Dave
If the average A-size sonobuoy weighs 15kgs then a MALE RPAS like Pred B can carry 1,500kgs then that's 100 sonobuoys. IIRC, Pred B has 7 hard points with a potential for a pod carrying 13 sonobuoys each.
I don't see that in the realms of Science Fiction? Don't forget that Pred B is bigger than an A-10 to look at, so it's a big old bird.
LJ