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Designing new aircraft that are state-of-the-art and beyond always requires the development of new technologies. This paper aims to present lessons learned while designing, building and testing new UAVs in the configuration of the flying wing. The UAV contains a number of aerodynamic devices that are not obvious solutions and use the latest manufacturing technology achievements, such as 3D printing.

The design solutions were applied on an airworthy aircraft and checked during test flights. The process was first conducted on the smaller UAV, and based on the test outcomes, improvements were made and then applied on the larger version of the UAV, where they were verified.

A number of practical findings were identified. For example, the use of 3D printing technology for manufacturing integrated pressure ports, investigation of the adverse yaw effect on the flying wing configuration and the effectiveness of winglet rudders in producing yawing moment.

All designed devices were tested in practice on the flying aircraft. It allowed for improved aircraft performance and handling characteristics. Several of the technologies used improved the speed and quality of aerodynamic device design and manufacturing, which also influences the reliability of the aircraft.

The paper presents how 3D printing technology can be utilized for manufacturing of aerodynamic devices. Specially developed techniques for control surface design, which can affect adverse yaw problem and aircraft handling characteristics, were described.

Aircraft structure mass estimation is a very important issue in aerospace. Multiple methods of different fidelity are available, which give results with varying accuracy. Sometimes these methods are giving a high discrepancy of estimated mass compared to the real mass of the structure. The discrepancy is especially noticeable in the case of small aircraft with a composite structure. Their mass properties highly depend not only on the material but also on technology and the human factor. Moreover, methods of mass estimation for unmanned aerial vehicle (UAV) platforms are even less established and examined. The purpose of this paper is to present and discuss various methods of mass estimation.

The paper presents different procedures of mass estimation for small UAVs with a composite structure. Beginning from the simplest one, where mass is estimated basing on a single equation and finishing with a mass estimation based on finite element method model and three-dimensional computer-aided design model. The results from all methods are compared with the airworthy aircraft and conclusions are discussed.

Mass of flying aircraft was estimated with different methods and compared. It revealed levels of accuracy of the investigated methods. Moreover, the influence on structure mass of human factor, glueing and painting is underlined.

Mass of the structure is a key factor in aerospace, which influences the performance of the aircraft. Thorough knowledge about the accuracy of the mass estimation methods and possible sources of discrepancies in mass analyses provides an essential tool for designers, which can be used with confidence and allows for the development of new cutting-edge constructions.

There are very few comparisons of mass estimation methods with an actual mass of manufactured and functional airframes. Additionally, mass estimation inaccuracies based on technological issues are presented, which is seldom done.

This paper aims to describe the enhancement of the numerical method for conceptual phase of electric aircraft design.

The algorithm provides a balance between lift force and weight of the aircraft, together with drag and thrust force equilibrium, while modifying design variables. Wing geometry adjustment, mass correction and performance estimation are performed in an iterative process.

Aircraft numerical model, which is most often very simplified, has a number of new improvements. This enables to make more accurate analyses and to show relationships between design parameters and aircraft performance.

The presented approach can improve design results.

The new methodology, which includes enhanced numerical models for conceptual design, has not been presented before.

Additive manufacturing technology, also commonly called as 3D printing technology, is entering rapidly into the aerospace world and seems to be its future. Many manufacturing processes are replaced by this technology because the ease of use, low costs and new possibilities to make complicated parts. However, there are only few solutions which present manufacturing of structurally critical parts.

Complete process of deriving loads, design of fitting geometry, numerical validation, manufacturing and strength testing was presented. The emphasis was made to show specific features of 3D technology in printed fittings for UAV.

The research confirms that the technology can be used for the application of fittings manufacturing. Attention needs to be paid, during the design process, to account for specific features of the 3D printing technology, which is described in details.

Without a doubt, additive manufacturing is useful for manufacturing complicated parts within limited time and with reduction cost. It was also shown that the manufactured parts can be used for highly loaded structures.

The paper shows how additive manufacturing technology can be used to produce significantly loaded parts of airplanes’ structure. Only few such examples were presented till now.

