Jane's at Paris Airshow 2001- Sonic Cruiser details leak out Among these is the power-plant. Here, both Boeing and engine manufacturers face a series of technical challenges. The engine will have to be based on current technology – most probably the General-Electric’s GE90, the Rolls-Royce Trent 800 and the Pratt &Whitney PW4098 – but designed to blend into the wing to obviate some of the high levels of drag needed for high-bypass engines. The semi-recessed design will borrow much from Boeing’s military programmes but will not automatically guarantee the noise, range and payload performance that Boeing is seeking. Noise, in particular, will be a major issue. Although the aircraft will be certified from day one to the new Chapter Four noise standards – a mere 10dB less than the current Chapter Three limits – it looks increasingly likely that many European airports will have introduced their own much more stringent noise limits by 2006. Which means that merely meeting Chapter Four requirements may not be enough – and that also implies new noise-reduction technology for wing, airframe and landing gear.