Re: Mechanics of Elevator Trim. In Detail.

Tina <tbaker27705@[EMAIL PROTECTED]
> wrote in news:54595019-a2b0-413e-aea8-
414ce92238c4@[EMAIL PROTECTED]
> 
>>
>> Yes, the time my son spent with canard aircraft brought out all sorts
>> of interesting information about canards and the history of trying to
>> scale up Rutan's original concept Beech Star****p.  The smaller true
>> canards like the Long-eze are pretty good aircraft.  However there is
>> a reason why we don't see large (six plus passenger) true canards.
>> It's the relation****p between CG, fuel load, payload and range.
>> Apparently in the scale up process there is a point where it is no
>> longer practical.
>>
>> Ron Kelley
> 
> Would it not also be true that passive stability is not as im****tant
> in larger modern airplanes? I would guess (again, I admit being
> ignorant of the realities) that adding a 10% aerodynamically induced
> increased load on bigger aircraft would be avoided for efficiency
> reasons? It might be better to have enough fly by wire and computer
> induced stability instead.  I don't know enough about this stuff to
> even find the back of an envelope, let alone do a calculation there.
> 

Yeah, that's one of the main reasons they're going for FBW. An aft cg also

improves buffet margins and allows a higher cruise altitude because of 
that. Some airplanes pump fuel aft after takeoff to bring the CG well aft.

Even ones that aren't FBW. you have to have the autopilot engaged to 
utilise this feature though. 


Bertie