Re: A3XX vs B747-600 (was: Airbus lawsuit coming?)

From:         kls@ohare.Chicago.COM (Karl Swartz)
Date:         18 Sep 96 13:50:35 
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> >From a regulatory standpoint, if the '747-700' has a totally new wing
> and a totally new fuselage, how can it be certified on the 747 type
> certificate?  Of course, I'm wondering the same thing about the new
> 737s.  They are exactly like the old 737 family except for the wing,
> tail, engines, landing gear, systems, horizontal tail, vertical fin,
> and other 'bits'.  Looks to me like the only thing they share in
> common with a 737-300/400/500 is the basic fuselage shell...

I think I heard that even the 747-400 has a new TC, and I'm pretty
sure the new 737 series does as well.  With derivatives, the border
is somewhat fuzzy -- recall that the FAA made MacDAC get a new TC for
the MD-90 even though it has the MD-80 (DC-9-80) wing, fuselage (with
a plug, maybe two, to stretch it), and the modified tail of the MD-87.
The FAA said they weren't sure at what point it stopped being the same
plane as the original DC-9-10, but they were sure that the MD-90 was a
new plane!

The other extreme is the L-1011.  The first model was the L-1011-385-1
and the FAA office in charge wouldn't allow them to change the -1 to a
-2 on the same TC!  Thus, the second version was the L-1011-385-1-15.
(Actually, the center fuel tanks weren't quite ready in time so there
was an interim -14 model, but you get the idea.)

Dealing with the government is never easy!

Perhaps a better question is how they manage to certify a new type
with the old design rules, which is part of the advantage us doing a
derivative type.  For example, as I understand it, the current 737 is
not certifiable under the current regulations, and there are some odd
regulartory quirks that have allowed the BAE 146-200 and -300 to ride
on the coattails of the -100 even though the later models don't meet
the regulations in question.  (Noise and/or weight in the case of the
146 -- neither the -200 nor the -300 could serve LCY, for example,
but for the *type* being allowed in.)

Karl Swartz	|Home
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills