External stores on low-speed rotorcraft are subjected to various external forces depending on the aircraft's operating conditions. While there are different types of external forces, this paper focuses on flight loads as defined by US defense specifications. Flight loads consist of static and dynamic loads. Static loads on aircraft external stores include inertial loads resulting from aircraft maneuvers and aerodynamic loads caused by the downward flow of the main wing. To define the inertial load, the inertial load factor on external stores was calculated, while the minimum analysis case for aerodynamic load was derived from trim analysis of rotorcraft blades. The critical design load diagram was developed by combining these factors, and ANSYS was utilized to analyze the structural robustness under static loads. Based on the characteristics of the main wing, a finite element analysis was conducted using a vibration profile tailored to the actual operating environment and an impact profile suitable for the impact conditions. Structural robustness was further assessed through actual tests. This analysis provides essential data for airworthiness certification, allowing for the safe installation of external stores on low-speed rotorcraft.

A pod mounted on an aircraft external must be installed on an aircraft after its structural safety is verified under flight conditions. This paper presents methods of flight load and test load generation. Evaluation of test result data and standards for failure mode are also presented. First of all, to verify the static structural stability, flight loads for the aircraft maneuvering conditions were calculated. Finite element analysis was then performed with flight loads. As a result of the analysis, structures were verified to have a margin of safety for a given design requirement. In addition, it was confirmed that the launcher tube had enough rigidity to support the missile. Thus, the role of stinger such as longeron and hardback was insignificant. Finally, based on results of tests and analysis, the static structural stability of pod was substantiated and the reliability and effectiveness of the analysis model were obtained. These results and dynamic stability verification results suggest that an optimal design is necessary.

The Store Automatic Fixing Equipment operates as an external force acting on fixing the Store during the flight and as a device designed to prevent the Store from being shaken when the aircraft is flying with the Store. In this paper, we derived the mathematical modeling of the Store Automatic Fixing Equipment through the analysis of the operating principles of the Equipment. The gap occurred by the external vibration forces was calculated through the mathematical model and structure analysis. And then the shape and stiffness design of the wedge, i.e., the Store Automatic Fixing Equipment was derived by the mathematical modeling and structural analysis. We made the Store Automatic Fixing Equipment and took the vibration testing under the aircraft flight conditions. We used the load cell to measure the reaction forces acting on the gap between the Store Automatic Fixing Equipment and the Store. The results of the reaction force measurements were compared with the analysis results of the design and the suitability of the Store Automatic Fixing Equipment’s design was verified based on the analysis.