It is not possible to follow the air war as conducted by naval aviators without understanding the conditions under which they flew and fought. As famed author and historian Stephen Ambrose noted in his many works, war is dominated by factors that constantly dominate the day-to-day life of those involved. They include the enemy, the terrain, and the weather. The enemy included the North Vietnamese, as well as their Communist allies. While effects of poor weather on operations are self-explanatory, the weather of the region wreaked havoc on daily sortie counts and Washington’s attempts to control the air war. The terrain incorporated the operations area throughout the Tonkin Gulf. Unfortunately for the aviators flying missions during Rolling Thunder, these factors could and often did affect the daily routine during the air war over North Vietnam
Before further discussions on the air war, it is essential to discuss North Vietnamese strategy and associated tactics. A reactive and thinking adversary, the North Vietnamese continually adjusted both their strategy and tactics during the course of Rolling Thunder. They continually exploited U.S. mistakes and weaknesses, especially with regard to the ROE. This adaptability, along with help from their Communist partners, ensured their success.
First and foremost in this success was the overall North Vietnamese strategy. The central factor in Hanoi’s strategic thought during the war was the Vietnamese Communist Party’s concept of dau tranh, or “struggle.” The concept was believed to be unique to the Vietnamese because of their tradition of unity and patriotism. Over the centuries, China, Japan, and France had all attempted, unsuccessfully, to exert control over Indochina. Out of this experience, the Vietnamese forged a strong collective identity. The emerging conflict with the United States was seen as a continuation of more than two thousand years of foreign oppression. By using dau tranh, Vietnamese leaders generated support for the cause and reunification. A firm belief in the righteousness of the Vietnamese cause was furthered by the political development of their armed forces. The great success of dau tranh in its forty years of use against France, the United States, and, later, China was twofold: it clouded enemy perceptions and nullified North Vietnam’s opponents’ overwhelming military power. Dau tranh proved highly effective against the United States. It complicated the Johnson administration’s strategy and caused great misconceptions in the United States about North Vietnamese goals and overall strategy, and it forced the United States to fight under unfavorable conditions.1
As Rolling Thunder began in 1965, American aviators fought an air defense system that had come into being only a few years earlier. Following the 1954 Geneva Agreement, the North Vietnamese leadership devoted very little support to their air force and air defenses. The fledgling Vietnamese People’s Air Force (VPAF) had fewer than a hundred aircraft, none of them fighters, and only artillery guns for air defense. In 1963 the VPAF and Vietnamese Air Defense Force merged, creating a combined force, the Air Defense Forces—Vietnam People’s Air Force. Unlike the Americans, who split the air campaign with bureaucratic controls, interservice rivalries, and global commitments, all aspects of North Vietnam’s air defenses became unified under this command, following the concept of dau tranh.
The North Vietnamese defenses began to expand in response to U.S. efforts to collect information under OPLAN 34A. Initial growth focused on radar systems, in part because American efforts in 1964 focused on harassing coastal radars stations.2 U.S. retaliatory strikes following the Gulf of Tonkin incident spurred a marked increase in Hanoi’s air defenses. North Vietnam opposed the first U.S. air raids solely with World War II era AAA units that had been produced by the Soviet Union, China, and Czechoslovakia. These included 100 mm, 85 mm, and 57 mm cannons with limited fire control systems, 37 mm and 23 mm self-tracking guns, and, amazingly enough, several of the feared German 88 mm guns captured by the Soviets in the 1940s.3 By February 1965 American intelligence estimated that almost a thousand antiaircraft guns were deployed in North Vietnam, manned by just five thousand personnel. More notable, however, was the arrival of the first VPAF fighter regiment. MiG-15 and MiG-17 fighters arrived at Phuc Yen airfield from bases in China on 6 August, the day after the retaliatory raids.
By the time President Johnson announced the end of Rolling Thunder, the North Vietnamese air defenses had evolved into a highly integrated network of SAMs, AAA, and fighters. These defenses were manned by about 110,000 personnel, of whom 90 percent were in the air surveillance, missile, and AAA units. U.S. intelligence estimates credited Hanoi with over 150 radar sites, almost 150 SAM sites, over 8,000 AAA guns of all calibers, and 105 MiGs.4 As with any triad, this three-pronged approach proved to be a very capable system. Hanoi could call on any combination of resources to meet the threat, whether it be AAA, SAMs, or fighters. Controlling it all was an extensive radar network providing early warning to the entire air defense system. If any segment took too many losses, the other two segments stepped up their efforts, allowing the third time to reorganize and regroup. This highly organized system forced the United States to develop extensive countermeasures and intelligence-gathering systems that required continuous upgrades to neutralize the North Vietnamese advantage. In this tit-for-tat game, each side struggled to gain and maintain any tactical advantage, however fleeting it was.
