Hello Vojto !

Thanks for posting on our forum !

Pascal has sent you a hint about the picture that you have posted with your mail.

The skirt you are showing has an important construction error.

As you can see on the sketch of Pascal, the "bag" of the segment has not to be sawn together at the bottom (along green line !).

If you do this, the air will not be able to form a jet downwards and thus will not lift your craft properly.

Regards,

Marc