Timz From United States of America, joined Sep 1999, 6634 posts, RR: 7 Reply 1, posted (10 years 8 months 3 weeks 4 days 9 hours ago) and read 6868 times:
Dunno about ICAO-- but if they're similar to FAR36:
FAR36 sets limits to takeoff noise (measured along the extended runway centerline a specified distance from the start of takeoff roll), approach noise (measured along the extended centerline?), and sideline noise. The limits are calculated from the logarithm of the MTOW for takeoff noise, and from landing weight (?) for approach noise (and sideline?). Also different limits for 2-engine/3-engine/4-engine, maybe?
And noise is measured in effective perceived decibels-- some frequencies are considered noisier than others.
B747skipper From , joined Dec 1969, posts, RR: Reply 4, posted (10 years 8 months 6 days 9 hours ago) and read 6654 times:
ICAO Annex 16, Chapter 1, Chapter 2 and Chapter 3 are equivalent to -
US FAR 36, Stage 1, Stage 2 and Stage 3...
(noise standards - measurements etc...)
Some old 747-100 and 200s are considered Chapter 2, but it is possible to reduce the effective noise by reducing the weight at which they are certificated to takeoff and/or land... - In that case, a little plaque may be placed in the flight deck, indicating "Chapter 2" or "Chapter 3"... i.e. an old 747-200 with T/O certification for 351 tonnes, might be restricted to 345 tonnes to comply with Chapter 3...
Newer 747-200 and all -300s are Stage 3 - Chapter 3...
ICAO Int'l Civil Aviation Organization (Montreal, PQ) - ICAO is a branch of UN...
Some ICAO field offices at other locations - Lima, Peru - Paris, France... etc...