It would be difficult to operate Stingray from a helicopter with a wire, it has a pre programmed search pattern, it's also a quite old design dates to 1976 in the first trials. Spearfish is an improved enlarged software and transducer array package from Stingray, I suspect its memory is now considerably greater than 6mb first announced in its launch, most of us were a touch sceptical when we went to the presentation. MSDS (Marconi Space Defence Systems) better known in submarines as Maybe Some Day Soon. However as both are still about I assume they have been improved and have outstripped their initial problems. I believe Spearfish has built in safety devices should the wire break when homing on the launching submarine, the active/passive homing is selected during the attack from the submarine, the wire is always connected to the submarine, whatever its attack state