Flight of the Intruder

Their assignment, February 26, 1967: Drop mines over Vietnam, something no jet had ever done.

stuball and dobie
Courtesy Dave Cable and Stuart Johnson

What Dave Cable remembers most about that night was the torrential rain. On February 26, 1967, a flight of seven Grumman A-6A Intruders, led by Commander A.H. Barie of squadron VA-35, took off from the USS Enterprise. The A-6s were loaded with Mk 50 and Mk 52 mines, which would be dropped into the Song Ca and Son Giang rivers in North Vietnam in an attempt to stop the flow of supplies and men into South Vietnam.

According to U.S. military officials, as quoted by the Los Angeles Times on February 27, the non-floating mines were meant for sampans and junks, and posed “no danger to deep water maritime traffic.” Hanoi radio, on the other hand, called the mining of rivers “a new escalation of the war by U.S. imperialists.” Either way, it was the first time mines had been dropped from the air since World War II, and the first time mines were dropped from jet aircraft.

Eight A-6s had been scheduled to depart from the carrier, but one aborted on the flight deck; its replacement aborted in flight, and returned to the Marine Air Station at Da Nang, South Vietnam.

“I remember so distinctly our pre-flight,” says Cable (above, right, with navigator/bombardier Stuart Johnson), who was a pilot with VA-35 that night. “The worst part of the flight from my standpoint was sitting on the flight deck, canopy open, in a downpour, soaking wet and cold. And we had to wait an extra amount of time because we had to get the system up and running, and get our inertial platform [navigation equipment] aligned.”

See the gallery below to learn more about this historic mission.


The A-6 crews on the Enterprise (pictured) were told about the assignment the day before. Stuart Johnson remembers, “The air intelligence people showed us where they wanted the mines, and turned it over—somewhat begrudgingly, I think—to the squadron as to how we would get [the mines] there. So the first part of the planning process was taking the plot of the minefields from the intelligence community, and converting that into a flight plan. The second part was when the crews got together and decided ‘This is where we're all going to be’ so we don’t run into each other at night going over the target.”

Rear Admiral Bruce Bremner was a young lieutenant at the time of the mission. “It was relatively uneventful compared to the many strike missions I had flown previously and flew subsequently,” he recalls. “We didn’t fly a complicated, devious approach to the target, but flew straight to the planned release point, flying a little over 400 knots and about 500 feet above the water. I don’t remember the weight or designation of the mines, but I do remember they were like speed brakes and had the aerodynamics of a safe.”

Mines Aboard

Johnson saw the mines being brought on board the Enterprise from the ammunition ships. “They were all packed in wood crates,” he recalls, “and they looked like garbage cans. And we wondered how an airplane could ever get off the flight deck of a carrier carrying those garbage cans.”

D.E. “Moose” Wheelock, a former member of the mobile mine assembly team, later wrote about the 1967 mission for the Association of Minemen. His job was to coordinate the setup to receive the mines and upgrade them for aircraft mining operations. When he arrived on the Enterprise the day before the mission, he met with the Operations Commander, who was very concerned about the arming depth of the Mk 50 mine (the depth at which it could detonate). Wheelock knew that 12 feet was the arming depth, but suddenly wondered about the tidal variations in the rivers. The mission was scheduled for 2200 [10:00 p.m.] on February 26. After learning that high tide, which would occur at 2230, added another 6 feet, the arming depth was changed accordingly.


VA-35 (the “Black Panthers”) had been flying A-6As since September 1965. “The A-6A was the newest airplane in the Navy then,” says Cable, “and the concept of the airplane was marvelous. But sometimes the execution through the computer and the radars gave us some difficulty. That’s why it was great to have a bombardier along, because we certainly wouldn’t be able to do what we did without having the human control and ability to adjust to things not working.”

Day to Night

Typically, the squadron flew two types of missions, recalls Ed Leonard, then a Lieutenant. For daylight missions, he recalls, “We had assigned targets that you would attack from altitude, go in at maybe 1,500 feet, then pop up to 6,000 and then do a dive bomb run.” Night missions at low altitude were also typical. “Most of the ones at night were single plane,” explains Leonard. “And low flying was better to stay out of radar tracking by the SAMs [surface-to-air missiles].”

“Single aircraft weapons delivery at night was something that evolved fairly early in our deployment,” says Cable. “We started out flying night formation, which in itself was pretty scary. This tactic, I believe, was a holdover from World War II and Korea. However, our flight crews, bombardiers in particular, were so well qualified and able to do the navigation and targeting, that it made no sense to fly formation at night. In formation you’re a bigger radar target. You couldn’t fly low, and you couldn’t fly at the maximum performance speed that would keep the crew safe and assure a high probability of being able to get to the target. Most of all, having several aircraft depend upon one lead bombardier negated the expertise of the accompanying bombardiers in a precision bombing attack. Little by little we grumbled, cajoled, and eventually convinced our senior officers that the best way to go was to fly single A-6 sorties—at night and at low-level.”

Mining Mission

On the night of the mining mission, “I remember we had a quarter moon,” recalls Eugene “Red” McDaniel (far right), who was a Lieutenant Commander at the time. “We got the briefing and prepared, and I know the aerodynamics of the mines were something we had not expected. They aren’t very sleek for jet aircraft.” (McDaniel would be shot down in May 1967, and would spend the next six years as a P.O.W. in North Vietnam’s “Hanoi Hilton” and other prisons. He wrote about his experiences in Scars & Stripes.)

“We went ‘feet dry’ [over enemy territory] and were in there, doing what we had to do, maybe three or four minutes, not long,” says Cable (second from right). “We released the mines—thump, thump, thump, thump—wrapped into a hard turn and got out of there, back to ‘feet wet.’ ”

“The nerve-wracking part of it,” says Leonard, “was that we would be going low into a heavily defended target. We’re kind of set up to get shot at. The intelligence center showed lots of flak sites.”

While Leonard doesn’t remember much anti-aircraft fire, others have different memories: “It depends on where you were in the string of planes,” says navigator Stuart Johnson (third from right). “My part of this action terminated when the first mine came off the airplane. We plotted a heading on which to approach, and then we plotted a release point, all done by the computer. Once I got the airplane to that release point and heard the first mine come off the airplane, I was essentially a passenger from there on in. So I took my head out of my radar scope and was looking around. The initial planes that made their runs attracted very little gunfire because it was a total surprise. But by the time the sixth or seventh plane started through, there was quite a bit of anti-aircraft fire, but it was all over our heads. They had no idea we were at 300 feet. They were shooting at 1,500, 2,000, 3,000 feet.”


The entire mission took less than four hours in the air. Cable’s logbook indicates that his total flight time was 1.4 hours, with perhaps five or six minutes over the target.

“Although we were at 300 knots and 300 feet,” says Johnson, “it was not a harrowing mission. We were comfortable flying there; other people, I’m sure, would be terrified. We flew so much at those altitudes that it was not harrowing at all.”

The mission was judged a success. Secretary of State Henry Kissinger would later tell journalist William Safire that if the U.S. had continued to mine rivers and started mining the harbors, the war would have been over in 1970.

In May 1972, President Richard Nixon ordered the aerial mining of Haiphong Harbor, an effort that planted more than 11,000 mines over an eight-month period. In cutting off the enemy’s supply route, the mining helped bring about a peace agreement. “It took us eight years to get permission” to mine Haiphong harbor, said Admiral Moorer, Chairman of the Joint Chiefs of Staff, in Lewis Sorley’s book A Better War. “Afterward not one ship entered or left the harbor until we took up the mines.”

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