Why would they need a log book to explain how and why an engine failed? Its simple. They pull it apart, find the broken bit. The blaming of the operator (need for log book) would come later yea? Thats the usual routine isnt it?
"oh, youve overheated it"
" umm, no I havnt, I have 4 channel EGT/CHT for entire life of (rebuilt) engine which clearly shows always in specs."
"Oh, well, in that case, you used the wrong fuel additives"
"Ummm, no, i dont use fuel additives"
Oh...fair enough, well, then im afraid youve overheated it"..
"Ummm..havnt we been over this?"..
"oh yea, sorry, i got confused who i was talking to. You must understand we deal with a lot of these failures every week, I got confused"
"ok, so can you please tell me why my factory engine died at 300 hours?"
" Yes, we probably can..But..Not right now..We want to quarantine the parts so casa can see them...one day..maybe."
"Ok, just let me know please..Now, can you put me through to the sales dept..i need to buy some new parts to fit to my factory engine that doesnt work anymore"
"yes certainly sir"
While you may think this is a joke, i assure you its not. every part of that conversation I have witnessed first hand.