The Whole Nine Yards.
I remember using this term in 1967 in Air Force Surviver Training. Not sure what the standard Airborne parachute line length line was then, but we would cut it up and make rope (3 twisted lines) for use going off cliffs. So the term was to make sure you used the whole nine yards. Which my understanding then was that if you parachute jumped you hoped the whole nine yards open, then you would go down with "the whole nine yards'.
Since this was standard in the '60s find no reference to parachute lines on any of the uses of this term, why?