Summary
We propose to adopt a new airworthiness directive (AD) for certain CFM International S.A. (CFM) CFM56-3, -3B, and -3C turbofan engines. This proposed AD was prompted by a report of dual-engine loss of thrust control that resulted in an air turn back. This proposed AD would require initial and repetitive checks of the variable stator vane (VSV) actuation system in the high-pressure compressor (HPC). We are proposing this AD to correct the unsafe condition on these products.