The U.S. Air Force announced a contract award on May 6 that it will integrate a new 5,000-pound (about 2.3-ton) GBU-72/B ground-penetrating bomb on the B-2 stealth bomber in the future as part of an ongoing upgrade effort to upgrade the B-21 before it enters service. As a replacement for the GBU-28, a 4,000-pound ground-penetrating bomb in the U.S. Air Force ammunition depot, the GBU-72/B's ground-penetrating capability will be increased to more than 50 meters. U.S. military experts say the GBU-72/B's operational targets will be North Korean or Iranian underground nuclear facilities and bunkers. #MCN首发激励计划#
GBU-72/B ground-penetrating bomb
The GBU-72/B ground-penetrating bomb looks like nothing more than a lengthened and thickened 2,000-pound Joint Direct Attack Munition (JDAM). So why does the U.S. Air Force continue to develop a new 5,000-pound GBU-57/B "Bunker Saboteur" ground-penetrating bomb after it already has a powerful 30,000-pound GBU-57/B ground-penetrating bomb? After all, this is not much bigger than the existing 4,000-pound GBU-28 ground-penetrating bomb.
F-15E投掷GBU-28钻地弹
The GBU-28 was developed by the U.S. military during the Gulf War in response to the lack of striking capabilities of the solid command structure in the Iraqi underground at that time. It took only two weeks from the design of this ground-penetrating bomb to the first bombing of Iraq by the US military. Since the US military did not demand much in addition to the hundreds of them purchased by Israel one after another, this type of ground-penetrating bomb was not upgraded much, and was only retained as a large ground-penetrating bomb in the B-2 ammunition depot.
GBU-72/B钻地弹测试效果
However, with the upgrade of the GBU-28's potential targets, this kind of "improvised bomb" that can penetrate about 50 meters of soil or about 5 meters of solid concrete can no longer meet the needs of the US military. In addition, there is also a "gap" between 2,000 pounds and 30,000 pounds in the "ground-penetrating bombs" in the US Air Force ammunition depot, and if you encounter underground facilities that cannot be destroyed by 2,000 pounds but use 30,000 pounds and are very wasteful, then you need a 5,000-pound drill-drilling horse like GBU-72/B.
2021 F-15E 进行GBU-72/B 投掷试验
And the adaptability of the 5,000-pound ground-penetrating bomb is also much better than that of the 30,000-pound class, and the GBU-72/B has completed the first launch test by the F-15E in 2021, which has preliminarily proved that the tactical aircraft can also operate this new 2.3-ton ground-penetrating bomb well. But after all, GBU-72/B is still an unpowered gliding bomb, if the US military wants to strike at underground facilities in the hinterland of other countries, then it is best to integrate it into the stealth aircraft, but the only stealth aircraft that the US military can hold this kind of "big guy" is only B-2. As a result, the U.S. Air Force asked Northrop, the manufacturer of the B-2, to add the ability to use the GBU-72/B ground-penetrating bomb to the upgrade and improvement of the B-2.
Effect of GBU-72/B Ground Penetrating Bomb after installing JDAM gliding kit
In fact, the GBU-72/B is a "regression" from the perspective of guidance mode, because it abandons the laser guidance used by the GBU-28 and is equipped with a gliding kit and GPS, but this can avoid the loss or poor laser signal caused by clouds or smoke, so that its hit rate is improved a lot. And in terms of penetration and destructive power, US military experts say that it has surpassed the GBU-28 by a lot. Therefore, the US Air Force will start development in 2017, and in 2021 it has already achieved good results in the first successful throwing test with the F-15E. This can be regarded as "god speed" in the field of key ammunition development of the US military!
GBU-72/B projectile body without JDAM gliding kit installed
According to the U.S. Air Force's procurement plan, it will spend $36 million to purchase 125 GBU-72/Bs in fiscal year 2022, and in the future, the U.S. Air Force said it may eventually purchase about 2,000 units. Considering that its unit price is about 288,000 US dollars, compared with other important ammunition of the US military, it is already considered a "cabbage price", and it is possible to purchase a large number of them. However, considering that the nuclear facilities, command structures, ammunition depots and other important underground facilities of North Korea and Iran have long been dealt with by the US military's ground-penetrating strike capabilities, and even in recent years, they have been gradually dispersed and deployed to mountainous areas, which will undoubtedly greatly weaken the expected power of the US military's ground-penetrating bombs - even the GBU-57/B "bunker destroyer" weighing 14 tons may not be able to do anything against a "mountain"!
F-15E正在挂载GBU-72/B钻地弹
However, while the GBU-72/B is not capable of striking underground facilities hidden in mountainous areas, it still poses a significant threat to the conventional underground nuclear facilities and other underground targets currently deployed inland by North Korea and Iran. That's why the U.S. Air Force is adding GBU-72/B support capabilities to the B-2 upgrade program. Because of its volume and weight of 2.3 tons, it is already the payload limit of the heavy tactical aircraft in service in the US Air Force, if you want to improve combat efficiency and reduce your own risk, the use of B-2 stealth bombers with a larger bomb load is undoubtedly the best solution.
The B-2 has a built-in bomb bay training device and a 30,000-pound GBU-57/B model effect
The B-2's built-in bomb bay capacity is huge, and it can not only carry 80 conventional bombs of 500 pounds, but even the 14-ton GBU-57/B ground-penetrating bomb can carry two at a time. Although the US Air Force has not announced how many GBU-72/Bs can carry in the built-in bomb bay of the B-2, but with reference to the fact that the B-2 can carry 8 GBU-37 of 4700 pounds, then the 5000 pound GBU-72/B can also carry at least 6-8 pieces. However, even the B-2 bomb load cannot "plow" all the important underground targets of North Korea or Iran at present, after all, there are only a dozen B-2s that can go to the sky at the same time, and even if it is calculated according to the calculation of 2 GBU-72/B per target, the entire B-2 fleet can only kill a few dozen targets - this is still based on the premise that the underground facilities of North Korea and Iran are not deep and the concrete defense layer is not thick.
You must know that GBU-28 reported on the Internet that its depth of destruction of reinforced concrete bunkers is only about 5 meters, and GBU-72/B, no matter how powerful it is, I am afraid it will not reach 10 meters. Moreover, judging from the local pictures exposed by Iran's underground nuclear facilities before, its interior is poured with thick reinforced concrete in key parts, and there is more space for underground facilities, and they are relatively isolated from each other, I am afraid that no matter how powerful GBU-72/B is, it will need more than one to effectively destroy.
As the most important "imaginary enemy" of the US military, China has naturally already listed many important underground nuclear facilities on the mainland as targets for attack. However, we are not the DPRK and Iran, and not only do we have a very large land area, but we also have one of the best comprehensive defense capabilities in the world. Therefore, even if the U.S. military is planning to increase the ability to carry GBU-72/B ground-penetrating bombs for the B-2 or future B-21, presumably those high-level Pentagon leaders will not consider using it, after all, this outdated weapon that almost still requires "volley bombing" will certainly not be used to strike China's underground targets. Besides, if these two countries have developed to the point of starting to strike at each other's underground nuclear facilities, then wouldn't it be nice to go directly to "S3"?