Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes

The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace Corporation (Gulfstream) Model GVII-G600 airplanes. The NPRM was prompted by a report that a failure mode in the data concentration network (DCN) software causes the pitch attitude value to freeze on the primary flight display (PFD) for up to 20 seconds. The NPRM proposed to require updating the DCN and flight deck master operating system (MOS) software. Since issuance of the NPRM, the FAA has determined that there is not an unsafe condition because all affected airplanes have updated software. Accordingly, the NPRM is withdrawn.