Communist support to North Vietnam was a key component of the North Vietnamese strategy. While many Communist governments supported the effort through either men, matériel, or money, the efforts by China and the Soviet Union were vital. The support given the North Vietnamese Air Defense Forces by the Soviet Union was the most significant. Both the United States and the Soviet Union fielded some of their best weapons in the skies of North Vietnam, making it significant to the global balance of power and far different from the war being conducted in South Vietnam. If an American unit defeated a North Vietnamese ground unit in the jungles of Vietnam, it had little bearing on whether or not that unit was capable of defeating a similar Soviet unit in Germany. But if American forces could operate freely in a Soviet SAM environment, there were serious repercussions for Soviet forces in Europe. Likewise, if North Vietnamese MiG-21s could shoot down the latest American fighters on a continual basis, it indicated how American aircraft might fare against the Soviets if war broke out.5
While the Soviets supplied the technology, the Chinese supplied manpower. Between 1965 and 1973 about 320,000 People’s Liberation Army (PLA) troops, both technicians and soldiers, served in North Vietnam. Over five thousand Chinese were killed or wounded, almost all casualties from U.S. air strikes.6 Chinese pilots downed at least nine American aircraft, while Chinese antiaircraft divisions took an additional, but unknown, toll. An additional eighty thousand troops labored to build and repair airfields, bridges, and other transportation routes.7 These numbers are a key but often overlooked aspect. Their presence allowed Hanoi to free an equivalent number of its own men to expand the fighting in the South. Even though the United States intensified its interdiction campaign, the sheer quantity of laborers allowed North Vietnam to increase capacity and improve capability. By the end of 1967, the North Vietnamese transportation system had become less vulnerable to interdiction than prior to the initiation of Rolling Thunder.8 The presence of these Chinese laborers also sent a clear signal to both North Vietnam and the United States concerning China’s willingness to influence or intervene in the ongoing war to its south.
In 1964, as North Vietnam began efforts to improve its air defenses, it asked for assistance from the Soviet Union to create an antiaircraft missile force. By the end of January 1965, preparations were completed, and the first group of Soviet advisors was scheduled to fly to Vietnam to conduct reconnaissance. This plan never came to fruition due to China’s Cultural Revolution, which caused a rift in Sino-Soviet relations before eventually resulting in clashes on Damanky Island in 1969. No Soviet shipments through China to North Vietnam were allowed. The Soviet plan of sending a brigade of twelve missile batteries, a radio-engineering battalion, and two regiments of MiGs was rejected by the Chinese, who insisted that they supply the manpower and training for Soviet equipment. The Soviet Union rejected this proposal.
The problem was resolved after a February 1965 visit to Hanoi by the Soviet leader, Alexey Kosygin. During Kosygin’s visit, the first American strikes of Rolling Thunder occurred. The strikes could not have been timed better. Hanoi leadership used them to their full advantage, instantly requesting the Soviet Union’s help in improving their air defenses with MiGs and SAMs. The Soviets promptly agreed, considering the aid project an emergency effort. Moscow began airlifting equipment, advisors, and, more importantly, Soviet air defense units. Chinese Foreign Minister Zhou Enlai followed the Soviets, visiting Hanoi in March. Because of the rivalry, Zhou told Ho Chi Minh that China opposed the Soviet aid program. Following Zhou Enlai’s warning, Ho Chi Minh challenged Beijing to provide an alternative. The result was parallel Soviet and Chinese military aid to North Vietnam, with each vying to outdo the other in an effort to gain influence over its Communist partner. The North Vietnamese used dau tranh to manipulate both friend and foe alike, sometimes even against each other in order to further their goal of reunification. For the VPAF this meant Russian SAMs and MiG-21 fighters, as well as the Soviet technicians required to train Vietnamese forces. The Chinese supplied MiG-17s and MiG-19s, as well as their own forces. These exchanges in early 1965 created the basis for the North Vietnamese air defenses that the United States faced throughout Rolling Thunder.9
SAMs were instrumental to the increased effectiveness of North Vietnam’s AAA defenses. While the number of aircraft lost to SAMs was never more than a small percentage of the overall totals, the mere presence of this new technology changed American tactics and caused greater losses. Once launched, SAMs disrupted American formations, driving aircraft to lower altitudes as they evaded missiles. At these lower altitudes, small arms and radar-controlled AAA took an excessive toll. Before SAMs were introduced, American aircraft could remain at altitude, above the effective range of even the largest guns.10 American pilots became even more vulnerable to AAA as the North Vietnamese massed guns on an unprecedented scale. Large numbers of guns were placed in small areas such as critical installations and population centers. As Rolling Thunder escalated, North Vietnam continued to increase its numbers of early warning and fire control radars, which in turn increased the lethality of its AAA. While electronic warfare technology eventually degraded the ability of the SAMs, any time a SAM was launched, aircraft were forced to defend with maneuvers. These maneuvers came at a cost of airspeed and altitude, which resulted in increased losses from AAA.
