FAA says 737s in storage are corroding during pandemic

Bloomberg

Boeing Co 737 planes in storage because of the coronavirus pandemic are at risk of losing power in both engines when they fly again and must be inspected, the US Federal Aviation Administration (FAA) said.
The emergency order applies to about 2,000 older Next Generation and Classic versions of Boeing’s workhorse single-aisle jet in the US, not the grounded 737 Max. Alaska Air Group Inc said an engine shutdown during a recent flight was probably one of four instances in which the FAA said a corroded valve caused a failure.
Regulators mandated the inspections after airlines began bringing back some of the thousands of jetliners that were parked earlier this year as the pandemic all but erased travel demand. While there are detailed steps airlines must take to maintain planes in storage, the order suggests that the corrosion issue wasn’t previously known.
The directive applies to aircraft that have flown 10 or fewer flights since being taken out of storage, and any jets still parked.
The Alaska Air incident occurred on July 15 on a flight from Seattle to Austin, Texas. The plane made an emergency landing and touched down safely. The company is carrying out required inspections on six 737s at one of its maintenance bases.
“We actually started our inspections of the check valves” before the FAA’s airworthiness directive was released, the airline said. “As additional aircraft are removed from storage, this work will be completed before they’re returned to service.”
The matter isn’t related to the software issue linked to two crashes of the Max that killed 346 people and prompted a worldwide grounding in March 2019. For the older aircraft needing the valve inspections, Boeing said it was helping operators handle any issues. Any plane that hasn’t flown for at least seven days must be checked.
“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 planemaker said. “Boeing is providing inspection and replacement information to fleet owners if they find an issue.”
CFM International, a joint venture of GE and France’s Safran that makes engines for 737 jets, said it was working with Boeing on the matter. “FAA’s action is related to a Boeing external bleed air valve that interfaces with the engine,” GE said. Some 3,200 airliners — roughly half of the US fleet — were parked as of mid-May after US passenger traffic plunged to less than 10% of prior-year levels in April, according to Airlines for America.