An old photo of a helicopter refueling in flight over a river
North Vietnam: Rolling Thunder. By 1968, typical USAF combat rescue packages included strike aircraft, aerial refuelers and rescue helicopters.

U.S. Air Force photo

When Dr. Wayne Thompson began working on his book “To Hanoi and Back”about airpower in the Vietnam War, he anticipated a focus on an unsuccessful air campaign in an unpopular war. But as the historian dove into his research, his work soon evolved into a history of how the Air Force learned lessons that it used to dominate the airspace decades later.

Thompson began paying close attention to the bombing of North Vietnam after he joined the Air Force History and Museums Program a decade after he was an Army draftee assigned to an Air Force intelligence station in Taiwan during the Vietnam War. The more he learned about air operations, particularly late in the war, the more the now retired historian saw his project as a positive side of the Air Force’s role in Vietnam.

“When I began to study these events, I thought I would write about one of the saddest portions of the Air Force’s history, but, gradually, I came to take a more positive view of the Air Force’s experience in Southeast Asia,” Thompson said. “The struggle for Southeast Asia helped to transform the Air Force from an almost total focus on potential nuclear warfare against the Soviet Union into a more varied and flexible force wielding increasingly sophisticated conventional weapons.”


Jets drop bombs from a high altitude
North Vietnam: Rolling Thunder. F-105 crews played a key role in ROLLING THUNDER.

U.S. Air Force photo

Although the Air Force sustained 1,741 combat deaths and lost 2,255 aircraft in the Vietnam War, statistics show a less costly air war than commonly believed. The Air Force flew more than twice the number of sorties as the Army Air Forces flew during World War II, yet had only a 0.4 loss rate per 1,000 sorties, compared to 9.7 during World War II and 2.0 in the Korean War, according to “The Air Force in the Vietnam War,” published by the Air Force Association and the Aerospace Education Association.

The war also provided a proving ground for new technologies, which Thompson described in “To Hanoi and Back.”

“While the bitterness of many who had served in a frustrating war was exacerbated by declining Air Force manpower and budgets, the service pursued new technologies stimulated by the Southeast Asian experience – new fighter aircraft, new radar aircraft, new means of countering enemy radar, new means of operating in darkness, and new guided weapons,” Thompson wrote.

Focused on nukes

Before the U.S. began combat operations in Vietnam, the Air Force was built around Strategic Air Command with a focus on the potential of nuclear war with the Soviet Union or China. It wasn’t well-prepared for a conventional or unconventional war in Southeast Asia, Thompson said. The emphasis shifted from the big bomber aircraft to fighters such as the F-4 Phantom, F-100 Super Sabre and F-105 Thunderchief.

The Air Force wanted to use the B-52 Stratofortress against 94 targets throughout North Vietnam because of its all-weather capability, large bombload and radar, and could have attacked in early 1965 without being hampered by clouds or surface-to-air missiles. Weather in North Vietnam severely limited bombing with any other aircraft from December through March. However, Johnson decided against the Air Force’s recommendation and restricted B-52s to targets such as depots and transportation routes near the border of South Vietnam and Laos.

The president was concerned about the threat of China entering the conflict, based on what happened during the Korean War.


A jet drops a bomb along a river
South Vietnam: A USAF F-100 of the 90th Tactical Fighter Squadron leaves the target area after dropping napalm on a suspected Viet Cong target, March 1966.

U.S. Air Force photo

“The Air Force leadership thought that was silly, that the Korean War analogy was wrong,” Thompson said. “What the Air Force was recommending was to start bombing the targets we knew about quickly, partly because it makes a big difference on the ground, but also because it could make a big difference in Hanoi’s thinking.

“With the B-52s, we could still go in bad weather around-the-clock, and with radar, we could do serious bombing, but the Johnson administration wouldn’t allow us to do that in the heartland of North Vietnam,” he continued. “So that left us to work with the fighters, which were fairly short-range, daylight and fair-weather aircraft.”

Air Force leaders asked to use the fighters to take out North Vietnam’s air defenses to eliminate the potential to develop surface-to-air missile sites. The administration refused because they didn’t want any bombing near the government in Hanoi for political reasons. Pilots were also often frustrated by the limitations on airstrikes, with prohibited zones 10 nautical miles in diameter at Hanoi and 4 miles wide at Haiphong and restricted zones extending 30 and 10 miles wide, respectively

 Start of combat ops

U.S. combat operations in Vietnam began with the Gulf of Tonkin incident in August 1964, when a U.S. destroyer exchanged fire with North Vietnamese torpedo boats. On March 2, 1965, the Air Force’s role escalated with Operation Rolling Thunder, a systematic but frequently interrupted bombing campaign designed to discourage North Vietnamese aggression,interdict supplies heading south and boost morale in South Vietnam.

