About 20 years ago, the existence of a new miniature turbojet engine inspired an imaginative designer to create a small unmanned aircraft for reconnaissance missions. This marked the beginning of a new era of turbojet development. Visionary designers predicted that miniature engines would someday perform missions comparable to those of larger unmanned aircraft.The WR2/WR24 series of engines has grown from the original 50-lb thrust to over 200-lb thrust. Unique challenges were encountered during the early period as the engine developers found themselves pioneering a specialized field. Innovative concepts were necessary to maintain simplicity, light weight and high performance.