Expert: Ismar Avdic, Eng. - 3/3/2011

Question
What is the average lifespan of turbine engine blades and vanes before they need to be replaced?

Answer
Good question Joe,
That greatly depends from engine manufacturer to manufacturer. As engine manufacturer is designing inspection maintenance intervals. Usually on major engine inspections, where an borescope inspection is recommended abnormalities in engine turbine blades could be detected, that is time when replacement is required. Another cases of those blades abnormalities is engine operations with high ITT temeratures where temperatures exceeding operational "red line" limits cause where excessive temperature literally start melting and causing blades to elongate and expand. Required borespoce inspections are required and upon detection replacement of blades is also required. Lately, Pratt and Whitney engines PT6 company has inspections their engine turbine blades that apparently because the design metal discrepancies do have corrosion issues after certain number of hours on engine, also in this case upon inspection and detection replacement of blades is required.

Ismar