Next step would be to rivet the rear spar, which you can see with the clecos in the image above. At this point I decided to stop to do some research. The thing is that the canadian MD-RA asks to see every rivet, I can't close any section before they review my work, because of that I've done only the top skin, the bottom one is not riveted in place in order to let them see everything. If I rivet the rear spar, it will be really difficult for me to rivet the front-spar and the HS-708 parts later on since the rear spar will be riveted in place. And if I don't rivet the rear spar at all I don't know if the MD-RA will complain that they will want to see the HS one more time. I'll do some research and/or contact MD-RA before I do anything.