Airship employs rigid carbon composite framework

Originally part of a DARPA heavy-lift airship program, the Aeros Pelican airship has buoyancy control and requires no ballast.

A radically new type of airship has been taking shape in Southern California, over the past 20 years. Aeros (Montbello, Calif.), founded in 1985 in Kiev, Ukraine by Igor Pasternak and relocated to the U.S. in 1994, has been quietly developing new concepts in airship and tethered aerostat design, and was recently featured as the cover story in the October 15, 2012 issue of Aviation Week & Space Technology magazine. The Aeroscraft’s Pelican  is billed by the company as a “rigid variable buoyancy air vehicle” and is intended for cargo transport, in a much different role from the airships seen at sporting events or as flying billboards.

A traditional airship uses helium contained within a flexible, non-rigid envelope to provide lift, and ground crews to stabilize the craft. Newer hybrid airships use lighter-than-air gas combined with aerodynamic lifting surfaces, and require a runway for takeoffs and landings. If such craft try to carry cargo, that weight has to be compensated for during offloading by ballast, typically water or soil, to combat the “static lift” of the gas. Because of the impracticality of ballast management, large airships have never been used successfully for cargo transport, says Aeros. A mid-2000’s DARPA program, dubbed Walrus, attempted to generate new concepts for heavy lift airships that could be operated without ballast to support military airlift efforts; while the Walrus program lost its funding, Aeros’ Pelican  has continued as an outgrowth of the company’s participation in the DARPA research. 

The 265-ft/81m long Pelican has a rigid airframe made of carbon fiber composite open trusses, which support an outer skin and the small engines, propellers and tail. The propellers can be rotated to create vertical takeoff and landing capability or straight-ahead propulsion, and no runway infrastructure is needed, says the company. The key to the variable buoyancy is air bladders inside the helium-filled envelope. Some of the helium is compressed and stored in tanks, creating a slight vacuum that allows outside air to enter the air bladders, thus making the craft heavier and allowing changes in buoyancy to account for fuel use and cargo. 

The AW&ST article says flight tests should be underway early next year. Aeros sees the craft as a way to transport large wind blades to wind farms, for example, or for luxury passenger service, in addition to potential military uses.