AD FAA-2018-1023

We are adopting a new airworthiness directive (AD) for all CFM International S.A. (CFM) LEAP-1B21, -1B23, -1B25, -1B27, -1B28, - 1B28B1, -1B28B2, -1B28B2C, -1B28B3, -1B28BBJ1, and -1B28BBJ2 turbofan engines. This AD requires removing certain electronic engine control (EEC) system operation (OPS) and engine health monitoring (EHM) software and installing versions eligible for installation. This AD was prompted by six aborted takeoffs on the similarly designed CFM LEAP-1A model turbofan engine after those engines did not advance to the desired takeoff fan speed due to icing in the pressure sensor line. We are issuing this AD to address the unsafe condition on these products.