500
i think most accidents have been pilot error
cant realy say about engine failures but i had a engine out landing at cranfield i must have been 100 ft and 20-30 kts well in the h/v curve but it landed safely on a taxiway and no damage
the cause was foreign bodies in the HMU it was a growth of bacterior that had blocked the fuel .the 600 is a quiet helicopter but its erie when it goes totaly quiet although it must have only been seconds it seemed ages