DUNCAN
If an aircraft has a thrust:weight ratio of 1 it can hover (provided ther is a means of maintaining control with no airspeed). If it has a thrust:weight ratio of greater than 1 it can climb vertically, with all of the weight being carried by the engine thrust. The type of wing has no relevance here. But if the aircraft is to climb vertically above a fixed point on the ground it will need to be flown at its zero lift angle of attack.