It won’t be quite so easy as there has to be a dozen different models of the 400. I think the latest is 747-400XQLR. Each aircraft has a different base weight and capacity weight that comes into play.
Not saying that it can’t be done but just that it won’t be real easy.
“It won’t be quite so easy as there has to be a dozen different models of the 400. I think the latest is 747-400XQLR. Each aircraft has a different base weight and capacity weight that comes into play.”
But, IIRC, all 747-400s have the engines mounted exactly at the same distance from the centerline, for starters. Daily observation, as was previously pointed out, could nail down VR for a particular scheduled flight.
BTW, on the blog there are links to a 747 takeoff cockpit Youtube there is a great head-on Youtube of a 747 during takeoff shot straight down the runway from a public access location. A terrorist with only an RC airframe might even achieve a direct hit from such a vantage point where only TWO dimensions are involved!