Boeing and SkyHook’s Zeppelin-Copter Faces Safety Challenges

7/11/08Follow @gthuang

OK, so this isn’t technically a Seattle story. But how can we resist a bizarre new flying machine being built by Boeing to travel to the farthest reaches of the Earth? This week, Boeing announced it is teaming up with Calgary, Alberta-based SkyHook to develop a “heavy-lift rotorcraft” that can carry a 40-ton load up to 200 miles without refueling. The JHL-40 (couldn’t they come up with a catchier name?) is designed to support drilling and mining operations in the Canadian Arctic and Alaska.

It certainly looks cool. It’s an airship, the length of a football field, with four helicopter rotors spinning alongside it. The ship will be filled with helium to make it neutrally buoyant—that keeps the vehicle and its fuel in the air—while the rotors provide lift and thrust to support whatever it’s transporting. The 40-ton capacity would be twice that of the world’s most powerful vertical lift aircraft, Russia’s MI-26 transport helicopter. Boeing is under contract from SkyHook to build two prototypes at its Rotorcraft Systems facility in Pennsylvania. Once built and tested, the craft will need to be certified by Transport Canada and the U.S. Federal Aviation Administration.

Boeing-Skyhook JHL-40 Airship -- Artist\'s Concept -- Arctic DeliveryBut there are some major safety and technical issues involved, which most news outlets aren’t talking about yet. Remember the Hindenburg? In 1977, my family spent a year in Germany, and I recall seeing the newsreel footage of the fiery disaster—it was the 40th anniversary of the German airship’s demise (the exact cause is still a mystery). Those images have always stuck with me, and with a lot of people, which is a big part of why zeppelins went out of style. Of course, today’s blimps don’t use flammable hydrogen for buoyancy, which was the Hindenburg’s fatal flaw. There are, however, other issues to consider—some of which helped to sink German company Cargolifter AG, which tried to build an airship capable of lifting 160 tons but went bust in 2002 after its prototype was destroyed in a storm.

To get the inside scoop on modern rotorcraft design, I went to Robert Breidenthal, a professor of aeronautics and astronautics at the University of Washington who has done consulting work for Boeing. Breidenthal points to three main challenges of the JHL-40′s design, which will need to be worked out before it can become a viable transport ship.

1. Vulnerability to turbulence
This is a “classic problem with neutrally buoyant vehicles,” says Breidenthal. “It might be necessary to limit operations to relatively tranquil atmospheric conditions, securing it during turbulence,” he says, adding that this might not be a problem in the Arctic, which has long periods of calm weather. But if a storm is coming, look out.

2. Aerodynamic control
Because the spinning rotors are close to the hull, they will affect the airflow and pressure along the side of the craft. That could lead to “substantial side forces,” says Breidenthal, which would need to be managed in flight. “It would be fun to work all the fluid mechanics of that out,” he says.

3. Price of helium
Because it’s so light, helium eventually escapes from the atmosphere into space, and is hard to find in the first place (only in natural gas wells). It is a “strategic resource with unique and valuable characteristics” so it’s under high demand, Breidenthal says. Helium prices have already, umm, ballooned by about 50 percent in 2008, and could keep going up.

Gregory T. Huang is Xconomy's Deputy Editor, National IT Editor, and the Editor of Xconomy Boston. You can e-mail him at gthuang@xconomy.com. Follow @gthuang

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  • http://dlweinreb.wordpress.com Daniel Weinreb

    On the other hand, having neutral buoyancy rather than floating upward ought to make it a lot easier to land. That’s always been a problem with airships.

    I sure hope it works. Airships are just so cool!

  • f.tuijn

    The remarks in this article are as foolish as the project they describe. A short range heavy lifter
    should be a helicopter, probably designed by Mil.
    Hindenburg took fifty passengers from Frankfurt to
    Lakehurst, loading 7 tons of diesel fuel, 3.5 % of its mass. Three quarters of a century later we should be able to build safe airships fast enough to dodge all the bad weather and as thrifty.

  • Tom Birchmire

    Why do you writers have a compulsion to bring the Hindenburg into every article about airships when there hasn’t been hydrogen used in airships since the Hindenburg. Possibly you needed some troll bait filler as the actual facts are boring.

  • P. Jos

    Great article! What a neat idea. But isn’t a football field a little big for a flying object? Is there anything else in the air that big? Can you play football in it?

  • http://www.mercenarymind.com Jay

    I wonder how the durigables of the past dealt with the aerodynamic issues, and turbulence issues. I guess there was more dangers about them then we think.

    Still I’d take a ride in an air ship just for the fun of it.

  • Alex

    Why does everyone make out the zeppelins always ran on hydrogen – they didn’t they ran on helium untill america stopped supplying germany with the helium it needed, this forced them to hydrogen, which the hindenburg wasn’t really designed to use.

  • john

    Or maybe the Nazis coated the Hindenburg with a impressive looking coating. Which primarily consisted out of what we cal solid rocket fuel these days.

    Hydrogen is just as safe, but ppl just cry “oh the manataa” everytime this subject pops up.

  • ruth

    I was told the Hindenburg actually failes because static electricity caused the surface coating (aluminium iirc) to burn – only after that did the hydrogen burn too.

  • roland

    I see a big market for this thing. Example: doing what the IceRoad truckers do, but in the summer. Two hundred mile range might be a problem. Can it compete with Sikorsky SkyCrane to (say) build powerlines thru swamps?

  • RawThinkTank

    use a smaller separate craft to pull the airship with ropes to avoid loss of thrust at the propellers.

  • Tim

    Ummmm…the envelope must rupture for and oxygen must mix with the hydrogen before it becomes flammable. Even then if skin is nonflammable you have jet of fire out the side of the ship. The fire could not travel into the ship and detonate it because of the lack of oxygen. The dangers of hydrogen are overrated, people climb into flying vehicles full of highly flammable material all the time, they’re called jets.

  • derrida derider

    Yep, hydrogen ain’t such a big safety deal. In any case you can use a hydrogen/helium mix with enough helium to reduce the partial pressure of hydrogen so it won’t burn in air (my physical chemistry isn’t good enough to work this ratio out – anyone wanna try?). That saves on expensive helium.

    Heavy freight is rarely time critical, so you just wait out bad weather (don’t forget weather forecasts are far far better now than in the airship’s heyday). And one-off lifts can live with a bit more risk than scheduled passenger services anyway.

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  • Anthony

    At least part of the Hindenburg’s fatal components was the dope they applied to the fabric skin. The dope was highly flammable and is what can be seen burning on the surface of der blimp after the initial pulse of flame.