Bill Sweetman Technically Speaking
Sonic Cruiser, loser
OVER THE DECADES, aerospace industry giants, startups, armed forces, and shipping companies have all floated (so to speak) dozens of ideas for airship designs. Why have none met with success?
Any practical application of the large airship poses formidable challenges. The first is finding a use for it. In the 1990s, the German Cargolifter project was sponsored by companies in the business of moving equipment weighing up to 160 tons. The idea was to go from factory to customer site in one operation, without ships or heavy road convoys. The company built a giant hangar near Berlin, then failed.
One project that did reach the mockup stage was the U.S. Navy’s YEZ-2A, an experimental airborne-early-warning craft. An airship’s envelope offers protection from wind, so it is a good place to put a very large radar antenna. And a large antenna is a simple, robust way to detect stealthy targets such as cruise missiles.
Westinghouse (now part of Northrop Grumman) was partnered on the YEZ-2A with the U.K.’S Airship Industries—one of a number of companies started by the late Roger Munk, the greatest apostle of the modern airship. Ultimately, the project fell victim to a fire that destroyed a sub-scale prototype and the mockup for the full-size ship’s gondola. (The Pentagon also decided that cruise missile defense was not the Navy’s job, but the Army’s.)
Munk went on to found the Airship Technologies Group, which by the late 1990s had designed Skycat, a hybrid airship with an airfoil-shaped hull designed to contribute lift to the buoyancy of its helium-filled envelope. It also had an air-cushion landing system. Munk knew the curse of the large-payload airship was its behavior on the ground. The slightest breeze makes the ship move, so once its payload is removed, the ship has to be secured and its buoyancy adjusted. Skycat could reverse the airflow through its air-cushion system and literally suck itself down while unloading.
In the early 2000s, the Skycat and Lockheed Martin studies inspired the Defense Advanced Research Projects Agency to launch a project called Walrus, an immense airship with a 500-ton payload capacity. The U.S. Army was fascinated by the idea of a vehicle that could pick up a large military force and deliver it
“from fort to fight.” But as Lockheed Martin Skunk Works boss Frank Cappuccio put it, Walrus “couldn’t pass the giggle test.” Munk didn’t live to see his hybrid design fly—and so far it has done so only once, in the form of the Army-funded Northrop Grumman Long Endurance Multi-intelligence Vehicle. But the LEM-V project was poorly managed: The vehicle was overweight, and the Army cut off funds after one flight. ATG’S successor company, Hybrid Air Vehicles, bought the prototype cheap and wants it to fly again.
The Pentagon has helped fund Aeroscraft, an airship concept led by Russian-born Igor Pasternak. It’s based on a system that controls buoyancy by pumping helium into tanks under high pressure.
Even Northrop Grumman’s Los Angeles-based Aerospace Systems Division—a separate entity from the radar outfit on the other side of the U.s.—took a long look at airships a few years back. It apparently was interested in moving high-demand, fashionable goods directly from Asian factories to Western distribution hubs. The project has since gone quiet. Why have so many airships failed? Two themes recur. One is grandiosity: Designers aim for 500 tons straight out of the box; why not try to build an airship with a C-130’s 20-ton payload instead? The other is cockiness. Inventors treat airships as if they’re proven technologies rather than experimental vehicles. That misapprehension stymied the British attempt at a flight to India, circa 1929, in the then-new R101, as surely as it afflicted the U.S. Army, which wanted the LEM-V to be flying in Afghanistan mere months after its first successful demonstration. A truly revolutionary idea in airship design would be to aim for modest goals on a realistic schedule. Because hardly anyone has tried that yet.
Why have so many airships failed? Grandiosity. Designers aim for 500 tons straight out of the box.