The United States Helicopter in Vietnam V
HH-53 rescue helicopter.
U.S. SAR tactics in Vietnam evolved from an operation developed by the German Luftwaffe during the Battle of Britain during World War II; they were refined during the Korean War. Four A-1Es called “Sandy” from their call signs, or A-7 jet fighters, broken into a high and low section of two aircraft each, escorted two HH-3 or, after 1967, HH-53 rescue helicopters into the Pickup Zone (PZ). The helicopters and two escorts orbited out of range of antiaircraft fire. The high section of fighters reconnoitered the site to determine enemy resistance and attacked antiaircraft weapons in the vicinity. The leader then called in the first helicopter with its two escorts. The second helicopter orbited out of danger, ready to replace the first if it was shot down or damaged. Many times the alternate helicopter swooped in to rescue both the downed helicopter crew and the object of the initial rescue mission. On several occasions, several U. S. aircraft and men were lost attempting to rescue downed airmen.
The helicopter most identified with U. S. long-range SAR operations in SEA first entered service as an ASW helicopter with the U. S. Navy. On March 11, 1959, Sikorsky Aircraft Corporation test pilots lifted off in the S-61, or H-3 Pelican, later known as the Sea King. The twin-engined, all weather Pelican became operational with the U. S. Navy in June 1961. The H-3, although designed primarily to detect, classify, track, and destroy enemy submarines, rapidly became a multipurpose ship or land-based aircraft with Navy, Marine, and USAF units. Powered by two GE T58-GE-10 1,250- horsepower turboshafts, soon upgraded to 1,400 horsepower, the H- 3 cruised at an airspeed of 120 knots to a maximum range of 542 nautical miles and reached a service ceiling of 14,700 feet. The H-3 had a maximum gross takeoff weight of 21,000 pounds, with the capability of a 6,000-pound slingload on some models.
Of conventional design, the Sea King’s five-bladed main rotor system measured 62 feet and its fuselage 54 feet, 9 inches. Designed for overwater flights the H-3 possessed emergency amphibious capabilities. The H-3 carried a crew of four and up to twenty-eight passengers in its transport configuration. For ASW operations the helicopter crew usually consisted of two pilots, two to three sensor operators, and up to three passengers. Dubbed the “Jolly Green Giant” by rescued aircrewmen, the USAF SAR version of the HH-3 usually carried two pilots, a door gunner, a parajumper (PJ), and a flight engineer who doubled as the rescue hoist operator. In 1967 two USAF Air Rescue and Recovery Service (ARRS) HH-3s demonstrated the viability of air refueling of helicopters by self-deploying from the United States to France in a flight of almost thirty-one hours (Pember 1998, 49).
Sikorsky produced two basic models of the S-61, the original with a watertight hull, which Navy personnel called “Big Mother,” and later, the elongated version with aft cargo doors and a loading ramp for larger cargo. The United States, Great Britain, Canada, Japan, Italy, Spain, Egypt, and Malaysia used several variants of the Sea King: search and rescue HH-3 and SH-3D also used to pluck U. S. Apollo astronauts and their space vehicles from the ocean after splashdown, ASW SH-3, tactical transport CH-3, mine sweeping RH-3, VIP transport VH-3 (used by the U. S. Marines to transport the president), special operations MH-3, and commercial transport helicopter. Armament included a dipping sonar, sonobuoys, magnetic anomaly detectors, two MK 46 torpedoes for ASW, and at least two 7.62-mm door-mounted miniguns on SAR helicopters for selfprotection. The aircraft contained cockpit instrumentation for allweather operations, including both search and weather radars. Later models included Doppler radar navigation systems. In the early 1990s many Sea Kings received upgraded T-58-GE-402 1,500- horsepower engines and global positioning systems (GPS). The USCG HH-3F had the capability to fly 300 miles, hover for twenty minutes, and return to base with fuel in reserve.
Sikorsky built more than 1,100 S-61s, while Westland, Mitsubishi, and Agusta manufactured over 400 versions of the H-3 under license. Westland installed a pair of Rolls Royce Gnome H. 1400 turboshafts and a Louis Newmark Mk 31 automatic flight control system in the British Sea Kings. The RN initially ordered fifty-six HAS1 Sea Kings, with 700(S) Squadron receiving the first for test and evaluation in August 1969. Testing resulted in the more powerful HAS2, and the HAS5 with a longer cabin to accommodate the Sea Searcher radar. Westland provided the Egyptian Air Force with a twenty-one-seat Sea King utility transport, minus the external floats, called the “Commando.” The British Royal Marines also ordered this version as the HC4, which conducted extensive combat operations in the Falklands War.
