Summary
We propose to adopt a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4158 turbofan engines. This proposed AD was prompted by several reports of high cycle fatigue (HCF) cracks found in the fuel nozzle supply manifold. This proposed AD would require replacement of the affected fuel nozzles and fuel nozzle manifold supply assemblies with parts eligible for installation. This proposed AD would also require installation of new brackets and clamps on the fuel supply manifold assemblies. We are proposing this AD to address the unsafe condition on these products.