A new dimension in naval aviation burst forth in South Vietnam in 1967. To fight an enemy with an extensive coastline and intricate system of inland waterways and to transform its antisubmarine warfare and search-and-rescue way of thinking, the Navy began to employ helicopters in direct-action missions against enemy ground forces. Those who were thrust into this underdeveloped method of warfare expanded and refined the tactical applications of maritime helicopter operations.
The Mekong Delta is a fertile agricultural region and consequently, highly populated. In 1970 almost half the republic's people lived between the Bassac and My Tho rivers.1 More than 80% of South Vietnam's rice crop is grown in this region.2 The area is swampy and susceptible to flooding in monsoon season, making bridge building difficult, if not impossible. In fact, in many areas of the delta, marine transport is the only feasible mode of travel. More important, because of the overland distance from North Vietnam, equipping communist sympathizers in this region was done most efficiently from the sea.
In addition to stopping infiltration, the goal was to ensure safe passage of friendly shipping along inland waterways, especially the Long Tau River. The primary transportation route between Saigon and the South China Sea, this was a crucial thoroughfare for provisioning U.S. forces. The Vietcong (VC) thrived in this region—labeled the Rung Sat Special Zone by the Military Assistance Command, Vietnam—mining the narrow river and ambushing merchant vessels from densely forested riverbanks.
In 1964, North Vietnam intensified efforts to ship large volumes of small arms and munitions to guerrillas in the south. In February 1965 a vessel containing a large cache of weapons was discovered at Vung Ro Bay. Additional stockpiles found nearby solidified the belief that stronger measures were needed to halt the flow of arms to the VC. Army General William Westmoreland met with Vietnamese officials on 3 March 1965 to initiate a plan to cut off VC maritime supply lines. This became known as Operation Market Time and was assigned to Task Force (TF) 115.
The South Vietnamese Navy (VNN) was tasked to handle enemy junks intertwined with legitimate traffic traveling parallel to the coastline, and the U.S. Navy was to tackle enemy vessels of trawler size or larger that approached South Vietnam from offshore. The inland push by the U.S. Navy expanded rapidly with the establishment of Operation Game Warden in 1965.
To restrain VC movement further within the delta, the Navy began in early 1966 to augment the VNN forces with its river patrol boats (PBRs). The Mark I PBRs (and their follow-on, the Mark II) were 31-foot fiberglass boats powered and steered by turnable water-jet nozzles and capable of making 29 knots. Their basic armament consisted of two .50-caliber guns, one M-60 machine gun, and a 40-mm grenade launcher. On 16 May 1966, a VC force with superior fire power ambushed a group of PBRs. This incident revealed the need for quick response.
The logical solution was to provide close air support (CAS) for the PBRs. Suitable airfields in the delta, however, were sparse. The only runways capable of handling fixed-wing CAS were at Vung Tau and Binh Thuy. Furthermore, the emphasis on the air war in North Vietnam occupied the large majority of U.S. fixed-wing aircraft.
The VC operated primarily at night. High-speed aircraft have a tough enough time picking out details during daylight hours; target identification at night is extremely difficult. Clouds, rain, or smoke also restricted visibility and necessitated slow airspeeds. Cloud cover meant aircraft either would have to fly below the clouds—in antiaircraft artillery (AAA) range—or come in on top and dive through the clouds, which curtailed target acquisition time. Naturally, the VC took advantage of these conditions.
Unlike their fixed-wing colleagues, helicopter pilots could lay down air-to-surface gunfire 20 meters from a known friendly location. These factors and others like them shifted the burden of CAS for the brown-water Navy away from the fixed-wing community and squarely onto the shoulders of helicopter gunships.
As hostilities escalated, the Army was assigned to support the Navy's inland and coastal operations with these gunships. But this joint arrangement was short-lived, because the Navy sought direct control of air operations to support its river patrols. Thus, the Army withdrew and transferred 8 UH-1B "Huey" aircraft to the Navy in 1966 and extended its allocation to 22 by the end of 1967.
