SumpThis: Fuel Contamination in General Aviation Aircraft

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Shirley, New York Trip Report
Concerning Water in the fuel of Piper PA-23 Aircraft

Background:

On May 24, 1994, Melvin Taylor, Atlanta ACO ACE-140A, and Sam Lovell, Small Airplane Directorate ACE-107 visited Brookfield Aviation in Shirley, New York, to look at aircraft wreckage of a Piper PA-23 (N54746) airplane involved in a July 26, 1991, accident (2 fatal owner pilot and wife) near Manteo, North Carolina.(NTSB Identification: ATL91FA142 [SumpThis].) Also, present were Jerry Wells and Norman Horton of Aviation Safety and Management Consultants (ASMC). Mr. Wells and Mr. Horton have written the FAA on several occasions of their concerns about water in the fuel system in Piper PA-23 aircraft. The FAA has visited their Auburn, Washington facility to observe their mockup of a Piper PA-23 fuel cell and test. They have also, stated their disagreement with the National Transportation Safety Board (NTSB) report on this aircraft, which indicated that the airplane sustained only a left engine failure. They indicated that after the NTSB had released the aircraft wreckage, they conducted their own investigation and had positive evidence of water in the fuel system of the right engine. The purpose of the FAA trip was to see any data or information concerning water in the fuel on Piper PA-23 aircraft.

Discussion:

On the morning of May 24, 1994, the FAA personnel met Mr. Wells and Mr. Horton at the Strathmore Hotel and followed them to Brookfield Aviation Inc., located at Brookhaven Airport, Shirley, New York. While waiting for Mr. Calabro, owner of Brookfield Aviation Inc., to open the storage area of the aircraft wreckage, we were informed that he was the son of the accident aircraft owner and pilot. Mr. Calabro opened a small storage hanger and left. Inside was what was indicated to be the important remaining propulsion items of the accident aircraft. The following items were found:

a.

2-two bladed propeller assemblies, one with the blades bend and twisted, the other with 1/3 to 1/2 of the blade lengths missing. The spinners mashed and damaged were still attached as were the propeller mounting flanges.

b.

A set of cylinder head jugs from the destroyed engine. The engine block was consumed in post crash fire.

c.

One basically intact engine minus the fuel filter bowl, and carburetor assembly.

d.

One tape closed box with Mr. Horton writing across the tape. The box contained the fuel filter bowl and carburetor assembly. (Note, it could not be determine if any fuel system modification had been performed.)

General discussions centered on what the NTSB had performed and reported. One prop was reported to be in a power setting I was asked if I could determine the power setting of the props based on their present state of assembly. I indicated that I could not tell what the power settings were unless the props were disassembled. The props had not been disassembled. From the NTSB report it appears that they made their finding based on the condition of the prop blades and the position of the blade angle observed relative to the mashed spinners and blade cuffs, and how the props penetrated through some trees at the crash site. Also, it was mention that the NTSB report did not indicate that the meteorological conditions the day prior to the accident was heavy rain, which delayed aircraft departure until the following day. Horton and Wells indicated that they were told that the owner had experienced water in the fuel problems previously and always performed preflight checks for evidence of water in the fuel.

It was indicated to Mr. Wells and Mr. Horton that we were not there to reopen the NTSB investigation of this aircraft accident, for the NTSB not the FAA have the authority for determining the probable cause an accident. I indicated to them that as with the FAA visit (May 17, 1994) to their Auburn, WA facility, we were there to receive, observe, and discuss any information concerning water in the fuel aspects on Piper PA-23 aircraft. They both seem to understand our reason for being there.

Mr. Horton showed what was indicated to be photos of the engines as they were after the NTSB had released the aircraft wreckage. Close-up pictures showed the safety wiring still in place on the fuel filter bowl and the carburetor assembly components. Other photos showed the associated safety wiring being cut. The contents of the box was removed. The carburetor assembly was in generally good condition. The fuel inlet screen was removed and fairly clean. The inlet fuel metering side diaphragm was remove and some brown discoloration was on the meter orifice. This they said led them to look at the fuel filter bowl. The fuel filter bowl was open and showed about 80 to 85 % of interior surface rusted and an approximate 15 % tear shaped area on one side of the bowl free of any rust. This they said was the positive evidence which clearly showed that this engine experience a water in the fuel failure, because if fuel was present no rust should form in this protected area.

Conclusion:

While Mr. Horton and Mr. Wells appear to be very experience and knowledgeable aviation consultants, I do not agree that what was shown constituted positive evidence that this aircraft experienced dual engine failure as a result of water in the fuel system. I believe the possibility of water in the fuel system was certainly increased by the information received, however, positive evidence would be an over statement. There are a number of unanswered questions which must be resolved before such a conclusion can be reach. Some of these questions are very difficult to ask and/or answer, nevertheless they must be asked. The asking and answering of these questions highlights the NTSB role and responsibility in investigating aircraft accidents. The following are some concerns/questions:

a.

While Mr. Horton and Mr. Wells appear to me to be very honorable aviation consultants, did anyone tamper with the wreckage after it was released by the NTSB?

b.

How long were these parts at this storage area before Mr. Horton and Mr. Wells began their investigation?

c.

Photos of the before condition are just that photos of what is said to be the components in their original state. The fact that the observed components were safety wired when released by the NTSB does not address what may have occurred after being released.

d.

