Water In Fuel Tanks

[170C]

One never knows who or what is at your local airport. I know we have a former astronaut, but who knows who else? Today as I was working in my hangar & I kept hearing a lot of noise in a hangar behind mine. I have never seen the door open so, being nosy, I walked around to see what was going on. The noise was not aviation related, but the hangar occupant introduced himself and proceeded to give me a 20 minute talk about water in aircraft fuel tanks. He showed me about six tanks, mostly from Cessna 150 & 152's as well as a Diamond DA-40. The Cessna tanks had large square holes cut in them for easy inspection. The gentleman's name is Robert Scovill, Jr and says he has had many, many discussions with both the FAA and NTSB regarding engine failures on his C-172P. He has read and studied many NTSB reports and told me all of the Cessna aircraft (as well as many other mfg's) have issues with water being trapped in the fuel tanks that cannot be removed via the sumps. He has this above C-172, which he purchased new, and after 4 engine stoppages, including at least on in a field near here (MBT-Murfreesboro, TN) he hasn't flown the plane since April of 1999!

I do not remember every reading of sever water problems in our planes, but that is what I was told. He provided me with a business card and a website which might be of interest. I am curious if members have had unusual problems with water in their fuel. Website is http://sumpthis.com/

[n3833v]

I have never had water in fuel. I use good source aviation fuel and haven't had any problems with condensation. I also sump every time.

John

[Avee8or]

in 50 years, only once have I had trouble, and only a couple of times have i found any traces of water in sumping an airplane. BUT--all of those cases were C150 or 172s.

The worst was a 1970's ferry flight in a late model 150 that sat outside for maybe 6 months without having been flown...tanks full. No water in sumping the tanks and gascolator. But, at about 50 ft, the engine quit cold...full flaps and a hard slip, and I stopped with a few feet of hard runway ahead of me. I then proceeded to drain several quarts of water from the wing tanks. The shop purged a bit more water before the next ferry attempt.

Lesson: water can get trapped in the tank where it will not immediately drain with the aircraft level...a thorough check requires draining. then lowering the tail to redistribute whatever is in bottom of tank, then re-draining. Some people maintain that rocking the wingtip a bit will do the same thing. I have had some tell me that agitating the fuel as described is a bad idea as water can become temporarily suspended in the fuel and then not reach the drain when immediately sumped. Personally, I subscribe to shaking things up a bit!

In the six months or so I have had 11A, I have not found any contamination...but I am careful in fueling, and the plane has a dry, somewhat warm hangar overnight and is usually put to bed with full tanks. (minimum room for any moisture in the air to condense in the tank--although I cannot imagine condensation to produce much contamination given the small volume of air involved.) Another (urban?) legend is that warm fuel and air in partly filled tank can become contaminated by condensation if airplane taken into the cold outside. I have never witnessed such an event however.

[MoonlightVFR]

I visited the sumpthis.com website. from your posted link.

Most of us GA pilots have an awareness of water in fuel contamination and we think we are taking ALL precautions. Well mostly.

Your hanger neighbor sounds obsessed with the problem.

Does he really have a collection of fuel tanks that are opened up for internal viewing?


Your emphatically listening to him may have lessened his angst and encourage him to fly his airplane again.

[170C]

I can attest to the fact that he has the tanks I mentioned since he showed each one to me. Mentioning my encounter with this "neighbor" to others at my airport, I find he has been around for quite a long time, has given numerous talks on the subject, annoyed many and is obviously very anal about the subject. Not saying there aren't some issues with water in fuel from time to time, but it would not appear to be a major problem considering the thousands of hours of flying planes do every year and few contaminated fuel incidents are reported. However it is interesting to see how many fuel sumps planes of our vintages have vs the number the newer Cessna 172's have.