Hunter-killer tactics in the Vietnam War was a revolutionary approach to aerial reconnaissance and ground attack operations.
The role of the hunter-killer helicopter pilots in this strategy was to combine the efforts of two types of helicopters: one to spot and identify the enemy (the “hunter”) and the other to launch the attack (the “killer”).
Hunter (Scout Helicopters)
Typically, this role was performed by smaller, agile helicopters like the OH-6 Cayuse, nicknamed “Loach” (from LOH, Light Observation Helicopter).
These helicopters flew low and slow, skimming the treetops, allowing them to observe enemy activities, spot enemy positions, or detect signs of recent enemy movement.
They were equipped with observational equipment and sometimes light weaponry, but their primary role was to identify and mark targets.
Killer (Attack Helicopters)
This role was performed by heavily armed helicopters like the AH-1 Cobra, which would circle above the scouts at a higher altitude. Once the scouts identified and marked a target, the attack helicopters would swoop in and neutralize the threat with their arsenal of rockets, guns, and other armaments.
Read More: AC-47 Spooky – From Transport to Terror
The hunter-killer tactic was innovative and effective in the challenging combat conditions of Vietnam, particularly given the dense jungle terrain and the often elusive Viet Cong guerrillas.
The strategy allowed U.S. forces to swiftly respond to enemy threats, combining reconnaissance and firepower in a coordinated aerial package.
However, the close-proximity flying style of the scout helicopters made them vulnerable to enemy fire, and many were shot down or damaged during the conflict.
As the war progressed and anti-aircraft weaponry became more prevalent among North Vietnamese forces, the hunter-killer tactic faced challenges, requiring adaptations in strategy and technology.
While many combat aircraft in Vietnam sought heights and speeds to evade anti-aircraft threats, the pilots of the U.S. Army’s Hughes OH-6A Cayuse helicopters adopted a different strategy: flying low to attract enemy fire, thereby positioning the Bell AH-1G Cobras above them for a counter-attack.
These daring hunter-killer operations ranked among the Vietnam War’s most perilous missions. The mettle of the OH-6 pilots and their aerial observers was continuously put to the test.
Despite many being in their late teens, their survival hinged on impeccable instincts, quick reactions, a fair share of good fortune, and a ton of courage and guts.
Given the extensive range of weapons that could be equipped on helicopters, their impressive resilience to damage, and their adaptability to handle most terrains for takeoff and landing, it’s unsurprising that they were integral to special operations during the war.
Helicopters were indispensable in surveillance, psychological operations, chemical deployment, assaults, and troop insertions. Their unparalleled adaptability was the key to executing such a wide array of missions.
In 1965, the idea of helicopter-based combat forces was in its infancy and largely unproven, with strategies being crafted on the fly in Vietnam.
The term “Air Cav” refers to the airmobile (later called “air assault”) cavalry units of the U.S. Army, particularly those that operated during the Vietnam War.
The concept combined helicopters with traditional cavalry tactics to provide a fast-moving and flexible form of light infantry. The history of the Air Cav in the Vietnam War marked a significant evolution in the way combat operations were conducted, utilizing the mobility and flexibility of helicopters
The U.S. Army initially deployed Bell OH-13 Sioux and Hiller OH-23 Raven helicopters, formerly used for artillery spotting, to reconnoiter ahead of UH-1D Huey squadrons just before air raids. This aimed to gather intel on landing zones and enemy positions.
However, Vietnam’s rugged landscape pushed these already outdated helicopters to their brink. Their limitations were evident: they weren’t nibble enough to evade enemy attacks, nor did they pack enough firepower to be truly menacing.
To address this, UH-1Bs equipped with rocket pods and machine guns were deployed to hover about 600 feet above the scouts and neutralise any potential threats to the impending troop landings.
Yet, the Hueys weren’t swift enough for this role, underscoring the urgent need to update both the scouts and their defenders.
Read More: AH-64 Apache – Overwhelming Firepower
That same year, a solution was emerging. A resourceful engineer from Bell Helicopter was diligently crafting the world’s inaugural attack helicopter.
Bell’s strategic choice to keep this project confidential allowed it to seamlessly integrate into service as an offshoot of the Huey model (refer to “The Birth of the Cobra,” Aug. 2017). By August 1967, the AH-1G Cobra made its debut in Vietnam.