Later in the war, the Navy acquired newer versions of the Huey as they became available, including the UH-1C, UH-1K, UH-1L, and UH-1M. The UH-1C (and later models) with its TH-53-L-11 engine, increased fuel capacity, and improved rotor system permitted the Navy to broaden its helicopter missions. Missions such as the airborne movement of Sea, Air, Land special forces (SEALs) played an important role in Operation Game Warden. In addition to covert operation, SEAL insertion/extraction teams were used to reconnoiter riverbanks in advance of PBR missions or to provide sniper fire. The UH-1\L, was unique to the HAL-3 mission because it was an unarmed "slick." This version arrived in time to participate in Operation SEALORDS (Sea, Air, Land, Ocean, River, Delta, Strategy), where its lift capability was useful for carrying SEAL teams. Together with PBR teams, SEAL-laden slicks enabled the brown-water Navy to support the III and IV Corps Tactical Zones' search-and-destroy campaign. The eight slicks built for the Navy transported special warfare personnel on more than 6,000 missions in 1970.3
By late 1965 many operational planners recognized that more rigorous actions were needed to tighten the noose around VC fighters. So on 18 December that year, Operation Game Warden was unveiled. Task Force 116 was charged with implementing Game Warden with the intent of "denying the enemy the use of the major rivers of the Delta and the Rung Sat Special Zone."4 To carry out its mission, TF-116 was assigned 120 PBRs, 20 LCPLs (landing craft, personnel, large), 1 LSD (amphibious transport, dock), 1 LST, and 8 UH-1B helicopters. The Army's 197th Aviation Company provided the Hueys, aircrew, and maintenance support. The first coordinated PBR/Huey mission was conducted on 10 April 1966. To alleviate the complexity of assigning Army helicopters for an extended period in support of naval operations, Navy pilots and crewmen from Helicopter Combat Support Squadron One (HC-1) were brought in to assume the mission. Between June and November 1966, HC-1 established four detachments (numbers 29, 27, 25, and 21) in South Vietnam. The Army crews trained incoming detachment personnel in theater, and then on 30 August relinquished ownership of their UH-1Bs to the Navy. By the end of 1966 the Navy recognized a more specific task structure was needed to expand helicopter gunship operations. Thus, the Navy helicopter community was solicited for volunteers to form a new command dedicated to support riverine action. The Navy began to augment its HC-1 detachments with 80 new volunteers, and on 1 April 1967, Helicopter Attack (Light) Squadron 3 (HA[L]-3 or HAL-3), under the command of Lieutenant Commander Joseph Howard, subsumed all gunship operations from HC-1.5
The command-and-control structure consisted of three major task forces. On 1 April 1966 Commander Naval Forces Vietnam was established. Shortly afterward, Coastal Surveillance Force (TF-115) was the first task force to be implemented. River Patrol Force (TF-116) was put in place concurrently with Operation Game Warden and was the organization to which HC-1 (and subsequently HAL-3) helicopters were assigned. As the U.S. commitment increased, riverine tactics continued to evolve in concert with the Army's shift in tactics toward search-and-destroy missions. On 1 September 1966, Mobile Riverine Force, River Assault Flotilla One, was created and arrived in theater in January 1967 under the command of the Riverine Assault Force (TF-117). The officer in command of the helicopter detachment reported operationally to the River Patrol Group commander while reporting administrational to the HAL-3 commanding officer.
HAL-3 evolved eventually into nine detachments that were scattered throughout the Mekong Delta. These were located at five airfields, three LSTs (a fourth LST was rotated off-station for maintenance), and a Mobile Advance Tactical Support Base called Sea Float. A typical detachment consisted of two helicopters, a lieutenant commander as officer in command, with seven additional pilots, eight air crewmen (door gunners), and an assortment of maintenance technicians. According to Howie Price, a HAL-3 pilot, "Airspace operating areas normally were limited to no more than four 'klicks' (1,000 meters) on either side of a main river branch."6 The HAL-3 detachments prided themselves on their ability to get airborne within three minutes of receiving a call.
The Navy armed its gunships with 2.75-inch folding-fin aerial rockets (FFAR), 7.62-mm flex guns, 40-mm grenade launchers, and lateral-firing cabin-mounted guns. The FFARs were carried in two seven-rocket pods mounted on pylons on either side of the airframe and preferably were fired by the pilot in the right seat. These air-to-surface weapons were outfitted with several different warheads. Rockets equipped with white phosphorous warheads could mark targets, inflict casualties, or start fires. The Flechette round was much loved by pilots but was not used often. The nose-cone of the warhead could be preset to pop off at certain intervals after launch and thus scatter 2,400 one-inch steel projectiles in a variety of patterns and densities. Also available were high-explosive warheads with either impact or proximity fuzes.
