EASA SIB NE-16-01R1
Pratt & Whitney PW4000 Engines — Low Pressure Turbine 4th Stage Vane Cluster
Summary
The Special Airworthiness Information Bulletin SAIB NE-16-01R1 is an FAA informational bulletin addressing Pratt & Whitney PW4000 series turbofan engines equipped with low-pressure turbine (LPT) 4th stage vane clusters that have a hollow internal airfoil configuration. It alerts operators, owners, and certified repair facilities to potential structural degradation caused by hot corrosion (sulfidation) inside the vane passages, which can weaken the vanes and lead to engine failures. The bulletin specifically references PW4000-94 model engines and provides inspection guidance to detect internal corrosion.
What Changed
This revision of SAIB NE-16-01 clarifies and corrects the introduction, background, and recommendation sections regarding the inspection and maintenance of the LPT 4th stage vanes. It emphasizes the use of magnetoscope inspection to detect internal sulfidation damage that borescope inspections cannot reveal. The bulletin updates the recommended inspection procedures as per the PW4000 series engine Clean, Inspect, Repair Manual dated January 15, 2015.
Why It Matters
This information is critical for aviation professionals because internal corrosion of the LPT 4th stage vanes can lead to vane liberation and engine failure, posing safety risks and potential operational disruptions. Operators and maintenance organizations need to adopt the recommended inspection techniques to identify hidden damage early and prevent uncontained engine events. Compliance with these recommendations helps maintain engine reliability and airworthiness without mandatory regulatory action.
What To Do
Operators and maintenance personnel should perform magnetoscope inspections on LPT 4th stage vanes with hollow internal airfoil configurations whenever the parts are exposed, following the procedures in the PW4000 series engine CIR Manual, P/N 51A357, Task No. 72-53-24-200-002 dated January 15, 2015. Any vanes found to be degraded must be removed from service. There are no specific compliance deadlines stated, but inspections should be conducted during piece part exposure.