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The fireworks didn’t let up for 10 days during the Vietnam War’s most successful aerial interdiction effort against the Ho Chi Minh Trail.

In the pitch-black early morning hours of December 19, 1970, a U.S. Air Force forward air controller—call-sign “Covey”— directed an attack against North Vietnamese trucks moving south on the Ho Chi Minh Trail. At the controls of his Cessna O-2A, Lieutenant John Browning, Covey 281, had lifted off from Da Nang at approximately 2215 hours, headed for the fabled trail. He began a slow climb to the west and leveled off at 8,500 feet. At the Laotian border he gave the traditional across-the-fence radio call, “Panama,” to the tactical radar control center, switched off all outside navigation lights, unsynced his props, then checked in with “Moonbeam,” the airborne battlefield command-and-control center inside an orbiting Lockheed EC-130. Arriving over the trail, Browning took up a heading for Delta 43, a prominent interdiction point at the 90- degree bend in the Xe Kong River near the deserted Laotian village of Ban Bak. From sensor readings the intel types swore there had to be an enemy truck park in the area, and Covey 281 was determined to find it.

In the O-2’s right seat, forward air navigator Captain Norm Monnig broke out his starlight scope and poked it out the open right window to search for any movement on the dark trail 4,000 feet below. He didn’t have long to wait; shortly after midnight Monnig detected “movers.” While Covey 281 radioed Moonbeam with a request for a tactical airstrike, Monnig used the light amplification from his starlight scope to pick out a convoy of 12 trucks running south without lights along a relatively clear stretch of the trail, designated Route 92. A convoy of that size definitely presented a juicy target, so it was a bitter disappointment when the trucks suddenly veered off the main road and disappeared beneath the jungle canopy. The two Coveys knew the convoy had to be somewhere down there in the darkness, so rather than go home empty-handed, they decided to probe around the area with ordnance from a set of fighters approaching Delta 43.

After briefing Iceman Flight, Covey 281 dropped a marker that ignited on the ground in the general target area, crossed his fingers and cleared the fighters in hot. Using the burning log as an aim point, the two McDonnell F-4 Phantoms dumped their heavy loads of MK-82 bombs right on the money. The exploding 500-pounders were always an impressive sight, especially at night, but this time the dark jungle erupted in an old-fashioned fireworks display.

In a matter of minutes the thick foliage had been ripped and splintered away by 28 secondary explosions. Circling overhead, the Covey FACs also counted seven big fires, including two fiercely burning trucks. Browning notified Moonbeam, saying, “You’re not gonna believe what’s going on down here.” Moonbeam replied: “Oh, we believe you. We’re orbiting right over your position and can see the show.” As the O-2 crew watched the jungle burn, neither the Coveys nor anyone else suspected that the fires and explosions at Ban Bak would continue without letup for another 10 days.

The Air Force’s all-out effort to disrupt the flow of weapons, supplies and troops streaming south from North Vietnam along the Ho Chi Minh Trail produced some strange but very effective hybrids. One of the war’s many innovations was the introduction of the forward air controller into the sensitive command-and-control system in Laos’ top-secret war. Air Force commanders inaugurated a program in which FACs flew daily missions over designated sectors of the trail. The FAC became the onscene strike controller and referee.With firsthand insight into the situation, the FAC could work out the political kinks of the airstrike through direct radio contact with Laotian officials, with the orbiting command-and-control center or with the U.S. Embassy in Vientiane.

The program worked so well that beginning in late 1968 Seventh Air Force planners implemented Operation Commando Hunt to place a constant air umbrella over the roughly 2,000-square-mile sector of the trail contiguous to South Vietnam. That section of roads running down the southern Laotian panhandle was code-named “Steel Tiger.” The Coveys at Da Nang were one of the FAC units assigned to work Steel Tiger around the clock, with North American OV-10 Broncos handling day duty and the O-2s fighting at night.

In the lethal airspace above the trail, the low-flying, slow-moving FACs flew against the same big guns that defended Hanoi: murderously accurate 23mm, 37mm and 57mm anti-aircraft artillery—AAA, or “triple-A.” It was a secret war over one of the most remote areas of the world, and it was brimming with weapons. With the 1968 termination of America’s sustained bombing campaign against North Vietnam, called Operation Rolling Thunder, there were virtually no U.S. airstrikes north of the DMZ. Safe from that threat, Hanoi upped the ante by increasing its anti-aircraft inventory along the trail by 600 percent, moving 2,000 of its triple-A weapons from the North to locations in Laos, making the Ho Chi Minh Trail one of the most dangerous and heavily defended stretches of road in the world. A single round from any one of those guns could blow an aircraft to bits—and from what the Coveys observed each day and night, the gunners on the trail had plenty of ammunition on hand.

NVA strength along the trail eventually rose to more than 10,000 anti-aircraft gunners, 60,000 support troops and 40,000 security troops. Clearly the major network for infiltration, the trail could transport 20,000 NVA soldiers a month from the North into South Vietnam. In response, the U.S. escalated its efforts. By the end of the war, combined American air components had dropped more than 3 million tons of bombs on Laos—2 million on the trail—three times the tonnage dropped on North Vietnam.

