Sump This

post was split from click herethis thread

In reply to:

That’s why I asked the question about his profession which he never responded. I was curious as to whether this was another troll or not. By the way, I changed the subject line back to “Sump This.” Doesn’t make sense to piggyback onto BRS posting.
Brian Fowler SR20 #1393


I agree - so I’m starting this as a new thread, in the hope that it continues that way.

  • Mike.

While I am not sure it is worthwhile to respond to anonymous posts, particularly one who believes that their experience with Cessna fuel tanks somehow indicates a problem with the Cirrus, here goes:

First, I have been through the factory tour in Duluth twice and I have seen the inside of the fuel tanks during construction. Even to the unaided eye, the tank appears to have a bottom that is free of obstructions and that there is a definite slope to the sump drain fitting.

Second, I sump religiously even when the ramp is so hot that I feel the greater hazard is in burning my knee doing the sampling.

Third, I personally have seen water in the sample only once. The plane was parked outdoors in Kansas overnight. A thunderstorm came through that was so violent that the plane was canted on the tie downs and in fact one of the tie down bolts that form the ring in the wing broke from the strain. I saw about 2 or 3 drops of water in the first and second sample from one of the tanks and then the subsequent samples were clear. The extreme wind must have forced a little water past the gasket.

Fourth, I always check the condition of the gaskets on the fuel caps.

Fifth, unless the plane is in my hangar or is basically in sight during a lunch stop I lock the fuel caps.

Sixth, AFIK although there have been engine failures on take off none have involved fuel contamination. I think one had a broken camshaft and possibly one broken crankshaft, but I am not sure. I would be very much surprised to hear of a water contamination accident unless the pilot failed to sump the tanks at all.

Seventh, I don’t think the Cessna experience is of much relevance to the Cirrus. Isn’t the Cessna a bladder design? I know there have been problems with water contamination with bladder tanks due to the uneven bottom surface. Since the Cirrus uses an integral tank of composite construction I don’t see any connection. Actually, the tab in the tank provides an additional index of fuel quality since with the tank full you can see the shiny reflection from the tab through the fuel and get some idea of the fuel quality that way.

Eighth, and finally, why are we spending all of this effort to discuss some ephemeral or hypothetical problem anyway. Someone unknown person posts “hey, what about…” and a whole thread ensues!

Cessna also has integral tanks that were approved by the FAA. The Cessna integral fuel tanks, as illustrated below, have water retention problems. Tests were conducted with the FAA present, the tanks failed. See Safety Recomendations 99.283 and 99.284 below. Who tested your integral fuel tanks?


Information: FAA Safety Recommendations 99.283 and 99.284
Date: March 10, 2000

Associate ACO, Manager Airframe and Services ACE-118W
Reply to J. D. Janusz
Attn. of:

Manager, Recommendation & Quality Assurance Division, AAI-200

We have completed our review of the subject recommendations. The subject recommendations cited an example of a Cessna Model 172P that had experienced one incident of a rough running engine and 3 separate in-flight shutdowns, which resulted in forced landings. This particular airplane was equipped with the original standard single wing fuel drain, located in the aft inboard section of each integral wing fuel tank (1 LH & 1 RH). Following the second in-flight shutdown, this operator had Cessna Service Kit SK182-100 installed, which added 4 additional drains at various locations throughout each integral wing tank. The operator experienced an additional in-flight engine shutdown following the kit installation, and has since determined his airplane to be unairworthy, and identifies it as such.

At this time the Wichita Aircraft Certification Office (ACO) has determined the following:

Safety recommendation 99.283: We have reviewed the water/contamination egress capability of the Cessna model 172P, and find that it is not adequate. Our findings indicate that this operator’s airplane was designed and manufactured in such a manner as to not provide adequate water/contamination egress capability. Based on our review, we have determined that other Cessna high wing airplanes use a similar design and construction method for their integral wing fuel tanks. Therefore, we believe this condition may exist on other integral fuel tank equipped Cessna high wing airplanes with gravity feed fuel systems.

Safety recommendation 99.284: We have reviewed the effectiveness of Cessna Service Kit SK 182 -100 and found that it is not adequate to perform it’s intended function of assisting in the detection and removal of water and/or contaminants in the integral wing fuel tanks when the airplane is in a normal ground attitude.

Based on our findings, the Wichita ACO will take the following action with Cessna
Aircraft Co:

Advise them we have determined their design does not comply with the requirements of CAR 3.444 for the model 172P, when equipped with integral fuel tanks.

Advise them we have identified an unsafe condition, which exists on the model 172P aircraft equipped with integral fuel tanks, and that this condition is likely to exist on other airplanes of the same type design.

Advise them that we will be taking Airworthiness Directive action based on the above findings.

Advise them the Administrator has determined that design changes are necessary to correct the unsafe condition, and requests their submittal of appropriate design changes for FAA approval within 30 days.

Advise them we believe this condition may exist on all Cessna high wing integral fuel tank equipped airplanes, and request their identification of applicable models and serial numbers and submittal of appropriate design changes for each model for FAA approval within 60 days.

Advise them that we will be making a Specific Finding to the requirements of 14 CFR part 23.971 on the current Model 182T and T182 programs.

Advise them we will request a full review of compliance substantiation for the model 172, 182 and 206 series airplanes manufactured since the restart of production (type certificated since 1996), with respect to the requirements of 14 CFR part 23.971.

Take any other action deemed appropriate based on the above actions.

We thank you for bringing this situation to our attention and trust that our action plan is considered sufficient to close the subject safety recommendations.

If you have any questions or need additional information regarding these issues, please contact Mr. Jeff Janusz, ACE-116W at (316) 946-4148.

David Ostrodlea
Ronald K. Rathgeber