Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes

We propose to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace Corporation Models G-IV and GIV-X airplanes. This proposed AD was prompted by a revision to the airworthiness limitations section (ALS) of the aircraft maintenance manual (AMM) based on fatigue and damage tolerance testing and updated analysis. This proposed AD would require revising the maintenance or inspection program to incorporate updated inspection requirements and life limits that address fatigue cracking of principal structural elements (PSEs). We are proposing this AD to address the unsafe condition on these products.