Surface Flatness, now Faraday cages

[Rcmaster199 at aol.com]

The windows are sized and shaped such that lightning will have practically  
no effect on passengers. 
 
MattK
 
In a message dated 11/24/2004 9:48:35 AM Eastern Standard Time,  
bob at toprudder.com writes:

I mentioned that the material used to construct RF shielded rooms would  make 
a good flat worksurface. Then somebody mentioned "Faraday cage" --  
completely off topic for the group. Funny, though, it made it back to "don't  build a 
fuselage out of this stuff". 
 
You mentioned full-sized aircraft fuselages being Faraday cages,  they are to 
some extent. Not only can the fuse shell keep signals out, they  can also 
keep signals in. Very high field strengths can be achieved with very  little 
power, and nodes can exist where reflections arrive in phase. This is a  very big 
problem, and compliance test standards (such as DO-160) exist to  insure that 
systems inside an aircraft don't emit strong signals that can  interfere with 
other systesms, and can also still operate when interference is  present. This 
is also why they don't want computers and electronic equipment  operating 
during the times that the instrumentation is most needed (takeoff  and landing, 
especially in IFR conditions). 
 
Bob Richards.


Rcmaster199 at aol.com wrote:

 
The tangents that some threads create are often much more interesting  than 
the original intent of the thread. 
 
Keith I would say it's not a good idea. If you built a fuse out of this  
material, (done everyday BTW),  I suggest you build it large enough to  accomodate 
the person flying it (vbg). I know Bill, Don Ramsey and Al Glenn  and 
probably several more, flew or still fly "Faraday Cages" for a  living
 
Now, how we went from measuring surface flatness to "shielding" devices  from 
EMI/RFI (regardless of what the emitting source is), is beyond me
 
MattK





 
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