Rotorcraft research must address the needs of society, industry, and the military in the field of rotorcraft. Increased automation, reduced pilot workload, improved performance, and quieter rotor blades are needed. These topics are covered by traditional rotorcraft disciplines. However, new challenges also arise. For instance, we must reduce CO₂ emissions by using hybrid or fully electric power trains and sustainable aviation fuels. Additionally, we must address new threats and operational concepts in today’s military environments. Uncrewed air vehicles with a high level of automation or autonomous operations are changing the landscape of civil and military operations. Well-established and new companies are trying to address these challenges with new approaches and configurations. As with any vehicle with a thrust-to-weight ratio greater than one, a technical solution for a rotorcraft must be highly efficient, limiting the innovative designs that can be considered. [...]

Rotorcraft technology is living in a moment of intensive development. Alongside traditional disciplines—aeroacoustics, aerodynamics, dynamics, flight dynamics, human factors, structures and materials, to name a few, other aspects are emerging. Uncrewed air vehicles and their autonomous operation, automation in support of crewed ones, crew management and coordination, special operations with a particular focus on those on ship decks, and lots, lots of interdisciplinarity surfaced as the topics most addressed in the papers selected for this issue. All selected papers have been extensively edited by the authors and peer-reviewed according to the standards of the CEAS Aeronautical Journal. [...]

Fidelity is a fundamental concept for crucial decision-making processes during engineering design, test and evaluation of aircraft and rotorcraft. Fidelity, as applied to rotorcraft, proves to be a prerequisite for most human factors research and simulator development programs. This paper reviews the concept of fidelity, its metrics and methods concentrating on rotorcraft applications. The paper stems from the Applied Vehicle Technology (AVT) Panel of the NATO Science and Technology Organization (STO) work of NATO AV-296 concentrating on recent advancements on rotorcraft flight simulation model fidelity prediction and assessment. Starting from the question of what is meant with the term simulation fidelity, the paper will demonstrate that even though the term fidelity can be loosely translated as simulation goodness or faithfulness to reality, when it comes to fidelity assessment, this concept has a multidimensional and multifaceted character depending on the configuration considered. A key message of the paper is that simulation fidelity should be decomposed in different dimensions and attributes with their own metrics. Using multiple fidelity metrics is therefore meaningful for assessing simulation fidelity in general and in particular for the case of rotorcraft.