SumpThis: Fuel Contamination in General Aviation Aircraft

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SUBJECT:

Fuel System Draining Procedure-Water Contamination

MODELS AFFECTED:

SERIAL NUMBERS AFFECTED:

PA-23-150/160 Apache

23-1 through 23-2046

COMPLIANCE TIME:

To be accomplished at each Pre-Flight Inspection.

Purpose:

The fuel strainers are at the low point of the fuel system for each engine. However, opening the quick drain on the fuel strainer only drains the tank and fuel lines on the selected tank. Therefore, it is necessary to drain the system successively in all configurations, (i.e. with the selector on each main tank and each auxiliary tank).

The accumulation of water and/or sediment in the fuel tanks and related lines could cause rough engine operation or complete power interruption. Strict adherence to the preventive practice specified below will keep water accumulation to a minimum and prevent power interruption due to fuel system contamination.

INSTRUCTIONS:

NOTE:

The following sections of the Service Bulletin refer to the Owner's Handbook and/or Pilot's Operating Manual. Therefore this Service Bulletin must be included with the applicable aircraft operating paperwork.

Aircraft Systems Operating Instructions:

1.

Fuel cells should be kept full of fuel during storage and the aircraft refueled as soon as possible after each flight to prevent accumulation of moisture and deterioration of the cells.

2.

The fuel system must be drained daily prior to first flight and after refueling to avoid the accumulation of water and/or sediment using the following procedure.

3.

The main fuel strainers are located in the inboard sides of the main wheel wells. They are fitted with quick drains and must be drained regularly through their access ports.

4.

To drain main (and auxiliary fuel cells if installed), open the fuel strainer quick drain with the fuel selector on the main cell. Drain as required to produce one-half (1/2) pint or more of fuel, per cell. After completion of draining the main cell, select the auxiliary fuel cell (if installed) and repeat draining process. Repeat procedure on both left and right wing main (and auxiliary) fuel cells.

5.

The crossfeed line drain valve control is mounted on the front face of the fuel control panel. To drain the crossfeed line, open the crossfeed valve and line drain, turn on the righthand electric fuel pump and allow to drain for a minimum of ten (10) seconds. Close crossfeed valve and turn off fuel pump. Open the line drain and turn on the lefthand electric fuel pump and allow to drain for a minimum of ten (10) seconds.

CAUTION:

Fuel should be collected in a container and examined for water contamination. If water is present, repeat the above procedures until all water is removed. If it is observed that any fuel cell is draining slower than normal, a complete check of the system should be carried out to determine the cause before flight. Ice formation may cause slow fuel drainage when the aircraft has been exposed to below freezing temperatures. If this is the case, the aircraft should be placed in a warm hangar until normal fuel drainage is attained and all water removed.

Handling and Servicing:

6.

All fuel cells are equipped with fuel caps that periodically must be inspected for proper sealing. In addition, each fuel cell has a filler neck scupper drain tube for water that may collect around the filler neck. These drains must be free flowing with no restrictions. Fuel cell filler cover plate gaskets must also be in good condition and show no evidence of aging, hardening or deterioration. Assuring that fuel caps are sealing properly, drains are unrestricted and cover plate gaskets are in good condition will keep water contamination of the fuel to a minimum.

7.

To minimize water contamination of the fuel during cleaning operations, avoid directing water into the vents, drain tubes, around sealed cover plates and filler cap access openings.

MATERIAL REQUIRED:

Not Applicable.

AVAILABILITY OF PARTS:

Not Applicable.

EFFECTIVEITY DATE:

This Service Bulletin is effective upon receipt.

SUMMARY:

This Service Release was issued to provide detailed instructions for fuel sampling procedures and should be complied with as indicated.

NOTE:

If you are no longer in possession of this aircraft, please forward this information to the present owner.

ATA: 2824

BULLETIN SUPPLEMENT - PROCEDURAL OPERATING INFORMATION

MATERIAL ALLOWANCE:

Not Applicable.

LABOR ALLOWANCE:

Not Applicable.

DISPOSITION OF PARTS IN STOCK:

Not Applicable.

DISPOSITIN OF PARTS REPLACED:

Not Applicable.

Home Documents Images Message Board
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SUBJECT:	Fuel System Draining Procedure-Water Contamination

MODELS AFFECTED:	SERIAL NUMBERS AFFECTED:

PA-23-150/160 Apache	23-1 through 23-2046

COMPLIANCE TIME:	To be accomplished at each Pre-Flight Inspection.

1.	Fuel cells should be kept full of fuel during storage and the aircraft refueled as soon as possible after each flight to prevent accumulation of moisture and deterioration of the cells.
2.	The fuel system must be drained daily prior to first flight and after refueling to avoid the accumulation of water and/or sediment using the following procedure.
3.	The main fuel strainers are located in the inboard sides of the main wheel wells. They are fitted with quick drains and must be drained regularly through their access ports.
4.	To drain main (and auxiliary fuel cells if installed), open the fuel strainer quick drain with the fuel selector on the main cell. Drain as required to produce one-half (1/2) pint or more of fuel, per cell. After completion of draining the main cell, select the auxiliary fuel cell (if installed) and repeat draining process. Repeat procedure on both left and right wing main (and auxiliary) fuel cells.
5.	The crossfeed line drain valve control is mounted on the front face of the fuel control panel. To drain the crossfeed line, open the crossfeed valve and line drain, turn on the righthand electric fuel pump and allow to drain for a minimum of ten (10) seconds. Close crossfeed valve and turn off fuel pump. Open the line drain and turn on the lefthand electric fuel pump and allow to drain for a minimum of ten (10) seconds.

MATERIAL REQUIRED:	Not Applicable.

AVAILABILITY OF PARTS:	Not Applicable.

EFFECTIVEITY DATE:	This Service Bulletin is effective upon receipt.

MATERIAL ALLOWANCE:	Not Applicable.

LABOR ALLOWANCE:	Not Applicable.

DISPOSITION OF PARTS IN STOCK:	Not Applicable.

DISPOSITIN OF PARTS REPLACED:	Not Applicable.