Originally Posted by
tdracer
GE has previously expressed concern regarding the use of PMA turbine blades (i.e. aftermarket blades). Their turbine disc life limits are based on the OEM blades - the PMA blades are typically a different material and significantly heavier than the OEM blades, which throws those turbine disc life limit analysis out the window...
I am not a gas turbine engineer, but even I'd stop and think about it before swapping in heavier blades, given the RPM these things run at. It sounds, well, risky... I'm slightly surprised that the certification system would allow that to happen. It seems like a massive departure from the designer's intents, like disabling the overweight trip on a 3 ton elevator in a building and then putting 4 tonnes in it and pressing the button for the 100th floor.
Do a lot of airlines tinker in this way? Any way for the flying public to find out in advance of getting on board?