For operators of the Rolls-Royce M250 series II engine, commonly found on the Bell 407, the problem of crumbling or broken plastic coatings on the inside of the compressor case has existed for more than half a century. That will change after yesterday’s announcement by StandardAero that it has created a new process–EnduroCoat–to combat the problem. The gas turbine engine, developed in the early 1960s, still employs a plastic lining on the inside of the compressor to protect the interior components from wear and corrosion. Despite several past attempts by the manufacturer and others to improve the plastic, it will still break, requiring regular replacement. The number of shops that can reapply this plastic coating at overhaul has declined from 10 to 15 to four worldwide, according to StandardAero.
Arizona-based StandardAero returned to U.S. hands last year after its purchase by Veritas Capital and has applied for a patent on its new process, which it claims will drastically improve the way the plastic coating bonds to the parent material. The process also provides increased protection from corrosion of the compressor stator vanes.
“It’s an old engine,” said Brian Hughes, director of sales and marketing for StandardAero’s helicopter programs, referring to the M250. “We’re hoping there’s another 10 to 20 years of life and we’re hoping we can save people a lot of money on this.”
The process takes a week to complete, according to Hughes. “When we first get the case we put it in an oven and we melt the plastic out, and then those stators all have to be inspected, so the EnduroCoat now is putting some protection on the stator vanes as well as making the plastic adhere more.”
The procedure comes with a “lifetime” guarantee, according to the company. “If the plastic breaks out at 1,750 hours you are going to get your plastic replaced at 50 percent pro-rata; if it breaks out in the first 500 hours of operation its going to be free,” said Hughes, who expects the procedure to be adopted in the new engine manufacture process as well.
