Fuel tank work requires broad knowledge -- and a bit of bravery

Dylan Paull finds his way to his Renton, Washington work space by climbing through a 10-by-17-inch 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 all seams and fasteners, Dylan’s work 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.”

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.

Because of the hazardous nature of the fuel that eventually fills the tanks, the team scrutinizes every square inch; even findings like metal shavings are removed and the lightest surface scratch must be polished away.

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 two feet wide by two feet tall, Dylan explains that staying relaxed is the key to avoid getting stuck or frightened. Safety measures are in place as well, including a radio that requires mechanics to periodically check in while inside the tank.

For Dylan, 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.