Performance Degradation Over Time
Did you ever fly a brand new ship for awhile then come back to it a few years later to find that it's become a real dog? What are some of the factors and what is their relative weight in decreasing the performance (or perceived performance) of an aircraft over time?
I can think of a few likely contributors:
First off the airframe gains weight, both through repairs and the addition of supplementary equipment. The main rotors, having been replaced individually rather than as a matched set don't track and balance as well. Erosion and other wear causes turbine engines to lose efficiency. Panels and doors no longer fit perfectly, disrupting the airflow.
What other factors might there be and how much of a decrease are they responsible for? Does surface dirt substantially affect the performance of modern rotors? How about erosion? Do worn bearings in the flight controls have much effect?
-Stan-