25/03/2026
A PW4056 engine on a B747-400 underwent a detailed on-wing borescope inspection, revealing extensive surge-related damage.
Severe defects were present in the HP compressor, with secondary damage to the LP compressor, combustion chamber, and turbine stages.
Inspection results exceeded allowable on-wing limits, emphasing the importance of advanced RVI techniques and careful preparation in evaluating high-damage scenarios.