- Airlines have put hundreds of aircraft in storage as demand dropped in the coronavirus pandemic.
- The FAA's inspection orders relate to older models of the Boeing 737, not the Max, which is still grounded worldwide.
- Some possible corrosion could cause dual-engine failure, the FAA warned.
The Federal Aviation Administration on Friday instructed airlines to inspect some stored Boeing 737 planes for corrosion that could lead to engine shutdowns as hundreds of aircraft remain idled because of a drop in demand amid the coronavirus pandemic.
The order for inspections on planes that have not been operated for a week or more will impact about 2,000 jets in the U.S., the FAA said. The orders do not relate to the Boeing 737 Max, which has been grounded worldwide since March 2019 after two deadly crashes.
Boeing said it advised operators of older 737 planes to inspect engine valves for corrosion. The airworthiness directive came after four reports of single-engine shutdowns caused by engine bleed air valves that were stuck open, the FAA said in its order.
"With airplanes being stored or used infrequently due to lower demand during the COVID-19 pandemic, the valve can be more susceptible to corrosion," the manufacturer said in a statement.
Alaska Airlines said that one of its aircraft experienced an engine shutdown on July 15 on a flight between Seattle and Austin, Texas, and that "the safety of the flight was not compromised." After an emergency landing the engine that had the issue was replaced in Austin, the airline said. The Seattle-based carrier is inspecting six of its 737s at a maintenance base, work that began before the FAA's order, the airline said.
American Airlines said four of its more than 300 Boeing 737 NG planes were inspected and cleared. The carrier's operations aren't expected to be disrupted, said American Airlines spokesman Ross Feinstein.
Southwest Airlines which operates an all-Boeing 737 fleet said that it "has not experienced the conditions described in the directive," but that it's reviewing the order to see if it applies to its planes.
"Currently, we do not anticipate any disruption to our operation as we work to review the aircraft in storage that are affected by the AD," the Dallas-based airline said in a statement about the airworthiness directive.
Delta Air Lines also said it doesn't expect any impact to its operation or flight schedule.
"Our commitment to safety for our customers and people calls for meeting and exceeding all directives from our regulators – including airworthiness directives," the carrier said in a statement. "We will ensure compliance with this directive as nothing is more important at Delta than the safety of our customers and people."
United Airlines also said that it is complying with the directive and that it doesn't expect its schedule to be disrupted.