Such engines are effective at lower speeds, than the pure jets, but at higher speeds than the turboshafts and propellers in general.

A mountain of pure jet Rears its sheer bulk to heaven; and no snows Tinge evening with rose.

In 1940, after the successful run of Whittle's centrifugal-flow design, their effort was re-designed as a pure jet, the Metrovick F.2.

Still, Hamilton Standard engineers say, the shriller sound produced by a pure jet is easier to block from the passenger cabin than the roar of a propeller.

"A pure jet is like a fast sports car whose wheels are always spinning," Mr. Levintan said.

In the 1950s Essendon Airport was too small for the larger pure jets, like the Boeing 707.

The main objective of the project was to demonstrate the ability of a pure jet to vertically takeoff, hover, transition to horizontal forward flight, and vertically land.

The colour is black, either pure jet or with a rusty tinge, and a little white on the underline is acceptable.

The house gleams in the moonlight: the roses he has planted, now flooding the night with perfume, appear jet black and pure white.

Speed was to be from very slow to medium subsonic, with much longer loiter times than a pure jet.