Sikorsky UH-34D Helicopter: Dog of War

Think of Yankee Lima Four Two as a time machine: Jump in and you’re back in Vietnam.

By Stephan Wilkinson
Air & Space Magazine, July 01, 2001

Its official name was the Sea Horse, but they called the big helo the Dog. Not because it flew like one but because you’ll never get a Marine to call any weapon by the name the Corps gives it. Marines use the phonetic alphabet in radio communication, replacing letters with words, and in the Korean War, well before today’s NATO-compatible alfa, bravo, charlie, delta for A, B, C, D, they used able, baker, charlie, dog. Because it was the D model of the Sikorsky H-34, the UH-34D came by its nickname honestly.

The Dog I met is one of two still flying in a coat of flat Marine green. Its owner is James Moriarty, a dogged, wealthy Houston lawyer. “I sue big companies that cheat people,” he says with in-your-face pride. “Erin Brockovich is my hero.”

Moriarty loves the Marine Corps enough to have spent an unspeakable amount of his own money restoring the 40-year-old UH-34D so that he can operate it as a living, breathing, shuddering, fluttering, flying Marine memorial. He takes his YL-42—in GI phonetics, “Yankee Lima 42,” the call sign of an actual helicopter that had a fatal crash—to airshows all over the country. It has been restored to the condition of one of the hard-working UH-34Ds that flew in Vietnam, just as it might have looked parked on the HMM-362 (HMM means Helicopters, Marine, Medium) “Ugly Angels” squadron ramp at Soc Trang, or “Marble Mountain,” the helicopter strip at Da Nang. The cabin is cluttered with toolboxes and spares, and the slightly askew clamshell nose doors are held together with a bungee cord just as they would have been during the war. There’s a small puddle of red hydraulic fluid on the cabin floor, and even an inert M-60 machine gun on a swivel mount in the main door.

Though Moriarty served three combat tours in Vietnam, he wasn’t an H-34 pilot—wasn’t a pilot at all, wasn’t even an officer. He was a Huey door gunner. A sergeant. “We used to occasionally see the UH-34s at Marble Mountain, but I thought those old radial engines were totally obsolete,” he says. “Hell, I was flying in turbines.”

He had a point. The H-34 family marked the end of the era of piston engine military helicopter design, an era that was coffin-nailed shut by humming, vibration-free turbine engines, sophisticated and durable rotor systems, and unimaginably light and reliable materials and devices. The H-34 (Sikorsky model number S-58) was derived from the H-19 (S-55), a late-1940s Sikorsky design that pioneered a unique engine configuration. The obvious place to put its big air-cooled radial engine would have been in the very center of the helicopter, right under the rotors and with the vertical driveshaft connected directly to them. But that would have pretty much filled the cabin.

Sikorsky’s solution was to stick the engine out in a big schnoz of a nose, with its crankshaft tilted back and the driveshaft angled up and aft, passing between the flight crew seats to the transmission and rotor hub at about a 45-degree angle. This left a boxy, unobstructed area for a cabin behind and below the cockpit.

Today, the turbine equivalent of the H-34’s 1,525-horsepower piston engine weighs about 25 percent of what the iron-mongered original did and fits nicely up above the cabin. Another example of the 34’s archaic complexity: The main rotorhead, about the size of a Stetson hatbox, has 84 grease nipples, every one of which has to be lubed before a flight. Today’s typical rotorheads—light composite sandwiches of elastomers and alloys that shrug off the torture of tons of centrifugal force from whirling rotor blades—have never seen a grease gun.

As hard as it is to fathom, the UH-34D was powered by the same Wright R-1820 Cyclone radial engine used in everything from the last Navy biplanes to the B-17s and DC-3s that entered service between the world wars. The Dog was never intended to do battle against ground troops, so UH-34Ds had no guns, no cannon, no rockets. No problem: The Marines welded up mounts for M-60 light machine guns, one on each side of the cabin, and installed them in the field. That was as much recoil as the airframe could take.

With the ascendancy of turbine engines, the Sea Horse was already obsolete by the time of its first flight in 1954, but a war spared it. Vietnam first began to heat up in the early 1960s, becoming a combat zone for lifers and professional warriors, many of them Marines. The Marines’ two dozen UH-34Ds were all that squadron HMM-362 had to work with when, on April 15, 1962, they landed at Soc Trang, a former World War II Japanese fighter strip on the Mekong River delta. The Ugly Angels, as they soon came to be known for their medevac missions, were eventually followed by nine more UH-34 squadrons.

