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The paper aims to detail the educational flight testing activities performed at the Department of Aerospace Science and Technology at the Politecnico di Milano (DSTA-PoliMi), including the development of low-cost, reliable flight testing instrumentation (FTI) and the administration of the graduate course in flight testing.

The flight testing course program closely adheres to the typical content of an introductory course offered in a professional flight testing school. However, within academic courses, it has a unique feature: each student is required to plan, perform and report on a real flight test experience, acting as a flight test engineer. Educational activities in this framework have been successfully matched to applied research and technical support for private companies.

At the educational level, several elements arise that are rarely concentrated within a single course, such as multidisciplinary integration, individual conceive-design-implement-operate (CDIO) project, real-life experimental procedures and techniques, teamwork, communication and reporting, relation with non-academic partners.

Based on the development of a FTI system for light aviation and on the flight testing course, DSTA-PoliMi has built a solid capability in flight testing, introducing graduate students to this specific niche of expertise and empowering co-operation with companies in the light aviation environment, while offering capabilities and tools that are typically regarded as a prerogative of major aerospace companies.

The paper discusses an original approach to flight testing education in an academic setting that avoids the high costs and complexity connected to certified aircraft flight operations and instrumentation, nevertheless allowing the achievement of significant results, also in applied engineering research.

The purpose of this paper is to present an approach to a polar graph measurement by a flight testing technique and to propose a baseline research method for future tests of UAV polar graphs. The method presented can be used to demonstrate a conceptual and preliminary design process using a scaled, unmanned configuration. This shows how results of experimental flight tests using a scaled flying airframe may be described and analysed before manufacturing the full scale aircraft.

During the research, the flight tests were conducted for two aerodynamic configurations of a small UAV. This allowed the investigation of the influence of winglets and classic vertical stabilizers on the platform stability, performance and therefore polar graphs of a small unmanned aircraft.

A methodology of flight tests for the assessment of a small UAV’s polar graph has been proposed, performed and assessed. Two aerodynamic configurations were tested, and it was found that directional stability had a large influence on the UAV’s performance. A correlation between the speed and inclination of the altitude graph was found – i.e. the higher the flight speed, the steeper the altitude graph (higher descent speed, steeper flight path angle). This could be considered as a basic verification that the recorded data have a physical sense.

The polar graph and therefore glide ratio of the aircraft is a major factor for determining its performance and power required for flight. Using the right flight test procedure can speed-up the process of measuring glide ratio, making it easier, faster, robust, more effective and accurate in future research of novel, especially unorthodox configurations. This paper also can be useful for the proper selection of requirements and preliminary design parameters for making the design process more economically effective.

This paper presents a very efficient method of assessing the design parameters of UAVs, especially the polar graph, in an early stage of the design process. Aircraft designers and producers have been widely performing flight testing for years. However, these procedures and practical customs are usually not wide spread and very often are treated as the company’s “know how”. Results presented in this paper are original, relatively easily be repeated and checked. They may be used either by professionals, highly motivated individuals and representatives of small companies or also by ambitious amateurs.

This article outlines the procedures being used at Westland Helicopters Limited to establish the fatigue lives of the dynamic and structural components of the Lynx and to demonstrate how an adequate safety level is achieved under the loading sustained by the aircraft. For the newcomer to the fatigue problem a brief introduction to the phenomenon of fatigue will be provided and it will be shown how it is applicable to a helicopter. A philosophical outline of the fatigue procedures in current use at Westlands follows and then a description of the Lynx is given. The article will then describe the fatigue testing, flight testing and substantiation procedures used with the Lynx and it will be shown how the eventual fatigue lives are estimated. Finally some thoughts are put forward about the future of fatigue substantiation.

The purpose of this paper is a development of a virtual flight test framework with derivative design optimization. Aircraft manufactures and engineers have been putting significant effort into the design process to lower the cost of development and time to a minimum. In terms of flight tests and aircraft certification, implementing simulation and virtual test techniques may be a sufficient method in achieving these goals. In addition to simulation and virtual test, a derivative design can be implemented to satisfy different market demands and technical changes while reducing development cost and time.

In this paper, a derivative design optimization was applied to Expedition 350, a small piston engine powered aircraft developed by Found Aircraft in Canada. A derivative that changes the manned aircraft to an Unmanned Aerial Vehicle for payload delivery was considered. An optimum configuration was obtained while enhancing the endurance of the UAV. The multidisciplinary design optimization module of the framework represents the optimized configuration and additional parameters for the simulator. These values were implemented in the simulator and generated the aircraft model for simulation. Two aircraft models were generated for the flight test.

The optimization process delivered the UAV derivative of Expedition E350, and it had increased endurance up to 21.7 hours. The original and optimized models were implemented into virtual flight test. The cruise performance exhibited less than 10 per cent error on cruise performance between the original model and Pilots Operating Handbook (POH). The dynamic stability of original and optimized models was tested by checking Phugoid, short period, Dutch roll and spiral roll modes. Both models exhibited stable dynamic stability characteristics.

The original Expedition 350 was generated to verify the accuracy of the simulation data by comparing its result with actual flight test data. The optimized model was generated to evaluate the optimization results. Ultimately, the virtual flight test framework with an aircraft derivative design was proposed in this research. The additional module for derivative design optimization was developed and its results were implemented to commercial off-the-shelf simulators.