Generally speaking, AAA came in two forms, radar guided and barrage fire. Early warning radars tracked flights coming from Laos or the Tonkin Gulf and before handing targets off to air defense sectors, where they would be engaged using SON-9 (NATO code name Fire Can) fire control radars, which calculated the trajectory of the aircraft and shot along the predicted flight path. But not all North Vietnamese guns were radar controlled. In fact, most were not—and they didn’t need to be. Radar control came at the cost of mobility. It was much better to have a highly mobile force that could be moved to new sites easily. Barrage AAA was more commonly seen, and American tactics resulting from the ROE and the cumbersome targeting processes certainly helped in this regard. With barrage fire, gunners did not need to aim at the aircraft but simply fired into a predetermined block of airspace that aircraft flew through to reach their target. Often, weather and low ceilings further restricted the directions from which American aircraft attacked, making North Vietnamese barrage fire even more effective.
With support from the new Soviet premier, Leonid Brezhnev, North Vietnam began receiving military aid and advisors as it built its air defenses. The aid included the S-75 Dvina (NATO code name SA-2 Guideline) SAM. First deployed to East Germany in 1959, the SA-2 had seen sporadic use since 1960. However, its first real test came in Vietnam. Designed to destroy high-altitude strategic bombers, it was used against smaller, highly maneuverable tactical fighters flying at low altitudes. The North Vietnamese had little choice, because although the Soviets had the S-125 Neva (SA-3 Goa), they were unwilling to supply North Vietnam with their most advanced SAM. One of the most important weapon systems of the Cold War, the SA-2 revolutionized modern air warfare. Its introduction to the skies of North Vietnam kicked off what came to be known as the “Wizard’s War,” which resulted in constant advances in electronic warfare, with each side battling to overcome the other’s electronic weaponry.
North Vietnam activated its first SAM regiment on 7 January 1965. The regiment received the highest national priority; political officers searched the armed forces, universities, and technical schools of North Vietnam to find the best electricians, technicians, mechanics, and engineers to fill its ranks.11 Vietnamese who had studied in the Soviet Union and knew Russian were the first ones selected to attend the training centers, followed by candidates with previous electrical and radio-engineering experience, as well as students. No one with less than eight years of education was permitted to attend.12 Soviet doctrine required four months to train a missile regiment; however, this was shortened to two and a half months. Due to Chinese demands, the number of personnel was also dropped from seventy-five specialists to thirty-six. By May Vietnamese students had begun training on the actual systems, though this training was also cut short in order to deploy the missile systems to Hanoi and Haiphong. Rolling Thunder had begun in earnest, and the systems were desperately needed to help bolster AAA defenses and defend the two cities.
As agreed upon, the Soviets took the lead for missile air defense. They trained North Vietnamese crews in the Soviet Union while sending large numbers of air defense (Protivo Vozdushnaya Oborona Strany, or PVO-Strany) personnel to man ten training centers being formed in North Vietnam. These centers became the core of new SAM regiments. Missiles, launchers, and Soviet advisors from the Moscow and Bako PVO-Strany districts, headed by Gen. Maj. Grigoriy Belov, arrived in late April 1965 to begin training the Vietnamese. The first few Vietnamese SAM regiments were based around Soviet cadres; for example, the 274th Missile Regiment was based around the Soviet 260th SAM Regiment from Bryanks. Soviet officers commanded the regiment, its four launch batteries, and its associated technical battalion.13
It was not until 24 July 1965 that the first American loss to a SAM occurred. While reconnaissance flights had detected SAMs as early as April, there had been no electronic intelligence (ELINT) indicating they were operational until 23 July 1965. On that day, an air force RB-66 electronic warfare reconnaissance aircraft picked up signals from the missile guidance radar. The ROE in place at the time prevented U.S. aircraft from attacking the site before it became operational. The next day, the 236th Regiment, commanded by Colonel Tsygankov, shot down an air force F-4C and damaged three others during a strike on the Lang Chi munitions plant northwest of Hanoi. Because there had been insufficient time to train Vietnamese crews, Soviet personnel actually conducted the engagement. North Vietnamese crews finally conducted a full engagement on their own on 24 August 1965.14
By autumn, a second SAM regiment, the 238th Missile Regiment under Colonel Bazhenov, became operational. The two regiments fielded anywhere from six to twelve missile batteries, which constantly moved between thirty-two prepared sites. Due to the small number of AAA batteries, there was no way to establish an effective, mutually supporting defensive system. After each engagement, missile batteries moved to lessen the chance of destruction.