By the time the media had swarmed into the war in the late 1960s, the chuttering rumble of the 34’s radial engine had largely been replaced by the raspy whine of the Bell UH-1B Huey. The nightly news resonated with the pounding beat of the Huey’s wide twin rotor blades, and most of us came to assume that Vietnam was the Huey’s war.

But in the seven mostly un-televised years that Marine UH-34Ds were “in country,” they served as everything but gunships. They carried troops, cargo, crates of ammunition that their crew chiefs kicked out the door during low passes over beleaguered landing zones, packages and paperwork on admin runs, chaplains (“holy helo” trips), bodies, and, perhaps most memorably, the wounded. Without the UH-34D’s endless medevac shuttles, many more wounded U.S. and South Vietnamese troops would have died.

The Sea Horse had been designed to be a carrier-borne Navy anti-submarine helicopter, fighting a relatively neat search-and-detect sonar war at sea. Unfortunately, the aircraft’s skin and such major items as the transmission case were made of superlight magnesium, which in the presence of saltwater did its best to become powder.

That magnesium was also to become a liability in battle. “On my second day of flying in Vietnam,” recalls former pilot Seppo Hurme, “one of our 34s was shot down, and you could see it from miles away, the magnesium burned so bright. But you never had to worry about ending up a cripple. Between the av-gas and the magnesium, you either walked away from a crash or you died.” Former HMM-363 pilot Joseph Scholle recalls, “We used to call it the world’s largest flashbulb. Get a fire anywhere and drop it in the water is about all you can do.”

Nonetheless, Hurme loved the old Dog. “That big engine up front was the equivalent of a lot of armor plate and gave you more protection than there was in other helicopters. I heard of one guy who took a hit from a 57-millimeter recoilless rifle that knocked one of the cylinders completely off. The engine kept running—rough, but they still got away. When I transitioned to Hueys, I felt naked.”

The Dog’s replacement was the turbine-engine, twin-rotor Boeing-Vertol CH-46, but the 46s soon experienced inflight failures, shedding their entire tails and tail-rotor pylons. Joseph Scholle recounts: “The H-46s would break apart right in front of the stub wings and become a section of two H-23s.” The accidents led to the CH-46’s grounding, so the Marines turned back to the faithful UH-34D. Says Scholle, “The part I grew to like was its reliability. We’d get more time out of our engines than the Hueys were getting. All that red-clay sand used to get sucked into their intakes and eat the turbine blades alive. We had an air cleaner, basically, like you have on a Pontiac. Take it out, bang it on the ground, rinse it in av-gas, and you’re back in business.”

The Dog could lose parts and survive: “It was one of the few helicopters that would fly with an inoperative tail rotor,” says Scholle. (A helicopter’s tail rotor is intended in large part to oppose the tendency of the fuselage to rotate rapidly around, and counter to, the main rotorshaft.) “A 34 has an awful lot of side area, and as long as you’re doing 45 knots, it swings around into about a 45-degree crab [angle] and stays there. It’s weird, but you can fly it.

“She’d also fly without transmission fluid,” Scholle continues. “Guys would have the transmission oil cooler shot out, the oil pressure went to zero and you’d just fly it back. You do want to keep the power up, though, because once the gearbox stops, it welds itself into a single piece.”

For their size, UH-34s were surprisingly nimble. They could get into and out of landing zones where no other helos could go, but once on the ground, the pilots were sitting 13 feet up in the air, and the people shooting at them were lying as flat on the ground as they could.

Rod Carlson was another re-routed CH-46 pilot, sent to HMM-361 to fly Dogs. Carlson drew his first night medevac mission soon after arriving at Marble Mountain, flying with Captain Rod Sabin. Wounded Marines who medics feared would die in the field before daybreak were flown out, but it was a dangerous undertaking. Carlson and Sabin waited for a summons in the squadron ready room, where, “with the red lights on to preserve our night vision, everything was the color of clotted blood,” Carlson recalls.

When the phone rang, Sabin and Carlson sprinted to their 34 and fired it up. “A constant blue-white flame from the exhaust stacks extended past my window like a huge blowtorch,” Carlson recalls. “Once we were airborne, Sabin flipped off the light switches overhead, and except for the flame, everything vanished in total darkness. I felt as though I were in free fall.”

Below them, Carlson says, “lights blinked like the small farms we flew over during night hops from Pensacola. But each [light] was the muzzle flash of a gun being fired at us.” The LZ—landing zone—was hot, so Sabin told the grunts on the ground to mark its center with a small strobe.

