On May 13, the "Kunlong" AG600, a large amphibious firefighting and water rescue aircraft independently developed by China, successfully completed the final flight of its airspeed calibration and reference stall speed test flights. It smoothly landed at the Pucheng National Civil Aviation Test Base in Shaanxi.

Airspeed calibration is one of the necessary subjects for an aircraft to enter TIA (Type Inspection Authorization). Among these, the stall segment and dive segment air calibration are high-risk subjects classified as Category I. The reference stall speed test flight will determine the aircraft's flight characteristics and performance in a stall condition, which is crucial for airworthiness certification. It is one of the essential test flights for the aircraft to enter TIA and one of the test subjects that challenge the limits.

On May 7, the AG600 successfully completed its first night flight test. Cheng Zhihang, Director of the General Department of the R&D Center at AVIC General Aircraft South China Company, told the Science and Technology Daily reporter that the completion of two high-risk test flight subjects—night flight test and airspeed calibration and reference stall speed test flight—lays a significant foundation for the AG600 model to successfully enter TIA and subsequently achieve the goal of airworthiness certification.