For fighter jets, their structures will also vary depending on their functions. Components that appear on a certain type of fighter may not necessarily appear on another type of fighter, and this is the case with tail sleds. Generally speaking, the tail sled, a small component that is installed at the tail of an aircraft and is not commonly known, is more commonly found on transport planes, bombers, and helicopters, while fighter jets have basically lost this "tail". The main function of the tail sled is to prevent the aircraft from "scraping the tail" during takeoff and landing. Generally speaking, transport planes and bombers have longer bodies, such as the Tu-16 and B-29 bombers, and they usually need to maintain a "head up and chest up" posture when taking off or landing on the ground. Especially when landing, adopting this posture can ensure that the main landing gear touches the ground first, thereby avoiding the relatively fragile front landing gear and nose from being impacted first. However, adopting this posture also carries risks - if the angle between the fuselage axis and the ground is too large, the tail of the aircraft may unintentionally "rub" against the runway, a phenomenon known as "tail scraping". Once a 'tail scraping' occurs, it can cause minor damage to the lower skin of the tail, severe damage to the internal structure, equipment, and pipelines, and may even lead to serious accidents. To prevent the aircraft from "scraping the tail", the R&D team designed a targeted tail sled at the rear of the aircraft. Some tail sleds have a protruding metal block installed at the bottom of the tail, which can be grounded first when the tail is about to touch the ground, withstanding impact and wear. Some tail sled structures are more complex, and can be lowered according to the pilot's operation or set automatic program after landing instructions are issued, always ready to replace the tail of the aircraft. Specifically, the tail sled will make contact with the runway before the tail of the aircraft, continuously absorbing impact energy through friction and its own compression deformation. During this process, the pilot will clearly feel this friction and quickly adjust the flight attitude to ensure safe takeoff and landing. Even if the "tail wiping" action is slight and the aircraft quickly returns to normal, pilots and maintenance personnel can determine the situation by checking the tail sled scratches or relevant indicator instruments after the aircraft lands. Some large helicopters, such as the Mi-26 and CH-54, are also designed with tail sleds. However, in addition to preventing "tail scraping", the tail sleds of helicopters can also protect the side mounted tail rotor to a certain extent, avoiding the tail rotor from touching the ground when the helicopter lands at high angles of attack. The tail sled looks unremarkable, but the design and manufacturing requirements are not low. Firstly, there is a high demand for materials. Due to the need to withstand enormous impact forces in an instant, the materials used must possess high strength, high toughness, high temperature resistance, fatigue resistance, and other properties. Researchers usually use special titanium alloys, high-strength steel, and advanced composite materials to manufacture tail sleds. Secondly, some tail sleds may adopt more complex designs. It is no longer a protruding metal block, but a hydraulic system that can overcome hardness with softness. When an impact occurs, the hydraulic buffer device can soften and control the impact received. In addition to the commonly used sled tail sled, there have been other solutions in aviation history. For example, the Tu-95 bomber uses retractable tail wheels to play the role of a tail sled. Compared with transport planes, bombers, and helicopters, there are few fighter jets that use tail sled design. This is because fighter jets have already taken into account high angle of attack takeoff and landing scenarios during design, and improvements have been made in landing architecture, tail design, aerodynamic flight control, and operational standards to avoid the phenomenon of "tail scraping". With the advancement of technology, some aircraft tail sleds have been upgraded from "passive protection type" to "active warning type". The advanced fighter jet's anti tail rubbing system can monitor the distance between the tail and the runway in real time, combined with data such as center of gravity and payload. Once a risk is predicted, the aircraft's elevation angle will be automatically adjusted to avoid accidents. This design allows the aircraft to achieve the purpose of preventing "tail scraping" without the need for a physical tail sled. (New Society)