AD 2021-12-01 Lowers The Initial Inspection Threshold And Requires Repetitive Ultrasonic Inspections
The FAA is superseding Airworthiness Directive (AD) 2019-25-13, which applied to all Engine Alliance (EA) GP7270 and GP7277 model turbofan engines with a certain low-pressure compressor (LPC) 1st-stage fan blade installed. AD 2019-25-13 required an ultrasonic inspection of the affected LPC 1st-stage fan blades and replacement of any affected LPC 1st-stage fan blade that fails the inspection. This AD lowers the initial inspection threshold and requires repetitive ultrasonic inspections on affected LPC 1st-stage fan blades. This AD was prompted by a report of an in-flight shutdown (IFSD) of an engine due to the fracture of multiple LPC 1st-stage fan