Membrane envelopes propel heavy-lift aircraft

By Katherine Carlson, a writer and editor based in St. Paul, Minn.

Membrane technologies can be found on land, water and in the air. Tensys Dynamics, Bath, U.K. and Melbourne, Australia, designs envelopes for a new type of aircraft, the Hybrid Air Vehicle (HAV). HAVs are heavy-lift aircraft combining a lifting body hull form with buoyancy from helium, and prototypes demonstrate that the technology works—so much so that an HAV that can carry 40 tons is in planning stages.

Aerospace industry software generally doesn&rsquop;t have the shape generation, fabric analysis or patterning capabilities of inTENS, a 3D finite element program suite developed by Tensys for the design of tensile structures. (Find out more about inTENS on the Tensys Web site at www.tensys.com). The software features modules for form finding (looking for the shape that holds under specified stress), load analysis, membrane patterning and geometric post processing. The hull form of the ATG Sky Kitten HAV is part of its function, and helps it lift the weight. Tensys is also investigating high-altitude tethered aerostats and the design of very large kite sails for use in auxiliary propulsion for cargo ships.