The Federal Aviation Administration is ordering emergency inspections of about 2,000 Boeing 737 airplanes because of a possible engine valve problem that could lead to engine failure.

The FAA's emergency air worthiness directive orders inspections of older 737 Classic and Next Generation planes that airlines have had in storage due to sharply reduced air travel demand because of the COVID-19 pandemic.

The FAA order indicates that inspectors found corrosion on some engine air check valves. The corrosion could cause the valves to become stuck in the open position, which could cause both of a plane's engines to lose power and prevent them from restarting.

The directive requires airlines and other aircraft owners and operators to inspect the valves on all of their classic and NG 737s that have not been in operation for seven or more consecutive days.

In a statement, Boeing says that "with airplanes being stored or used infrequently due to lower demand during the COVID-19 pandemic, the valve can be more susceptible to corrosion."

Boeing says it is providing inspection and replacement information to fleet owners if they discover an issue.

The valve problem is not related to Boeing's grounded 737 Max aircraft.

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