Westland also produced a completely self-contained SAR helicopter that carried a crew of four, nine stretchers, a weather/search radar, smoke and flare dispensers, a flight director system with an auto hover mode, and folding blades for shipboard storage. The RAF made use of this version as the HAR Mk3 and the West German Navy as the Mk 41. Westland exported Sea King variants to India, Norway, Belgium, Pakistan, Australia, and Qatar.
In 1962 the U. S. Marine Corps awarded Sikorsky Aircraft a contract to design and build a new all-weather assault transport helicopter. The S-65, designated the CH-53A Sea Stallion, made its first flight on October 14, 1964, and in 1966 it entered service as the Marine Corps’s heavy lift helicopter, as well as replacing the H-3 as the primary USAF SAR helicopter. The Navy also purchased the Sea Stallion to bolster its ASW and SAR operations. Twin T64-GE-6 turbines powered a 79-foot, seven-bladed main rotor that turned above a 73-foot, 4-inch fuselage, designed for emergency water landings. The tailboom supported a tall vertical fin, which in turn supported a horizontal stabilizer attached to the starboard side and a four-bladed tailrotor mounted on the port. Capable of carrying a 14,000-pound load, which might include thirty-eight troops or twenty-four stretchers and three or four medical attendants, the CH-53 “Super Jolly Green Giant” could also accommodate fifty-five passengers with center seating installed. In one emergency situation in Vietnam the CH-53 lifted off with seventy-five Marines aboard. Large rear doors and a ramp facilitated loading either wheeled or palletized cargo.
Designed with a flight direction system and folding blades for shipboard or land-based operations, the big machines soon earned their own distinctive place in aviation history. In August 1970 two CH-53s assigned to the U. S. Air Force Air Rescue and Recovery Service (ARRS), using integral aerial refueling systems, completed a nonstop flight across the Pacific Ocean. The same year the United States used HH-53As in the daring raid on the Son Tay prisoner of war camp, only 23 miles outside Hanoi. Although the pilots and Special Forces troops executed a perfect raid, the NVA had previously moved the prisoners to another location. Variants of the helicopter include the HH-53A/B, HH-53C, CH-53D, RH-53D, CH-53G, and HH-53H. Sikorsky Aircraft built a total of 412 Sea Stallions with an additional 110 built in the Federal Republic of Germany. Austria, Iran, Japan, and Israel also employed variants of the CH-53. Sikorsky engineers later used the S-65 as a basis for developing the three-engined CH-53E Super SeaStallion/MH-53E Sea Dragon.
The Sikorsky Aircraft S-64, which first flew on May 9, 1962, was the last Sikorsky project in which Igor himself was personally involved. It was a company-funded “flying crane” designed to lift a minimum of 10,000 pounds; Pratt & Whitney T73-P-1 4,500-horsepower engines turned the 79-foot, 6-inch six-bladed main and 15- foot, 4-inch four-bladed conventional tailrotors. Final versions of the helicopter could carry a maximum load of 22,800 pounds. Able to reach a top speed of 111 knots, the large aircraft had a service ceiling of 13,000 feet. Resembling a large insect, the machine sat on an extended stiltlike landing gear that allowed the helicopter to straddle large, palleted cargo loads, or a “people pod” capable of holding forty-five infantrymen or twenty-four litters and fifteen seated passengers. The helicopter could also transport pods containing a mobile headquarters or field hospital. Two pilots sat side by side in the forward flight deck, and a third pilot sat in a lower, rear-facing cockpit that allowed him to fly the aircraft during slingload operations.
It was first delivered to the West German Defense Ministry in 1963, and the U. S. Army ordered six of the machines in June 1963; they eventually bought ninety-seven CH-54 Tarhees between June 1964 and 1972, the last being retired in 1993 from the 113th Aviation Company of the Army National Guard. The CH-54 set several international records, including a time-to-climb record and, in 1965, a world record by lifting off with ninety persons aboard, including eighty-seven combat-loaded paratroopers of the 82d Airborne Division. During the aircraft’s service in Vietnam, in addition to a gamut of heavy lift missions in support of U. S. and RVN operations, the “flying crane” recovered 380 downed aircraft. The “Sky Cranes” continued flying in civilian service, fighting forest fires, and in construction, remote oil exploration, and logging operations.