Game Changer to the Hunter-Killer Tactics
The Cobra boasted both speed and lethal prowess. The pilot, positioned in the rear cockpit, could unleash rockets from launchers mounted on the stub wings, while the front-seated co-pilot managed a chin turret equipped with a minigun and a grenade launcher.
Its vast array of firepower include, a mini-gun loaded with 4,000 rounds of 7.62 ammunition, capable of firing between 2,000 to 4,000 rounds per minute.
It’s also equipped with a 40mm automatic grenade launcher, holding 200 to 400 rounds, and is complemented by four rocket pods, housing a collective 52 rockets of diverse specifications.
Distinct from its predecessor, which was designed for troop transport, the Cobra resembled a World War II fighter plane in agility and might.
Read More: Mil V-12 – The Biggest Helicopter Ever
As Jim Kane, from Richmond, Virginia, remarked on his experience piloting AH-1s from 1968 to 1971 in Vietnam, “Flying a Cobra was exhilarating.”
After a selection process riddled with accusations of corporate spying and political bias, the first Hughes OH-6A observation helicopters touched down in Vietnam in December 1967. The Army affectionately dubbed the OH-6As as “Loaches,” short for “light observation helicopters.”
Hunter Killer Helicopters Back to Basics
This aircraft was impressively lightweight with ample power, making it ideal for close-to-ground flights. Its 26-foot main rotor diameter allowed for easy access to tight landing zones.
Uniquely simple for its era, it relied on minimal hydraulics and used its electrical system mainly for engine startups, translating to straightforward maintenance and increased resilience against enemy fire.
However, its thin aluminum exterior was susceptible to small arms fire.
The aircraft’s design allowed it to crumple upon impact, thus dissipating crash forces. Additionally, a robust internal truss shielded vital components—including its occupants. As a result, Loach crews often survived crashes that would have been fatal in other aircraft.
The OH-6 Cayuse helicopter, often referred to as the “Loach” derived from its LOH (Light Observation Helicopter) acronym, played a pivotal role in the hunter-killer missions of the era.
The “hunters,” or Loaches, were outfitted with side-facing radar or infrared sensors that detected heat. These helicopters typically flew close to the ground and maintained slower airspeeds.
Their primary tasks included identifying enemy trucks and gathering intelligence on enemy activities and troop movements.
Upon detecting enemy targets, the Loaches relayed this information to the AH-1 Cobra attack helicopters, also recognised as Huey Cobras.
Acting as the “killers” in these missions, Huey Cobras were heavily armed. Their arsenal often comprised one or two machine guns, grenade launchers (up to two 40-millimeter), a 7.62-millimeter minigun positioned in the nose turret, and a capacity to carry as many as 76 2.75-inch rockets under their stub wings.
As the H-13s gradually retired from service, Loaches began to operate in tandem with Cobra gunships. Typically manned by a pilot and an observer, and occasionally a door gunner, Loaches soared just 10 feet over the canopy, moving at speeds between 45 and 60 mph, vigilantly searching for enemy activity.
Meanwhile, the Cobras, often referred to as “Snakes,” hovered approximately 1,500 feet above, poised to strike based on the intelligence provided by the Loaches.
The Vietnam War presented a unique combat environment for the US forces. Instead of distinct frontlines, the battlefield was a complex tapestry where the Americans needed constant situational awareness.
Hugh Mills, who piloted both Loaches and Cobras between 1968 and 1972, describes the scenario: “Our bases were like isolated islands in our control, with potential enemy territories encircling us in every direction.”
He emphasised the importance of close collaboration between aviation units and ground forces, both American and South Vietnamese, to accurately differentiate friend from foe.
Over time, the primary mission of the Loach-Cobra teams transitioned from securing landing zones to more general reconnaissance and intelligence collection.
Hunter-Killer Pink Teams
Every day at sunrise, crews gathered for briefings on flight destinations and objectives. Commanders dispatched a duo of one Loach scout and a Cobra for backup, termed Pink Teams, to search for enemy camps, bunkers, or other telltale signs.
(The scout teams were labeled White, while Cobras were designated Red, merging the colors to create ‘pink’.
In some regions, Purple Teams – composed of one Loach and two Cobras – were prevalent, with other combinations also seen.) Bob Moses, an observer, recalls, “We flew so near the elephant grass that our downdraft would part it, revealing anyone concealed beneath.”