“The standard procedure was to spiral down directly over the LZ, in order to present the smallest target for the shortest time. In daylight, this approach was dangerous. At night, I was sure it was impossible.” Carlson remembers that Sabin dropped the collective to the bottom stop to reduce the pitch on the blades to zero, cut the throttle, dropped the nose, and spiralled down like a duck with a shot wing. “After five complete revolutions he straightened out,” Carlson recalls, “and the strobe was dead ahead. I could feel him raising the nose to slow our forward movement and twisting on full power to stop the descent.”

Sabin maneuvered to put the strobe between the helicopter and the waiting Marines, but the light kept moving: The Marine carrying it had mounted it on his helmet, figuring that would make it a better beacon, and now he realized Sabin might try to land on top of him. “Rod landed with his side toward the shooting, so the exhaust stacks wouldn’t be a target, and we picked up our guy,” says Carlson. “I remember as we headed back toward Marble Mountain, Sabin got on the intercom and asked the corpsman down in the cabin, ‘How’s he doing?’ The medic said, ‘I’ve got my hand inside his chest, but he’ll make it.’ ”

Before the end of Carlson’s first night aloft, he and Sabin would do it 11 more times, a typical shift for a ready-when-you-are Dog.

Ron Ferrell was also a corpsman on UH-34Ds, and he and many another pilot particularly appreciated the big, fat wheels and tires mounted on gear struts with generous travel to absorb heavy landings. “We were lifting off under fire one day,” Ferrell says, “and the pilot took a hit in the head just as we took off. We were nose-down, tail-up, and he had the rotors cranked up to full rpm, and then boom, we set right back down. We probably dropped a good 10 feet. I watched those struts go damn near to the ground and then spring back up.”

John Downing, a former HMM-361 pilot, remembers that the big landing gear made it easier to get into a tight LZ. “You could stand it up and put the tailwheel on the ground, haul back on the cyclic, and get it about 40 degrees nose-high; just put the tailwheel on the ground and it’d stop on a dime,” he says. “That got me in trouble when I transitioned to the Huey, because you definitely don’t want to do that in a UH-1. The first thing that hits is the tail stinger; next is the tail rotor.”

H-34s were the first helicopters to get a true stability augmentation system, called the ASE, for “automatic stabilization equipment,” a kind of primitive autopilot that did its best to counter a helo’s tendency to do anything but fly straight and level. When it was working, it created a stabilized feeling; when it wasn’t, they just flew without it.

Well, they did if they were sharp stick-and-rotor guys. HMM-362 door gunner Bobby Johns recalls, “There were pilots who wouldn’t fly it if the ASE was not engageable. It’s a hands-on bird, and with the ASE working, you could set the trim and actually turn loose of the controls.”

The aircraft is extremely sensitive to the controls. Just think about doing something and you’ve already done it, pilots say. It took a lot of coordination to manually adjust the engine rpms with the motorcycle-grip throttle on the collective that controlled the blade pitch. You could overspeed it quite easily, so you had to listen to the sound of the engine and the rotor blades without looking at the gauges. Some pilots compare it to the way the barnstormers flew in the 1920s, listening to the sound of the wind in the wires.

Former crew members’ affection for the Dog originates in a belief that the helicopter would get them back alive. George Twardzik was a door gunner with the HMM-163 Angry Eyes, a squadron named for the glaring samurai eyeballs painted on the nose doors of their UH-34Ds. Twardzik remembers the day in March 1966 when an Army Special Forces unit under siege in the A Shau Valley called frantically for help. When the first helo to assist them was promptly shot down, all units were ordered to stay away from the fight. “For three days, we could hear the troopers begging over the radio for medevacs, ammo, and water,” he says.

Finally, Twardzik’s squadron skipper could take no more. He strode to his 34 and announced that he was going for a ride, and if anyone wanted to join him, he wouldn’t stop them. The entire squadron fired up and headed for the valley. The skipper and three other 34s in the first wave were immediately shot down. It was late in the day, so the surviving helos returned to Phu Bai to regroup. First thing the next morning, the Angry Eyes returned to the LZ and began pulling out soldiers.

Twardzik remembers his aircraft taking fire from a .50-caliber machine gun. Eventually it found them. Twardzik took a ricochet squarely on his flak jacket, and during liftoff the impact blew him out the door. His safety belt snapped him right back into the cabin, where another round hit and ignited a five-gallon can of crankcase oil. The pilot autorotated down into a clearing, where the crew pitched the flaming can out and extinguished the fire. With the engine restarted and the rotors re-engaged, they took off, dragging the main gear through the trees as they headed back to Phu Bai. “I got out of the 34 to view the damage, and the aircraft was literally sieved with bullet holes,” Twardzik says. The Angry Eyes nonetheless managed to save every one of the HMM-163 air crewmen who’d gone down the day before, as well as 190 of the 220 Special Forces troops.

