Bell 212 "Shark" Fin
I realize that these posts are dated but we recently have taken responsibility for a 1977 212 that has the Dihedral Sail. In the Flight Safety training manual it states (as an addendum) "The dihedral sail, initially an integral part of the FFA IFR Package, is no longer needed. There appears to be some discussion that it actually flies better w/o the sail (understanding that this aircraft has a single channel stab system) any feedback from the field. I flew the UH-1N (granted a different stab system) which did not have the sail.
We cannot find any notification nor service bulletin that allows for the removal of the sail.