Re: Singapore picks the A340-500 over the 777-200X

Date:         26 Jun 98 02:37:47 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
References:   1 2 3 4 5
View raw article
  or MIME structure

>The A340-500 will be powered by 4 53K-lb-thrust engines,
>while the proposed -200X would be powered by 2 102K engines.  I believe
>the A340-500 will have a slightly higher MTOW than the B777-200X.

More than a little bit -- the latest figured on http://www.airbus.com/
have the A340-500 with a MGTOW of 804,700 lbs, whereas Boeing now has
the 777-200X at 750,000 lbs MGTOW, a recent boost from 735,000 lbs.
Engines for the 777-200X are now in the 104,000 lbs thrust range.

>However, the -200X is a twin, twins generally should have higher
>thrust-to-weight ratio than four-engine planes (and this has been
>discussed many times in s.a.a).  Relative to other B777 variants, an
>102K engine does seem to be adequate for the proposed MTOW for the
>-200X.

model        MGTOW    thrust   t/wt    1out
-----       -------   ------  ------  ------
757-200     240,000   38,250  0.3187  0.1594
777-200     545,000   84,000  0.3083  0.1542
777-200IGW  648,000   92,000  0.2840  0.1420
777-200X    750,000  104,000  0.2773  0.1387
A340-500    804,700   53,000  0.2635  0.1976
A340-600    804,700   56,000  0.2784  0.2088

I included the 757-200 as it is notorious for being overpowered.  You're
right, with 104,000 lbs thrust engines, the 777-200X does look somewhat
anemic.

--
Karl Swartz	|Home	kls@chicago.com
		|Work	kls@netapp.com
		|WWW	http://www.chicago.com/~kls/
"The average dog is a nicer person than the average person." - Andrew A. Rooney