The Heart of the North

April 1, 2014

During the Vietnam War, if a “Thud Driver” took off from either Takhli or Korat Royal Thai Air Base (the two US Air Force F-105 bases in central Thailand), a 400-mile straight line course to the northeast would put them in the midst of downtown Hanoi’s surface-to-air missiles, MiGs, and anti-aircraft gun defenses. Haiphong and the Gulf of Tonkin were 130 miles farther east, and the Chinese border 140 miles farther north.

Despite this, it was seldom that pilots could fly in a straight line between any two points in Vietnam due to aerial refueling, weather conditions, restricted and prohibited locations, and the temperament of defenses.

Those of us who traveled the area on regular combat missions had perhaps the most amazing travel opportunity available anywhere in the world. However, given the Thud loss rate during Operation Rolling Thunder, there was an ever-present anxiety you might not be able to return to relate what you saw. But from the moment 60,000 pounds of Thud, fuel, and munitions banged into afterburner, and you gazed down that long runway toward the Thai rice paddies ahead, there was a lot to see.

Once F-105 flights were joined up, the immediate concern was the KC-135 refueling tankers. Tankers were deployed in cells, designated by color codes, and orbited about 200 miles north of the fighter bases. Thud flights were assigned to specific tanker orbits, and you could count on five elliptical orbits across Laos, and two orbits over the South China Sea. While refueling from the tankers over Laos, you could view the most gigantic, persistent, and severe thunderstorms in the world, whose tops were still boiling upward above 50,000 feet. You could appreciate their menace just trying to navigate around them, and the darker it was, the more awesome their constant lightning became. Excitement bordered on terror and demanded utmost skill when the pulse of war forced pilots to find a tanker inside one of those storms, then hang on for desperately needed fuel.

Zero Visibility

If you were assigned to an overwater tanker cell, you could anticipate the possibility of crowded US Air Force, Navy, and commercial air traffic over the ocean. An unattractive aspect of those tanker cells was the tendency for Air Force single-engine fighters to develop rough running engines when they crossed the coastline outbound, seemingly without fail.

Once off the tankers, if weather was acceptable, the endless green jungles and rugged peaks along the mountains running the length of Laos were spectacular to view. One could look down and easily imagine seeing giant white elephants trooping below.

Precise navigation was of paramount importance, since everything was geared to arriving over a specific spot in hostile territory at your appointed target time. Flying at 500 mph, there was little room for error.

The Thud’s navigation gear included a navigation receiver with an omnidirectional needle and distance to station readout allowing pilots to monitor position in relation to a transmitting station. Aircrew also had a sophisticated onboard Doppler navigation system that allowed them to input their exact position when they taxied onto the end of the runway, then steer to any selected pinpoint target. The Doppler system was quite allergic to jungle heat and humidity, however, abhorred lots of high maneuvering, and had trouble keeping up with fast maintenance turnarounds. It was a good bet that if you could get it working at all, you could depend on it going belly up shortly after you left the tankers but before you got to the target. Flight leaders were usually forced into basic time, distance, and eyeball navigation.

The weather varied between monsoon season and almost monsoon season, and see-for-miles days were not common. Rice farmers burned all crop waste, and a day without a breeze could quickly produce absolutely zero visibility. Thus, the few good landmarks in an empire of rice paddies were very important.

Our Wild Weasels entered target areas to hunt for and kill surface-to-air missile sites, and their radio transmissions were a preamble to the action just ahead. But all the noise sort of bounced off our flight leaders, whose sole task was to get themselves and their wingmen to the pop-up point and kill the target.

Landmarks became increasingly important as you got closer to targets, and the worse the weather the more important they were. Our working area stretched from the Laotian border on the west to the Gulf of Tonkin on the east. We usually approached from the west, to avoid the more intense defenses; thus our first good landmarks were the bends and twists of the Black and Red rivers, feeding the rice lands of the Red River Valley.

Regardless of our target, we drew courses to steer clear of Yen Bai, located on the Red River, 120 miles west of Hanoi. You could immediately tell if you were off course and were too close to the place if the skies lit up with all sizes of flak coming straight up. There wasn’t much to the town, but it was rumored to be the hometown of Ho Chi Minh. They sprayed the skies at any excuse, with nothing resembling tracking.

The prime marker in North Vietnam was the long bony “finger” that ran from northwest to southeast and pointed directly at the heart of Hanoi. It was known as “Thud Ridge” since it identified the unintended end destination of so many of our Thuds and their pilots. Its highest peaks were about 5,000 feet, and its heavy green foliage stood out against the surrounding flatlands.