By February 1966 two more missile regiments had been fielded, the 261st, commanded by Colonel Zavadskiy, and the 274th, commanded by Colonel Fedorov. By 1967–68 Vietnamese officers had gradually taken over regimental command, with a Soviet officer delegated as a technical advisor, although some Soviet officers remained as battery commanders through 1969. Despite North Vietnamese successes with the SA-2, Soviet advisors and technicians continued to serve with North Vietnamese missile units at the battalion and regimental level for the remainder of the war.
Typical SA-2 batteries consisted of four to six missile launchers deployed around a circle. From overhead, crisscrossing supply roads looked like a Star of David, with the missiles at the ends—the telltale sign of the SA-2 layout per Soviet doctrine. At the center of the circle was the SNR-75 (NATO Code name Fan Song) radar needed to guide missiles, as well as communications vans supporting the battery. Most sites had their own early warning radar, a P-12 (NATO code name Spoon Rest). All sites were interconnected and capable of handing off targets to others nearby. Later in the war, P-35 (NATO code name Bar Lock) early warning radars added to this capability. These radars also did double duty, as the air picture they provided was then used to control intercepts of the emerging MiG forces. Because of the conspicuous Star of David pattern, each battery had additional sites that they rotated between. No less than three AAA regiments protected each battery or simulated position.15 SAMs and AAA proved to be a deadly combination, something the Vietnamese and their Communist allies proved time and again. By June 1967 Hanoi was protected by the most lethal air defense network ever assembled. The 365th and 367th Air Defense Divisions had been brought into Hanoi to reinforce the 361st Division. The Air Defense Command had committed ten AAA regiments and five SAM regiments, totaling 60 percent of North Vietnam’s available AAA batteries and 52 percent of its SAM battalions along with the entire VPAF to the defense of Hanoi.16
The fighters flown by the VPAF provided the final critical link in the North Vietnamese Air Defenses. Because of their limited numbers and their pilots’ limited abilities, MiGs were used sparingly. As pilot training continued and capabilities increased, MiGs tended to attack only when the outcome favored victory. Their focus remained intercepting American strike packages and forcing them to jettison their bombs prior to reaching the intended target. As Rolling Thunder progressed, the North Vietnamese fighter regiments became more critical in the integrated defensive network. As losses mounted within the AAA and SAM battalions, MiGs became more active in order to lessen the pressure. Conversely, when fighter regiments suffered setbacks and losses, the AAA and SAM battalions stepped up to fill the void.
The 921st Fighter Regiment arrived at Phuc Yen in August 1964 and was followed by the 923rd Fighter Regiment a year later at Kep. They would eventually be consolidated under the 371st Air Force Division in March 1967. In 1965 the 921st Fighter Regiment consisted of thirty-six MiG-15 and MiG-17 fighters flown into Vietnam from Mengtzu, China. Chinese pilots stayed at Phuc Yen as instructors into early 1965.17 In December more MiGs arrived from China, bringing the total to fifty-three. The Chinese pilots served under the pretense of instructors, though they sometimes engaged in combat. Training fledgling Vietnamese pilots was a gargantuan task, because many of the men had never operated anything more advanced than a bicycle. To train these Vietnamese not only as pilots but as advanced tacticians in jet aircraft was no small feat. There were no tour-of-duty limitations for the Vietnamese pilots. Once they started flying, they flew combat missions until they were killed or they were promoted to training and administrative roles. While the Vietnamese pilots did not keep log books, it was not unusual for VPAF pilots to accumulate six hundred to seven hundred missions during the war.18 The VPAF quickly grew from a poorly organized group of inadequately trained pilots flying antiquated Communist aircraft into a highly effective fighting force capable of holding its own over the skies of North Vietnam.
