WHEN THE NORTH VIETNAMESE OUTSMARTED AMERICAN BOMBERS
The Air Force Lost Big in 1965’s Operation Spring High
By MARK CARLSON
On July 24, 1965, four McDonnell F-4C Phantom fighter-bombers of Leopard Flight joined an airstrike against the Dien Bien Phu munitions storage depot and the Lang Chi munitions factory in the northwestern part of North Vietnam. The Phantoms bombed their assigned targets and withdrew to provide cover for the incoming Republic F-105D Thunderchief fighter-bombers of the 80th Tactical Fighter Squadron.
“As we started climbing out of the area after our single pass at the target,” recalls F-105 pilot Capt. Vic Vizcarra, “our mission commander informed the Phantoms that we were departing. We all remained on the same frequency as we climbed and headed south. I was left of Lead, which placed me on the Phuc Yen MiG base side of the flight. Suddenly we heard a call from the F-4s. ‘What the hell was that?’ one of them said.”
Leopard Lead called for others in his flight to check in. Leopards 3 and 4 responded, but 2 was never heard from—blotted out of the sky by a guided missile. The blast also damaged the other three Phantoms in the flight. They were the first victims of the soon-to-be-infamous SA-2 surface-to-air missile, or SAM.
North Vietnamese SA-2 surface-to-air missiles, most often arranged in groups of six, sit on launchers near their radar guidance system housed in a van among a cluster of trucks and huts (upper right). This facility—discovered by an Air Force photo reconnaissance plane—was typical of the SAM sites that Operation Spring High was targeting on July 27, 1965, when disaster struck. (U.S. Air Force)
Four months earlier President Lyndon B. Johnson, intent on preventing North Vietnam from putting its full military weight into an invasion of South Vietnam, had authorized the Operation Rolling Thunder bombing campaign. The bombing began on March 2, 1965, and targeted North Vietnamese transport and communications lines. However, the White House prohibited U.S. air operations in a 10-mile radius around Hanoi. In addition, restrictions were put on target selection in a larger 30-mile radius, which was under the control of the White House. Only Johnson, with advice from administration officials such as Defense Secretary Robert
McNamara, had authority to order any air operations within that area.
The Johnson administration was afraid that a more aggressive bombing campaign would increase civilian casualties and could escalate the war by provoking the Soviets and Chinese. For example, bombers were banned from the entire seaport of Haiphong Harbor because Soviet ships offloaded cargo there. Those constraints would soon manifest themselves in the debacle of Operation Spring High.
The appearance of the SA-2—code-named “Guideline” by NATO and known to the Soviets as the S-75 “Dvina”—came as a rude shock to the West in the early 1960s. Although the U.S. was aware that the Soviets had developed an anti-aircraft missile, the SA-2 exploded onto the world stage when it shot down a Lockheed U-2 spy plane piloted by Francis Gary Powers of the CIA at an altitude of 70,000 feet.
President Lyndon B. Johnson confers with Defense Secretary Robert McNamara on Dec. 1, 1964. They were reluctant to bomb SAM sites near Hanoi fearing it would be an escalation of the war that would draw in China or the Soviet Union. (Getty Images)
The SA-2’s liquid-fueled second stage, 35 feet long and carrying a 440-pound warhead, was launched by a solid-fuel booster and streaked to its target at Mach 3.5, about 2,500 mph. The warhead’s lethal radius was more than 220 feet wide at low altitude but spread out to more than 800 feet above 60,000 feet.
Previously, fighter-bombers like the F-4 and F-105 had been able to avoid small-arms anti-aircraft artillery by flying at altitudes out of range for the Soviet-made ZPU-23 and 37 mm guns, but the high-altitude SAMS, guided by SNR-75 azimuth and elevation radar (NATO code-named “Fan Song”), were an extreme hazard to every American plane.
