Re: Engine noise

Date:         06 Jan 97 01:41:44 
From: (Larry Stone)
Organization: InterServe Communications, Inc.
References:   1 2
Followups:    1
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In article <airliners.1997.110@ohare.Chicago.COM>, "Dave & RuthAnne
Clickner" <> wrote:

>Stage 2 or 3 is based on the weight of the aircraft and the noise level.  A
>767 can make a lot of noise and be stage 3 while a 727 can make less and be
>stage 2.  And yes there is a very large difference in the noise levels of
>stage 2 and stage 3 for a single aircraft type.

I was quite surprised recently to discover that our (United's) older
747-100's and 200's, which are Stage 2, get classified Stage 3 when flying
red-eye from HNL to SFO, apparently due to a pre-dawn noise requirement at
SFO. I've been unable to determine if the "modification" is anything more
than placing a placard in the flight deck that in essence says "this is a
Stage 3 airplane". Perhaps there's also a largely irrelevant maximum
take-off weight reduction - irrelevant due to the relatively short flight
and resulting fuel on board as I've never been aware of a 747 off HNL to
the West Coast being wwight restricted (unlike the DC-10-10's).

-- Larry Stone ---
   Belmont, CA, USA
   My opinions, not United's.