In the above picture, on the deck of a US Navy aircraft carrier, an F-35C stealth fighter jet is waiting in line to attack, while another F/A-18F "Super Hornet" with four auxiliary fuel tanks is towed by a tractor to the launch position - it will undertake the task of "partner refueling" for airborne fighter jets. Partner refueling "is a commonly used aerial refueling method between carrier based aircraft. Due to the lack of large refueling aircraft on US Navy aircraft carriers, they can only rely on fighter jets equipped with refueling pods as "part-time" refueling aircraft. This choice is truly helpless. Before the 1990s, US Navy aircraft carriers were equipped with dedicated refueling aircraft modified from attack planes, such as KA-6D, with a total fuel capacity of nearly 12 tons and the ability to transport over 6 tons of fuel to carrier based aircraft from 700 kilometers away. With the end of the Cold War, all these refueling aircraft were retired and subsequent projects were cancelled one after another. The US Navy once used anti submarine aircraft to retrofit refueling aircraft for emergency purposes, but with the retirement of the last two anti submarine refueling aircraft in 2016, the US Navy's dedicated carrier based refueling aircraft completely exited the historical stage. Afterwards, the main fighter jet of the US Navy Carrier Air Wing, the F/A-18F Super Hornet, was forced to shoulder the heavy burden of "partner refueling". From a tactical perspective, this model has certain advantages: firstly, the platform is universal, with refueling and receiving aircraft of the same type, and logistics support and pilot training are highly unified, eliminating many troubles; Secondly, with strong accompanying support capabilities, refueling aircraft can be deployed together with the attack formation, providing flexible refueling throughout the entire process, avoiding the limitations of previous dedicated refueling aircraft being slow and only able to wait in fixed areas for the fleet to return. However, its disadvantages are equally evident. Firstly, the efficiency is low. The F/A-18F Super Hornet has a huge fuel consumption, and when equipped with refueling pods and auxiliary fuel tanks, the actual amount of fuel it can deliver to friendly aircraft is less than 6 tons, which is lower than that of a dedicated refueling aircraft. Secondly, it consumes fighter jets to take off. Every time a partner tanker is dispatched, it means sending one less fighter jet loaded with missiles, forcing the commander of the carrier strike group to choose between "fuel supply" and "strike firepower". The retirement of dedicated refueling aircraft to the struggling support of fighter jets reflects the development dilemma of the US Navy carrier based air squadron, which is further exacerbated by the F-35C stealth fighter aircraft landing on aircraft carriers. There is a significant difference in performance between stealth fighter jets and non stealth refueling aircraft. Not only does the advantage of refueling the same type of aircraft no longer exist, but non stealth refueling aircraft may also expose the whereabouts of stealth fighter jets when accompanying attacks. Combined with the higher fuel consumption of stealth fighter jets, the fuel supply of "partner refueling" is difficult to support large-scale combat needs. In this situation, the US Navy has launched a research and development project for a new generation of shipborne unmanned stealth refueling aircraft. (New Society)