This paper proposed the application of UAV derivative design optimization for the virtual flight test framework. The methodology included the optimization of UAV derivative utilizing MDO and virtual flight testing of an optimized result with a flight simulator.

To provide a general review of the flight flutter test techniques utilized in aeroelastic stability flight testing of aircraft, and to highlight the key items involved in flight flutter testing of aircraft, by emphasizing all the main information processed during the flutter stability verification based on flight test data.

Flight flutter test requirements are first reviewed by referencing the relevant civil and military specifications. Excitation systems utilized in flight flutter testing are overviewed by stating the relative advantages and disadvantages of each technique. Flight test procedures followed in a typical flutter flight testing is described for different air speed regimes. Modal estimation methods, both in frequency and time domain, used in flutter prediction are surveyed. Most common flight flutter prediction methods are reviewed. Finally, key considerations for successful flight flutter testing are noted by referencing the related literature.

Online, real time monitoring of flutter stability during flight testing is very crucial, if the flutter character is not known a priori. Techniques such as modal filtering can be used to uncouple response measurements to produce simplified single degree of freedom responses, which could then be analyzed with less sophisticated algorithms that are more able to run in real time. Frequency domain subspace identification methods combined with time‐frequency multiscale wavelet techniques are considered as the most promising modal estimation algorithms to be used in flight flutter testing.

This study gives concise but relevant information on the flight flutter stability verification of aircraft to the practicing engineer. The three important steps used in flight flutter testing; structural excitation, structural response measurement and stability prediction are introduced by presenting different techniques for each of the three important steps. Emphasis has been given to the practical advantages and disadvantages of each technique.

This paper offers a brief practical guide to all key items involved in flight flutter stability verification of aircraft.

This paper aims to present assessment of models and simulation results used in the development process of flight stabilisation system that uses trim tabs for PZL-130 Orlik turboprop military trainer aircraft. Flight test of the system allowed to compare software and hardware simulation results with real flight recordings.

Proposed flight stabilisation system was developed using modern techniques of model-based design, automatic code generation, software and hardware in the loop testing. The project reached flight testing stage which allowed to gather data to verify models and simulation results and asses their quality.

Results of the comparison showed that the trim tab actuator model used in simulation can be improved by adding play. This reduced the difference between simulation and real flight system output – actuator angle. The influence of airloads on the flying actuator angle compared to hardware in the loop simulation in lab is less than ± 0.6°.

Proposed flight stabilisation system that uses trim tabs has several benefits over classic automatic flight system in terms of weight, energy consumption and structure simplicity and does not need aircraft primary control modification. It was developed using modern techniques of model-based design, automatic code generation and hardware in the loop simulations.

In this paper, results of the flight‐testing of an unmanned aerial vehicle (UAV) flight control system are presented. APC‐4 “SkyGuide” autonomous navigation and control system, designed and developed by the research team of the Department of Avionics and Control at Rzeszów University of Technology, has been tested. Properties of this flight control system, as well as selected results of the in‐flight tests conducted on board of the PZL‐110 “Koliber” aircraft, are presented. Results obtained confirm that design assumptions of the navigation and control system and research methodology have been appropriate and APC‐4 autopilot can be used on UAVs board.

The purpose of this study is to lead to an improvement in pilot-aircraft interaction. The goal of the performed tests is an assessment of haptic feedback, which mediates flight parameters to the pilot. Pedals indicate side-slip angle by vibrations, whereas a sliding element inside the control stick is able to continuously indicate both angles of attack and side-slip.

Haptic feedback applied on rudder pedals and control stick were tested on a flight simulator and flight tests in a couple of tasks. Pilot workload, readability of feedback and side-slip were then evaluated when the flight was turning.

As a useful instrument for aircraft control, haptic feedback was assessed. The feedback settings were then individually perceived, and haptic feedback slightly improved side-slip while turning in a flight test; however, the results are not statistically significant.

The tests provided promising results for human pilot performance. The training phase and personal settings of haptic feedback is an approach for improving the performance of human pilots.

The designed and tested device is a unique tool for improving pilot-aircraft interaction. This study brings valuable experiences from its flight simulator and in-flight tests.

The peer review history for this article is available at: https://publons.com/publon/10.1108/AEAT-12-2019-0265/

The XH‐59A ABC™ demonstrator aircraft is a research vehicle designed to investigate the unique characteristics of the Advanced Blade Concept. The aircraft, shown in Fig. 1, has now completed an extensive flight test programme investigating its full airspeed, altitude, and manoeuvring envelope. Aircraft design was initiated in 1972, with first flight in July 1973, with certain interruptions to review and analyse flight data and make modifications to the aircraft. The culmination of the flight test programme was a 12.7 hour evaluation of the aircraft by the US Army Aviation Development and Test Activity at Ft. Rucker, Alabama. This evaluation is the subject of this technical report. Reference 1 is the Army report documenting their evaluation. The XH‐59A programme has been jointly funded by the US Army, Navy and Air Force, the National Aeronautics and Space Administration, and Sikorsky Aircraft. The majority of funding has come from the Army.