Barrington Tennant wrote:
> I put it down to vapour lock - everything under the cowling was
> extremely hot.
> ...
> I don't know exactly what the problem was but I suspect that the original
> fuel lines had become porous as I can see cracking on the ends of the
> pipes. I also fitted pipes without the metal armour to be better able to
> see any weeping in the future.
>
> It was a scary experience and I am putting the clear plastic pipe check
> for air in my 100 hour check list.
> ....
I have been assuming that firelsleeve can be effective in reducing
temps in the fuel line, in providing some airspace within. Whereas
steel braid is the opposite. While reflective, it still absorbs (low
emissivity), as does the black organic material of the fuel line.
Like baking a potato wrapped in aluminum foil. Is this correct?
FWIW, I located the following quote in an NTSB report, from an STC
applicant seeking approval for auto fuel use in the Beech B-19: " the
applicant's tests found the airplane's engine would not operate on
auto fuel due to severe vapor lock. The vapor lock was caused by a
number of items according to the applicant: length of fuel
lines, number of bends in the fuel lines, fuel tank venting, and the
cowl's internal temperature."
Regards,
Fred F.
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