The story of the aerial interdiction slugfest at Ban Bak first surfaced a few years ago with the 2001 declassification of a document titled “20th TASS After Action Report, Ban Bak: Storage Area Strike Summary, 19-28 December 1970.” The report graphically depicts the ferocity of the combat, from beginning to end.

At dawn on December 19, OV-10 Broncos picked up where Lieutenant Browning and the rest of the Covey night shift had left off. Not only was the burning jungle now bathed in daylight, the battle’s complexion had also changed. A new infusion of enemy gunners near Ban Bak reacted fiercely, hosing FACs and fighters with an unusually heavy barrage of 23mm and 37mm triple-A. Most Coveys were conditioned by regular hampering fire from guns along the trail, but nobody had ever seen the likes of the flak at Ban Bak. An estimated 30 gun positions opened fire against the Americans. By midmorning the sector FAC was reporting, “The stuff’s so thick you can get out and walk on it.”As an added safety measure, the squadron at Da Nang launched a second FAC to fly high cover. His job would be to call out the gunfire, letting the primary FAC concentrate on directing airstrikes.

Flying the second OV-10 mission of the day, Captain Larry Thomas ran through the target briefing with Gunfighter 66 Flight. As he was about to mark the target for the orbiting F-4s, Thomas detected a truck sneaking away from the area through a streambed. Using a quick, practiced movement, he selected the left outboard rocket pod on his armament panel, flipped on the master arm switch and turned on the gunsight. Then he reefed the OV-10 into a near vertical dive toward the smoke-filled jungle below. With the fleeing truck lined up perfectly in his sights, Thomas fired two white phosphorus marking rockets and then yanked the stick back into an eye-watering 5G climbing right turn. He glanced back over his right shoulder just in time to see the white smoke of the first rocket hit short and the second one score a direct hit through the windshield. Jubilant, Thomas yelled into the mike: “Hot damn! Scratch one truck and driver!”

Gunfighter Lead began cackling about a lucky shot, but Thomas was too busy to trade quips. A trio of 23mm and 37mm guns opened up simultaneously, pumping more than 600 rounds at the slow-moving OV-10. No matter how he maneuvered, the guns kept tracking, firing and following him with deadly white and gray airbursts. At one point the high-cover FAC saw that Thomas’ aircraft was totally bracketed and obscured from view by exploding flak. Miraculously, the Covey dished out of the bottom of the ugly cloud without a scratch.

After spending three hair-raising hours over Ban Bak, Thomas turned control over to Captain Eldon R. “Sonny” Haynes. Before he had a chance to work a single set of fighters, Haynes watched through his binoculars as fires on the ground from Thomas’ airstrike touched off several more large secondary explosions. It was becoming clear that the Coveys had found something a lot bigger than just a 12-truck convoy. The target area was by now an approximately one-square kilometer inferno, with many fires and detonations visible in all quadrants. As Haynes studied the destruction, his UHF radio receiver announced the arrival of another set of fighters: “Covey 262, Black Lion Flight at base plus 11. We’ve each got eight MK-82s, 10 minutes of playtime. Gimme a hold down, over.”

In his easygoing Texas drawl, Covey 262 began the briefing that had become second nature to him. As he talked, a navigation needle on Black Lion Lead’s instrument panel homed on Haynes’ voice, pointing directly at the low-flying Bronco. Lead banked his flight 10 degrees to the left and continued homing as the FAC spoke: “Do I have a good deal for you––trucks and supplies right out in the open! Target elevation is 2750. High terrain is 15 miles east, going up to 4550. Wind is out of the northeast at less than 10 knots. There are at least 20 23mm and 37mm guns in the area, all active. If you get in trouble, your best emergency bailout is the high stuff to the east. If you end up on the ground, stay cool, work with me, and I’ll save your butt for mama. One last thing: These gunners are really good and they’re mad, so whatever you do, keep it moving and don’t be predictable.”

As with all of Covey 262’s airstrikes, the attack proceeded like a well-choreographed ballet. Black Lion’s bombs touched off 30 secondary explosions. While navigating through the smoke and clouds, trying to determine the nature of those detonations, Haynes ran into an intense barrage of fire from four 23mm weapons that poured out more than 300 rounds in his direction. Several of the airbursts were so close that the concussion jolted his OV-10. When Haynes returned to Da Nang, the ground crew and several other pilots noted that his face was totally covered with black cordite from exploding flak.

The day- and night-shift Coveys directed 35 flights of fighters against Ban Bak on the 19th, touching off thousands of explosions and drawing hundreds of rounds of anti-aircraft fire. Typical of the bomb dump missions was one flown by Lieutenant Arch Battista and his navigator on the 20th. While expending ordnance from Pepper and Gunfighter 10 flights, Battista dodged almost 200 rounds of triple-A. Yet in spite of the deadly groundfire, the two strikes set off 12 large secondary explosions, 15 medium and 65 small secondary explosions.