During the Vietnam War the success of U. S. helicopters radicalized modern warfare. Generals and admirals the world over realized that the helicopter had become an integral, and indispensable, element of war planning. Boeing CH-47 Chinooks, Sikorsky CH-54 Tarhees (Skycranes), CH-3 Sea Knights, and CH-53 Sea Stallions magnified the combat versatility of units in Vietnam by lifting towed 155-mm and 8-inch artillery pieces to remote firebases that provided fire support for infantry units moving into contact. Helicopters inserted large numbers of infantrymen and Marines onto precarious mountaintop LZs and, employing a long rope ladder that dangled down through the trees, delivered Rangers and Special Forces into triple canopy jungles. Outlying firebases and Special Forces camps relied on frequent resupply from U. S. workhorse helicopters. Airmobile units used helicopters to preposition fuel and ammunition for future operations. Forward Area Refueling Points (FARPs) reduced the turnaround time for helicopters to return to their missions. By slingloading downed aircraft back to repair facilities the CH-37, CH-47, CH-53, and CH-54 salvaged aircraft that would have been a total loss in other circumstances.
Marine helicopter operations followed much the same pattern as the U. S. Army, with a few innovations. Despite visibility limitations, Marine helicopter crewmen conducted several early night operations. In August 1965 they flew the first night assault in Vietnam, using CH-34s to insert Marine grunts into Elephant Valley northwest of Da Nang. Marine medevacs also extracted several severely wounded men during night operations. Radar operators guided the pilots to the wounded while other aircraft dropped flares to illuminate LZs long enough for the medevac to evacuate casualties.
Radar guidance allowed the Marines to resupply units under inclement weather conditions. During the siege of Khe Sahn and operations in the A Shau Valley in 1969, CH-46s and CH-53s made instrument climbs through the overcast at Quang Tri and Da Nang, and with radar directions flew to the beleaguered Marines. When an opening in the clouds appeared the pilots spiraled down to drop their external loads of water, rations, ammunition, and medical supplies into small LZs hacked into the cloud-covered rain forests.
From administrative assignments (“ash and trash” missions) to combat and service operations, helicopters changed U. S. military doctrine forever. Used properly, helicopters proved much less fragile than some doomsayers had predicted, flying thousands of hours per aircraft lost or damaged. By the end of 1972, U. S. helicopter losses neared 4,500, but most were lost to operational accidents and mechanical failures. Many of those listed as destroyed in combat were lost to mortar and rocket fire while the aircraft sat on the ground, partially protected by sandbag revetments.
During the Vietnam War, medevac and SAR pilots flew their aircraft into every conceivable situation: firefights, dense jungles, remote mountaintops, rice paddies, river bottoms, steep ridges, even to the outskirts of Hanoi itself, considered the most defended city in the world. For example, the USAF Aerospace Rescue and Recovery Service, flying a variety of helicopters, rescued 3,883 U. S. servicemen in SEA who might otherwise have been killed or captured. U. S. helicopters also evacuated hundreds of Americans and South Vietnamese during the fall of Saigon in April 1975.
From the late 1950s through the mid-1970s helicopters proved their adaptability and capability to operate in searing desert heat, Arctic cold, and all environmental conditions in between. Flying a miscellany of missions including military assault and transport, SAR, vertical replenishment of both military and commercial shipping, minesweeping, advanced early warning, and various humanitarian aid missions such as air ambulance and disaster relief, helicopter pilots aptly demonstrated that rotorcraft are much more versatile than conventional airplanes. Flying these missions in all weather conditions, aviators permanently established the helicopter’s reputation as a machine that could accomplish any assigned task. As to air ambulance and rescue, Igor Sikorsky, in 1969, stated: “For me the greatest source of comfort and satisfaction is the fact that our helicopters have saved . . . over fifty thousand lives and still continue with their rescue missions. I consider this to be the most glorious page in the history of aviation.” Both Larry Bell and Sikorsky believed that of the “great varieties of service rendered by the helicopters . . . the most important [have been] the saving of many thousands of lives” (Keogan 2003, 44).
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