The SA-2 surface-to-air missile had a range of about 25 miles and it accelerated to Mach 3.5 while closing on its target. At medium and high altitudes . . it was deadly.

The first SAM sites in North Vietnam were detected in April 1965. US military commanders wanted to destroy them right away. But McNamara refused permission, fearing that Soviet technicians might be killed and the conflict would escalate.

On July 24, 1965, an SA-2 missile shot down a F-4C Phantom . . the first of one hundred and ten USAF aircraft lost to SAMs [ in SE Asia.]

The White House approved a retaliatory air strike. But by the time we got there, the SAM's were long gone. Instead, dummy missiles had been placed at the former site as a " flak trap," and instead, attacking aircraft were lured within range of concealed air defense guns.

In August, US Pacific Command set up operation " Iron Hand," in which Air Force and Navy aircraft would try to destroy or defeat the SAMs. But, Iron Hand did not yet have the necessary tools being developed in a rush USAF project : " Wild Weasel."

Two-seat F-100F Super Sabre fighters were outfitted with Radar Homing And Warning [ RHAW ] gear to detect radar emissions from the SAM's site's fire control. The F-100F was armed with 20MM and rockets to mark or attack the SAM site. SAC Navigator/electronic warfare officers were recruited to fly the Super Sabre's backseats and operate the special equipment. In November, the first Weasels reported to the 388th Wing, at Korat and teamed up with F-105D fighter-bombers for Iron Hand missions. It worked reasonably well, the Weasels found and marked the SAM sites, and the F-105s attacked them with missiles and bombs. The Weasels flew as escorts with F-105D strike flights. When in SAM territory, they moved out in front. The main problem was that the F-100, flying at 400 knots, was too slow. And the F-105s, zooming along at their preferred airspeed of 500 knots, had to weave around behind to keep from overtaking the Weasels.

A number of two-seat F-105F two-seat trainers were promptly modified for Weasel duty. Like the F-100s, they had 20MM cannons. But instead of target-marking rockets, they carried Shrike missiles, with the capability to home right in on the SAM sites' radar.

The first 11 of the F-105 Weasel aircraft arrived in May 1966. And another seven deployed to the 355th TFW at Takhli, Thailand, a couple months later.

Unfortunately, the Air Force was not adding Wild Weasels as fast as the North Vietnamese were adding SAMs. By August, there were more than 100 SAM sites in operation. At first, they were clustered around Hanoi. But coverage soon extended to military and industrial areas, as far south from Hanoi as Vinh.

The Weasels took their toll in destroying the SAMs. But Weasel losses were stiff. And within six weeks, all seven of the Takhli F-105Fs were shot down.

Success against the SAMs improved as the Weasels gained experience and improved tactics. But to personally fly 100 missions over North Vietnam-the number that counted for a full combat tour and a ticket home-was a difficult mark to reach. One Weasel pilot saying emerged : " By your 66th mission . . you'll have been shot down twice . . but picked up only once."

The early concept of Wild Weasel hunter-killer teams to fly around searching out and destroying SAMs did not last long. The early Weasels were too few in numbers. And all of them were necessary to escort the strike forces.

The regular practice was for a four-ship Weasel flight to accompany the fighter-bombers when they went north. Ideally, all four aircraft in the flight would have been full-up Weasels. But there were never enough of them for that. Sometimes only the flight leader was a Weasel.

All Weasel missions were into high-threat areas.

On the other hand, that's where the SAMs were.

The Weasels, went in several minutes ahead of the main strike force to clear a path through the SAMs. " In essence, we would go in high enough to let somebody shoot at us, then go down low enough to get them," said Leo K. Thorsness, leader of the Takhli's Weasels. If the site operators ( 1 ) turned on the tracking radar or ( 2 ) fired a missile, the Weasels would attack.

Each SAM site had five or six launchers, situated in a six-pointed star pattern around a 40-foot ring. The missiles were guided by a Fan Song radar in a van in the ring's center. In addition, it took only 6 hours for the North Vietnamese to pack up the entire site, re-deploy, and quickly become operational elsewhere.

The SAMs weren't effective below 3,000 feet. But the North Vietnamese covered this with anti-aircraft weapons particularly lethal at a closer range.

When the Weasels eluded the SAMs by rapidly diving to lower altitudes, they often became a prime shooting gallery for the enemy anti-aircraft guns.

The SAM sites themselves were usually well-camouflaged and difficult to see before the missile launched. However, when the Weasel aircraft was painted by the beam from the Fan Song, the crew would hear a distinctive crackle of sound in their headsets. They called it the " rattlesnake."

The Fan Song needed about 75 seconds to acquire the target make its calculation then fire the SAM. This gave the Weasels time to home on the SAM's radar and shoot first.

