Re: Safety and design rankings (was Re: Flight controls)

From:         drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Organization: Boeing
Date:         29 Dec 92 22:53:51 PST
References:   1 2 3
Followups:    1
Next article
View raw article
  or MIME structure

In article <airliners.1992.173@ohare.Chicago.COM> hoyme@src.honeywell.com (Ken Hoyme) writes:
>
>In article <airliners.1992.163@ohare.Chicago.COM> kls@ohare.Chicago.COM (Karl Swartz) writes:
>> My understanding was that the 747-400 does *not* have a new wing but
>> rather a tweaked version of the original.  I recall some statement
>> from Boeing regarding the lack of winglets on the 777, which noted
>> that the 777 had a new wing and starting from a clean slate it was
>> more efficient to not have them, whereas working from an existing
>> design as with the 747-400 it was helpful to have them.

One further comment.  The 747 is constrained on span, therefore the
winglets were the optimal choice for improving the efficiency of the wing.
The 777 has chosen to offer two options:  folding wingtips, and 'ignore the
existing infrastructure'.  Both options allow an unconstrained span, which
gives better induced drag performance.

>I believe the winglets issue on the 777 was also complicated by the
>folding wing option.  Which no one has ordered -- even those airlines
>who originally expressed interest in the option.  Has development on the
>folding wing stopped??  I had heard that Boeing was getting tired of the
>investment required to keep the option open while not receiving any
>orders for it.

I don't think I'm giving anything away by saying that the folding wingtip
option is still being studied, primarily by the New Large Airplane
Division.  They apparently don't think they can get away with a 'damn the
infrastructure' attitude.  :-)


-- 
Terry
drinkard@bcstec.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."