A photograph taken in Beavercreek has some hoping it's proof of top-secret 'pulse jet' tests.
By By Jim DeBrosse

Staff Writer

Monday, January 08, 2007

BEAVERCREEK — A Beavercreek man's photograph of an unusual aircraft condensation trail has sparked a high-flying debate among scientists and aviation fans over whether the Air Force or NASA is flying an aerospace vehicle with an exotic new propulsion system.

The photo of the vapor trail, taken Nov. 10 by amateur meteorologist Bill Telzerow from his backyard, shows a distinctive "doughnuts-on-a-rope" shape.

The photo has raised questions about whether an experimental propulsion system that uses pulse detonation engine technology is being tested here. The propulsion system could potentially hurtle manned craft at six times the speed of sound (Mach 6).

The photo has been downloaded several thousand times each day since it was posted on the Web a week ago by the Federation of American Scientists (www.fas.org/irp/mystery/donuts.html), a Washington, D.C.-based group of scientists and engineers who monitor national policies on technology and research.

"I don't think (the photo) is proof positive, but I think it's interesting and suggestive," said Steven Aftergood, a senior research analyst at the federation.

Similar vapor trail sightings nationwide from 1988 to 1992 fueled speculation that the Air Force was working on a top-secret successor to the SR-71 Blackbird spy plane.

Pulse detonation engines, or pulse jets, contain no moving parts and are lighter and more efficient than regular jet engines.

Fuel is injected into the air inside the tube and ignited in a rapidly-occurring series of pulses. General Electric and Pratt & Whitney are both exploring the technology.

The Air Force Research Laboratory at Wright-Patterson Air Force Base has conducted runway tests on a small version of a pulse detonation engine, but officials there say they have not yet flown a PDE craft.

Telzerow, a spotter for the National Weather Service, said he was photographing the wind gauge in his backyard when he noticed the unusual formation.

He snapped four photos over several minutes because "I'd never seen anything like it before."

He said he had no idea what it was until he talked to two ex-pilot friends, both of whom speculated it was from a pulse jet.

Tim Fry, an aerospace research engineer at the University of Dayton Research Institute, said he isn't convinced. Vapor trails "do wacky things. There could be any number of atmospheric disturbances going on that could cause it to lump together like that," he said.
http://www.daytondailynews.com/n/con...7pulsejet.html