Progress on the DarkAero 1 prototype continued in February, with the team focused on the landing gear retract hardware and flight test planning.

Landing Gear
The gearboxes that retract the main landing gear were manufactured in February. Several of the gearbox components were outsourced through Xometry to allow them to be manufactured in parallel and compress the project timeline. While outsourcing provided convenience over manufacturing the components in-house, the outsourcing process still required concise engineering drawings to be drafted to ensure all tight dimensional tolerances in the design were met. The engineering drawings also helped guarantee the outsourced components would fit together during assembly and function as intended. The gearboxes were received near the end of February, and they are currently being installed in the airframe. 

Each gearbox contains a clutch mechanism that disengages the drive motor from the gear strut in the event of a system failure. This allows the struts to extend under gravity with the assistance of gas springs that overcome aerodynamic drag loads and force the struts into their down locked position. Initial testing was performed with off-the-shelf gas springs, but a set of custom gas springs were ordered that better meet the specific requirements for force, stroke length, and damping. 

Each retract motor is controlled by a module that contains a motor speed controller, relay, and logic board. Previously, the electrical hardware components in the control module were validated through bench tests, but now the components are being arranged onto a mounting frame that can be installed next to each gear strut in the airplane. 

Flight Test Planning 
Discussions have been progressing with an FAA Designated Airworthiness Representative (DAR) to obtain an airworthiness certificate for the prototype DarkAero 1 and establish the area for flight testing. In parallel, the team has been working with test pilot Sean VanHatten to refine the plan for upcoming flight testing. This includes reviewing the center of gravity envelope, critical V-speeds, and airports of interest in the flight testing area.

Aerospace Composites Course
New modules were recently added to the Online Aerospace Composites Course. These additions include: 

Course Purchase Guide (PDF) - A complete reference guide that covers all of the materials, tools, and equipment required for manufacturing composite parts along with links to purchase these items.

Infusion Demonstration of a Soric Panel (video) - This video details the important steps for establishing a successful infusion process. The tools and materials in the demo can all be sourced from the Course Purchase Guide, allowing students to go from no experience with infusion to making their first infused part. A Soric core sandwich panel was chosen because it can be turned into a broad range of complex structures by scoring one side and folding the panel into a 3-dimensional shape. 

Infusion Process Guide (PDF) - This guide documents the infusion process and also provides important details on the factors that influence the quality and consistency of parts. This is the latest revision of the document previously shared with in-person course students. Future revisions of the Infusion Process Guide will also be posted to the online course.

Bonding Guide (PDF) - This guide details how to correctly bond composite parts to achieve maximum strength, quality, and consistency in bonded joints. This is the latest revision of the document previously shared with in-person course students. Future revisions of the Bonding Guide will also be posted to the online course.

Additional modules that will soon be added to the online course include a vacuum bagging guide and more composite laminate design examples of both structural and non-structural components.

The next two upcoming sessions of the in-person Aerospace Composites Course will be held on March 3-4 and March 30-31. Learn more and sign up for the course here:

Sign Up for the DarkAero Aerospace Composites Course!

Aerospace Mold Making Course
Session 3 of the Aerospace Mold Making Course was held in February. The lectures and demonstrations in this session were filmed, and the material is being compiled for an online version of the course that will enable access for students who cannot attend in-person. Precision molds and tooling are critical for manufacturing high-quality composite structures, but tooling is often overlooked as the composite components themselves receive most of the attention. The objective of the Aerospace Mold Making Course is to bring attention to the importance of manufacturing while providing hands-on training so that mold making does not become a bottleneck in the process of manufacturing composite designs.

Learn more and sign up for the Aerospace Mold Making Course here:

Sign Up for the DarkAero Aerospace Mold Making Course!

Looking Ahead
In March, installation and testing of the main landing gear retract system will continue. A number of miscellaneous tasks remain to be completed with the control system and cabin, and these will be worked through as well.