Dylan Paull finds his way to his work space by climbing through a 10-by-17-inch (25-by-43-centimeter) opening.

It’s a narrow entry into confined 737 MAX fuel tanks, where specialized tank closure experts ensure integrity in the final stages of airplane assembly.

From inspecting plumbing inside the fuel tank, to cleaning every surface and watertight sealing of all seams and fasteners, Dylan’s work at our Renton, Washington production facility is as varied as it is critical for safety.

“We’re the custodians of the tank,” he explains. “The airplane is almost complete at this point, so we’re fine-tuning the work that’s already been done.”

Dylan inside the fuel tank
Dylan, inside the fuel tank of a 737 MAX, is handed a cleaning tool for performing in-tank work. (Photo courtesy of Jim Anderson)

Before a drop of fuel can ever enter the airplane, Dylan and his tank closure teammates must be certain that the tanks – all three on a 737 MAX – are perfect.

Dylan brings with him a set of carefully tracked tools required for the job. Nothing can be left behind or unaccounted for when he leaves the tank.

Working in a space as small as 2 feet (.6 meters) wide by 2 feet tall, Dylan says a tight work space is worth the diversity of tasks he gets to take on. Many airplane mechanics are experts in a single task, such as applying sealant to fasteners and joints (a role Dylan had for five years prior to his current job). Completing a fuel tank could require expertise in sealant work, wiring, plumbing, or structural work, and the list goes on.

“In tank closure, we work on a variety of tasks each day,” he says. “This job definitely requires the desire to learn and adapt, which I really enjoy.”

As the job name “tank closure” implies, Dylan and his team on the 737 MAX are among the last sets of eyes to inspect and perfect the inside of a fuel tank before it’s permanently closed off from the light of day. When that moment occurs, they know they are ready to send the airplane on to receive fuel, go through test runs and be delivered to an airline.