On Sun, 05 Dec 2004 15:29:44 +0100, Stefan
wrote in ::

Larry Dighera wrote:

A Piper PA28-235 can have 84 gallons of fuel in 4 tanks, so leaving
them half empty, for instance in a humid maritime environment,
overnight where the temperature drops sufficiently to cause the
moisture to condense out of the 40 gallons of air contained in them,
will result in enough water in the fuel system to interfere with
operation of the aircraft's power plant.

At 40 degrees Celsius, 1 cubic meter of saturated air contains roughly
40 grams of water. (I leave it to you to convert this to US units.)
Hardly significant.

While the amount of water in the fuel system may be small, so is the
diameter of the fuel lines. In the cool environs at altitude, what is
to prevent the water from forming a frozen 'cork' blocking fuel flow?

Aircraft with fuel bladders that have become deformed or otherwise
lack a smooth bottom surface are capable of trapping significant
amounts of water and preventing it from reaching the fuel sumps for
removal without tipping the wings and other effort. The later model
Cessna 172s now have 10 wing drains as a result.

I submit, that water in an aircraft fuel system has the potential for
disaster. To argue otherwise seems absurd.