It's time to put the physics of flight to the ultimate test. Can the Flite Test boys get a cinder block to lift off of the ground? We're using an electric motor that has 15 lbs. of thrust and the cinder block weighs 39 lbs. alone. The whole plane weighs about 49 lbs. The challenge was to create a super efficient airframe that would fly this much weight with as little energy as possible.