SD, some further comment re the 67 and wings on helicopters. NASA commissioned a maneuverability test program on the S-67, to include maximum G capability, wings on and wings off. We were a bit surprised that the G advantage with wings ON was less than some aerodynamic predictions. They add extra weight, and they produce vertical drag thus reducing hover performance, thus for any new design, there are puts and takes to weigh ( no pun ) before deciding.
As for responding to the subject of acoustic stealth to SAS and IFMU,I cannot. Other than my lovely spouse accusing me ( correctly so ) of having very selective hearing,I am deaf on the subject.