Astartes_Librarius

I realize that Lift isn't thrust, but as this is the first time I've ever made something that flew on Kerbin with a TWR<1, I wanted to make sure. Is there a way to find a lift-weight-thrust ratio to be able to determine if something can actually fly? Like for say a 10 ton spaceplane, with a TWR of .75, how much lift would you need to get off the ground? And would it be possible to implement this into MechJeb?

So I've got a question. Does MechJeb's Delta-V stats thing account for Lift in the TWR calculator? Because I've got a rocket-powered Spaceplane that according to MechJeb only has a starting TWR of .74, but I've been able to fly it quite well since I first built it before even unlocking MechJeb. It's a pretty simple design using 3 AV-R8 winglets (2 for the canards, 1 for the tail), 2 Type B Wing Connectors (each with a lift rating of 2), the Mk 1 Cockpit, the Science Jr., two FL-T400s and a LV-909 with tricycle landing gear.