When President Lyndon B. Johnson halted the bombing of North Vietnam in time for Christmas Eve, many pilots had mixed emotions. The Air Force had established a policy of pilots and electronic warfare officers returning stateside after they reached their 100th mission over North Vietnam until all similarly rated aviators served their tours, said retired Col. Bob Krone, former commander of the 469th Tactical Fighter Squadron at Korat Royal Thai Air Force Base in Thailand.

Halting Rolling Thunder meant an interruption in pilots reaching that magic milestone.


A soldier walks by three helicopters
Secret War: Green Hornets, Dust Devils and Blackbirds on alert at Ban Don, South Vietnam, in July 1970. From locations along the borders with Cambodia and Laos, the US Air Force helicopters covertly inserted reconnaissance teams, which included local peoples like the Hmong, along the Ho Chi Minh Trail.

U.S. Air Force photo

“The U.S. Air Force’s 100 missions over North Vietnam policy was unique in history. It had never been official policy before, nor has it been since the Vietnam War,” Krone said.

After Krone’s 100th mission on June 3, 1966, he was selected as a fighter pilot member of a new office at Headquarters Personnel at Randolph Air Force Base, Texas, and later helped the National Museum of the Air Force at Wright-Patterson AFB, Ohio, create the “100 Mission Exhibit” that opened in 2009.

“The policy was based on the high risks of flying into the North Vietnam air defense system, which was judged to be very dangerous,” he said. “Many pilots did volunteer for second tours, and many of those became casualties.”

To reach their 100th mission, pilots faced MiG-17 and 21 fighters, surface-to-air missiles and a combination of anti-aircraft artillery and automatic weapons. On Nov. 15, 1965, the 469th TFS lost its first pilot two days after it arrived in Thailand. Krone assumed command of the squadron on April 24, 1966, after Lt. Col. Bill Cooper was killed over the Phu Lang Thuong Bridge.

“Those of us who reached the 100 counters were the lucky ones,” Krone said. “Thirty-five percent of all the F-105D/F pilots and electronic warfare officers who flew in the Vietnam War between 1965 and 1968 did not reach the 100th mission.”

The 100-mission policy ended as Rolling Thunder began winding down in March 1968. During the operation, U.S. aircraft dropped 643,000 bombs and inflicted about $300 million of damage on North Vietnam, but lost 900 aircraft and failed to achieve any of Johnson’s strategic objectives.

New approach

In the spring of 1972, President Richard M. Nixon responded to the overt North Vietnamese invasion of South Vietnam by ordering Operation Linebacker I, an aerial interdiction campaign against North Vietnam. After B-52s bombed fuel storage tanks at Haiphong and fighter-bombers hammered a tank farm and warehouse complex outside Hanoi, the Nixon administration extended the aerial interdiction campaign throughout all of North Vietnam.

Linebacker was a considerably less gradual campaign than Rolling Thunder. Bombing throughout North Vietnam disrupted the flow of supplies and reinforcements to the south. Thompson said the use of newly developed laser-guided bombs was effective, especially against bridges. Among the more than 100 bridges destroyed by 2,000- and 3,000-pound laser-guided bombs during Linebackerwere the Thanh Hoa Bridge and Hanoi bridge over the Red River.

In December 1972, Nixon ordered the most intense bombing of the war, Operation Linebacker II, to force the North Vietnamese into negotiations for a cease-fire agreement. Linebacker II intimidated the North Vietnamese by making unprecedented use of B-52s at night and in bad weather to attack rail yards and other targets near Hanoi. By Dec. 29, the 700 nighttime sorties flown by B-52s and 650 daytime strikes by fighter and attack aircraft persuaded the North Vietnamese government to return to the conference table.

In 1972, 200 B-52s were operating in Southeast Asia, up from 60 in Guam and Thailand in 1967. The use of B-52s and laser-guided bombs made a difference in the effectiveness of bombing operations in 1972, Thompson said. Guided bombs could do more damage than hundreds of unguided bombs exploding in the area around a target.

Two decades later,the lessons the Air Force learned in Vietnam proved victorious in the skies above Iraq when Operation Desert Storm kicked off in January 1991. Six weeks of bombing enabled U.S. and coalition ground forces to push the Iraqi army out of Kuwait in four days, with fewer than 200 American Soldiers killed in action, Thompson said.

“With guided bombs, you can make every bomb count,” Thompson said.“We already had rudimentary laser-guided bombs by the end of the Vietnam War,but by the time we got to the Gulf War, we had laser-guided bombs which we could use at night and could be carried by a stealth fighter. That meant we could basically bomb any target that we knew about, no matter if it was in Baghdad or elsewhere, from opening night. That was a big step forward.”