Great confidence was placed in being able to reduce the noise of a turbojet and massive strides by SNECMA in silencer design were reported during the programme.[93] However, by 1974 the spade silencers which projected into the exhaust were reported to be ineffective but "entry-into-service aircraft are likely to meet their noise guarantees".[94] The Olympus Mk.622 with reduced jet velocity was proposed to reduce the noise[95] but it was not developed.