The SA-2's missile range was 17 miles . . about double the normal range of the Weasel's Shrikes. But Thorsness and his EWO, " Harry" Johnson neatly resolved that problem :

" We were consistently outgunned by 10 miles . . until Harry and I came up with the Shrike Toss : Climb to 35,000 feet, plug in burner, pull nose up to 45 degrees-'til nearly stalled out. And we could hit SAMs about 35 miles away with this maneuver. And it was a celebration time."

The next problem was to deal with the oncoming SAM, itself : " The first stage booster that launches the SAM creates a good-sized dust storm on the ground. IF . . you happen to be looking that way when it blasts off, you know that Sam is on the prowl," said Jack Broughton, Takhi vice-wing commander. "After the booster has done its job, it drops off and falls back to earth, leaving the propulsion to SAM's internal rocket power. If you can see the SAM, you can usually escape. It has little, stubby wings and it is going like hell, so it can't turn very well. You can take it on just like another fighter aircraft. "

" And if you force the SAM into a ' commit position ' . . then turn inside the missile . . it will stall out . . then auger in."

At the warning cry of : :

" T-A-K-E I-T D-O-W-N ! "

. . the Weasels went into [ SAM BREAK ] a high-speed maneuvering dive past the fast-rising missile, followed by a sharp pull up and change of direction.

" Sometimes by rapidly descending you can lose the SAM's tracking radar. Or force the SAM to overshoot and pass harmlessly by," said Captain Don Carson, a Weasel at Korat.

" If that does not work, you have accumulated one heck of a lot of airspeed you can use to make a break at the last moment . . and maybe make the SAM miss."

Another tactic, developed by Captain Jerry N. Hoblit at Takhli, was to split the four-ship flight into two pairs. One Weasel element on the left side ahead of the strike force and the other on the right. This allowed them to provide more coverage. Although at increased personal risk.Sometimes the SAM site operators fired their missiles in groups of three. "We came up with a new tactic we called Dr. Pepper and wound up dodging missiles coming at them from 10 . . 2 . . and 4. All at one time," Broughton said. [ Dr. Pepper had a 10, 2, and 4 o'clock clock logo. ]

The Weasels were not only first in . . they were also the last ones out.

Their presence was often enough to intimidate the SAM operators . . make them inclined to turn off their radars. To maintain the SAM suppression, some of the Weasels would remain as a rear guard until the strike departed.

In late 1967, the Weasels upgraded to an F-105G with improved avionics and a better weapon . . a faster more devastating AGM-78 with four times greater range.

The Weasels were less enthusiastic about another innovation-electronic countermeasures jamming pods. The defensive advantages of an ECM pod were offset by the fact that the pod rendered the radar homing and warning gear useless. " And toward the end of our era there, I was given the option of carrying one Shrike and one ECM pod. I had confidence in the evasion tactics we had then developed but less confidence in the ECM pod. So we always went with two Shrikes . . instead of the pod . . for more killing power," Thorsness said

Weasel aircraft, already in short supply, were spread even thinner when some of the F-105Fs were modified for night and all-weather bombing under the Commando Nail program.

Some pilots flew both Wild Weasel and Commando Nail missions. Among those little impressed with the latter concept was Gen. William W. Momyer, commander of Seventh Air Force in Saigon, who would have preferred to use all of the F-105Fs to fight SAMs.

The Weasels, like other aircrews in Vietnam, were hampered by operational constraints. "Knowing that US rules of engagement prevented us from striking certain kinds of targets, the North Vietnamese placed their SAM sites within these protected zones whenever possible to give their SAMs immunity from attack," said Momyer.

"Within 10 miles of Hanoi, a densely populated area that was safe from attack except for specific targets from time to time, numerous SAM sites were located. We could not, however, permitted to strike the SAMs being unloaded and stacked in rows at Haiphong harbort. Sometimes, the Russian ship was still unloading them. But we could not touch the ship. Or the SAMs. Stupid war ! " said Thorsness.

The effectiveness of the North Vietnamese SAM operators declined from 5.7 percent in 1965 to less than one percent in 1968. The toll was further reduced by the intimidation factor ; some SAM crews would shut down their systems for fear of Wild Weasel attack. Unfortunately, US aircraft losses were still high, because the North Vietnamese launched many more missiles each year of the war.

The worst year was 1967, when 3,202 SAMs were fired and brought down 56 American airplanes.

The epic battle between Weasels and SAMs tapered off in 1968 with the halt of US bombing of North Vietnam. When the fighter wing at Takhli was deactivated in 1970, most of the surviving Weasels pulled out of Southeast Asia, and those that remained were consolidated into a single squadron at Korat.

In January 1970, the Weasels began escorting RF-4C reconnaissance aircraft on flights over North Vietnam, but were tightly restricted in the circumstances under which they were allowed to fire on a SAM site. Under the "protective reaction" rules of engagement, a Weasel could not engage until the Fan Song radar was activated against it or an RF-4.

