"why the US is still using it?"
I just listed simple reasons,as Crobato point out another reason on that.in fact,There are real background. This is a well-known analyst of the transcript,just for reference.
the article below:
reporter: Not long ago, the Commissioner of the National Assembly has asked the Government to formulate a timetable for withdrawal from Iraq, but Bush rejected. U.S. towed inaction in the Middle East a few years, the loss of an aggressive global expansion momentum, the U.S. military appeared in the development of what?
Song Yichang: The overall impression that the U.S. military status quo is: although some new equipment highlight of the new concept, but the overall sense of the ageing equipment, while supporting an increasingly expensive a few arms manufacturers. With the passage of time, this framework has become increasingly clear. The structure of the U.S. military for the equipment and maintenance of global hegemony, such as from the Air Force, in terms of a variety of voyages transport, and various kinds of strategic and tactical transport aircraft, various types of early warning aircraft, anti-submarine patrol aircraft and electronic warplanes, helicopters and other types, These updated equipment is impossible. Therefore it can only update arms in a "tip of knife" that some, such as fighter jets, but "back of knife", "handle of knife" on the part of only partial upgrade to the aging of the slowdown. As a KC 135 air refueling tanker has already spent 40 years. Expected to reuse 30. In the 1980s production of A may serve to a 10 after 2030.
Afghanistan and
Iraq war, the United States is the budget adopted by the Council 560 billion US dollars, and extrabudgetary spending, according to the calculation of economist Joseph E. Stiglitz is 1400 -1600 billion dollars. The enormous impact of the war the United States consumption of the new weapons developed and updated many of its equipment has been very dated. For example, its retired nuclear warheads, submarines, warships, the nuclear reactor wastes, and nuclear power plant spent fuel, accumulated over several decades, to 10,000 tons, the nuclear waste should be dealt with. However, the United States has dealt with all the money. Apart from the Han Ford plant, the majority of treatment plants were closed. It had hollowing out of the mountains, these wastes are packaged reactor in the mountains inside. But like France, Japan and other countries are dealing with the nuclear waste again after purification,
serve as reactor fuel. So important to the United States after the nuclear deal with the steps has been omitted, would like to be stretched to what extent. Again an old B 52, the final model has been serving for 50 years. "Ohio" class submarines in service 10 has been about a 20. General of the United States, "Los Angeles" class will serve 18-20 years, according to the standards of the United States there are about 22 attack submarines also be retired. Nuclear submarines with conventional submarines are not the same, reactors strong steel structure of atomic radiation caused the aging and become fragile. Pipes, pumps, valves can be easily leakage, the need for regular maintenance of the reactor and other systems. British "Trafalgar" on the leakage of nuclear submarines in the class is an example.
High end
Song: The above is from the point of view of the U.S. military plane equipment. If the vertical view of things, and I think it has three levels: the highest level is aimed at Russia and China for the middle level, the lowest level rather vague, the main target those "rogue states", the most typical of which is that it bogged down in Iraq.
These three aspects of the development requirements of the equipment is different. At the highest level, the United States dare not relax slightly new concept of the development of new equipment, because Russia may at any time to play some surprise beyond the United States. From the United States themselves must also support these military institutions, in the nuclear area, such as the Los Alamos Laboratory and the Lawrence Lifumo. Once the United States to abandon its nuclear weapons development, human re-organization will be very difficult, it can only be launched continuously developed small nuclear bombs, ground-penetrating nuclear bombs, and other items or various new concepts, these nuclear research agency personnel eat. Again Leiti TU, strategic early warning radar it is engaged in, such as in Greenland Toole's "Cobra Dane" radar system from the beginning of the 1960s today, has been updated several times. From Reagan to Bush has not abandoned updated strategic early warning radar, and the TMD and NMD program is, in fact, used the state budget to Leiti TU funding. Leiti TU 90% are military, it is not so strong in the production of civilian areas. TU is a Leiti electronics companies. Is said is to be in the IT and mobile digital products both compete in the market, but it no competitive edge in these two areas, not profit. Leiti TU has been merged with a man named "Beach" small business aircraft production company, the profit is not high. Therefore Leiti TU relies on the military, as long as a reduction of military orders. Face it immediately survival issues. In these circumstances a lot of strange things there: These long-range anti-missile radar foundation sold to Japan first. Then sold to Taiwan, and now it is sold to the Czech Republic. Final are Leiti TU gave the orders. Leiti TU or the "Patriot" missiles, and "Standard" missile manufacturers, the United States also rely on Taiwan and its allies to support the orders it.
In the high-end level, as a result of Iraq war on the defense of the huge consumption, the United States has been insufficient research and development efforts.
In the midrange level. Issue facing the United States is no clear response. Because in the high-end, Russia and the United States rules of the game is basically the same: you have bombers that I have bombers,you have multiple-warhead that I have multiple-warhead,you have a certain amount of a weapons system I also have a certain number of The system, you have the most is aircraft carrier that I strengthens the missiles,both side basically form a broadly balanced. China is not in an arms race got, in the end China to develop its not clear what, in the end this it dare not relax. China and the United States in dealing with Russia's tactics, in addition to sharing the ABM outside, it always threatening China, for example, "no attack on its satellites, equivalent to declaring war if attacked. More the United States launched many satellites and space weapons", and so on, in fact really it is not easy to do.
The United States, the massive and outdated military system like it in the space shuttle. The shuttle also has been used for more than 20 years, launched a liver flutter once, it is likely to the International Space Station, the last of the Soviet Union as the "Peace" space station as a tasteless. The United States also continues the old thinking, in the new context it is not aware of how dry, but it is not enough money. From the mid-1980s onwards, the United States production of civilian ships have been zero, it would retain five large and several small and medium-sized naval shipyards, specializing in the production of warships
