Roadie3rd

Can Anyone Help Ive got a bit of a problem with getting it into the air. I bought a Beamer 7M kite and im having trouble with it taking off. I have been up in 6-18Mph wind but no luck at all Some times it wont even go up at all but when it does It goes into the air about 10 feet then rotates to the left and plumets to the ground.Also if it doesnt do that it takes of then it looks as though the brakelines are pulled then it slowly decends to the ground but the actual lines themselves are slack. its getting irritating. Any idea