Were there conditions at the aircraft wreckage site which could have introduced water into this portion of the fuel system (i.e. water under pressure). It should be noted that after returning from this trip contact was made with the past and present Manteo, N.C. airport managers, both of whom worked at the airport during July of 1991, and the Assistant Roanoke Island Fire Chief at that time. The following is some information gather from these three people:

1.
The aircraft arrived in Manteo approximately one week prior to its July 26, 1994, departure and was topped off with fuel. Old style fuel caps were noted on the aircraft.

2.
During the week of stay the Manteo and Roanoke Island area experienced several unusually heavy thunderstorms.

3.
The aircraft delayed departure one day due to heavy thunderstorms.

4.
The aircraft departed (approx. 6:15 AM) before any airport personnel arrived and as a result it was not known if a pre-flight had been performed.

5.
The aircraft crashed in a heavily wooded area.

6.
The assistant fire department chief indicated that extreme heat and fire resulted in the surrounding woods being on fire.

7.
He also, indicated that foam and water was used to extinguish the aircraft and woods fire. Foam was used mainly in the main landing gear area because of its magnesium material.

e.

A review of the accident report raised additional concerns/questions:

1.
Since the accident occurred during take-off wouldn't the aircraft orientation have been the least likely for water in the fuel tanks to enter the engines.

2.
In order for water to enter the fuel line when the aircraft is in the take-off orientation, there would have to be more than 15 ounces of water (the amount determined by FAA in the 1988 investigation) in the fuel cell. If this is true then indications are that no preflight draining was performed.

3.
No maintenance records were provided , indicating whether or not AD 88-21-07 R1 had been complied with. This AD required the inspection and repair of the fuel vent/drain lines, thermos type fuel cell caps, and fuel filler compartment covers.

I find it difficult for the FAA to properly address such concerns as above nor is it our responsibility. It is part of bigger questions which are, under what conditions would the NTSB reopen an accident investigation it had concluded and how does it satisfy themselves about the integrity of new found data? Situations such as this emphasizes the role of the NTSB in minimizing such concerns/questions and is the reason for indicated to Mr. Horton and Mr. Wells our purpose for meeting with them.

Recommendations:

It is recommended that we look at the water in the fuel system of Piper PA-23 aircraft from the following perspective:

a.

Is the Airworthiness Directive (AD) which changes the pre-flight procedures sufficient? If it is not, then can it be modified or should the AD be rescinded?

b.

Should AD 90-23-18 be reinstated to require the installation of wedge blocks along the aft wall of the fuel cells?

c.

Determine if an AD could be written which adds a drain, in the aft inboard corner, through the already installed fuel cell without having a sizable undrainable area or creating a leakage problem.

Melvin Taylor

07 June 94

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	a.	2-two bladed propeller assemblies, one with the blades bend and twisted, the other with 1/3 to 1/2 of the blade lengths missing. The spinners mashed and damaged were still attached as were the propeller mounting flanges.

	b.	A set of cylinder head jugs from the destroyed engine. The engine block was consumed in post crash fire.

	c.	One basically intact engine minus the fuel filter bowl, and carburetor assembly.

	d.	One tape closed box with Mr. Horton writing across the tape. The box contained the fuel filter bowl and carburetor assembly. (Note, it could not be determine if any fuel system modification had been performed.)

	a.	While Mr. Horton and Mr. Wells appear to me to be very honorable aviation consultants, did anyone tamper with the wreckage after it was released by the NTSB?

	b.	How long were these parts at this storage area before Mr. Horton and Mr. Wells began their investigation?

	c.	Photos of the before condition are just that photos of what is said to be the components in their original state. The fact that the observed components were safety wired when released by the NTSB does not address what may have occurred after being released.

	d.	Were there conditions at the aircraft wreckage site which could have introduced water into this portion of the fuel system (i.e. water under pressure). It should be noted that after returning from this trip contact was made with the past and present Manteo, N.C. airport managers, both of whom worked at the airport during July of 1991, and the Assistant Roanoke Island Fire Chief at that time. The following is some information gather from these three people:

		1.	The aircraft arrived in Manteo approximately one week prior to its July 26, 1994, departure and was topped off with fuel. Old style fuel caps were noted on the aircraft.

		2.	During the week of stay the Manteo and Roanoke Island area experienced several unusually heavy thunderstorms.

		3.	The aircraft delayed departure one day due to heavy thunderstorms.

		4.	The aircraft departed (approx. 6:15 AM) before any airport personnel arrived and as a result it was not known if a pre-flight had been performed.

		5.	The aircraft crashed in a heavily wooded area.

		6.	The assistant fire department chief indicated that extreme heat and fire resulted in the surrounding woods being on fire.

		7.	He also, indicated that foam and water was used to extinguish the aircraft and woods fire. Foam was used mainly in the main landing gear area because of its magnesium material.

		1.	Since the accident occurred during take-off wouldn't the aircraft orientation have been the least likely for water in the fuel tanks to enter the engines.

		2.	In order for water to enter the fuel line when the aircraft is in the take-off orientation, there would have to be more than 15 ounces of water (the amount determined by FAA in the 1988 investigation) in the fuel cell. If this is true then indications are that no preflight draining was performed.

		3.	No maintenance records were provided , indicating whether or not AD 88-21-07 R1 had been complied with. This AD required the inspection and repair of the fuel vent/drain lines, thermos type fuel cell caps, and fuel filler compartment covers.

	a.	Is the Airworthiness Directive (AD) which changes the pre-flight procedures sufficient? If it is not, then can it be modified or should the AD be rescinded?

	b.	Should AD 90-23-18 be reinstated to require the installation of wedge blocks along the aft wall of the fuel cells?

	c.	Determine if an AD could be written which adds a drain, in the aft inboard corner, through the already installed fuel cell without having a sizable undrainable area or creating a leakage problem.