If we could see Thud Ridge, despite the weather, we knew we could thunder along its sides, be protected from radar from the east, and be zeroed in on downtown Hanoi. That put the pilots in the heart of the North—the box bounded by Haiphong and the Gulf of Tonkin on the east, the junction of the Red and Black rivers on the west, Thai Nguyen on the north, and Hoa Binh on the south. That’s where the US Thud drivers fought against some of the fiercest defenses in the history of aerial warfare.

As we continued to descend inbound to our target, our altitude dropped to 200 to 300 feet, and our speed increased to about 620 mph. Turbulence became intense, so a landmark had to be big and easy to see to be of value. MiGs sent up to pursue Thuds increased the urgency of the sortie, as well as SAMs whistling about and ugly blankets of white, black, and red flak greeting us.

All of our missions were complicated by our maps of North Vietnam, full of seemingly endless little squares and circles representing US self-imposed forbidden areas. The largest no-no was an irregular, 30-mile wide swath across the entire Vietnam-China border where our leaders decided we must not venture.

I will quickly admit when you are lead man for 72 F-105s, each carrying eight tons of bombs and fuel, nibbling on Mach 1, bouncing wildly at 200 feet in the midst of a flak storm, it is very difficult to see and obey those imaginary lines on the ground.

The earphones inside our helmets were a constant, piercing source of reminders that we were involved in a complex, noisy, and violent endeavor. As we approached downtown, the noise tempo was ever increasing.

One of the most bothersome noise sources was our big four-engine headquarters command and communications relay aircraft, orbiting high and far out over the South China Sea. Their radio transmitters and onboard radar monitors were powerful, and they had an amazing capability to block all truly crucial chatter at the wrong moment in combat. As flights were desperately trying to exchange life-or-death warnings, the C2 aircraft could be counted on to transmit an eardrum-shattering MiG warning code of the day such as “Orphan Annie-Orphan Annie,” then a set of map coordinates that meant nothing at the instant, then, “MiGs heading 265 degrees, angels 20 (altitude in thousands of feet), Orphan Annie -Orphan Annie.” They also had code words to warn those of us who might be approaching a restricted area. As we entered the hot areas, we always turned off the IFF radio transponders that transmitted our identification code, so our headquarters monitors could not tell which one of us to turn in for disciplinary action.

Imagine the frustration if the C2 aircraft blocked the airways in the middle of a furball, with your element leader trying to warn you that you had a MiG closing on your tail.

On our normal attacks against sensitive downtown Hanoi area targets we powered along between the green crests of Thud Ridge and the busy MiG airfield of Phuc Yen, located abreast of the southern tip of Thud Ridge. It was utterly frustrating to see the MiGs, sitting ducks in takeoff position on the end of their runway, and not be allowed to splash them. As we passed them heading south, they would take off to the north and turn onto our tails.

A Fiery Trap

The lead pilot on any strike had the responsibility to make the go or no-go call for all flights on that strike sortie. You never wanted to call off a strike just miles from the target, but you also didn’t want to drag your force over an unbelievably fierce storm of enemy gunfire, if weather would prevent them from a good attack pattern ensuring bombs on target. Sometimes you couldn’t make that decision until you were within visual range of the target. Thus, if it was a last second call, and if the target was downtown, passing Phuc Yen was a gut-check moment. You were 25 miles north of downtown, and at 620 mph that gave you 60 seconds to decide: Either attack or break away.

If your target was Thai Nguyen, just north and west of the Ridge, the flak, SAMs, and MiGs were always there to point it out for you. If you could afford a glance at the massive facility you could see a huge railroad complex, with an absurd choke point diminishing four rail lines into one, a steel mill, multiple power generating facilities, a barge factory, a chemical facility, and more. It was perhaps the most heavily defended spot in the history of air warfare. It was easy to see why the commander of Pacific forces had it high on the on the list of 94 targets he wanted destroyed.

The Air Force almost certainly could have done that swiftly at the start of the war, since the North had no MiGs, no SAMs, and limited AAA. But the US decided to wait until it became a fiery trap. Pilots were only allowed to hit it on restricted, stop-and-go strikes.

We had multiple targets in the Viet Tri-Phu Tho area. If the weather was anywhere near decent when we were approaching Viet Tri from the west, it was an easy target to find, since that’s where the Red and Black rivers came together to identify a major thermal power plant.