A few hours later Lieutenant Browning returned for his second mission against Ban Bak. With Major William Scannell in the right seat, he directed the strike of a single Martin B-57B, call-sign “Spare.” The results included in excess of 500 medium secondary explosions, 30 large secondaries and so many small secondary explosions that they lost count. And the blasts kept coming. On December 21, the sector FAC observed fuel barrels exploding every few seconds over 2½ hours.

During the next three days the Coveys continued to pound Ban Bak. The airborne command-and-control center cooperated by diverting all available strike aircraft to the area, advising the fighters to “Rendezvous with your FAC over the Covey Bomb Dump.” During the night of December 22, Covey 276, Lieutenant Gary Beard, and his navigator, Major Hall Elliott, watched in disbelief as the bombs from Wolfpack 72 Flight ignited a spectacular fireball that reached a height of 2,000 feet. Detonating tracers from the blast shot up to 9,000 feet.

On the 23rd weather socked in the trail, shutting down virtually all bombing missions against Ban Bak. But the sector FACs reported seeing the eerie glow of fires and secondaries reflecting through the clouds shrouding the bomb dump. Anyone rash enough to venture under the low ceilings found that NVA gun crews still seemed well supplied.

Back at the informal party room in the Covey barracks known as the “Muff Divers’ Lounge,” excitement kept building. The restless pilots stood around talking with their hands and comparing strike results, in the best traditions of one-upmanship: “I’ll see your two trucks and raise you three more,” or “I’ll see your five large secondaries and raise you 500 small ones.” There was even a lively debate surrounding reports that NVA gunners were firing red and green tracers in honor of Christmas.

In keeping with the spirit of the season, a Covey had managed to scrounge one of the tree-shaped acoustic sensors normally dropped along the trail to monitor trucks. Several Air Force nurses showed up with an assortment of Christmas decorations and went to work, planting the “tree” in a trash can filled with dirt.

Decorated with tinsel, ornaments and a star, the pathetic-looking holiday display resembled a surrealistic Christmas tree worthy of Salvador Dali. It was the perfect addition to the lounge, which was then doing land-office business generated partly by holiday thoughts of family and friends back in “the World” and partly by the tension surrounding the life and-death struggle at the Covey Bomb Dump.

By late afternoon on December 26, the weather over the trail broke, and pilots began radioing back incredible descriptions. The area around Ban Bak resembled a vast landscape on the surface of the moon. The jungle was gone, bomb craters pitted the black, scorched ground in all directions and smoldering vehicles lay scattered about in twisted, contorted heaps. Through breaks in the clouds the fliers could see the billowing smoke and fires from 25 miles away. And then there was the stench. The smell of burning rubber, fuel and cordite permeated everything––cockpit, flight suit, helmet, eyes, nose and mouth. It was actually possible to taste the smell. Some of the odors were strange and nauseating. The pilots tried not to think about those smells.

For Lieutenant Rick Ottom, the euphoria of three earlier missions against the bomb dump gave way to the grim reality of routine. Tall, slender, introspective and good at his job, even Ottom began to feel the grind associated with missions over Ban Bak. No matter where he directed strike aircraft, their bombs always ignited spectacular secondary explosions. And every time the young Covey rolled in to mark a specific target, the enemy gunners responded with a vengeance. Ottom sincerely believed the missions had become a deadly game, a test of wits and nerve rather than skill. As he pulled off one rocket pass, a pair of 23mm guns opened up with 70 rounds in a classic tail shoot. But this time the play backfired: Tide 71 Flight, holding over the target, spotted the guns and, after receiving clearance from Ottom, blew the positions away with well-placed canisters of CBU-24. In addition to taking out the guns, the exploding bomblets set off hundreds of small secondary explosions and seven sustained fires.

The destruction at the bomb dump continued through the night of December 26, but the morning of the 27th saw a perceptible decrease in secondaries. During the remainder of the day, the Coveys used 13 sets of fighters to destroy seven trucks and 75 stacks of camouflaged supplies.

The Covey Bomb Dump drama finally played out on December 28. During 10 incredible days, Coveys had logged more than 300 hours over one of the most heavily defended targets in Southeast Asia. Flying low and slow, the O-2s and OV-10s had jinked and maneuvered through thousands of rounds of antiaircraft fire without a single loss. By contrast, the enemy on the ground suffered horribly. More than 340 FAC directed fighters destroyed 46 trucks, 10,000 rounds of ammunition, countless drums of fuel and well over 1,000 tons of supplies. During the bombardment, the aircrews counted more than 6,500 secondary explosions and 225 sustained fires. By any standard, the Covey Bomb Dump operation earned its place as the largest and most successful single interdiction effort waged against the Ho Chi Minh Trail.


Colonel Tom Yarborough served in the U.S. Air Force for 28 years, logging more than 1,500 combat hours. During his two tours in Vietnam as a FAC, he earned the Silver Star, Distinguished Flying Cross and Purple Heart. He is the author of Da Nang Diary: A Forward Air Controller’s Gunsight View of Combat in Vietnam, recommended for further reading. Also see his companion piece to this article, “Truck Hunting on the Ho Chi Minh Trail,” in the October 2013 issue of our sister magazine Vietnam, available on newsstands through October 7 or at

Originally published in the November 2013 issue of Aviation History. To subscribe, click here.