Hi, I saw yesterday a reportage on TV about test flights, and I saw a very impressive take-off of a test plane A330 at VMU:
1/ what is exactly the VMU? I guess it's the minimum speed you have to reach for take-off, but is it calculated without pax/freight?
2/ Is the VMU dependand of the weight of the aircraft?
3/ If yes: If there is pax/freight, what's the difference between VMU and Vr? Vr is the "rotation speed" (ie) the speed you have to reach to rotate and take-off, so it's "the smallest" speed you can take-off and so Vr=VMU?
4/ If no: is there any use to know this speed for an air carrier pilot?