EAA Sport Aviation - September 2011

The rest of the volume is filled by two inflatable bags called ballonets—one forward, one aft—that are filled with air. There are valves and fans that can be manually operated or set to automatically adjust the air pressure in the ballonets to counter the expansion or contraction of the helium as it heats or cools. “The ballonets can be up to 27 percent of the volume,” Matthew said.

The Zeppelin is propelled by three 200-hp Lycoming IO-360 engines—one on either side of the hull, which are attached to the main crossbeam, and one at the tail end of the ship.

There is a 110-gallon fuel tank on each side of the main cross-
beam, and an aft fuel tank that holds about 85 gallons. “One really
interesting thing, we can transfer fuel from aft to forward, for-
ward to aft, right to left, left to right. But we don’t have fuel
lines,” Corky said. “The fuel goes through the carbon fiber frame
so they didn’t have to add weight by adding fuel lines. It’s cool.
You can transfer fuel to adjust your trim.”
The side engines provide vectored thrust with the ability to
rotate up to 120 degrees with variable-pitch propellers. The aft
engine drives two propellers, one that provides lateral thrust
similar to a helicopter tail rotor and the other that can rotate 90
degrees down to provide hover capabilities or forward thrust
when it isn’t rotated down. “The most significant thing they
[Zeppelin] did is they put two props in the tail,” Corky said.

Combined with fly-by-wire controls connected to three tail fins, the airship is extremely maneuverable. It can stop, hover, land, and climb vertically, which allows Airship Ventures to land the aircraft with only a three-person ground crew.

The vectored thrust engines give the airship the ability to literally land on a dime. “It’s by far the most controllable airship ever built,” Corky said.

A blimp, with no internal structure, has the engines fixed to the gondola, creating more noise and vibration than the Zeppelin. A blimp is flown much more like a fixed-wing aircraft, needing space for a final approach for landing and a large ground crew to help secure it.

AT THE CONTROLS

One look at the panel and you know this isn’tyour usual aircraft. The throttle quadrant is in the shape of a “T”—blue pitch control levers are on the top left close to the panel, with the red mixture controls to

INSIDE A MODERN AIRSHIP

Airship Venture's Zeppelin NT, Eureka, is one of two flying in the world.

Its range is 560 miles; it can fly at a height of 9,350 feet, and reach a top speed of 78 mph.

SEMIRIGID S TRUCTURE: Unlike a blimp, which has no internal structure, Eureka is braced by aluminum and carbon fiber. All main components are mounted to this framework.

ENVELOPE: 296,643 cubic feet. Filled with nonflammable helium and made of a laminate material from the same company that creates the fabric for NASA space suits.

LATERAL ENGINES (two): Provide thrust and are positioned to provide maximum maneuverability.

BOEING 747: 232 FEET

AMY GESCH COCKPIT: The pilot controls the airship with a sidestick using fly-by-wire technology to precisely control speed and direction. CAPACITY: 12 passengers SIZE: 35 feet long