Due to a wrong drawing in the construction manual, we did countersunk the holes of the main gear angles in the wrong direction. On the photos you can see the rivets sticking out into the gear box. Later, we were informed the countersunk rivet-heads should be on the inside of the gearbox. Due to the countersinking, the inner side of the gear mounting box should be flat to pick up the landing-gear....
The ribs for the rear floor were initially prepared on the 04th November 2023. As the M4 rivenuts did not fit into the holes, we asked for clarification by the distributor. After some messages back and forth, they asked us to expand the holes to fit the M4 rivenuts. It seems that those ribs were initially made for the Sling 4 and not the Sling TSi. Once the basic assembly of the rear floor was in place, we added the bracket for the elevator autopilot servo....
The main spar comes already pre-assembled by the factory. We did a basic inspection of the assembly and added the brackets for the aileron autopilot servo to the spar. The bracket is screwed onto the main spar by using screws and nuts. As the space between the nuts is quite narrow, we used some tape to hold them in place whilst inserting the screws from the bottom.
On the 07th of November, we built the rear spar. The spar itself contains multiple separate parts which are stacked above each other. Besides the rivets, the parts are hold together by three bolts. Based on the type of bolts and the information in the construction manual, they should be tightend to 2 NM. A support jig is added to the top to make the construction more stable.
Today, it was time to prepare the rear fuselage floor. After removing the foil, we used a orbital sander with an attached scotch brite pad to prepare the surface. Once the surface is prepared on both sides, the inner side is cleaned and primed. The outer side will be painted at a later stage. Once the primer dried, the longerons are fitted and attached to the skins with clecos. Finally, the clecos are replaced by the blind rivets....