Chinese influence began to fade in mid-1965 as Soviet advisors assumed a bigger role. This coincided with the arrival of Soviet-supplied MiG-21s in July 1965. From that point on, the Soviets began intensive training of the Vietnamese ground-control intercept (GCI) network. Soviet pilots typically flew the target aircraft, teaching Vietnamese pilots how to perform the intercept. At the same time, the Vietnamese trained with their ground controllers, who were also being trained by the Soviet advisors. The total number of Soviets involved with training, including pilots, controllers, and advisors, never totaled more than thirty men at any given time, and they restricted their activities to training and performing acceptance test flights of the new MiG-21s. However, despite all this effort, Soviet pilots avoided actual combat.19
North Korea also sent pilots to help the North Vietnamese. Unlike the Soviets and Chinese, however, their sole purpose was to fight. The first contingent arrived on 20 September 1966 and eventually grew to thirty-four MiG-17 pilots. Initially deployed to Phuc Yen, the North Korean pilots deployed to Kep in April 1967 just in time to take part in some of the largest air battles of the war. Despite losses, they continued to participate in engagements throughout the remainder of Rolling Thunder, eventually withdrawing in early February 1969.
The VPAF used three different jet fighters throughout Rolling Thunder. These included the MiG-17, MiG-19, and MiG-21, all products of the famed Soviet aircraft manufacturer Mikoyan-Gurevich. The MiG-17, though antiquated by the start of the bombing campaign, remained the workhorse throughout the conflict. The MiG-19 was used in very limited numbers and was only supplied to the Vietnamese after 1968. The MiG-21, however, proved itself a deadly opponent upon its introduction in January 1966. It represented a colossal leap in capabilities for the VPAF, including air-to-air missiles. The MiG-21 could carry two Soviet K-13 (AA-2 Atoll) heat-seeking missiles. The AA-2 was reverse engineered from the U.S. AIM-9B Sidewinder. Besides the fact that it represented an espionage coup by the Soviets, the mere presence of the AA-2 in Vietnam forced a change in American tactics. Because of this capability, the bulk of the VPAF’s air-to-air victories were made by pilots flying the MiG-21, which was at the time the best fighter produced by the Soviets.
Although North Vietnamese MiGs did engage navy strikes, air force missions were more frequently targeted. The reasons for this were twofold. First, the proximity of aircraft carriers to the coast meant that navy aircraft spent less time en route to the target, denying the Air Defense Command sufficient time for the elaborate ground-controlled intercepts needed by MiG pilots. Second, the tactical formations flown by the navy, known as “Loose Deuce,” proved relatively hard to counter. The air force’s rigid formations were dictated by its electronic jamming pods, which made them easier prey for Vietnamese hit-and-run tactics, because if an aircraft broke formation, it lost its jammer protection and disrupted the overall protection of the flight.20 These formations and the long distances flown by the air force from Thailand to North Vietnam meant the North Vietnamese had plenty of time to set up attacks in which MiG-21s attacked unseen from the rear and could usually escape before their presence was known.
