Clink, Clink, Clink
Just yesterday I was out and about working. My travels took me to the Greensboro airport. I noted 7 L-1011's of various apparent heritages. On my way out I drove past 4 which were parked at one corner of the airfield. The four, with IAG markings looked to be in pretty good shape, although one was missing a few cowlings and engine covers. Now for the question- close up on one of the A/C the 1 and 3 engines were windmilling. At least one was making a consisting clinking sound, fairly loud and inconsistent. Can, over time, engines be damaged this way? Thanks in advance.