## 1 Introduction  
In recent years, research on high aspect ratio wings [1; 2; 3; 4; 5; 6; 7; 8; 9] has significantly stimulated the aeroelastic community, leading to extensive work on design challenges, the development of new tools to address increased flexibility, and experimental validation [10]. While the benefits of increasing the aspect ratio, such as reduced induced drag and improved aerodynamic efficiency, are well known, the drawbacks of a more slender wing are considerable. The increased aerodynamic forces, especially the bending moment, demand additional structural mass to withstand the loads, and greater flexibility can introduce aeroelastic instabilities that may compromise aircraft safety (e.g., flutter, control reversal, or divergence). One possible mitigation for reducing the increased load due to the span extension is the use of the folding wing tip (FWT). The concept of folding wings dates back to 1913, when it was first developed and patented by the British manufacturer Short Brothers plc for ship-borne aircraft [11]. By the late 1930s, the folding mechanism had become fully automatic and hydraulic [12], although it remained exclusive to naval aircraft. The first use of a folding wing tip for maneuverability came in the 1960s with [13], where the outer wing could rotate up to 65\({}^{\circ}\) to enhance lateral stability at supersonic speeds. Other aircraft have incorporated foldable components to fit within existing airport infrastructure, such as the Saab 37 Viggen's vertical tail. More recently, Boeing introduced the B777X, an upgrade to the existing B777, featuring folding wing tips that reduce wingspan during ground operations, allowing for a higher aspect ratio without altering the aerodrome reference code [14]. Historically, these designs were primarily aimed at reducing aircraft dimensions when not in flight, either to maximize storage on carriers or to fit within airport spaces. However, the potential for load alleviation through folding wings has been recognized since the late 1930s, when the Rey R.1 prototype was patented [15]. After a long hiatus, McDonnell Douglas revisited the idea in 1999 with a patented folding wingtip featuring load alleviation capabilities. Boeing, in 2004, compared the flared folding wing tip with the aeroelastic tailoring [16], and Airbus UK patented a similar concept in 2007. Since 2013, researchers like [PERSON] and [PERSON] have extensively studied this concept, making it a key topic in modern aeroelasticity research. Further information about the history of the folding wing tip concept can be found in [17]. More recently, extensive research and development have been conducted on the design of folding wing tips and the simulation capabilities required to model their behavior [18; 19; 20; 21; 22; 23; 24; 25]. In parallel, experimental activities in wind tunnels have also been carried out [26; 27; 28; 10]. On the other hand, active controllers for gust load alleviation (GLA) have been studied since the 1950s, when a feed-forward controller for GLA enabled a structure to be 20% lighter than required [29]. Since then, various active control techniques have been explored and implemented in both commercial and military aircraft. While a full bibliographic review is beyond the scope of this paper, a comprehensive survey up until 2012 can be found in [30]. Within this context, the U-HARWARD project [2; 31; 32] explores various technologies to enhance the aspect ratio of aircraft, while minimizing weight increase and addressing aeroelastic phenomena. Specifically, two strategies for gust load alleviation were examined: an active Static Output Feedback (SOF) controller [33; 34], which utilizes conventional control surfaces (ailerons and elevators) and developed by Politecnico di Milano, and a flared hinged folding wing tip (FWT) [35; 36; 37], investigated by the University of Bristol. In the U-HARWARD project, a dedicated study examined the gust load response of a scaled wind tunnel model equipped with folding wing tips (FWTs) [10].