One advantage the proximity-fuzed rockets offered over impact-fuzed warheads was that if an impact version hit muddy or swampy terrain, the explosion redirected vertically. High-explosive rockets were preferred over guns in conditions where the aircraft could not get a firing axis that would provide a margin of safety for friendly troops. Oddly enough, in instances of close-contact support, these rockets were more likely to be used than the guns because the ricochets and long ranges of bullets from automatic weapons generated more risk to friendlies than the rapidly decelerating fragments from a rocket. The M151 ten-pound warhead had a lethal radius of around 50 meters.7 The rocket load-out for a routine fire-team mission consisted of one white phosphorous and six high-explosive rockets in each launcher.8
The forward firing guns were mounted above the rocket pods and were commonly called flex guns because they could be fired from the cockpit. Designated the XM-6 weapon system, the twin 7.62-mm, M-60 machine guns were mounted on hydraulic turrets and could be moved through an 80° arc (from 10° on the opposite side, outward to 70° off centerline). The muzzles also could be elevated 10 deg above the horizon or depressed 85 deg downward.
By mid-1970 virtually all the HAL-3 aircraft had had their 7.62-mm flex guns replaced with the M-21 "minigun," a six-barrel Gatling gun capable of firing up to 4,000 7.62-mm rounds per minute.
In place of the twin M-60s, .30-caliber or .50-caliber guns could be used, but the bigger guns required frequent cease-fires to reload.9, 1 To complete the armament, door gunners manned hand-held (or mounted) M-60s on either side of the fuselage. Occasionally, Mark 18 Honeywell 40-mm grenade launchers or .50-caliber guns were mounted in the cabin door.10 The grenade launcher could fire tear-gas rounds, which were helpful in flushing out concealed Vietcong. The chief flaws of the .50-caliber machinegun were that it was not as accurate as the smaller guns and it created large volumes of smoke.
With two pilots sitting in a glass bubble on the nose of the aircraft and two door gunners leaning out either side, the detection capabilities of an experienced crew were considerable. What was more, the shape of the aircraft and orientation of the crew enabled at least one member to maintain visual contact, even in a high angle-of-bank turn. Such visual acuity led to another tactical benefit: Navy helicopter gunships invoked the dread of reprisal on the enemy. For all the benefits the AH-1G Cobra two-water brought to the fight, the Vietcong were quick to recognize and exploit its blind and undefended aft end.11
Seawolves typically flew in a two-aircraft section called a Light Helicopter Fire Team (LHFT). The lead aircraft was the primary delivery platform, with the wingman providing suppression fire and cover. Dash-2 (the wingman) usually positioned himself in echelon and maintained 500 to 1,000 feet of separation. This wide spacing gave the lead maneuvering room and allotted Dash-2 more time to scan for hostile fire. In addition, Dash-2 flew about 100 feet below the lead for a clear field of fire. The team normally would fly at 1,200 feet above ground level.12
Once the target was within a mile of the gunship, the lead aircraft would commence its dive. The LHFT normally would start the profile at 60 knots and accelerate rapidly during the dive, so the pilots had to work efficiently to maintain flight integrity while lining up the target. To make an accurate attack, pilots sought to get as close to the target as possible. On the other hand, to minimize their exposure to hostile fire, the flight needed to maintain airspeed and finish the attack run with sufficient distance and altitude to turn away from the target and pull out of the dive. This was no easy task. By about 800 feet the first rocket salvo was fired, the pilot paused briefly to observe the results, maneuvered the aircraft to refine the firing solution, then fired another salvo. At about 500 feet and less than a klick away, the copilot would commence firing the guns. As soon as the lead finished with his rocket run and began to break away, he provided suppression fire for Dash-2. One technique used at this phase was for the lead to break hard left about 90º and come back 90º right. This would put the target at the two to four o'clock position and allow the flex guns and the .50-caliber to deliver flanking fire. Simultaneously, Dash-2 would roll in to deliver the goods from his rocket pods. This maneuver would be repeated as many times as conditions merited or until the firepower was expended.
One difficulty helicopters confronted in Southeast Asia is a condition known as high-density altitude (DA), which conveyed the effect temperature and humidity had on atmospheric conditions. The hot, moist climate diminished engine output and degraded rotor-blade lift. It was routine to have density altitudes that exceeded 3,500 feet at takeoff. Once forward airspeed is acquired, an overloaded aircraft may be able to maintain level flight on a high DA day. But once forward airspeed is depleted—at the end of an attack run or for landing in a confined area, for example—it may not have sufficient power to arrest the rate of descent. Such conditions curbed take-off weight, and more often than not, ship-based aircraft would depart with only ten rockets and less than a full bag of fuel.
