Engineering topics

Levitt, B. B.

Publications and source records attributed to Levitt, B. B..

3 records

NASA NTRS1983

1983 LTA technology assessment

Several aspects of LTA (lighter-than-air) technology development are reviewed. Technological developments of classical airships through 1974 are examined. A brief historical and technological summary of five specialized LTA equipment concepts is presented: metal-clad airships, free balloons, semibuoyant vehicles, high-altitude platforms, and tethered aerostats. Current LTA technology developments are reviewed with particular emphasis on VTOL airships capable of heavy lift and on long endurance types for coastal maritime patrol. Finally, the future prospects of LTA system development are considered with attention given to manned conventional and hybrid vehicles, tethered vehicles, and RPVs.

Ashford, R. L.↗

NASA NTRS1981

1981 LTA technology assessment - Past and present

A four-part presentation is made of (1) lessons learned from the design and operation of the 'classic' airships of the 1920s and 30s, with respect to such issues as construction, propulsion, control, instrumentation, ground handling, habitability, aerodynamics, and structure and construction; (2) lessons learned from the development of such specialized lighter-than-air (LTA) concepts as metal-clad airships, semi-buoyant lifting bodies, experimental, sport and commercial free balloons, high-altitude platforms, and tethered aerostats; (3) the current status of LTA technology in various countries, with emphasis on significant developments in configuration, dynamics, control, structures, materials, and propulsion; and (4) a projection of future trends. It is concluded that socio-economic factors will strongly influence and encourage LTA development in the 1990s.

Ashford, R. L.↗

NASA NTRS1973

The many uses of the dirigible.

Prospects for a revival of large airships are based on a number of unique services which can be provided by the dirigibles. It is shown that airships are not unduly weather-sensitive. Modern technological advances will give the airship of the future operational features which will be greatly superior to those of the Zeppelins of the past. Projections set the payload of a 22-million-cu ft conventionally propelled airship of conservative design at 615,000 lb for a range of 2950 mi. The corresponding figure for the C-5A aircraft is only 265,000 lb. Dirigibles could, therefore, become merchant ships of the air, carrying low-density and large-dimension cargoes that jet freighters find economically unattractive or practically impossible to handle. The absence of landing-facility requirements would make the airship a logical candidate for introducing trade into otherwise inaccessible regions of the world.

Hunt, J. R.↗