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From the early 1960s till the late 1980s, the Sikorsky HH-52A (S-62C) was the U.S. Coast Guard’s (USCG’s) primary Short Range Recovery Helicopter. By the mid-1980s, the HH-52A began to be replaced by the Aérospatiale HH-65A Dolphin at air stations around the U.S. By September 1989, the conversion from the HH-52A was complete, but the aircraft has never been forgotten. For one aircraft, this has led to a whole new life after retirement, thanks to an enterprising operator in Riverside, California.
The story of the HH-52A begins with the USCG’s intended procurement of 96 Sikorsky HUS-1Gs — a military version of the Sikorsky S-58 — in 1959. After the first six were put into service, two unexplained ditching accidents within an hour of each other in Tampa Bay, followed by another airframe loss in a crash in the Gulf of Mexico, forced the USCG to cancel the procurement. The search began for a different aircraft to meet the mission requirements. The new amphibious Sikorsky S-62 was examined, and almost perfectly fit the USCG’s needs. With a boat hull fuselage, it was able to land and taxi on water, and it also had a cabin large enough to carry 10 survivors. The fact that it had an economical and reliable turbine engine, as well as the proven drivetrain of the Sikorsky S-55, gave the USCG the confidence it had a winner. The aircraft was tested and refined with the USCG’s equipment, including a three-channel Automatic Stabilization Equipment (ASE) system. Other Coast Guard additions included a hydraulic rescue hoist, a rescue basket, and a sea rescue platform that allowed the crew to recover victims while on the water by sliding them into the cabin. In January 1962, with final testing complete, the USCG put an order out for 99 HH-52A Seaguards (or HU2S-1Gs, as they were known at that point). The first was delivered on Jan. 15, 1963, and the last on Jan. 17, 1969.
After procurement, the HH-52As were based at air stations and on ships, including Coast Guard cutters and icebreakers. The HH-52A traveled the world performing missions for the USCG, from the Arctic to the Antarctic and everything in between. Over the years, it was credited with rescuing over 15,000 people — at the time, the most of any helicopter in the world. The Seaguard worked for the Apollo space program during training scenarios, during post-hurricane rescue operations, and on daily and nightly rescues across the U.S. The aircraft flew its last operational USCG flight on Sept. 12, 1989, after which the airframes were either sent to museums, testing facilities, or the “boneyard” at Davis-Monthan Air Force Base in Tucson, Arizona.
Starting a New Life
Today, a surviving HH-52A Seaguard still flies with Aris Helicopters of Riverside, California. “We’ve been operating older Sikorsky helicopters since the early 1990s, when we bought two piston radial engine S-58 helicopters to do lift work,” Scott Donley, owner of Aris Helicopters, told Vertical. “We flew these workhorses till until 2004, and stayed with the S-58 series, but upgraded to the PT-6 Twin-Pac Turbine powered S-58T.”
Today, the company still operates two S-58Ts — and recently added to its fleet of Sikorsky helicopters when the opportunity arose to purchase a standard category Sikorsky S-62A from an operator in Australia, and a flyable Sikorsky HH-52 from a company in Alaska.
From Aris’s records the last USCG operational base of the HH-52 (ship number 1403) was New Orleans. It was bought by Northern Pioneer Helicopters of Alaska in 2000, and operated by the company until 2006. Two owners later, Aris found the aircraft for sale. The company flew up to Alaska to inspect the aircraft, bought it, and then trucked it straight down to California. The flight to Australia to inspect the S-62A soon followed, and, following an inspection, Aris purchased the aircraft, disassembled it, and packed it into a container for shipment across the Pacific.
“When 1403 arrived at our hangar, we disassembled it, did inspections and repairs, sent the engine in for inspections and updates, and then the HH-52A was reassembled,” said Donley. “After this two-year process, the aircraft was repainted into Aris company colors, all the details sorted out, and finally test flown. The helicopter flies great, and now we are progressing to making a water landing.”
In terms of its size, the main rotor diameter of Aris Helicopters’ HH-52A is 53 feet (16 meters), its overall length is 62 feet and three inches (19 meters), and the static ground height to the top of the rotorhead is 14 feet and two inches (4.3 meters). The aircraft has a large main cabin — large enough to allow a person to stand and have room to move about. This helped reduced fatigue during search-and-rescue missions. Aris’s HH-52A sits at an empty weight of 4,927 pounds (2,235 kilograms), giving a useful load of 3,373 lbs. (1,530 kg) with no fuel. The helicopter has two fuel tanks: one forward that has a 187-US gallon (708-liter) capacity, and one aft at 138 US gallons (522 liters).
