EASA SIB NE-15-19
Pratt & Whitney PW4000 Engines — Low Pressure Turbine 4th Stage Vane Cracks
Summary
The FAA Special Airworthiness Information Bulletin SAIB: NE-15-19 provides information regarding potential cracks in the low pressure turbine (LPT) 4th stage vane of certain Pratt & Whitney PW4000 series turbofan engines. Affected engine models include PW4052(-3), PW4056(-3), PW4060(-3), PW4062(-3), PW4062A(-3), PW4152(-3), PW4156A(-3), PW4158(-3), PW4460(-3), PW4462(-3) with LPT 4th stage vane cluster assembly P/N 51N674-01, and PW4164, PW4164-1D, PW4168, PW4168A, PW4168-1D, PW4168A-1D, PW4170 with LPT 4th stage vane cluster assemblies P/N 51N774-01 or P/N 52N774-01. This bulletin alerts operators and maintenance personnel to the risk of vane cracks due to a non-conforming fillet radius in a high stress area but does not mandate regulatory action.
What Changed
This bulletin introduces awareness of a manufacturing defect in certain LPT 4th stage vane clusters produced between May 1992 and February 1999, which may lead to vane fractures and engine failures. It provides information on inspection procedures and references Pratt & Whitney Service Bulletins PW4ENG 72-804 and PW4G-100-72-251 for inspecting and removing affected parts. No new regulatory mandates or airworthiness directives are issued at this time.
Why It Matters
This information is critical for aviation professionals including operators, maintenance, repair organizations, and compliance teams to prevent potential engine failures caused by vane fractures. Early detection and removal of affected parts can avoid in-flight engine issues and ensure continued airworthiness and safety. Understanding this issue helps maintain operational reliability and avoid costly unplanned maintenance or incidents.
What To Do
Affected stakeholders should follow the inspection and removal instructions outlined in Pratt & Whitney Service Bulletins PW4ENG 72-804 and PW4G-100-72-251 when disassembling the LPT 4th stage vane cluster assemblies. Operators should coordinate with certified repair facilities to inspect these parts proactively. No specific compliance deadline is provided, but timely action is recommended to mitigate risk.