However, the North Vietnamese had upgraded their defenses. They tracked the US reconnaissance flights with long-range radars whose emissions the Weasels could not detect. The Fan Song, netted to these radars, could wait until the last minute to turn on. In one four-month period, some 200 SAMs were launched at US aircraft.

This set up a vast controversy in which Gen. John D. Lavelle, commander of Seventh Air Force, reasoned that the air defense system was thus activated whenever US fighters were present and that a protective reaction strike was justified.

In 1972, it came to light that operations reports had been falsified to indicate that the RF-4s had been fired upon when, in actuality, the "preplanned protective reaction" strike was against targets developed by intelligence reports. General Lavelle was summarily relieved from command, ordered back to the United States, and retired with a two-grade reduction in rank.

The Lavelle imbroglio was still swirling in March 1972 when a large North Vietnamese military force smashed across the Demilitarized Zone in the " Easter Invasion." Suddenly, the war-and the bombing of North Vietnam-was back on.

The resumed air campaign in North Vietnam was named Operation Linebacker. Under President Nixon's "Vietnamization" policy, most of the US ground forces had been withdrawn. In response, the Air Force and Navy, launched an airpower buildup.

In December 1972, the Wild Weasels final mission, escorted the Linebacker B-52s in bomb strikes against Hanoi.

There were some F-105s left at the end of the war, but their day was over. All models of the Thud had taken terrible losses and those not shot down were wearing out. Forty-six Weasel F-105s and two Weasel F-100Fs were lost in combat.

The number of SAMs destroyed is uncertain. "A Soviet general who served with the North Vietnamese air defense forces claimed that they were provided with 98 missile systems and 7,500 missiles and finished the war with 45 sites and 2,300 missiles," said Hoblit, who has collected a trove of data about the Weasels and the SAMs.

To the number, must be added the beneficial effect of suppressing and deterring the SAMs through intimidation of its ground operators. And there's no way to guess how many USAF pilots and crew who lived through the Viet Nam war because of the Wild Weasels courage.

Today, the Wild Weasel mission is performed by specially trained F-16CJ crews, carrying on the Wild Weasel tradition of their comrades in the F-100s and F-105s in combat over North Vietnam.

Weasels of Note Two Weasel pilots from the Vietnam War were awarded the Medal of Honor:

Capt. Merlyn H. Dethlefsen. On March 10, 1967, Dethlefsen was leading the second element of the Weasel flight from Takhli, escorting a large strike force against the Thai Nguyen iron and steel works north of Hanoi in North Vietnam. When the flight leader went down, Dethlefsen took over. His aircraft was hit numerous times and sustained severe damage, but he made five passes against the air defenses, suppressed the SAMs, and destroyed at least one SAM site. He remained in the target area for an incredible 10 minutes in the face of an intense flak barrage.

Maj. Leo K. Thorsness. On April 19, 1967, Thorsness was leading the Wild Weasel flight from Takhli, escorting a strike force headed for the North Vietnamese military complex at Xuan Mai in the Red River delta.

Thorsness and his EWO, Capt. Harold E. Johnson were credited with taking on "most of North Vietnam," including MiGs . . SAMs and . . air defense guns. They shot down a MiG-17 and probably got another MiG ; it was unconfirmed because their gun camera had . . ran out of film. When they had expended their Shrikes and cluster bombs, they hit the tanker. Then armed with just 20MM guns they returned to combat to fly protective cover for air rescue.

Thorsness received the Medal of Honor and Johnson was awarded the Air Force Cross. Eleven days later, on their 93rd mission, they were shot down and spent the rest of the war as POWs.

Fifteen Wild Weasels were awarded the Air Force Cross for action in Southeast Asia: Maj. Robert S. Beale; Lt. Col. Earl G. Cobeil; Capt. John A. Dramesi; Capt. Kevin A. Gilroy; Maj. Gerald C. Gustafson; Capt. Jerry N. Hoblit; Capt. Harold E. Johnson; Lt. Col. James E. McInerney Jr.; Maj. Paul J. Mongillo; Maj. William P. Robinson; Capt. Fred Shannon; Capt. Rowland F. Smith Jr.; Maj. Bruce D. Stocks; Maj. Peter Tsouprake; and Capt. David H. Williams.

Two Wild Weasels from the Vietnam War went on to become USAF 4-star generals. Chuck Horner, air boss in the Gulf War, was a Weasel at Korat in 1967. Joe Ralston, later vice chairman of the Joint Chiefs of Staff and NATO's supreme allied commander in Europe, was at Takhli in 1970.

Air Force Magazine July 2010

Take It Down ! The Wild Weasels in Vietnam [ abridged ]

By John T. CorrellContributing Editor