The phone rang — it was my dad, and it was bad news.
“I’m standing on the sand,” he said, using a phone borrowed from the resident of a Malibu beach house. “I’m looking up the hill and the fire’s heading right for our house. The guys fighting it on the ground can’t get in there. The only hope we’ve got is those big helicopters. One of them’s filling up right behind me.”
In the background I could hear roaring turbines and whopping rotors. Living in Oregon, I knew exactly which big helicopters he meant. The huge orange Sikorsky Skycranes owned by Erickson Air-Crane are based in the southern Oregon town of Central Point. Now, with southern California burning up, they’d flown south and were in the air constantly, pumping tons of water out of the ocean and delivering it minutes later into otherwise inaccessible folded hills and canyons, trying desperately to save homes, stables and entire communities.
As it turned out, nothing — helicopter or otherwise — could have saved my childhood home, but Skycranes have certainly saved others … perhaps thousands of others. And they’ve also delivered towers to mountaintops, air-conditioners to skyscrapers and the injured to hospitals. They’ve hauled timber without needing roads and pulled wrecked aircraft out of combat zones. The bronze Statue of Freedom atop the United States Capitol? A Skycrane put it there.
A Big Idea
Designed half a century ago, the Skycrane derived from an idea promoted by Igor Sikorsky himself. In 1955, he proposed a helicopter that would carry all its loads externally. A minimal airframe would consist of just the structure necessary to hold the engines, rotors, fuel and crew. Unencumbered by doors or internal dimensions of a cabin fuselage, it would handle objects of sizes and shapes that could never be carried internally. Essentially, it would be a crane that was free to move in three dimensions. The only restriction would be the amount of lifting capacity available — and that could be overcome by building a very big, very powerful helicopter.
Sikorsky’s first effort at a “sky crane” was the S-60, which flew in 1959. Powered by two Pratt & Whitney R-2800 piston radial engines, it was essentially a “backbone” fuselage with a tail rotor on one end, a cabin for a crew of two seated in tandem in a pod on the front, and a big rotor in the middle. The engines were mounted in pods, high on each side. Long, spindly landing gear allowed the helicopter to sit high off the ground and straddle loads. The rear-seater could turn his seat around and fly facing the load.
The S-60 did its job, demonstrating the usefulness of the crane idea and impressing military planners and buyers. But it wasn’t really a practical machine. The piston engines were at the limit of their development. It was obvious that lighter and more powerful turbine engines would be the key to the crane concept. By the time the S-60 was lost in an accident in 1961, its turbine-powered successor was well under way.
Powered by two Pratt & Whitney JFTD12A turboshafts producing about 4,000 shaft horsepower each, the S-64 Skycrane reminded many people of a huge insect. It does look like one, if you can imagine an insect 88 feet long and weighing 10 tons with a six-blade fan 72 feet in diameter on its back. The engines and immense transmission were mounted in the open on top of the fuselage. The aft-facing pilot feature pioneered on the S-60 was retained, although it required an extra crew member. A large winch could lift loads up to the hovering aircraft, or the craft could simply straddle loads the size of a large bus, hook on and fly away.