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
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
ZEPPELIN NT: 246 FEET
S TERN ENGINE: Two propellers
powered by one engine. One provides
thrust, the other provides lateral
control like a helicopter tail rotor.