From: D.P.Rhodes@lboro.ac.uk (Darren Rhodes) Organization: Loughborough University Date: 20 Jul 96 15:56:07 References: 1
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On 14 Jul 96 22:43:23 , Daan Vlaskamp <email@example.com> wrote: >Could anyone give me more information on the coming "Stage III noise >limitations" by ICAO ? (These frequently pop up in environmental discussions >concerning our local airport). I would like to know which types would not be >allowed anymore (which have to be modified/hushkitted/rendered out of >service). I looked at the ICAO website but found no info. Does anyone know >of a document somewhere on the Net ? Stage 3 or Chapter 3 already exists and is a requirement for all aircraft built on or after 6 October 1977. The following types therefore meet these standards: Airbus A300-600 Airbus A310 Airbus A320 Airbus A330 Airbus A340 Boeing 737-300/400/500 Boeing 747-300/400 Boeing 757 Boeing 767 Boeing 777 McD MD-80 McD MD-11 McD MD-95 The above list is an example, it is not complete. The noise is measured at three reference points: Approach Reference Point: 2000m from the threshold along the extended runway-centre line. Assuming a 3° glide slope orignating from a point 300m past the threshold, this gives an aircraft height of 120m above the measuring point. Max level: 105EPNdB for MTOW >280,000kg decreasing linearly with logarithmic MTOW to 98EPNdB for MTOW of 35,000kg, below which it stays constant. Lateral Reference Point: The point on a line parallel to and 450m from the runway centre-line, where the noise level is a maximum during take-off. Max level: 103EPNdB for MTOW >400,00kg decreasing linearly with logarithmic MTOW to 94EPNdB for MTOW of 35,000kg, below which it stays constant. Flyover Reference Point: The point on the extended centre line of the runway and at a distance 6.5km from the start of roll. Max level: 2 Engines or less: 101EPNdB for MTOW >385,00kg decreasing linearly with logarithmic MTOW at a rate of 4EPNdB per halving of mass to 89EPNdB, after which it stays constant. 3 Engines: 104EPNdB for MTOW >385,00kg decreasing linearly with logarithmic MTOW at a rate of 4EPNdB per halving of mass to 89EPNdB, after which it stays constant. 4 Engines: 106EPNdB for MTOW >385,00kg decreasing linearly with logarithmic MTOW at a rate of 4EPNdB per halving of mass to 89EPNdB, after which it stays constant. ICAO plans to introduce a rule to ban all Stage 2 aircraft operated regardless of age in 2002. This is why many airlines, particularly US are either replacing DC-9/Boeing 707/727/737-200 type aircraft, or re-engining, or hush-kitting them, in preparation for 2002. Re-engining is expensive and on an old airframe or questionable value. Hush-kitting is cheaper, but reduces max thrust and often increases fuel consumption and emissions produced. Now, I have deliberately left off some new aircraft from the above list which come into a new category. ICAO iand the industry is currently discussing stricter noise limits than Stage 3. These will not be as severe as the change from Stage 1 to 2, and have therefore been nicknamed 'Stage 3.5'. The current estimate is that they will be Stage 3 minus 1-3 EPNdB at each or the three measuring points. Currently the MD-90, Boeing 737-600/700/800 and Boeing 777 will meet these proposed standards. Indeed all new aircraft on the drawing boards are considering Stage 3.5 in the design process. Apologies to the group for the long discussion!