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The
Dynalifter® hybrid airship offers unique capabilities allowing it to
fulfill certain specialized roles in a manner that will prove superior
to conventional airplanes, helicopters, or airships. The most unique
feature of Dynalifters in general is their ability
to
fly on low amounts of power at low speeds, much like airships, but
without the operational drawbacks of a traditional airship.
This offers long
endurance
and
range.
Most
of the skepticism surrounding new airship concepts focuses on
ground-handling under windy conditions. All Dynalifters have
been designed to land without a mooring crew and
do
not require a
weight transfer system under normal conditions.
Dynalifters have been designed to withstand up
to 30 knot crosswinds after releasing their useful load. In addition to making Dynalifters
more operationally robust, this allows for unique capabilities such
as precise airdropping and mission-specific,
detachable cargo pods.
Under extreme conditions (winds in excess of 30 knots), the Dynalifter can
remain firmly on the ground either by pointing it into the wind, refueling
before the cargo has been released, not releasing the cargo at all, or tying it
down.
Dynalifters avoid the
operational drawbacks of a traditional airship associated with takeoff,
landing, and ground operations. The conventional airship is difficult to
handle on the ground. It requires a large number of people to grab lines
during landing, or it must use equipment of some sort to "catch" the airship
and attach it to a mooring mast. With passengers and fuel removed, the
airship experiences excess buoyancy and so must be over-ballasted before
unloading. When fuel is burned during flight, it becomes too light to land,
requiring either valving off lifting gas or use of an elaborate mechanism to
recover water vapor from the engine exhaust.
The Dynalifter® avoids many of
these problems [with airships] because it isn’t
"lighter-than-air".
With a large fraction of its
weight carried by aerodynamic lift on the wings and hull, it has a substantial
net download when sitting on the ground allowing it to withstand a gusty side
wind. It lands like a normal aircraft, decelerating on a runway as its weight is
transferred from the wings to the tires.
The company subcontracted
conceptual design engineering to defense contractors Conceptual Research
Corporation, Analytical Methods, and Composite Engineering. Together, the
companies completed conceptual designs for four different sizes of Dynalifters
ranging from the 120 ft. Dynalifter® Patroller and RV to the 990 ft. Dynalifter®
Freighter. The concept has been evaluated
by engineering studies that included computational fluid dynamics, initial
fabrication selection, and cost analyses.
OAI was not the first to conceive an airplane / airship hybrid. One of
Howard Hughes’ last projects was development of the heavy-lift
Megalifter hybrid. Unfortunately, the project died with him.
OAI improved upon the Megalifter concept most notably with the
Dynalifter’s patented internal frame. The company borrowed a concept currently used in modern bridge
construction known as “stay bridge construction” and applied it to the
Dynalifter’s design. Stay bridge construction is a method bridge builders
use to distribute high loads (i.e. cars and trucks) along the length of the
bridge while dramatically reducing the total weight of the bridge. These
features were exactly what the Dynalifter needed for distributing the
high concentrated loads it would encounter during operations.
Dynalifters are capable of releasing detachable cargo pods without the
need for a
weight transfer
system. First, this would allow for rapid
loading and off-loading. Loading and off-loading the pods could
actually take place without the aircraft’s presence, further reducing
aircraft vulnerability and deployment time. Second, detachable pods could
carry the next mission’s fuel and supplies, allowing for in-flight refueling
and quick turnarounds. Third, detachable pods could be uniquely designed for
each mission. There would no longer be a need to modify aircraft for special
missions; modify the cargo pods instead. Fourth, detachable pods could
provide instant infrastructure at the destination point. Like building
blocks, Dynalifters could drop off multiple pods, building temporary repair
facilities, field hospitals, and barracks. A small base could be assembled
remotely with unprecedented speed.
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