Ownership: ‘We figure it out’
SEAL Aviation makes wet wings dry again
Photography by the author
The term “wet wings” takes on new meaning when unwelcome puddles of avgas show up on the hangar floor, and telltale streaks of blue dye mark the escaping fuel’s pathways across the wings.
Wet wings are ideal in theory.
The wings themselves are fuel tanks so there’s no wasted space, no extra weight, and no need to add troublesome internal tanks or bladders. Mooney Aircraft has long been a believer in wet wings, and so was Grumman, which used them on its iconic flying boats in the 1940s and 1950s.
One of those flying boats, a twin-engine Widgeon built 80 years ago, has frustrated multiple owners with ongoing fuel leaks despite several attempted repairs. One owner even slathered fuel tank sealant on the outside of the wings in a futile attempt to stop them.
The current owner recently hired SEAL Aviation to fix the problem. The Florida company has mobile teams of fuel tank repair experts who travel the country drying out weeping wings.
The process isn’t quick or cheap.
Repairs typically take hundreds of hours of labor, up to three weeks of calendar time, and $20,000 or more to complete. But the alternative for the Widgeon owner—removing the wings from the airplane’s center section and reskinning them—would cost far more. And the wings and center section on this airplane appeared to be in excellent shape, if only they’d hold fuel.
“This kind of work requires being patient and thorough,” said Jerel Bristol, a former U.S. Air Force F–16 crew chief who founded the 40-employee company in 2007. “It starts with a detailed evaluation where we follow the leaks to their source. Then we pressurize the tanks, identify the exact locations of the leaks, and decide how to stop them.”
Fasteners, seams, and panels are the usual leak suspects. Fasteners tend to be simple to repair or replace; seams and panels, less so.
“Our process is exactly the same whether we’re working on a corporate or military jet or a vintage seaplane,” Bristol said. “We perform multiple pressure tests, we get inside and thoroughly prep the wing and apply new sealant. Then we verify that everything works the way it should, and we don’t leave until the job is done properly.”
That sounds straightforward, but the work itself is difficult.
Grumman, for example, put rubber between metal panels to make them impervious to fluid—avgas on the inside and water on the outside. Those joints have been incredibly durable for decades, but now the rubber itself has deteriorated. Residue from previous repairs must be scraped out completely by hand, and it’s nasty stuff that only harsh chemicals can soften.
“If you’re going to paint your house, the first thing you do is remove the peeling paint. You don’t paint over it,” Bristol said. “What we do inside fuel tanks is much the same. You take it down to bare metal so the new sealant can adhere to a clean surface.”
SEAL Aviation mostly works on corporate jets, but Bristol said he enjoys the challenge that vintage airplanes and warbirds present.
“They’re pieces of history and works of art,” he said. “There’s no manual for how to remove a self-sealing fuel tank from a Sea Fury and replace it with something entirely new—but we figure it out. And we meet some really great people along the way.”
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