seem to recall a tale (thought i'd read it here, but couldn't locate any threads on it) of someone in a R44 coming back across the Blue Mountains in severe turbulence, when he finally got back to Bankstown it was discovered that the nylon 'pads' on the mast had been creased (& i think cracked), pretty sure it was grabbed by heliflite & sent back to 'the States' for examination, as no one had ever seen one (mast bump in a Robby) that hadn't ended in catastrophe.
lucky fellow
there may be someone lurking in the forums that might be able to confirm &/or clarify the details as i don't have any (it was a 2nd hand story).