According to the study of the space flight market, there is a demand for space suborbital flights including commercial tourist flights. However, one of the challenges is to design a mission and a vehicle that could offer flights with relatively low G-loads. The project of the rocket-plane in a strake-wing configuration was undertaken to check if such a design could meet the FAA recommendation for this kind of flight. The project concept assumes that the rocket plane is released from a slowly flying carrier plane, then climbs above 100 kilometers above sea level and returns in a glide flight using a vortex lift generated by the strake-wing configuration. Such a mission has to include a flight transition during the release and return phases which might not be comfortable for passengers. Verification if FAA recommendation is fulfilled during these transition maneuvers was the purpose of this study.

The project was focused on the numerical investigation of a possibility to perform transition maneuvers mentioned above in a passenger-friendly way. The numerical simulations of a full-scale rocket-plane were performed using the simulation and dynamic stability analyzer (SDSA) software package. The influence of an elevator deflection change on flight parameters was investigated in two cases: a transition from the steep descent at high angles of attack to the level glide just after rocket-plane release from the carrier and an analogous transition after re-entry to the atmosphere. In particular, G-loads and G-rates were analyzed.

As a result, it was found that the values of these parameters satisfied the specific requirements during the separation and transition from a steep descent to gliding. They would be acceptable for an average passenger.

To verify the modeling approach, a flight test campaign was performed. During the experiment, a rocket-plane scaled model was released from the RC model helicopter. The rocket-plane model was geometrically similar only. Froude scales were not applied because they would cause excessive technical complications. Therefore, a separate simulation of the experiment with the application of the scaled model was performed in the SDSA software package. Results of this simulation appeared to be comparable to flight test results so it can be concluded that results for the full-scale rocket-plane simulation are also realistic.

It was proven that the rocket-plane in a strake-wing configuration could meet the FAA recommendation concerning G-loads and G rates during suborbital flight. Moreover, it was proven that the SDSA software package could be applied successfully to simulate flight characteristics of airplanes flying at angles of attack not only lower than stall angles but also greater than stall angles.

The application of rocket-planes in a strake-wing configuration could make suborbital tourist flights more popular, thus facilitating the development of manned space flights and contributing to their cost reduction. That is why it was so important to prove that they could meet the FAA recommendation for this kind of service.

The original design of the rocket plane was analyzed. It is equipped with an optimized strake wing and is controlled with oblique, all moving, wingtip plates. Its post-stall flight characteristics were simulated with the application of the SDSA software package which was previously validated only for angles of attack smaller than stall angle. Therefore, experimental validation was necessary. However, because of excessive technical problems caused by the application of Froude scales it was not possible to perform a conventional test with a dynamically scaled model. Therefore, the geometrically scaled model was built and flight tested. Then a separate simulation of the experiment with the application of this model was performed. Results of this separate simulation were compared with the results of the flight test. This comparison allowed to draw the conclusion on the applicability of the SDSA software for post-stall analyzes and, indirectly, on the applicability of the proposed rocket-plane for tourist suborbital flights. This approach to the experimental verification of numerical simulations is quite unique. Finally, a quite original method of the model launching during flight test experiment was applied.

This paper aims to describe the concept of morphing tailless aircraft with discontinuous skin and its preliminary kinematic solution. Project assumptions, next steps and expected results are briefly presented.

Multidisciplinary numerical optimization will be used to determine control allocation for wing segments rotation. Wing demonstrator will be fabricated and tested in wind tunnel. Results will be used in construction of flying model and design of its control system. Flight data of morphing demonstrator and reference aircraft will result in comparative analysis of both technologies.

Proposed design combines advantages of wing morphing without complications of wing’s structure elastic deformation. Better performance, stability and maneuverability is expected due to wing’s construction which is entirely composed of unconnected wing segments. Independent control of each segment allows for free modeling of spanwise lift force distribution.

Nonlinear multipoint distribution of wing twist as the only mechanism for control and flight performance optimization has never been studied or constructed. Planned wind tunnel investigation of such complex aerodynamic structure has not been previously published and will be an original contribution to the development of aviation and in particular to the aerodynamics of wing with discontinuous skin.