After 45 years, scholars are still looking for an answer to the question: Why Vietnam can defeat the B-52?

The North Vietnamese’s complicated air defense system

In early December 1972, the US suspended the signing of the Paris Agreement, Nixon threatened to destroy Hanoi with bombs, forcing Hanoi to “kneel” to accept terms that were favorable for the US at the Paris Conference. From the evening of December 18 to 29, 1972, the United States launched Operation Linebacker II, mobilizing 193 B52 strategic bombers, more than 1,077 tactical aircraft of all kinds. There were also 50 KC-135 aerial refueling aircraft, six aircraft carriers and the most modern warfare equipment. Hanoi, Hai Phong, Thai Nguyen and several other provinces became the target of the attack. Continuously for 12 days and nights, B52 dropped more than 20,000 tons of bombs and ammunition of all kinds. These were the most intense bombing raids of the Vietnam War as well as in the history of the wars.

Vietnam battlefield was the first and only time that saw the failure of the B52 Stratofortress. In the 12 days and nights of fighting, the Vietnamese side claimed to have shot down a total of 81 US aircraft, including 34 B52s.

According to wikipedia, during Operation Linebacker II, fifteen B-52s were shot down, five were heavily damaged, and five suffered medium damage. A total of 25 crewmen were killed in these losses.

S-75 Dvina SAM-2
S-75 Dvina SAM-2

The North Vietnamese’s complicated air defense system

After 45 years, scholars are still looking for an answer to the question: Why Vietnam can defeat the B-52?

Peter MacDonald, an officer in the British Army, in his book “Giap: The Victor in Vietnam” said that, the air defense system that the North Vietnamese created was very complicated and harmful. It was judged by American experts to be comparable to NATO’s sophisticated network to defend Western Europe.

The core of this air defense system was the S-75 Dvina missile, or SAM-2, and the MiG-21 fighter jet. Supporting them were about 4,000 guns and artillery from 12.7mm to 100mm, 2,000 of which were deployed to protect Hanoi and Hai Phong.

S-75 Dvina SAM-2

In Vietnam, S-75 Dvina is widely known as SAM-2, which is the abbreviation of “Surface-To-Air Missile Type 2”. The S-75 is a Soviet-designed, high-altitude air defence system, built around a surface-to-air missile with command guidance. Following its first deployment in 1957 it became one of the most widely deployed air defence systems in history.

Dvina has a mass of 2.3 tons, length of 10.6m, diameter of 0.7m. It carries a 200kg Frag-HE warhead. The S-75 uses a two-stage missile, consisting of a solid-fuel booster and a storable liquid-fuel upper stage. Its operating range is 45km (28 mi), flight altitude is 25,000m, top speed is Mach 3.5.

The SAM-2 missile was useless when jammed too hard

The SAM-2 was equipped with the Vietnamese air defense force in early 1965 and became one of the main weapons to protect Hanoi, Hai Phong and some other key targets against American aircraft.

The most significant improvement of the SAM-2 system in Vietnam is the technical improvements that can deal with both passive and electromagnetic jamming from the US Air Force.

The B-52 is a strategic bomber capable of extremely strong electromagnetic jamming. A group of three B-52s had 45 jammers, rendering the enemy’s radar completely useless. The Escort B-52 was a formation of electronic warfare aircraft, which paralyzed enemy radar systems. The P-12 radar stations of the S-75 missile battalions only received dense noise, sometimes whitening the screen. Most of Vietnam’s radar stations at that time reported that they were heavily jammed, unable to detect the target.

In fact, the SAM-2 missile can destroy the target at an altitude of over 24,000 meters while the service ceiling of the B-52 is only 17,000 meters, and only 10,000 meters when bombing, so the SAM-2 could reach B-52. However, given the powerful jamming ability of US aircraft, the SAM-2 missile was almost useless.

Secrets are revealed

The North Vietnamese immediately set up a Jamming Reconnaissance Team in order to learn about the technical features and tactics of the enemy jamming. They discovered something special, the enemy jammers did not work at a wavelength of 3 cm. In fact, the B-52 had an ALR-18 jammer operating at a wavelength of 3 cm, but was to deal with the MiG-21’s radar, the jamming antenna was directed towards the tail, so, did not affect the ground radar.

For the North, this discovery was extremely valuable. In their hands were equipped with a type of radar working at a 3cm wavelength, the K8-60 radar station for the 57mm artillery, funded by China. The Vietnamese air defense took advantage of this to defeat the B-52.

Although by today’s standards the SAM-2 was obsolete, at the time it was a formidable weapon. Highly maneuverable, the launchers can move half an hour after firing and re-position after 1 hour. This flexibility makes it very difficult to detect. One trick for the Vietnamese army to gain advantage was that the gunmen launched an unguided missile and turned on the radar to control it at the last phase, allowing enough time for the missile lock the target but not enough for the American aircraft’s interceptors.

Another trick was to launch at least two S-75 missiles one after another. The first shot was high, forcing American aircraft to use electronic equipment to evade them. While the defense system is busy, the second missile was fired along the first path until the target was locked and destroyed.

After more than 40 years, the secrets have been revealed, and that is the story of S-75 Dvina of Vietnam. If you are interested in the topic of the Vietnam War, let me know in the comments. It will motivate me to do the next videos.

Thank you for visiting I’m Dung Tran, the person behind all this content. I know some websites are copying my articles. Stop this, or at least respect me by citing the source from Thank you.


Please enter your comment!
Please enter your name here