Re: Phase III Engine

Date:         15 Nov 97 16:24:43 
From: (Malcolm Weir)
Organization: Little to None
References:   1 2 3
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On 01 Nov 97 18:55:51 , Marc Schaeffer <> 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.