SumpThis: Fuel Contamination in General Aviation Aircraft

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11 March 1992

FAA Central Region
Office Of The Assistant Chief Counsel
Attn: Rules Docket Number 91-CE-95-AD
Room 1558
601 East 12th Street
Kansas City, Missouri 64106

RE: Water retention in the fuel system of the PA-23 aircraft

Dear Sirs:

The writers of this letter informed the FAA about this design defficiency in the tanks of the PA-23 aircraft the first time by an M or D in June of 1985. The FAA denied that the problem existed. It was again denied by the FAA in September of 1987. The entire story is much too long to relate here. Suffice it to say that after much prodding by a congressman and the NTSB, the FAA agreed to actually examine a real aircraft in December of 1987. The did so in February of 1988 and then agreed with our assertions that water in excess, far in excess, of the capacity of the gascolator could be trapped in the after inboard corners of all of the tanks in the PA-23. A letter from the owner of the aircraft tested revealed that the water not able to be drained from each tank was 3½ times the capacity of the gascolator. I recommend that you read this letter from Dr. Paul J. Yocom to the Aviation Consumer dated 2-17-88.

The history of the attempted corrections by the FAA, and the demise of Piper as a viable manufacturer has not assisted in a timely correction of this relatively simple problem.

Water that is niether detectable nor drainable will and does accumulate in the after inboard corner of each tank in sufficient quantities to cause engine failure. The problem of how it got there is surely important, and those maintenance items which will prevent rain and wash water from entering the tanks must be complied with. But regardless of how the water got there, once it is there it cannot be detected nor eliminated by any draining method proposed so far…….as long as the aircraft remains in the normal ground attitude. That fact alone disqualifies this aircraft from certification since it does not meet the requirements of CAR 3.444(c). Secondarily, it does not meet the requirements of CAR 3.553 on draining.

A reasonable analysis of the regulations and just plain common sense demands that a drain be located at the lowest point of each tank as well as at the lowest point of the entire fuel system with the aricraft in the normal ground attitude. Any design which does not meet this criteria not only does not meet certification requirements, it defies logic and common sense. It further misleads the general aviation population to the belief that once the FAA certifies an aircraft it is a safe mode of transport as long as the FAA and manufacturers procedures are complied with. The public, and the courts generally, really believe that the FAA eliminates unnecessary risk factors in aviation when they are made aware of them.

You were made aware of this problem in June of 1985. It is now March of 1992, going on seven years that the problem has been known, and no corrective action of lasting value has been taken to alleviate this hazard.

To ignore the problem because the statistics do not show this to be a serious cause of accidents is to ignore the real world and the recommendations of the NTSB, (A-87-127 through -130, dated December 30 1987). The problem was not recognized by your own investigators, and hence it was not reported as an accident cause. When it was later discovered the pilot was blamed for not performing a proper pre-flight. The reasoning being, had he done so, all the water would have been eliminated according to the manufacturer's Owner's Manual which was approved by the FAA.

Of course, no loyal subject would ever publicly admit that the King is wearing no clothes.

Enough said.

1.

Put a drain in the after inboard corner of each tank and have done with this problem….and save lives.

2.

As an alternative, change the normal ground attitude of the aircraft so that the tank outlet is the lowest point of the tank……if you can…..you might find that the propellors have insufficient clearance.

or

3.

Fail to comply with your own regulations and doom those uninformed individuals to risks of engine losses, the probability of forced landings and fatalities.

All the PA-23 pilots can't be as good as Dr. Yocom, or as lucky…..and most do not fly at nearly sea level most of the time.

Respectfully,

Norman L. Horton

Jerry L. Wells

Here's another letter from a Mr. C. O. Miller who comments on Rules Docket Number 91-CE-95-AD. (SumpThis).

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	11 March 1992

	FAA Central Region Office Of The Assistant Chief Counsel Attn: Rules Docket Number 91-CE-95-AD Room 1558 601 East 12th Street Kansas City, Missouri 64106
	RE: Water retention in the fuel system of the PA-23 aircraft

	Dear Sirs:

	The writers of this letter informed the FAA about this design defficiency in the tanks of the PA-23 aircraft the first time by an M or D in June of 1985. The FAA denied that the problem existed. It was again denied by the FAA in September of 1987. The entire story is much too long to relate here. Suffice it to say that after much prodding by a congressman and the NTSB, the FAA agreed to actually examine a real aircraft in December of 1987. The did so in February of 1988 and then agreed with our assertions that water in excess, far in excess, of the capacity of the gascolator could be trapped in the after inboard corners of all of the tanks in the PA-23. A letter from the owner of the aircraft tested revealed that the water not able to be drained from each tank was 3½ times the capacity of the gascolator. I recommend that you read this letter from Dr. Paul J. Yocom to the Aviation Consumer dated 2-17-88.

	The history of the attempted corrections by the FAA, and the demise of Piper as a viable manufacturer has not assisted in a timely correction of this relatively simple problem.

	Water that is niether detectable nor drainable will and does accumulate in the after inboard corner of each tank in sufficient quantities to cause engine failure. The problem of how it got there is surely important, and those maintenance items which will prevent rain and wash water from entering the tanks must be complied with. But regardless of how the water got there, once it is there it cannot be detected nor eliminated by any draining method proposed so far…….as long as the aircraft remains in the normal ground attitude. That fact alone disqualifies this aircraft from certification since it does not meet the requirements of CAR 3.444(c). Secondarily, it does not meet the requirements of CAR 3.553 on draining.

	A reasonable analysis of the regulations and just plain common sense demands that a drain be located at the lowest point of each tank as well as at the lowest point of the entire fuel system with the aricraft in the normal ground attitude. Any design which does not meet this criteria not only does not meet certification requirements, it defies logic and common sense. It further misleads the general aviation population to the belief that once the FAA certifies an aircraft it is a safe mode of transport as long as the FAA and manufacturers procedures are complied with. The public, and the courts generally, really believe that the FAA eliminates unnecessary risk factors in aviation when they are made aware of them.

	You were made aware of this problem in June of 1985. It is now March of 1992, going on seven years that the problem has been known, and no corrective action of lasting value has been taken to alleviate this hazard.

	To ignore the problem because the statistics do not show this to be a serious cause of accidents is to ignore the real world and the recommendations of the NTSB, (A-87-127 through -130, dated December 30 1987). The problem was not recognized by your own investigators, and hence it was not reported as an accident cause. When it was later discovered the pilot was blamed for not performing a proper pre-flight. The reasoning being, had he done so, all the water would have been eliminated according to the manufacturer's Owner's Manual which was approved by the FAA.

	Of course, no loyal subject would ever publicly admit that the King is wearing no clothes.

	Enough said.

	1.	Put a drain in the after inboard corner of each tank and have done with this problem….and save lives.

	2.	As an alternative, change the normal ground attitude of the aircraft so that the tank outlet is the lowest point of the tank……if you can…..you might find that the propellors have insufficient clearance.

	or

	3.	Fail to comply with your own regulations and doom those uninformed individuals to risks of engine losses, the probability of forced landings and fatalities.