We are already off to a busy new year in 2020 at DarkAero! There is a lot of good progress to report on for January and we are excited about how things are taking shape. 

Nose Gear Machining
We have been working through machining the nose gear components for the DarkAero 1. A few weeks back we made several upgrades to the CNC mill which included improved coolant flow, a coolant and chip enclosure, and a new air hose setup. These upgrades allowed us to proceed with machining the engine mount and now the landing gear components. In January we finalized the computer simulated machining tool paths for all nose gear components including the retract links. We also ordered and received the billet stock and workholding needed to complete the machining of all the nose gear components. Machining of the nose gear fork is nearly complete. For the DarkAero 1 prototype, much of our machining work is also “prototype” meaning our setups and workholding is not optimized for production. For each component we machine, we record timing and notes on what changes we need to make for production. For the nose fork, we have already learned enough to cut the number of setups and timing in half from what was done for the prototype. Going into February, we will be finalizing the machining for the remaining nose gear components.
 

Landing Gear Load Testing
Once the nose gear and main gear are finished, the first order of business will be drop testing each to ensure they meet their desired load capability requirements. These tests will be performed in accordance with FAR Part 23 for all specified landing conditions. Our intern from last summer, Ryan, was back in town for a few weeks over college winter break and stopped by to lend an extra hand. Ryan was able to build the entire drop test fixture for the nose gear and design the main gear drop test fixture. The nose gear drop test fixture will also be supporting the engine mount. Each fixture will be loaded with sand bags that will simulate mass and impact load the gear would potentially experience under different landing conditions based on aircraft weight, sink rate, and touch down type. 

Rudder Pedal Progress
More progress was made on the rudder pedal system in January. We machined the new carbon fiber tube connectors we have been developing and assembled them with the carbon fiber tubes that make up the rudder pedal system. We also machined a set of acetal bearing blocks that the rudder pedal torque tubes pivot on and installed them in the fuselage. Basically, we finished up everything in the rudder pedal system except for the travel stops and the return springs. These tasks will get finished up in the next month along with finishing up the rudder cables to attach the pedals to the rudders. There was also some miscellaneous composite work we finished up in the forward fuselage area around the rudder pedals and nose wheel well. This work included closing up a few areas of exposed honeycomb and adding in some structural reinforcements. 

Further Testing and Data Collection
You may recall from some of our previous updates that we have worked with the UW Madison Department of Engineering to test out 3D printed components for the DarkAero 1. Our most recent print from them was the submerged inlets or “NACA ducts” for the cabin air vents. At the start of this year we continued to work with the University and initiated some further testing on several of our adhesives and epoxy systems. With the University's testing equipment, we will be able to expand on our current data set to gain more confidence with some of the new materials and manufacturing processes we have been experimenting with. 

Flying Magazine Article
In addition to our recent coverage in Sport Aviation, we were also featured in Flying Magazine in January. Dan Pimental’s article goes into some of the background on our company and talks about our approach to funding and design work. You can read the whole article at: https://www.flyingmag.com/story/aircraft/darkaero-spring-flight-test/

Waunakee High School Aero Club Talk
One of the fun aspects of starting DarkAero has been hearing from younger aviation enthusiasts and discovering that they are inspired by what we are attempting. When possible, we try to set aside some time to further connect with future aviators. The president of the Waunakee High School Aero Club reached out to us on social media several weeks back and asked if we would be willing to give a talk to their club on our experience with DarkAero and we happily agreed. Our presentation went well and we answered some good questions about our project. The local newspaper made a visit as well and gave us a little added local exposure. 

Canopy Mold Upgrades and Form Test
We successfully installed and tested zoned heaters inside of our upgraded canopy mold. These heaters allow our canopy mold to achieve a uniform outer temperature of 250F, which improves the optical properties of our canopy plastic while it’s being formed over the mold. We test formed a canopy using this new internally heated mold, but unfortunately the test did not yield an optimal result. We will be running a new test with a different polycarbonate sheet at the beginning of February.  

Final Fuel Tank Leak Check
We performed a final cure cycle on the wing, and afterwards we checked the wing tanks to inspect for any leaks that may have come about during this process. The inspection process involved filling each wing tank with a trace gas and using a chemical “sniffer” to find any leaks. We also ran long term pressure tests. We were happy to confirm the only leaks that came up were just in a few fuel fittings and vents and were easy to correct. This final check gave us more confidence in the quality of our wing assembly process. 

Builder Instructions
Work continues on the build instructions for the DarkAero 1. We use a spreadsheet to keep track of build instruction status and use a gate review system for each section of the build. The gate checks include things like physical build completion, production changes needed, photo documentation, rough draft, rough draft completion, and final revision. When we aren’t in the shop making progress on the prototype, we are generally working on company paperwork and these builder instructions. In January we continued work on the build instructions for the horizontal and vertical stabilizer. In February they will be finalized as we will be proceeding into permanently attaching these structures to the fuselage.

YouTube Channel
We had some fun in January making more YouTube videos showing more aspects of life in the shop building the DarkAero 1 as well as some of the details behind our design philosophy. If you haven’t seen the latest videos yet, we recommend heading over to our YouTube channel to check them out. We also recommend subscribing to our YouTube channel to stay up to date on the latest content we release.
DarkAero YouTube Channel: https://www.youtube.com/darkaeroinc

February and Beyond
Next month we will be continuing work on the fuselage systems installation, landing gear machining, and canopy forming. We will be permanently installing the horizontal and vertical stabilizers to the fuselage as well as beginning firewall forward and avionics installation.