We were recently told that it was not a good Idea to post about defects to our brand. Although in sales this may hold true. Aviation is a hobby that deals in life and death, we feel safety is of the utmost importance. We have come across a crack in an Aventura UL tail post. There is a sleeve in where the tube cracked, coupled with the fabric this seems to be the only reason that the tail stayed together. Very little history of this aircraft is known including how it was flown. We have been made aware of a second defect that occurred in an improper towing trip. We advise that this be inspected on the UL/ HP at preflight and postflight.