The Hortens had in their previous airplanes a problem called "Middle Effect". The airflow messed up in the middle. The sweep in the wings would have been source of this. The parabol wing was thought to be the solution to that problem. They made this glider to proof their findings, but the glider was deformed during the winter (stored outside??) and burned even before it could fly.Hi! Honestly speaking, I can't understand the objective of this glider.
View: https://www.youtube.com/watch?v=YVwic2m_pVk
https://www.nevingtonwarmuseum.com/ho-parabel.html