The uncertain and unpredictable nature of the Vietnamese weather was a factor that heavily favored the North Vietnamese and significantly improved their defensive capability. Precision weaponry such as GPS and laser-guided bombs that have dominated recent American conflicts did not exist during Rolling Thunder. In order to successfully bomb a target, the pilot had to see it. Any obscuration of the target or the route used to fly and navigate to the target could and often would result in the strike being canceled. During certain months of the year, the weather over North Vietnam posed severe limitations to air operations. During the winter, or the northeast monsoon, which starts in November and lasts until mid-May, the weather over North Vietnam and the Gulf of Tonkin is characterized by heavy clouds and large amounts of rainfall. Conditions are especially harsh when a weather phenomenon known as “crachin” occurs. Crachin is characterized by thick clouds and ceilings as low as 100 feet in combination with fog and persistent drizzle. Conversely, during the summer, or the southwest monsoon from May to October, the skies are generally clear and dry. This is the opposite of the monsoon seasons in South Vietnam and Laos. It is important, therefore, in any discussion of air operations over North Vietnam to keep in mind what weather period was involved.21
During the winter monsoon, cloud cover is usually low, about 6,000 feet, with solid overcast above. For a pilot to acquire the target in such weather, he had to descend through the cloud layer and fly between 4,000 and 6,000 feet, where he became increasingly vulnerable to ground fire. North Vietnamese gunners regularly knew the altitude of the cloud ceilings, so pilots were forced to fly even lower, into the effective range of small arms, to avoid being at a known altitude. The low ceilings also required the use of horizontal or low-angle bombing, which also brought aircraft closer to AAA. Finally, the low ceilings restricted the directions from which American aircraft could attack, making North Vietnamese barrage fire more effective. Under these conditions, strikes into North Vietnam would often be canceled, and the already strenuous task of landing aboard an aircraft carrier became a recipe for disaster.22 Rear Adm. Dave Richardson, who commanded Carrier Task Force 77 (CTF-77) during 1966 and 1967, described how the weather affected the air war: “The nature of the weather in Vietnam was also a vital factor in the interdiction campaign that was never fully appreciated by Washington. With the centralized control of the war from afar, Washington could not keep in touch with the ever-changing weather which often required on-the-scene changes in target and weapon assignments.”23
The weather’s influence on operations cannot be understated. It was often responsible for hundreds of canceled or aborted missions; it delayed launch and recovery aboard the ship, which in turn delayed formation rendezvous; and it prevented aerial refueling or created difficulties for aircraft attempting to rendezvous for in-flight refueling. Poor weather forced aircraft to deviate from planned routes or planned targets, leaving pilots with the option of hitting their secondary target or aborting the mission. Quite simply, the weather was a large factor that played into every mission flown over North Vietnam and was not understood by the civilian leadership controlling the air war from thousands of miles away.
When examining the factors affecting the navy’s air war, the geography of the northern Tonkin Gulf also deserves special consideration. The Communist Chinese island of Hainan dominates the Tonkin Gulf. While launching planes in an already constrained area, the navy was required to honor the 3-mile international limit, further restraining the already crowded waters of the gulf. At 13,000 square miles, Hainan boasted numerous airfields, from which Chinese MiGs harassed and sometimes even attacked navy aircraft. Throughout the war, navy fighters flew combat air patrols (CAPs) to prevent not only North Vietnamese aircraft from attacking the fleet but also Chinese aircraft. These missions were a constant requirement for fighter squadrons whose pilots and maintenance personnel were being worn out by the pace of Rolling Thunder operations.
The Tonkin Gulf also had large amounts of seaborne traffic. Although CTF-77 usually operated more than 100 nautical miles from the coast, it was constantly surrounded by hundreds of small fishing boats and junks. Under the international law of the sea, these vessels often had the right-of-way. Therefore, it was not uncommon for a fishing trawler to cross the bow of an aircraft carrier engaged in flight operations, forcing it to alter course and cause a delay of critical launches and recoveries. The greatest danger, however, came from the early warning capabilities of these vessels. Most boats carried a radio, and within minutes of the navy launching aircraft, these boats would send Air Defense Command in Hanoi information about the number and types of aircraft bound for North Vietnam.24 The Soviets excelled at this practice, and wherever the carrier went, a Soviet “trawler” was always within sight. Known as “tattletale ships,” their ongoing mission was to relay the number and type of aircraft launched. As a reminder of Cold War tensions, the Soviets occasionally attempted to interrupt flight operations by crossing in front of the carrier, thereby forcing it off course. As this all happened in international waters, there was little that could be done to stop it.
Despite the early warning provided by Soviet and North Vietnamese vessels, the Tonkin Gulf did give the navy a tactical advantage not available to the air force. Because aircraft carriers could be positioned close to the shore, little to no aerial refueling was needed for large strikes over North Vietnam. There are several instances of captains sailing their aircraft carriers north, away from Yankee Station, in order to lessen the premission refueling requirements or to give fuel-critical aircraft a chance to make it home safely following harrowing missions. Additionally, the navy strikes could fly extremely low over the water, below radar coverage, and get to their target in a matter of minutes, limiting the time available for North Vietnamese defenses to react. Even when navy aircraft struck as far inland as Hanoi, the time from the coast to the target was much less than the time it took an air force strike group to arrive from Thailand via Laos.25 This became more of a factor later in the campaign as the VPAF grew and trained, eventually allowing them to begin intercepting Rolling Thunder missions more frequently. Unlike the hostile terrain of North Vietnam and Laos, the gulf also provided a safe haven for crippled aircraft. The probability of a successful rescue increased dramatically if a pilot could just make it past the coastline, where rescues could be performed with much less opposition.