Moses, drafted at 19, undertook two year-long stints in Vietnam, starting in 1970, and subsequently served as a therapist and administrator for the Department of Veterans Affairs.
Matted grass could indicate recent enemy movement – it would stand upright again after about eight hours of being flattened. Since teams typically operated in specific areas, they became deeply familiar with the terrain, readily noticing any anomalies.
Stained With Blood
Mills elaborates, “We were essentially combat trackers. We’d trace footprints, spot still-smoldering cigarette butts, and even discern the age of footprints based on their appearance.”
Mills recalls, “In most confrontations, we were merely 25 to 50 feet from the Viet Cong when we began firing.” He continues, “I’ve locked eyes with them, seeing the fear and determination up close…many times I would return back to base with my windshield stained with blood. It might sound gruesome, but that’s the proximity we’re talking about.”
As the Loach weaved between trees, the pilot of the overhead Cobra kept vigilant watch, while the gunner took notes on the Loach observer’s communications. When confronted with enemy gunfire, the immediate protocol for Loaches was to retreat, releasing smoke grenades to pinpoint the adversaries for the Cobras to strike within moments.
Even as they retreated, Loach crews, armed with light weapons, didn’t hesitate to retaliate. They employed grenades and sometimes even makeshift explosives. Some of the bolder units even fitted their Loaches with front-facing miniguns.
Cobras, on the other hand, primarily launched attacks with rockets known for their long-distance precision, resorting to the less accurate turret-mounted machine guns or grenade launchers only when at a safe distance from their own troops or when their rocket supply—up to 76 in some cases—was exhausted.
Nearby, four Huey helicopters, referred to as a Blue Team, stood ready either to deploy troops if a valuable target was identified by the Pink Team or to launch rescue operations if a downed aircraft called for it.
Many Army pilots, particularly those who piloted Cobras or Hueys, viewed Loach pilots as somewhat unconventional, and mavericks. “Scout pilots were a unique sort,” remarks Cobra pilot Jim Kane.
He draws a comparison between them and the Tunnel Rats – soldiers who bravely ventured into Viet Cong tunnels, not knowing what dangers lurked ahead.
Romero reflects, “I was brought down nine times and injured three times.” He adds, “A scout pilot’s tenure was typically about six months. Either you faced death, were shot down, or the fear became too overwhelming, leading you to step down”.
Hunter-Killer was Effective
For several years, the hunter-killer strategy proved effective. However, by the time the U.S. began its exit from Vietnam, the tactic had become outdated.
In 1972, as American forces started their gradual pullout, the North Vietnamese Army launched a significant assault known as the Easter Offensive.
Read More: The Bizzare Design of Quadcopters
This offensive marked the war’s first substantial use of Soviet-made, shoulder-fired anti-aircraft missiles. The SA-7 Grail heat-seeking missiles had the capability to bring down a Loach before its crew even knew they were targeted.
While the Cobras flying higher up had a brief moment of alert—spotting the missile’s trail—they were more vulnerable due to their elevated position, making them more conspicuous than the smaller Loaches.
With the introduction of numerous such missiles by the North Vietnamese, both the scout and the attacking helicopters adopted a more covert approach.
As the war neared its end, the transition from the Loach was evident. Despite vocal opposition from crews stationed in Vietnam, the Army began to introduce the Bell OH-58A Kiowa, which ran on the same Allison T-63 engine as the OH-6.
Many in the scout division believed the Kiowa couldn’t match the agility of the Cayuse. However, aerial reconnaissance strategies were evolving. The previously dominant high-low hunter-killer approach transitioned to a level-altitude tactic, with helicopters uniformly skimming the terrain.
Although Kiowas mainly undertook low-risk cargo and liaison roles in Vietnam, post-war they were employed to identify distant targets and direct Cobras (and subsequently, Boeing AH-64 Apaches) to optimal attack positions.
Further reading and many images come from here this great site: www.centaursinvietnam.org
A stark fact stands out: Of the 1,419 Loaches produced, a staggering 842 met their end in Vietnam, with many being shot down or falling victim to accidents from close-to-ground flights.
In a comparison, out of the approximately 1,100 Cobras supplied to the Army, 300 met a similar fate.