"G.R. Patterson III" wrote in message
...
This is just about impossible in the air. Moving water stays liquid at a
much
lower temperature than standing water. You are postulating a situation in
which
the water in the gas tank is above freezing and the temperature in the
fuel
lines is about 0 degrees Fahrenheit. Of course, it's possible for water to
get
into the lines on the ground and freeze when the temperature gets below
freezing, but then the aircraft would never start.

Actually, ice in the fuel can freeze in the tanks, forming crystals small
enough to pass into the fuel lines, and then form an aggregate large enough
to restrict (or even block entirely) that fuel line.

An alternative possibility is that the water may freeze in a larger form in
the tank, but not block the fuel intake port from the fuel tank until
something during flight jostles it enough to block the port.

Of course, there is always the standard issue of liquid water in the fuel
tank, possibly shifting and/or coalescing enough during flight to create a
problem just after takeoff or well into the flight.

IMHO, the only real question is how much water you might accumulate due to
condensation. That water in the tanks can cause a problem, whether due to
freezing or otherwise, is simply not a question. It can. As I've said in a
different post, I agree that the chances of condensate accumulating in large
enough quantity to cause a real problem is extremely low. But I don't think
it's reasonable to claim that it could never happen.

Pete