“With a total of 325 [US] gallons [325 liters] and an optimal best burn rate of 70 gallons [264 liters] per hour, we can fly about four hours before needing to refuel,” said Steve Bull, a pilot at Aris Helicopters. Bull has recorded many hours in both the S-58 and S-58T, and has also spent time in the Sikorsky S-55B and CH-54A Skycrane — as well as flying the latest members of the company’s fleet, the HH-52A and S-62A.
In a lifting role, the aircraft’s cargo hook system is rated at 3,000 lbs. (1,360 kg). “We’re confident [that] with a light fuel load it can lift 2,500 to 2,800 lbs. [1,134 to 1,270 kg] without problem,” Bull added.
He said the most unique characteristic of the HH-52A is its ability to land and taxi on water. “In calm seas it could be shut down if needed,” he said. “It’s truly a flying lifeboat. Although other helicopters followed its lead, the S-62A series were the first amphibious helicopters to fly.”
The Pilot’s Perspective
The history behind the Seaguard made flying it “an honor” said Bull. “In many ways, it’s like flying any other helicopter with the typical cyclic between the legs for the right hand, pedals to control the tail rotor with your feet, and a collective with two throttle grips on the pilot’s left side for the left hand,” he said. The furthest forward throttle works as the primary, and is very similar to a typical throttle, said Bull. The other, located immediately behind the primary on the same collective, is an emergency throttle, and serves as a backup in case of a primary fuel control problem.
The aircraft is powered by a General Electric T58-GE-8 turboshaft, capable of producing 1,250 shaft-horsepower on a standard sea level day. When installed in the HH-52A, the engine is de-rated to 730 shaft-horsepower due to the limitations of the helicopter’s dynamic components. This was accomplished by derating the fuel control and limiting fuel flow to a maximum of 575 pounds per hour.
“During engine start, the engine can have the rotor brake applied while at flight idle,” said Bull. “After verifying all the items on our flight checklist, we can release the rotor brake and allow the rotors to start slowly turning at engine idle speed. We then verify the primary and aux hydraulic system are functional per the checklist, freewheeling unit check ‘split the needles,’ and we can then gently and smoothly roll up the throttle to the detent position, setting NR to 100 percent, and [we then] release the wheel brakes, unlock the tail wheel by pushing in the knob between the pilot and co-pilot seat, and start our ground taxi out to the runway. Or, if desired, we can pick up into a hover like a skid-type helicopter and make a normal departure, or a vertical takeoff to clear an obstacle if in a confined area.”
Bull said the aircraft’s flight characteristics were somewhere between the other Sikorskys that he has flown. “The HH-52A is leftseat pilot certified and looks like a Sikorsky and feels like a Sikorsky both inside and out,” he said. “The S-62/HH-52 were designed by many of the same engineers as the S-58, so if you understand one, you’ll know the other. What I have noticed with the HH-52A are the three main rotor blades turn comparatively slowly.”
Bull said this was the reason the HH-52A sounds like a Bell UH-1H when it comes in for a landing. Calculating the comparative blade movements, he said the Huey’s two blades turn at 325 rotations per minute (for a total of 650 “whops” each minute), and the HH-52A’s three blades turn at 221 rotations per minutes (a total of 663 “whops” each minute).
“It’s also a bit sluggish to cyclic inputs compared to the four-bladed S-58T that I fly,” said Bull. “It’s like comparing the Hughes 500D to the Bell 206B-3, which, like all helicopters, have their own particular handling characteristics. Its not that one is better than the other — just different.”
Overall, Bull said the HH-52A is a stable and predictable flying machine without showing any bad tendencies. “It also has amazing visibility from the cockpit, and even the cabin with as many windows as it has must have been an excellent search platform with its excellent internal and external visibility,” he said. “The turbine engine has good power and the rotor system is very smooth, quiet, and relatively responsive. That said, the HH-52A is no speedster with a maximum never exceed speed of 109 knots at sea level at a gross weight below 6,500 lbs. [2,950 kg]. Bring it to its maximum gross weight of 8,300 lbs. [3,765 kg] and you need to slow it down to a never exceed speed of 88 knots.”
The HH-52 is a classic helicopter, and despite being over 50 years old, it still has some life left in it. “We’re not sure what the future holds for HH-52A 1403, but its nice to see the old bird still flying,” said Bull.