21.02.2022

Inside Pie Aeronefs: achievements of 2021 and goals for 2022

The beginning of a new year is always a moment of reflection, even within companies. 2021 was an incredible year for Pie Aeronefs. Through the progress made, our company has consolidated its position as a pioneer in the electric aviation landscape. On the other hand, there are still many challenges to take on in 2022: The startup is near to achieving our primary goal, which is to manufacture the first Swiss all-electric race plane, UR-1.

Additionally, other cutting-edge projects are underway and through them our company has planned to reach the general aviation market. This is one of the reasons why Pie Aeronefs is on a hiring streak since January 2021.

We would like to share with you how significant the past year has been. Here are our milestones reached in 2021 and our new ones for 2022.

Goals achieved in 2021

  • January: Identified flaws with the original structural concept, and started a new one;
  • February: Refined our infusion and wet laminate processes;
  • March: Closed out the wing design concept and outer mold line;
  • April: Began machining our original MDF wing molds, released wing design;
  • May: Infused and laminated original upper wing skin;
  • June: Laminated Main Wing Spar, realized dimensional stability issue with wet laminate process;
  • July: Began transition to Pre-preg process, began retrofitting oven;
  • August: Started carbon mold process for pre-preg laminates, released tail design;
  • September: Completed PID-controlled oven upgrade;
  • October: First pre-preg parts completed;
  • November: All carbon molds complete, except main wing and fuselage;
  • December: Completed detailed design of fuselage.

Another big achievement reached in 2021 was our project approval from EAS (Experimental Aviation of Switzerland) association.

Company's top goals for 2022

In 2021, the company also lays the foundations for the goal it is going to achieve in the near future. In a nutshell, these are our macro goals that we expect to reach within 2022:

  • Complete and fly the UR-1
  • Optimize the UR-2 wing
  • Start the UR-2 prototyping

Therefore, our main efforts will focus on completing UR-1, as detailed in the next paragraph. Another crucial phase is related to the development of UR-2.

Next steps in the development of the UR-1 aircraft in detail

First and foremost, it is important to specify that Pie Aeronefs is proceeding in the manufacturing of the race plane UR-1 under the EAS supervision. In 2022, the association will verify the construction quality of the wing before we close the skins. It will also require the limit load testing for the wing and primary structures when they are completed. As soon as the construction and ground testing of the aircraft is complete, we expect to receive a “permit to fly” which will allow us to conduct our flight test program. Following these tests, we will receive an registration and the aircraft will be certified “Experimental”.

Obviously, before getting to this stage, there is some work to be concluded. The company is going into the most important points of our project and, at time of writing, it's possible to subdivide the 2022's work-load into four different fields: design, manufacturing, electrical arrangement, tests.

Design

We are currently carrying out the final step in the design phase of the fuselage, which is in turn the last piece of the primary aircraft structure. At this point, there are three major remaining elements of the aircraft design: the control systems (which are in advanced development), the cockpit seat, and the landing gear. Once these pieces are in place, all that will remain are the final integration details.

Manufacturing

Construction of the aircraft is proceeding apace, especially since our change to a pre-preg process which significantly increased our throughput and quality. The tail structure is mostly complete, and the new carbon wing mold is in the process of being infused. We will be milling the master plug of the fuselage over the coming weeks. We still require several weeks of lamination of the new pre-preg wing and fuselage structures, and following that process we will begin assembling all of the parts into a single aircraft.

electrical arrangement

On the electrical side, we are finally assembling our battery stacks and they will soon be ready to power our inverter/motor unit for a full power test. The inverter/motor has been ready for quite some time, however we were unable to draw the 150 kW necessary to test it from the municipal power grid, and it would have been unsafe to hook up the battery cells without the BMS safety systems.

Tests

We will soon be testing the drivetrain in a fully integrated, full power test. This will give us good information for the overall drivetrain efficiency and the shaft power output of the system. When the new wing is ready, we will also be performing a limit load test to confirm the performance of the wing structure. Later on, when the fuselage is assembled, we will attach the tail and perform similar load testing on the V-tail.

The cutting-edge projects: UR-2, UG-3, UB-4

Pie Aeronefs is also working on some cutting-edge projects. The engineering team is designing the UR-2 aircraft, which is the second plane after UR-1's manufacturing, UG-3, our general aviation aircraft, and UB-4, the business aviation model.

The company has quietly been working on the physics behind our aspirated wing designs which will be featured in the UR-2, UG-3 and UB-4 aircraft. We have identified a number of feasible concepts and developed CFD analysis tools to evaluate them. Once we have progressed sufficiently on the UR-1 project, we will begin fabricating wind-tunnel models to validate our CFD models and confirm our findings. This will allow us to conduct our vehicle design phase for the UR-2, and begin preliminary work on the UG-3.

Pie Aeronefs' Team

In order to achieve all the objectives set, Pie Aeronefs has decided to expand its team. The company is in fact hiring a number of new staff members. Some of our team were volunteers during the pandemic, and are now returning to their “day jobs”. Other positions are being filled to bring even more skills and experience the team. Stay tuned on LinkedIn to see our newest teammates' profiles. And Pie Aeronefs family is about to get bigger too: we've had two babies over the past year, and a few more are on the way!