JimL :
Extremely remote events are not expected to occur during the total operational life of a random single rotorcraft of a particular type,but may occur a few times during the total operational life of all rotorcraft of a particular type, that are based on a probability on the order of between 10-7 to 10-9.
....it's still fuzzy......what particular type was used in the original calculation ? all Sikorskys ? all Blackhawks ? all CAT A ? ...........?