Flying what is a fairly new type, we have introduced a TGT limit for normal operation to limit the amount of wear, which has been noticed, on the hot end of the engine.
This figure, from what I can ascertain, has just been plucked out of the air and is some 80% of MCT. But still the engines are falling short of their expected life by 20% due to excessive wear of the turbine blades. These engines are FADEC controlled and P&W have changed the fuel nozzle spray pattern to try and help matters, but to be honest there seems to have been little affect.
The manufacturers don't seem to think that this reduced TGT is going to make any difference, but then follow that statement by remarking they have collated little data or evidence as the engines are too new/young. I think what they are trying to say is they don't want to commit themselves.
So anyway to my question.....
It stands to reason that treating engines carefully will increase ther life and not flying around at MCT is going to reduce centrifugal faorces and temperature extremes in the engine. But what if this limit is too low, can that have a detrimental affect on the engine. My point being is there a theory out there that if the engines are run continuously "too cold" could this lead to hot spots being formed as the mass flow through the engine is not sufficient and in turn causing damage. How about formation of deposits on the blades etc etc.
I would be very interested to hear your views.
