Original Message

To my knowledge, there has never been a single hydraulic failure in 135, let alone dual fail.  If one was to fail the remaining system is more than adequate to maintain full boosted flight.  On other comment there is no helicopter out there that is impossible to fly with failed single hydraulic system.  some pilots may not be to handle it properly thru poor technique, but all are very flyable with single failures.  Wouldn't be certified otherwise.