Originally Posted by
CLUTTER
Flight hours and cycles are two almost totally Independant contributors to structural damage. The Hawaii 737 is the poster child for the importance of cycles. If cycles were an issue for tour hellos, something would have popped up by now. There is another issue involved in this accident.
That is why most helicopters track "RIN's", which for those that do not know is "Retirement Index Number". So for example on the L4, lets say I flew 6 hours, 4 landings and lifted 37 buckets of water, the RIN count for the day would be 2(lifts + landings), therefore 2(37 +4) = 82. This number is then used as a multiplication factor on various life limited components.