Yeah, I’m scratching my head over that one. The best I can come up with for now is that like many rotorcraft, there are different transmission and engine combinations depending on lot number. Quite often there are different operating limits for the different combinations, and also gross weight can play a role. For example, 80 KIAS could be for a certain gross weight or above. I was at AVSCOM St. Louis until the move to Redstone in 1997. Vans full of historic documents were sent to storage somewhere. That included decades worth of manuals and specs. On top of that, many of the guys who would know things like this without hesitation have either retired, died, or both. I do know at least one live one, though. Will ping him this week to see if he remembers.