This is a work in progress...
With the advent of the Korea War in mid-1950, enemy-opposed rescue of pilots who had been shot down had become a mission for which the U.S.Navy was unprepared. The obvious solution was the use of the Sikorsky HO3S helicopter that had only recently become the standard plane guard for carrier takeoff and landings, supplementing the destroyers that had been utilized for that role. It had a rescue hoist and could carry three passengers, although from a practical rescue mission standpoint, the crew was limited to a pilot and a hoist operator and only one passenger, the rescuee. For a combat rescue, the pilot was armed with a revolver and the hoist operator, a carbine. There was minimal protection from small arms and none from heavier weapons. This is a screen grab from one of the most accurate aviation movies ever produced, The Bridges at Toko-Ri (also see https://thanlont.blogspot.com/2008/11/most-accurate-aviation-movie-ever.html):
As upon occasion in real life, the movie did not end well for the downed pilot and the helicopter crew.
After the armistice in July 1953, the priority for maintaining a combat-rescue capability rapidly lowered to be indistinguishable from zero, with no chance of rescue in August 1964 for the first Navy carrier-based pilot to survive being shot down over North Vietnam. He was quickly captured and remained a prisoner of war for more than eight years.
The solution was again to assign the mission to the existing carrier plane-guard helicopters, the Kaman UH-2A/B Seasprite* and the Sikorsky SH-3A Sea King. The former was assigned to air groups on the attack carriers and the latter, ASW carriers that had ASW Sea Kings assigned for detection and destruction of enemy submarines. At first the addition of armor and armament to them was not significantly improved over that implemented for the HO3S but it was constantly upgraded as quickly as possible. In addition, both contractors began to design significant modifications to improve both passive and active protection from enemy fire.
Early in the war, only offshore rescue attempts were attempted but on 20 September 1965, the crew of an HC-1 UH-2 flying from the cruiser Galveston—to minimize the distance to be flown—and escorted by two VA-25 Skyraiders was able to rescue a pilot unable to get past the coast and over the water before ejecting. In August 1965, Hornet had deployed to WestPac with five of its 18 HS-2 SH-3As stripped of ASW systems, minimally armed and armored by later standards, and with subdued markings to provide more range and payload capability than the smaller H-2's.
Kaman received a contract for 12 HH-2Cs, which added a second engine for better hover and payload performance, armed not only with M-60 door guns but a remotely controlled turret under the nose that contained a 5.56 mm six-barrel "microgun", and with some armor protection.
However, only six were delivered, the turret was deleted early on for various reasons, and the second engine further reduced range and endurance. While it was used for combat rescues beginning in 1970, the Sikorsky H-3, nicknamed the Big Mother in view of the size difference, was more capable with a bigger cabin and eventually replaced it.
Twelve HH-3As were delivered beginning in 1970 although not operationally employed until 1971. The prototype was a heavily armed and armored Sikorsky modification of an early (No. 14) SH-3A, BuNo 148036:
Uprated T-58-GE-8F engines were installed to somewhat compensate for the greater weight. A window was added in the aft fuselage for the aiming of the remotely controlled miniguns. It was located one frame forward of a similar window in the RH-3A minesweeper variant (see https://tailspintopics.blogspot.com/2022/12/sikorsky-rh-3a-seaking-minesweeper.html):
Note that some SH-3As modified for combat rescue and painted/marked accordingly are misidentified as HH-3As since they lack that aft cabin window, not to mention the additional armor:
The HH-3A engine and transmission armor:
The remotely controlled turret was not used operationally because of weight among other shortcomings:
It was replaced by a cabin-door mounted minigun and an M60 machine gun located in the forward entry door.
Note that the forward entry door has been modified to provide a larger opening. A second M60 was reportedly employed from a left-side window but I have not seen a depiction of that option.
The HH-3A was also intended to carry two 175-gallon external tanks for additional range.
In addition to the prototype, BuNo 148036, 11 SH-3As were modified from Sikorsky-furnished kits by the NARF at NAS Quonset Point, RI: 149682, 149896, 149903, 149912, 149916, 149922, 149933, 151531, 151552, 151533, and 151556. All 12 were initially assigned to HC-7, tail code VH. It is a credit to the modifications, training, tactics, and mission planning that none were lost in combat rescue missions. Most of the 10 remaining were transferred to HC-9, a Reserve squadron dedicated to maintaining combat-rescue capability, when HC-7 was deactivated in June 1975**. 151531 had crashed in California while on a training exercise and 149896 was stricken in May 1973, an innocent bystander parked on a carrier, when an A-3 Skywarrior landed too far to starboard on 8 January 1973, hitting it with a wingtip.
HC-9, tail code NW, was capable of deploying around the globe within 15-days
of notification. In 1986, a two-aircraft detachment was deployed in
support of Operation Prairie Fire in the Gulf of Sidra, Libya. Three
Carrier Strike Groups in the Mediterranean Sea needed CSAR support due
to possible overland operations while enforcing freedom of navigation. The detachment was based on Coronado (AGF-11), the command ship of the U.S. Sixth Fleet.
When HC-9 was disestablished on 31 July 1990, replaced by Helicopter Combat Support (HCS) squadrons assigned the much more capable Sikorsky HH-60S Sea Hawks, that was still not the end of HH-3A air frame utilization (helicopters are the aeronautical equivalent of George Washington's proverbial ax). One, 151556, is on display at the American Helicopter Museum in West Chester, PA. The other eight survivors** were eventually purchased for civil applications (one even became an S-61T). In most if not all cases, the extra rear windows were no longer present on the fuselage. This is the former 149916, in civil service for fire fighting and heavy-lift construction:
One remaining mystery is the purpose for the four "lunch boxes" (my nickname for them) scabbed onto the HH-3A fuselage—two on each side and one each fore and aft, with no apparent opening— following Vietnam, possibly following transfer to HC-9. They are faceted, with the side not being a rectangle: the side of the aft box is angled slightly forward; the forward box is a mirror image of it with the side angled slightly aft. My guess is that they are associated with a warning system, either radar or gunfire detection.
*For a complete history of the H-2 Seasprite, buy this book: https://thanlont.blogspot.com/2025/06/hu2k-seasprite-book-wayne-mutza.html
** At least one HH-3A, BuNo 149912, was transferred to HC-1 and subsequently stricken in October 1976.
