Corrosion caused by storage prompts FAA to order Leap-1B checks

The FAA is requiring airlines perform checks to prevent storage-induced corrosion issues involving CFM International Leap-1B engines. The agency issued an airworthiness directive this week to address the concern, which it says can lead to degraded thrust. The order comes as airlines return 737 Max to service after storing the jets amid the 20-month grounding, and the pandemic. Europe’s regulator issued a related AD last month. The checks must be completed before each flight during the first 15h of power being applied to engines following prolonged storage. The order responds to reports from CFM of “multiple instances” of faults with the “pressure sub-system” (PSS) units in Leap-1Bs, which power Boeing 737 Max. “The manufacturer reported these faults have been occurring since October 2020 and are a result of pressure transducer corrosion following extended storage periods,” says the FAA’s AD. It cites “moisture ingress from long-term on-wing storage, coupled with certain manufacturing processes of the affected pressure transducers”.<br/>