Moriarty’s UH-34D was originally an HSS-1N he found corroding in a New England farm field. He bought it without realizing what he was in for. “I paid $45,000 for it, figured we’d fill it with gas and fly away. What did I know?”

Moriarty himself couldn’t fly it, since he had never flown a helicopter, so the hulk was trucked to a restoration shop in Tucson, Arizona. “I had no reason to believe that it was anything I could ever fly,” he admits. “This is one huge, powerful, noisy, intimidating machine.” But Moriarty learned to fly helos in a little two-seat Hiller and added a rotary wing rating to his pilot’s license. “At the end of my first trip riding in the left [helicopter copilot] seat, I began to figure maybe I could learn to fly this thing,” he says. “If you can fly an underpowered little Hiller, you can do aerobatics with an H-34, it’s so powerful.”

He wouldn’t fly the first aerobatics in a 34. “Oh yeah, they were maneuverable,” laughs Joe Scholle. “I remember a guy did a couple of rolls and then looped it, for the benefit of the A-4 and F-4 pilots sitting on the beach at Chu Lai, in late ’67. Of course, you don’t get a real circle out of it; it looks more like a backward nine.”

Moriarty has logged over 400 hours in YL-42, much of that flying to airshows. He and his crew chief, J.T. Nelson, wear full Marine flightsuits, complete with flight crew wings and HMM-362 squadron patches and insignia. At first you think Uh oh—middle-aged men playing boy soldiers, but in fact they do all of it out of respect for the tradition, history, and sacrifice that YL-42 represents. “One of the rules of the aircraft,” Moriarty says, “is that when you fly or crew it, you wear the uniform. Not because I think it’s fun but because I want to honor the people who flew them. I will not fly this aircraft in shorts or jeans or tennis shoes.”

At U.S. airshows the missing link seems to be Vietnam-era aircraft, especially helicopters, say those who applaud Moriarty’s effort. The aircraft attracts a crowd of people who want to see things exactly the way they used to be. Some aircraft owners charge a fee to climb into the cockpit or whatever, but not Moriarty.

One remarkable feature of his helo, although few notice it, is that all of the complex data stencils on the underside of its four rotor blades are in French: The blades are surplus parts from an Armée de l’Air H-34. Even though YL-42 is 40 years old, getting spare parts is not a problem. Various versions served with the Coast Guard and CIA as well as 25 nations—even the Soviet Union: When Communist Party Chairman Nikita Khrushchev visited President Dwight Eisenhower in 1959, before the U-2 spyplane incident soured their relations, he rode in Ike’s Marine One, a UH-34D, and liked it so much that he bought two of them.

The government sold tens, even hundreds of 34s for pennies a pound, Moriarty points out. “It costs $150,000 to $250,000 to buy one now and make it ready for flight, and when you’re done, you have an aircraft with a market value substantially less than that. All offshore [oil industry] work is twin engine, and jet choppers are far more reliable. So there’s very little economic justification for keeping 34s in the air, and as a result, the hundreds of them sitting in boneyards and back yards will provide a source of parts for years to come.”

Moriarty guesses that last year, 20,000 people clambered through and around YL-42 at various shows. “At first, I wondered: Should I put a rope around it, only let certain people get close to it?” he admits. “But I decided no, that wasn’t going to be its mission. You see kids up in the cockpit, their feet can’t even reach the floor, and you can tell they imagine themselves as heroes, as people someday willing to fight for their country, as people who want to care for and protect others. They need to be able to touch that dream.”

Moriarty exhibits YL-42 not because he’s trying to re-create the Vietnam War; nor is he an aviation buff or a warbird fanatic. He does it, he says, because “we lost 58,000 people over there, and all of their mothers and fathers, sons and daughters, brothers and sisters, wives and husbands still think about them all the time, and it’s important that they never be forgotten.”

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Sikorsky’s H-34 Sea Horse

Derived from the Korean War-era H-19 (ghost image), the larger, stronger H-34 was designed around its predecessor’s propulsion arrangement, with a large radial engine in the nose, its crankshaft canted upward and to the rear. It had a lower, stouter aft fuselage and an airplane’s traditional tailwheel landing gear, which gave the 34 a longer and wider stance than that of the 19, with its tighter four-legged-barstool arrangement.

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