If you were coming from the east, you could follow the railroad and take your choice of the railroad staging area or proceed a bit farther into the center of town. The town was built around a large, square, four-story gray building, with rows of windows on all floors, known to us as “the hospital.” Previously it was a chemical production facility, but now had huge white circles painted on the walls, with equally large red crosses centered in the circles, to preserve it from attack.

If your course took you near the hospital, the circle and cross were immediately highlighted for you by solid walls of relatively small-arms gunfire coming from all the windows, on all floors, and a solid ring of 37 and 57 mm gunfire outlining the flat, open roof.

It was difficult to get to the power plant without lighting up the hospital.

We were always assigned three targets when we went north. The primary was always hot, since the North knew when we were coming. The secondary often didn’t seem very important, and the third usually fell into the category of what was dubbed a “suspected Vietnamese turnip patch.” If I had to scrub on the primary target, I usually took my troops hunting to either Dien Bien Phu, just a few miles east of the Laotian border, or to the Hoa Binh area south and west of Hanoi on the Black River.

Looking at Dien Bien Phu was always a surprise, since one might expect to see something of the historic battle site where the French were defeated in 1954. There were some primitive looking shacks spread randomly around the crude dirt road that ran west to east. One never hung around to survey the area in detail, but at 500 mph you could make out the bowl-shaped valley where the French were slaughtered and the surrounding higher ground from which the Vietnamese ended French colonial rule.

You could depend on it for an alternate target. We almost always found six to 10 wooden, single-story Quonset hut-like buildings spaced along the dirt road. We would bomb them and they would blow sky high and burn, indicating fuel and ammunition storage. The next time we got weathered out and came back, they would have rebuilt some huts, others would be under construction, and we would repeat the routine.

Get Me Home Tankers

If we got skunked downtown, and the weather didn’t look good out at Dien Bien Phu, I’d take my guys hunting along Route 5, to the southwest toward Hoa Binh.

The area seemed quiet, I never saw any people moving about on the ground, but we always found a target. Once we discovered a significant supply area and got a lot of major secondary explosions. When we came back the next day with a full strike force, we did significant damage.

Quite logically, the Navy provided the workforce for the seaward side of the Hanoi-Haiphong complex, and they didn’t often need any Thud augmentation for their missions. The prime target of Haiphong was always off-limits, ensuring the North of a viable harbor, extensive storage facilities, and access to supply routes south.

The Thuds did have the dubious distinction of responsibility for the small portion of the northeast rail line that remained open to attack.

This link between North Vietnam and China was protected by the prohibitive Chinese border zone to the north and the Hanoi prohibited zone to the south.

That left a 15-mile middle segment that Thuds were tasked to hit with two four-ship flights every morning and two four-ship flights every afternoon. However, there was never anything at the site other than a few boxcars we had destroyed earlier—and devastating flak.

Our directed times on target, altitude, airspeed, and direction of flight were always exactly the same. Every morning a flight out of Korat and a flight out of Takhli would refuel over the water and cross the coastline inbound at the same spot and almost immediately be on a 15-mile run for their lives. The insane practice would be repeated every afternoon.

The North Vietnamese moved every gun they could onto that stretch, and in mid-1967 there was an average of one anti-aircraft gun every 18 feet. The Thuds were like clay pigeons on a skeet range at this point. The only thing to see was how many made it out and how many holes pilots had in their aircraft when they returned.

The “get me home tankers” always flew in what looked like beautiful sky to us as we left the heart of the North. We never could have done the job without them, and when we came out all shot up and desperately needing fuel, they seldom hesitated to come after us. That resulted in formal, career-damaging discipline for some tanker crews that broke rules, but if they knew we needed them, they didn’t care. The sight of a tanker, when you were close to losing it, was one of the best in all of Southeast Asia.

If the weather was nasty, all you saw on the way home was the inside of clouds. If it was clear, and if your fuel was good, you could drop down, take your oxygen mask off, and cruise home. The tougher the mission had been, the longer it seemed to take to get past those hundreds of miles over nothing but scrubby trees and rice paddies.

It was a neat time to think of the ice-cold towel and the thermos of ice water your crew chief had waiting for you once you landed.

Jack Broughton is a retired USAF colonel and fighter pilot. During his time on Active Duty he was the recipient of four Distinguished Flying Crosses, two Silver Stars, and the Air Force Cross. He is the author of two memoirs from the Vietnam War era, Thud Ridge and Going Downtown. His most recent article for Air Force Magazine, “The Blooding of America’s Jet Fighters,” appeared in February 2013.