When it “floats” off the assembly line, one might wonder if Boeing’s heavy lifter—capable of flying a Caterpillar D8 to a roadless jobsite—is airship, helicopter or crane. Pete Jess, who invented the JHL-40, just calls it a “blimp on steroids.” If the project flies, even larger aerial lifters may hit the sky as construction firms fall under increased pressure to limit their impact on the ground.

Skyhook International Inc. Boeing venture may build up to 60 airships, starting this year with two prototypes.

The 302-ft-long, 217-ft-wide and 118-ft-tall aircraft would be the world’s biggest aerial crane, with a 40-ton capacity twice the size of the largest helicopter, the Russian-built MI-26. It would carry equipment and materials 200 miles and back at 70 knots without refueling using a helium-filled balloon supporting four Chinook helicopter rotors and thrusters.

Jess, who is president and chief operating officer of Calgary, Alberta-based SkyHook International Inc., says he had been refining the design for 25 years before floating the patented system to Chicago-based Boeing Co. in 2006. The aircraft builder agreed to start assembly this fall on two prototypes set to fly in 2011. After their certification, it would then build 50 to 60 more.

The “Jess Heavy Lifter” employs the idea of neutral buoyancy, which allows helium to carry the static weight of the machine while freeing up rotors to handle sling loads. “You’re not heavier than air like a helicopter; you’re not lighter than air like the Goodyear Blimp,” explains Ken Laubsch, Boeing’s project manager. Initially, it will take a few years to build up and prove out the machine, but Laubsch says 80% of its components are already in stock. Drive-by-wire controls will compensate for problems like ground resonance, which led to a fatal crash in 1986 of a similar ship that Piasecki Aircraft Corp. built for the U.S. Forest Service. Jess says he has studied the accident and worked out the kinks.

First units will target arctic oil drillers, but executives have loftier goals. “We will have all kinds of applications that we’ve never thought of,” says Laubsch. The technology “opens up a whole new ballgame,” adds Jess.

The ballooned behemoth could compete with niche lifters, though some think the blimp will lack the same maneuverability. “The thing basically is a big sail,” says Dennis Hubbard, marketing chief of Central Point, Ore.-based Erickson Air-Crane, which supplies Sikorsky S-64 heavy-lift choppers. They are more nimble, moving up to 110 knots, but can only haul 12.5 tons. Hubbard adds that controls and pilot stations on aircraft need to be fine-tuned to allow for precise picks.

JHL’s capacity also may not be enough to change existing transport methods, but Piasecki’s Website notes that larger airships could haul up to 200 tons. If so, airships may offer a “step change” over helicopters, as modular buildings and plant vessels are gaining bulk and mass, says Jeff Latture, vice president of Memphis-based Barnhart Crane & Rigging Co.

Speed and range still are limitations. “Find me an aircraft that has 200-plus-ton capacity, a ground speed of 300 to 400 knots and range of 5,000 miles, and you have something I’d like to use,” says a source at a major civil-engineering firm.

Either way, it would be an efficient hauler. The MI-26 uses 22,000 hp to lift 22 tons; JHL-40 would double the capacity with about the same power. SkyHook plans to rent it out but has not yet named costs. Heavy-lift choppers cost $20,000 or more per day, Latture says.