Germany produced 32 aircraft during World War II. In July 1940, the prototype of the new carrier-based helicopter Hummingbird helicopter developed by Flett rolled off the assembly line. The aircraft began test flights in early 1941 and performed well. The German army immediately ordered 15 pre-production models and 30 formal production models, mainly assembled in the new factories in Johannest and Bad Tolz. In order to put the aircraft on the ship, Flett organized pilots to fly the Hummingbird helicopter to conduct take-off and landing tests in the 4-meter by 4-meter landing area designated on the German Navy cruiser. The Hummingbird helicopter is fully capable of taking off and landing in such a small area, even at night. Can. The first two Hummingbird helicopters shipped from the factory used fully enclosed cockpits, and subsequent production models used semi-enclosed cockpits. By the summer of 1943, approximately 20 Hummingbird helicopters had rolled off the assembly line. It was delivered to the Navy and followed the fleet to fight in the skies over the Mediterranean, Aegean Sea and Baltic Sea. It was not only used as an anti-submarine aircraft to observe Allied submarines around the fleet, but also as a transport helicopter to provide vertical supplies to the ships. Flett also planned to develop an improved version for the German Army with better performance and larger take-off weight on this basis. However, it was already the end of World War II, so there was no further development. Since the Hummingbird helicopter can only carry one pilot, it cannot meet the needs of artillery observation and other tasks. Later, Flett temporarily installed a chair behind the engine compartment so that it can accommodate an observer, thus completing the artillery school. Mission accomplished. In 1944, the German Army specially formed an artillery school shooting team, equipped with 3 Hummingbird helicopters and 3 Fi-223s. In February 1945, several Hummingbird helicopters participated in the Battle of Pomerania, but at this time they were at the end of their rope. The Nazi army was no match for the Soviet Red Army. The participation of Hummingbird helicopters in the battle did not have much effect. The remaining few played a role in the defense of Berlin, but in the end they were all sacrificed by the Soviet Red Army's anti-aircraft artillery. Before the end of World War II, the German army destroyed most of the Hummingbird helicopters, and only three prototypes were captured by the United States and the Soviet Union. The Hemingburg (Hummingbird series) helicopter is based on the S-52 helicopter developed by Sikorsky Company. It is one of the first general-purpose helicopters to be certified by the U.S. Federal Aviation Administration (FAA). The U.S. Army, Marine Corps and Coast Guard have successively ordered hundreds of S-52 helicopters to undertake maritime search and rescue, transportation, medical rescue and other tasks, and have been well received by customers. On the basis of maintaining the original excellent design, American Vertical Aviation Technology Company has combined with Bell Helicopter's technology over the past two decades to conduct a comprehensive modernization upgrade of the S-52 helicopter certified by the Federal Aviation Administration. , including a more aerodynamic shape design, advanced rotor fairing, nose, horizontal and vertical tail surfaces, electronic gyroscope, GPS, night pilot and electric fine-tuning joystick, etc. The unique wheeled take-off and landing system is The helicopter provides the ability to land directly when the horizontal speed is greater than zero, can perform short-distance taxiing takeoff when fully loaded, and provides the ability to move autonomously on the apron.