if you put it on top of the umbrella, pulling up would blow the air onto the wrong side of the umbrella. If I did that it would be difficult to control, but if I put say 4 flaps about 8 inches by 8 inches on every other side of an 8 sided umbrella I could get "rudder" and "elevator" movements in hoa flying, which is a good start. but how to get the umbrella to stop the spinning motion as mentioned above

different thought
maybe a norvel 15 with an 8x4 prop.....a hole 9 inches in diameter cut directly out of the top of the umbrella so the blade could act as the nose of the umbrella and still let prop blast move over balsa or coroplast surfaces at the bottom of the umbrella which would act as elevator and rudder....or stabalizers Which would mean that...hmmm...