Rethinking Air Power: How Hybrid Airships Haul More Than Hot Air
A blimp. A Zeppelin. A dirigible. All are variations of airships, but what if it was as tall as an eight-story building, had a cargo ramp and door similar to a C-5 Galaxy and hauling capacity of a C-130 Hercules? What if this vehicle could carry a crew, land on any surface and provide access to remote locations around the world that until now were virtually inaccessible? Then you’re talking about a next generation airship.
More than two-thirds of the world’s land area and more than half of the world’s population do not have direct access to paved roads or runways. This lack of infrastructure presents numerous challenges for worldwide humanitarian relief, natural resource extraction and heavy cargo operations. In most cases, developing these areas to accommodate roads or airways is not an option, so for centuries they’ve remained isolated.
True to form, the Skunk Works ® team in Palmdale, California, recognized this challenge and since the early 1990s has developed technologies that evolved into today’s Hybrid Airship; a cargo airship that revolutionizes remote access through patented innovations such as the Air Cushion Landing System (ACLS), thrust-vectoring propulsion and a Self-Propelled Instrument for Damage Evaluation and Repair (SPIDER).
While the concept of cargo airships has been around for more than a century, it has yet to be put into useful service. When people think of the inception of flight, they often think of powered flight and the Wright brothers’ first flight in 1903. But one might argue that human flight actually started with the Montgolfier brothers in 1783 when they left the ground in a lighter-than-air balloon for a flight that lasted about 10 minutes. With the Hybrid Airship, the brothers could have flown 2,000 miles on a single tank of helium hauling a fully assembled front-end loader, 19 passengers and 10,000 pounds of additional supplies. We’ve certainly come a long way.
A Cargo Ship In the Sky
The Hybrid Airship efficiently provides access to underdeveloped regions without disturbing natural habitats and avoiding costly infrastructure development. From carrying heavy equipment to undisturbed regions of Alaska, to serving as a flying clinic for disaster relief efforts, there is almost no mission this ship can’t perform. No runway, landing pad or flat surface needed, the Hybrid Airship can descend, land and be unloaded on land, ice and even water thanks to its unique Air Cushion Landing System (ACLS). Operational any time of day or night, in wind, rain or snow the Hybrid Airship is no ordinary balloon.
No Strings On Me
The ACLS is a game-changing technology never before seen in the airship industry. Typically a dirigible descends and uses tethers to be moored to the ground, but by utilizing three underbody hover pads, the Hybrid Airship floats along the ground nearly friction free on a pocket of air. When it needs to remain stationary, the same pads ‘grip’ the ground with light suction pressure to keep the airship from moving in variable winds.
The ACLS hover pads are inflatable toroids — think of a doughnut — attached to the airship’s envelope with an electric fan system that blows air through its center to create the cushion of air. “Fingers” made of lightweight material hang below the toroid while hovering to create a seal with the ground, and if the ground isn’t perfectly flat, the fingers make up for the variation. These fingers also allow for taxiing over obstacles up to two feet tall, such as tree stumps or rocks, so extensive site preparation is not needed to set up a high volume cargo flow.
While parked, the ACLS internal fan flow is reversed to grip the airship to the ground with low suction pressure (less than 0.2 psi) to stabilize the airship during cargo operations. When flying, the ACLS pads are retracted and covered with a furling system to improve cruising efficiency.
Similar to traditional aircraft landing gear, the ACLS pads are configured in a tricycle arrangement to provide reliable ground-handling characteristics. The nose pad is attached under the gondola while the main pads are attached directly to the outer lobes of the envelope.
Unlike traditional aircraft, where heavy landing gear is used to absorb concentrated landing loads, the large size of the ACLS pads distribute the load over a wide area, allowing for lightweight fabric and air to perform the same job.
Not Your Run-of-the-Mill Airship
The Montgolfier brothers may have pioneered the use of airships in 1783, but it’s clear the Hybrid Airship is not your grandfather’s airship. The possibilities are just being discovered and simultaneously changing how the world views remote cargo transportation. Harnessing buoyant lift is not a new concept, but using it as a source of heavy lifting is novel. Coupling its strength with technologies that preserve the environment and create efficiencies is downright revolutionary.
Written by Erica Turner, a Communications Representative at Lockheed Martin Aeronautics.