HUS / UH-34 Seahorse
The selection of a utility helicopter was extremely important as the Marine Corps desperately needed an all-around utility aircraft. It was not recognized at the time, but the choice would eventually have a definite influence upon the entire Marine helicopter program . The small H03Ss and the HTLs were being used in a utility role since there were no other helicopters available. The Marine Corps desired to assign two new and larger utility aircraft to each helicopter MAG headquarters squadron for carrying cargo and bulky aircraft replacement parts. Also, two utility helicopters were to be assigned to each Marine aircraft wing headquarters squadron, each major air station, and air facility. Then, as a secondary mission, the utility aircraft could be used to transport combat troops and evacuate wounded personnel.
On 5 December 1952, the CNO informed BuAer of the Marine Corps' utility helicopter requirement. It was explained that in order to meet the specification, it appeared that modification to an existing Navy program would be desirable in the interest of economy rather than initiate a new design. In this respect, the CNO was referring to a new Navy ASW model, one being developed by the Sikorsky Aircraft Company.
The HRS-4 had to be modified to meet the utility requirements of the Marine Corps which consisted largely of rearranging the interior of the cabin. The necessary changes involved removal of the ASW equipment, installation of a cargo deck with tie-down rings, provisions for carrying 8 litters or 12 combat equipped troops, a 400-pound rescue hoist, and a 5,000-pound external cargo hook. The basic weight of the utility version was 8,598 pounds with a maximum take-off weight eventually approved at 13,300 pounds. This allowed for a payload of approximately 4,000 pounds without fuel. The forward air speed was restricted to 123 knots. The 65-foot diameter 4-bladed main rotor was driven by a 1,525-horsepower Wright engine where the smaller HRS had a 600-horsepower engine propelling only 3 main rotor blades. The Navy' s official designation for the HRS-4 later became the HSS-1 and the Marine version the HUS-1 (H-helicopter, U-utility, S-Sikorsky). Sikorsky designation was the S-58.
When the CNO instructed BuAer to develop the HUS-1 for the Marine Corps in December 1952, he also defined its procurement status. Fortunately in this respect, the Fiscal Year 1954 aircraft procurement list was revised by the CNO to allow for the modification of 33 HSS-ls to HUS-1s. This meant only that money would be available for beginning its fabrication. Delivery of the first production HUS-1 to the Marine Corps was initially estimated as occurring sometime during 1955.
The replacement helicopter for the HRS was received shortly before the HR2S. In February 1957, both HMR(L)-261 and -363 began exchanging their HRSs for the larger and faster HUS-1. Since the HUS-] was essentially the same aircraft as the Navy 's HSS-1 except for the cabin's interior arrangement, flight evaluation at Patuxent River was waived, thereby expediting its availability to the operating units.
In 1961 a Marine UH-34D was used in the recovery of astronaut Alan Shepard following his splashdown in Freedom 7. This event marked recovery. In all, more than five hundred UH-34s were built for the Marines. The US Marine Corps version, UH-34, was the primary Marine utility/assault helicopter used in Vietnam.
Beginning in 1956, the H-34 saw its introduction into combat during intensive operations with the French in Algeria. In 1955, the U. S. Marine Corps received its first HUS-1s as an interim type, ostensibly until the HR2S (later H-37) entered squadron service. However, the HUS lasted far longer in USMC service, and in much greater numbers, than the HR2S ever did. Ultimately the Marine Corps took delivery of 515 UH-34Ds. From the late 1950s until the CH-46 entered service in 1965, the UH-34 operated as the mainstay of Marine Corps helicopter units.
On April 15, 1962, Lt. Col. Archie Clapp's Marine Medium Helicopter Squadron 362 (HMM-362), know as Archie's Angels, deployed to Soc Trang in the Mekong Delta in South Vietnam as part of Operation SHUFLY. This was the Marine Corp's effort to support the Army of the Republic of Vietnam (ARVN) troops in actions against the Viet Cong. HMM 162,163, 261, 361, 364, and 365 joined the operation later. During late 1962, the SHUFLY H-34s traded places with an Army squadron and moved to Da Nang because the H-34 was more capable in the mountainous terrain of northern South Vietnam than the Piasecki H-21.
An example of the actions experienced by H-34 crews occurred on 27 and 28 April 1964 with the helicopters of HMM-364, commanded by Lt. Col. John Lavoy. The squadron received orders to insert a regiment of ARVN troops into a Landing Zone (LZ) that they believed to be unoccupied. Upon arrival at the LZ, the aircraft became the target of an ambush, which presumably occurred because of leaked information. A South Vietnamese Air Force (VNAF) A-1 Skyraider attempted to dive-bomb one of the many gun positions but was shot down. Later, courageous Army pilots, flying armed UH-1 Hueys (see NASM collection) suppressed some of the fire, but .50 caliber guns and hundreds of smaller weapons continued to pour fire into the landing zone. Despite the intense fire, Lt. Col. Lavoy led his helicopters into the zone, disembarked the ARVN troops, and departed. Every Marine H-34 suffered from damage inflicted from the ground fire, which resulted in the loss of one aircraft. An H-34 specifically tasked to rescue downed crews immediately picked up the crew.
During the course of the day, HMM-364 entered the zone four times, suffering further damage on each flight. On the fourth assault, ground fire claimed a Vietnamese Air Force (VNAF) helicopter. Once more, the rescue H-34 came to their aid. At the end of the day, every helicopter that participated in the operation displayed battle damage. Miraculously, not a single HMM-364 crewmember suffered an injury. For this action, every Helicopter Aircraft Commander (HAC), including Lt. Col. Lavoy, received the Distinguished Flying Cross. The pilot of the rescue helicopter, John Braddon, also received the Silver Star for the action. This operation was the first action in Vietnam that included multiple lifts of troops into a heavily defended LZ and foreshadowed the hundreds of similar operations that followed.
In August 1969, the last Marine UH-34D in Vietnam was retired from HMM-362 at Hue Phu Bai. It had served the Marine Corps in Vietnam for seven years. During that period, enemy action and operational accidents downed 134 of the venerable helicopters. To this day, whether they were pilots, crew chiefs, gunners or maintenance troops, the Marines who operated H-34s (which they affectionately labeled the "Dog") all fervently believe that "When you're out of H-34s, you're out of helicopters."
In the late 1950s, Air America, a CIA-created airline, began flying UH-34Ds in Laos, manned by crews on leave from the Marine Corps. When the last military UH-34 left Vietnam, Air America was still in operation with the type, including upgraded S-58Ts powered by the powerful turbine PT6T-6 "TwinPac."
The UH-34 Seahorse, which was the first helicopter model that took the role of a executive support mission. This role fell upon the squadron by accident. While traveling around Newport, R.I., a crisis presented itself requiring President Dwight D. Eisenhower's immediate attention at the White House. He required rapid transport, which HMX-1 successfully provided with its search and rescue platform, the UH-34. Pleased with the capability of the Seahorse, Eisenhower made other local trips via HMX-1 aircraft.