Most people who think of medevac operations during the Korean War think of the Bell 47, the helicopter model that was popularized in the television series M*A*S*H. In fact, there was another aircraft serving medevac duty alongside the Bell 47 in theater — the Sikorsky HO5S-1, known in the civilian world as the S-52. The Bell 47 carried patients on external litters, but the S-52, with its larger cabin, was able to carry two patients internally. It also had room for a medic who could tend to the wounded in flight, a model that laid the groundwork for the medevac system that emerged during the Vietnam War, and which endures today.
The S-52’s life-saving legacy is one of the things that inspired Sikorsky test pilot Alex Anduze to restore his own S-52, which is now the oldest flying Sikorsky aircraft in existence. We caught up with Anduze at Helicopter Association International’s Heli-Expo 2014 in Anaheim, Calif., where his S-52 was proudly displayed alongside more cutting-edge technology, including a mockup of the coaxial, high-speed S-97 Raider. There, Anduze told us more about the S-52 and the process of restoring it. He also told us about a conversation he had in 2002 with legendary Sikorsky test pilot Harold “Tommy” Thompson, who was the first person to loop a helicopter — in an S-52.
“I feel honored to have heard it directly from him,” Anduze said of the story of Thompson’s first loop, which occurred during an hour-long maintenance test flight with a mechanic also on board. According to Anduze, Thompson told the story something like this:
“I was a fixed-wing pilot in the war, so I knew how to do aerobatics. So I was doing these large wingovers, and then pulling out the bottom. And my mechanic suggested, ‘Hey, why don’t we just go all the way around?’ . . . I thought about it and I said, ‘Yeah, sure, let’s try it.’ So I concentrated on keeping the aircraft in trim, dove it as fast as it would go, pulled back and as I came through the top I knew I was doing well, came back on the backside, and the aircraft shook violently and I thought, ‘Oh my God, what just happened?’
“[We] both turned pale white . . . My mechanic leaned over and he says, ‘I think you flew through your own wake.’ Well, the next nine loops we did on that flight, I just kicked in a little left rudder at the top.”
After he landed, Thompson told Anduze, the chief pilot came out to the helicopter and told Thompson, “You have to go to Mr. Sikorsky’s office right now.” Thompson walked into Igor Sikorsky’s office thinking he might lose his job. Instead, Sikorsky asked him, “Could you please do that a little lower so I can get it on film?” (Click here to see footage of Thomspon’s loops on YouTube, along with written commentary from Thompson’s son.)
Anduze explained that the S-52’s innovative design — including all-metal rotor blades and an offset blade flapping hinge — gave the aircraft the agility it needed to perform a maneuver like a loop. “All the pilots that flew it in Korea that I spoke to loved how agile it was and how stable it was,” he said. He granted that the S-52 flies like “a 1950s truck” compared to modern, sports-car-like helicopters such as the S-76. Nevertheless, certain aspects of the S-52’s design, including the offset flapping hinge, were so successful that they have carried forward into modern Sikorsky helicopter models. “It was an innovation at the time that was unparalleled anywhere else,” said Anduze.
