Date: 15 Nov 97 16:24:43 From: email@example.com (Malcolm Weir) Organization: Little to None References: 1 2 3 Followups: 1
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On 01 Nov 97 18:55:51 , Marc Schaeffer <firstname.lastname@example.org> caused to appear as if it was written: >Brian Clouse wrote: >>(SNIP) For regulatory purposes, the FAA has a complex formula based >> on measured decibel levels at prescribed locations on an aircraft >> submitted for certification. > >I would guess that this FAA formula is valid for every country, or are >there different formulas for EU and US ?? The formulae are the same, however the interpretation varies! If I recall correctly, the US permits "averaging" of some of the values, while the EU does not. Thus if the noise is a touch too high at one point, but lower than the limit at another, the FAA will accept the certification while the EU's JAA won't. Malc.