowers the tail enough to go through.
The aircraft is then slowly wheeled forward. The angle of the lift of the nose is crucial, as engineers must be careful not to cause a tail strike, which would be extremely costly.
The video below shows how incredibly tight the clearance of the tail is.
The clearance is less than 15 centimeters, or 6 inches.
With the aircraft safely out of the hangar, it can continue assembly, rather than be held up by a slightly delayed aircraft at the front of the queue.
You might wonder why Airbus would design a hangar that its aircraft are too big for once assembled inside. The answer is that it hasn't: It inherited the Toulouse site from Sud-Aviation, a pioneer in commercial aviation. This hangar was originally built for the final assembly of the Caravelle —a French twinjet which holds the distinction of being the world's first jet-powered airliner to be developed for the short/medium-range market.
Soon after, final assembly of the Concorde took over the hangar. Timing deliveries of the supersonic jets perfectly wasn't exactly an issue: only 20 were built, for all of two customers.
And now the site is home to the final assembly of the world's best-selling single-aisle aircraft family, the A320, which has received 13,241 orders, with a backlog of around 5,450 jets still to be assembled.