41. The pure turbojet engine is not fuel-efficient. 42. Saab had initially envisaged powering the " P1150 " with the indigenously produced STAL Dovern turbojet engine . 43. One of the last applications for a turbojet engine was the Concorde which used the Olympus 593 engine. 44. The J40 represented a big opportunity for Westinghouse to become a prominent player in the turbojet engine market. 45. This configuration was formerly very commonly used in aircraft engines before being superseded by turboshaft and turbojet engines . 46. Heinkel had developed the turbojet engine and the testbed aircraft, the Heinkel He 178 V1, in great secrecy. 47. The X-48C was instead modified to use two Advanced Micro Turbo ( AMT ) turbojet engines in 2012. 48. The Comet was powered by two pairs of turbojet engines buried in the wings close to the fuselage. 49. The development of this engine lost focus in favor of the new hypersonic precooled turbojet engine ( PCTJ ). 50. In 1991 Ohain and Whittle were jointly awarded the Charles Stark Draper Prize for their work on turbojet engines .
