Re: Blended-body snag?

Date:         03 Feb 97 03:18:34 
From:         Joules Potter <>
Organization: Typhoon
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In article <airliners.1997.378@ohare.Chicago.COM>, adopt
<> writes
>In article <airliners.1997.317@ohare.Chicago.COM>,
>(Ostreger) wrote:
>>How do the new blended-body airliners claim to handle pressurisation
>>....This means near on a couple of thousand
>>tons is trying to tear one apart, distorting it and - critically -
>>fatiguing it.
>Not a technical answer... but do wonder if a design could be
>similar to a submarine.  The guts of the passenger/flight crew
>pressure shell could still be cylinderical... although blended
>with the whole 'wing'.

Sounds like a good idea, maintain a pressurised semi-monocoque shell
within the unpressurised remaining wing area.

Nobody has yet mentioned fuel storage.
 A 747-400 can hold a max of 173000kg(382999lbs) of fuel, which should
get it LHR-HKG for example. Taking into consideration new engine
developments which lead to better fuel consumption, to have any sort of
range this aircraft is going to have to carry, or have provision to
carry, a lot of fuel. So where are they going to put it?

What about the engines?

Modern engines are tending towards higher and higher bypass ratios, can
you imagine 4 next generation RR Trent/GE engines mounted internally?
Quite apart from the size of the engine, the intake/exhaust ducting
would be enourmous, having to pass through the length of the aircraft,
disrupting the passenger carrying compartment and creating even more
structural questions.

>If part of the wing is used for passenger/pressurised cargo
>area... then could low level flight/slow(er) speed minimise
>the pressure differential?  Would it need to have a significant
>increase in capacity to offset that 'slower' speed?

Same old story, fly lower and slower costs more and reduces range,

>>(Conventional airliners have an equivalent problem, but
>>their circular fuselage does not distort with pressurisation - though the
>>Comet III exploded nonetheless!)

Round fuselage, square windows.... oops     :-)

Unless there are some real wayout advances in all aspects of aircraft
construction, eg materials, engines etc, then this incredible flying
machine IMHO will never get off the drawing board and into the air as a
commercially viable passenger aircraft. It could perhaps go the way of
Concorde instead.



Joules Potter

Licenced Aircraft Engineer