A month after the start of Rolling Thunder, five SAM sites under construction were discovered inside the 10-mile area of prohibited bombing. The Joint Chiefs of Staff were adamant that the sites be destroyed before they could be completed, but McNamara convinced Johnson to keep the SAM sites on the off-limits list. Between May and July1965 the Joint Chiefs asked the White House no fewer than three times to allow the Air Force and Navy to bomb the SAM sites. Each time they were turned down.
After the shootdown of the Phantom on July 24 by SAMs launched from two new batteries, site 6 and site 7, on the western edge of the 30-mile restricted zone, the Joint Chiefs again urged Johnson to authorize a strike on the SA-2 batteries. At last, the Pentagon prevailed. Johnson gave the order: “Take them out.”
The mission was assigned to four Thailand-based tactical fighter squadrons that flew the supersonic F-105D Thunderchief, known affectionately as the “Thud.” The F-105 was the world’s fastest fighter-bomber capable of nuclear weapon delivery. It could carry 8 tons of ordnance.
Even as planning for the mission, code-named Spring High, progressed, the Johnson administration was concerned that the U.S. operation could lead to increased Soviet or Chinese involvement. McNamara argued that only the SAM batteries that fired on the Phantoms, sites 6 and 7, should be eradicated because Russian advisers working with the North Vietnamese Army at other SAM sites might be killed, incurring the wrath of the Soviet government.
On the morning of July 27, 1965, the pilots of four tactical fighter squadrons woke to begin their mission. They would attack only sites 6 and 7. “So the prior night’s flight planning went up in smoke, and we were left scrambling at the last-minute requirements,” Vizcarra said. The mission start time was delayed into the afternoon.
North Vietnamese troops ready an SA-2 surface-to- air missile for a launch. The SAM’s ability to reach high speeds and a high altitude was an extreme threat to U.S. bombers flying over North Vietnam. (© RIA Novosti / Alamy)
The 12th and 357th Tactical Fighter squadrons, flying out of Korat Royal Thai Air Force Base, were to attack the North Vietnamese 63rd Missile Battalion at site 6. The 80th and 563rd Tactical Fighter squadrons from Takhli (pronounced “Tak-Lee”) Royal Thai Air Force Base would hit the 64th Missile Battalion at site 7.
Each squadron was segmented into three four-plane flights. The Korat flights were named for trees: Pepper, Willow, Redwood, Cedar, Chestnut and Dogwood. The Takhli flights bore automobile names: Healy, Austin, Hudson, Valiant, Rambler and Corvette. A total of 48 F-105s participated in the strike.
Not all of the Thunderchiefs would attack the actual SAM batteries. Some would hit command radar vans, missiles and launchers, while others bombed support facilities and barracks. A portion were deployed to fight possible MiG attacks or held in reserve to cover aircraft that needed to abort their mission. Yet none of the Thuds were assigned to attack the anti-aircraft guns protecting the SAM sites.
Moreover, higher headquarters had the F-105s approaching their targets in a “finger four”—a four-plane flight with a two-plane lead element and a two-plane second element in a formation that looks like four outstretched fingers of a hand. That formation was ill-suited for a low-level, high-speed attack on a fixed site protected by anti-aircraft artillery, Vizcarra explained. “What did they think this was—an air show? One hit could wipe out the whole flight. Four big F-105s flying close together on the deck, nothing like making oneself a bigger target.”
SAM sites 6 and 7 were nestled in the wedge of the delta between the Black and Red rivers about 450 miles from the Thailand bases. Both the Korat and Takhli forces would refuel from orbiting Boeing KC-135 tankers and head into North Vietnam via Laos. The Korat group would approach SAM site 6 from the south, while the Takhli aircraft would fly east and south down the Red River Valley to site 7.
In the Takhli force, a squadron’s first flight carried CBU-2 “cluster bomb units,” or bomblets. Each bomblet, with the explosive force of a large hand grenade, was filled with ball bearings that shot out of the bomblet at high speeds when it struck the ground or some object. When the bomblets were ejected, the 480-knot (550 mph) airstream sent them over a wide area, where they tore through swaths of enemy troops and vehicles. The second and third flights in a squadron were loaded with four BLU-27 napalm canisters.
