Progress continued on the DarkAero 1 prototype in November with work primarily focused on the main landing gear. Efforts over the past month culminated in mating the main gear struts with the trunnion frame to create a fully assembled landing gear structure. The second session of the DarkAero Aerospace Composites Course was held in November as well.

Main Landing Gear
The main landing gear of the DarkAero 1 is an assembly built up from a number of CNC machined aluminum components and molded carbon fiber structures. Each gear strut consists of a carbon fiber main segment that is molded in two halves and bonded together to form a hollow tapered tube. The carbon fiber tube is closed out with CNC machined aluminum ends that are both bonded and bolted into place. The aluminum ends have geometric features that allow the struts to be attached to the rest of the main gear assembly. These parts were manufactured over the past few months, and it was finally possible to assemble them all together in November.

The process to assemble the main gear struts required some planning. A specific assembly sequence was required, and the strut components had to be positioned in an assembly fixture to ensure proper alignment. It was necessary to electrically isolate the aluminum strut ends from the carbon fiber main segment to prevent galvanic corrosion on the strut ends. This was accomplished by adding a thin layer of fiberglass on the inside faces of the carbon fiber strut and installing hollow fiberglass tubes through the bolts holes that run through the assembly. The aluminum landing gear components have had no corrosion protection applied yet, but they will ultimately be protected through anodization or paint. 

The struts were assembled successfully, and a number of ideas were generated for design improvements that will be implemented in production to improve the manufacturability of the struts. One of the planned changes is to create the carbon fiber portion of the strut in a flat sheet and then cut out the four sides of the structure using the CNC router. This will reduce the number of infusion operations for a pair of gear struts from four operations down to one. It will also make the trimming operation automated rather than manual.

After the main gear struts were assembled, it was possible to join the struts to the rest of the landing gear hardware and the trunnion frame. While the landing gear was fully assembled, fit checks were performed with each strut to test the alignment as the struts were moved between their retracted and extended positions. The fit checks confirmed the physical parts matched up with the intended geometry and spacing that was established in the 3D CAD environment. A fit check was also completed between the gear assembly and the fuselage. This allowed a few minor adjustments to be identified, which will be completed prior to permanently bonding in the trunnion frame.

It was rewarding to finally see the main gear come together after all the work that went into designing and manufacturing the system. The remaining tasks on the main landing gear include permanently bonding the trunnion frame together, manufacturing the actuation hardware, and installing the landing gear assembly into the fuselage. Once the landing gear is installed, it will be possible to close out the fuselage by installing the skin on the belly of the airplane aft of the wing.

DarkAero Aerospace Composites Course
Another successful session of the DarkAero Aerospace Composites Course was held this past month. Those who attended went through two days of instruction ranging from technical theory to hands-on demonstrations centered on building a small wing section. The material covered in the course shares aspects with the training and instruction that will be used to build a skilled workforce to manufacture DarkAero 1 kits in production. The next session of the course on January 28-29, 2022 is already fully booked. The following session on February 18-19, 2022 is filling up as well, so another session is planned for March. If you are interested in joining the February or March sessions, contact us at courses@darkaero.com to register. 

YouTube
The inception of the DarkAero CAD Library was mentioned earlier this year in the September monthly update. A new video was released that highlights the CAD Library as well as the motivation and objectives behind it. Check out the video below to learn more: 

The Ultimate Aerospace CAD Resource - DarkAero CAD Library!

Another video was released that summarized the progress on the main landing gear including the strut assembly process and the fuselage modifications that were made to integrate the landing gear into the airframe. Check out the video linked below:

Carbon Fiber Landing Gear!

Looking Ahead
The focus in December will be on integrating the main landing gear into the airframe. Other projects on the horizon included cockpit and canopy work as well as assembling the full airframe with the landing gear installed.