RAMJET

Set to 6 different clues across 6 published puzzles, most often “Engine using a stream of compressed air” — The New York Times, Saturday, 8 December 2007.

6 letters

Every clue on record, most used first

Engine using a stream of compressed aironce
The New York Times — Saturday, 8 December 2007
Engine for missilesonce
The New York Times — Thursday, 1 June 2000
Big airplane engineonce
The New York Times — Monday, 27 March 2000
Aircraft engineonce
The New York Times — Wednesday, 1 December 1999
Simple propulsion unitonce
The New York Times — Saturday, 15 March 1997
Airplane engineonce
The New York Times — Tuesday, 11 October 1994