nuckolls.bob(at)cox.net Guest
|
Posted: Mon Dec 24, 2007 11:16 am Post subject: Wire |
|
|
At 09:54 AM 10/4/2007 -0700, you wrote:
Quote: | ========
Allow me to suggest that M22759 Tefzel from the popular
suppliers to the OBAM aircraft industry is the finest
wire we've used in GA aircraft to date, is widely available
and reasonably priced. Praying over the Concise Dictionary
for Wire is probably not a good use of your time beyond
expanding your intellectual horizons on the universe of
wire types.
Bob . . .
========
Is that the stuff that is "Flammable producing copious amount of Dense
toxic smoke (96%+ density) when it burns rendering it virtually impossible
for flight crew to see their flight instruments." ?
Not that I would be able to afford/obtain anything better, but I'm
guessing now that's why my flight instructor told me that if I have an
electrical fire in-air. that I have a poor chance of making it to the ground.
|
Your instructor's statement was about as
useful as commenting on your ability to
survive an encounter with your propeller
or live through a loss of a wing. Yes,
there are characteristics of virtually EVERY
material used in the fabrication and operation
of the airplane that pose some hazard to property
and body if containment within the designed
operating envelope is lost. An obvious case
would be gallons of fuel that become a real
nuisance if (1) allowed to get loose and (2)
become ignited. More subtle examples might
include substitution of hardware store
wagon bolts for the Grade 8 devices that
are normally used to hold critical parts
in assembly.
The evolution of failures that progress to the
point of becoming an in-flight fire are the
same for any fire. You need (1) an energy source
to start combustion. You need (2) a material that
will oxidize readily at the temperatures of
open flame and (3) a continuous source of
oxygen to support ongoing combustion.
The BIG variable in this equation is (1)
energy sources that start things off.
Obviously, we want to accomplish due diligence
in craftsmanship . . . select materials and
install/maintain them in a manner that
reduces risk. We do this by putting
circuit breakers and/or fuses in series
with wires that are at-risk for making
smoke. But this doesn't include ALL
wires. I'll cite dozens of discussions over
the years concerning the value of having
current limiters in the battery and starter
feed paths.
A thing that's easy to control is the
oxidizing characteristic of materials used
in the project. Many millions of person-hours
have been invested in the study of materials
suited to the task (adequate performance)
minimizing if not eliminating that material's
ability to propagate a fire.
Tefzel has been used in tens of thousands of
airframes for decades with great service life
and resistance to hazard escalation when
the wires are participants in a malfunction of
of some portion of the electrical system.
Take care lest you fall victim to folks who
seem to relish application of data (perhaps
questionable) taken out of context and
extrapolating it into ideas of hysteria-
provoking significance. Far too many folks
in our culture seem to enjoy this pastime.
Some have refined the practice to professional
status and make quite a good living at it.
Quote: | Michael
RV-7a panel building with tefzel
|
It's a fine wire. Fly it in confidence and
good health my friend.
Bob . . .
| - The Matronics AeroElectric-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|