Helicopters require less power for takeoff if they can get a running start. Those stationed at airfields could take advantage of this phenomenon and thus carry heavier loads than those on board the anchored LSTs. Rear Admiral Kevin Delaney, formerly of HAL-3, recalls that because of these weight sensitivities, land-based detachments tended to accrue a lot of former football players.
There were, however, two big advantages in stationing helicopters on board LSTs. First the LSTs typically were closer to the action. Second, the aircrews were stationed with PBR crews. This ensured open lines of communication between teams, particularly with regard to premission briefs and post-mission lessons learned. The LSTs had a draft of only 13 feet and thus could move upriver. They also could provide additional firepower with their rapid-firing 40-mm guns, as demonstrated by the USS Jennings County (LST-846) in May 1968 when she was credited with 17 Vietcong kills.13
HAL-3 was in the thick of things for four years, and 44 Seawolves lost their lives in the line of duty. This small group of naval aviators flew an amazing 78,000 missions. Flight crews averaged 600 combat missions during a 12-month tour. In their first year alone, they fired 155,000 2.75-inch rockets. They had the distinction of flying more combat missions and collectively earned more awards than any other squadron in Vietnam. Among their many awards, the men of HAL-3 received 5 Navy Crosses, 31 Silver Stars, and 156 Purple Hearts.16
One example of the dangers that confronted Seawolf aircrews was an incident that occurred on 9 March 1968. Lieutenant Commander Allen Weseleskey was section leader of an LHFT attempting to rescue two wounded U.S. Army advisors. While attempting to land, the two airships were caught by intense ground fire, which wounded a pilot and crewman in the wing aircraft. After instructing his wingman to depart, Weseleskey was joined by an Army AH-1G gunship. In the face of withering fire from automatic weapons, he maneuvered his helicopter into a tight landing zone, picked up the two advisors, and took off. For his extraordinary heroism that day he was awarded the Navy Cross.17
Perhaps the greatest benefit Navy attack helicopters provided does not appear directly in any statistic. The hard-hitting, dependable reputation that the HAL-3 gunships built lifted Navy morale throughout the delta. Instilled with the knowledge that one of their own was just a radio transmission away, PBR sailors and SEALs were encouraged to push deeper and more boldly into VC territory. HAL-3 was disestablished in March 1972, but the lessons on Navy attack helicopter tactics they left behind undoubtedly will resurface.
1. S. A. Swarztrauber, "River Patrol Relearned," in ed. Frank Uhlig, Vietnam: The Naval Story (Annapolis, MD: Naval Institute Press, 1986), p. 336.
2. John Forbes and Robert Williams, Riverine Force (New York: Bantam Books, 1987), p. 18.
3. Philip D. Chinnery, Vietnam: The Helicopter War (Annapolis, MD: Naval Institute Press, 1991), p. 73.
4. R. L. Schreadley, From the Rivers to the Sea (Annapolis, MD: Naval Institute Press, 1992), p. 228.
5. HAL-3 official website, http://www.seawolf.org/history/asp
6. Howie Price, HAL-3 pilot 1968-69, telephone interview with the author, 26 March 2001.
7. FAS Military Analysis Network, "Hydra-70 Rocket System," http://www.fas.org/man/dod-101/sys/missile/hydra-70.htm, p. 3.
8. Howie Price, telephone interview.
9. Chinnery, Vietnam, p. 73.
10. "LCdr. A. E. Weseleskey, USN, "The 'Seawolf' Helo Pilots of Vietnam," U.S. Naval Institute Proceedings, May 1968, p. 129.
11. Thomas Phillips, "Scramble Seawolves!" from the HAL-3 official website, http://www.seawolf.org/scrmb104.asp, 1997.
12. Forbes and Williams, Riverine Force, p. 68.
13. Swarztrauber, "River Patrol Relearned," p. 398.
14. From HAL-4 Official History, Located at Helicopter Combat Support Special Squadron 4, Naval Air Station Norfolk, Virginia.
15. HAL-3 official website, http://www.seawolf.org/facts.asp.
16. RAdm. Kevin Delaney, USN, speech to Seawolf reunion, 1994.
17. HAL-3 official website, http://www.seawolf.org/navycross.asp.