You know, I've looked a million times at that illustration that SAS posted and I never before noticed that it's an H-46 and not (as I assumed) a Huey. I guess I made that mistake because the drawing was always associated with Harry Reasoner's comments about Viet Nam helicopter pilots, and the iconic image of Viet Nam for me is the Huey. In my brain, I added 2 + 3 and got 4.
Probably won't be the last time...