Main Page | See live article | Alphabetical index F-18 demonstrating singularity effect The Prandtl-Glauert singularity, at which point a sudden drop in air pressure occurs, is generally accepted as the cause of the visible condensation cloud when an airplane breaks the sound barrier, though there remains some debate. It is an example of a mathematical singularity in aerodynamics. See also: Ludwig Prandtl Herman Glauert Prandtl-Glauert method External links http://www.eng.vt.edu/fluids/msc/gallery/conden/pg_sing.htm This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.