Airworthiness Directive · Amendment 39-19600 · Engine fuel distribution
Pratt & Whitney Division Turbofan Engines
This AD applies to Pratt & Whitney Division PW4158 turbofan engines designated by a -3 on the Engine Data Plate and with the following engine serial numbers: 728534 to 728555; 728557 to 728585; 728587 to 728591; 728593; 728598; 729808 to 729824; or 729826 to 729864.
We are adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4158 turbofan engines. This AD was prompted by several reports of high cycle fatigue (HCF) cracks found in the fuel nozzle supply manifold. This AD requires replacement of the affected fuel nozzles and fuel nozzle manifold supply assemblies with parts eligible for installation. This AD also requires installation of new brackets and clamps on the fuel nozzle supply manifold assemblies. We are issuing this AD to address the unsafe condition on these products.
No later than the next engine shop visit after the effective date of this AD, do the following:
(1) Remove any of the 24 fuel nozzles, part number (P/N) 51J235 or 51J344, and replace with P/N 51J397.
(2) Replace the fuel nozzle manifold supply assemblies and install new brackets and clamps on the fuel supply manifolds in accordance with the “For Engines Installed on Aircraft” or “For Engines Not Installed on Aircraft” sections, as applicable, of the Accomplishment Instructions in Pratt & Whitney Service Bulletin (SB) PW4ENG 73-224, dated November 8, 2017.
For the purpose of this AD, an “engine shop visit” is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine case flanges, except for the following situations, which do not constitute an engine shop visit:
(1) Separation of engine flanges solely for the purposes of transportation of the engine without subsequent maintenance.
(2) Separation of engine flanges solely for the purposes of replacing the fan or propulsor without subsequent maintenance.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
