Putting an LV-N on the frame designed for my ion powered plane resulted in a very quick liftoff at about 30m/s, mind you an LV-N and 400L 1M tank is a lot heavier than an ion set. I think the issue is drag. The new parameters mean that you have to do everything you can to keep drag to a minimum. Edit: Ion powered flight IS possible once you get off the ground. http://images.akamai.steamusercontent.com/ugc/44251225245006344/539F923052B81DB620AB99E5E35F4E19A9FB60BC/ I piggybacked this one using a jet-sled to place it at 15km, and once I got a feel for the controls have it simultaneously gaining speed and altitude. Just at ground level, the max thrust of the ion engine is not enough to overcome the drag of the wing and get it above stall speed, even if there was nothing else attached based on my stall-sled tests. Under the new aerodynamics model, airfoils must exceed approximately 20m/s just to support their own mass let alone provide any lift to a load, while the best ion-only drives I've seen are unable to exceed approximately 10m/s on the ground. I think my next attempt is going to use an ion-powered catapult to try and accelerate the craft up to liftoff speed, but even then it will quickly slow back down and stall on ions alone I think