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Naval Aviation Maintenance Program for Fuel Surveillance

References:

1. OPNAV 4790-2G: Establishes the Fuel Surveillance Program

Requirements.

2. NAVAIR 01-1A-35(Aircraft Fuel Cells and Tanks): Provides

procedures for fuel sampling and states that only

trained and experienced personnel shall perform the fuel

sampling process.

3. NAVAIR 15-01-500(Aircraft Preservation Manual): Directs

when fuel samples are to be taken given material

condition of the aircraft.

4. Maintenance Requirement Cards (MRCs)/Maintenance

Instruction Manuals (MIMs): Direct when fuel samples are

to be taken for specific Type Model Series aircraft and

test cells.

5. NAVAIR 00-80T-109: Aircraft Refueling NATOPS Manual.

6. MIL-HDBK-844: Aircraft Refueling Handbook.

Objectives:

The Fuel Surveillance Program:

a. Establishes policy, responsibilities, and requirements for implementing procedures to maintain a satisfactory level of aircraft and engine fuel systems purity.

b. Standardizes fuel systems contamination prevention procedures within all Navy and Marine Corps activities.

Background:

In order to maintain a satisfactory level of aircraft and engine fuel systems purity, both military and civilian aviation maintenance activities monitor and maintain fuel surveillance programs for all type model series aircraft and engine test cells. In commercial and general aviation, the Federal Aviation Administration (FAA) advises civilian aviation to develop fuel sampling procedures (Aviation Circular AC150/5230-4). Similar procedures are used by Naval Aviation as outlined in OPNAVINST 4790.2G.

Whether a commercial or military application, fuel quality has a direct bearing on the condition of aircraft and engines. Stringent requirements are applied to aircraft fuel quality due to aircraft high performance criteria and safety of flight constraints. Proper Fuel Surveillance prevents the harmful effects of fuel contamination which include erratic or incorrect fuel quantity indications, fuel system icing, and damage to engines and fuel system components. Even though filters are installed in the fuel systems of aircraft and support equipment, contamination can still occur. Condensation of moist air can introduce small amounts of free water in empty or partially filled fuel cells/tanks. Microbiological organisms can grow if free water is present. Also, particulate matter contamination may be generated within fuel cells/tanks and lines or be introduced during maintenance. Even minute amounts of dirt and water in fuel can cause aircraft engines to fail with possible injury or loss of life and very high repair or replacement costs. For example, if fuel contamination results in an engine flame out, damage to the aircraft may be incurred or the engine may require replacement. In the case of an F/A-18C squadron, the cost of an engine repair/replacement, loss of aircraft due to mishap, or defueling for maintenance action is as listed below:

F404-GE400 engine (Material)

Average AIMD Repair Cost: $ 84,700.

Average Major Depot Repair cost: 403,000.

Average Regular Depot Repair cost: 253,000.

Replacement cost: 1,800,000.

Average Manhours to

Remove/Replace engine: 20 Hours

(4 Pers/5 hrs)

Average Manhours to

Repair Engine at AIMD: 67 Hours

F/A-18C Aircraft

Cost to replace: $35,000,000.

Cost to defuel:

Fuel (12,800lbs) 1,220.

Manhours (2 pers/3 hrs) 6 Hours

As a precaution against damage from fuel contamination, aircraft maintenance personnel and test cell operators must regularly inspect for water and foreign matter in fuel cells/tanks. For aircraft, fuel samples are taken as a part of the Daily/Turnaround Inspection or after maintenance to fuel cells per MRC/MIM. For engine test cells sampling is conducted weekly. In both cases, an individual fuel sample is drawn from the lowest point on the engine or fuel tank, normally a pencil drain, into a glass container. The sample is then visually inspected for a clear bright appearance per reference 5 by swirling and checking directly below the vortex for any discoloration, water, cloudiness or sediment. If a sample indicates contamination, it is retained and a second larger sample, not less than one gallon, is taken. If contamination is still present, the aircraft or test cell is downed for maintenance.

Effectiveness:

During calendar year 1999, Type Commander Aviation Maintenance Management Team evaluators conducted a survey throughout several type/model/series aircraft. In each activity, the fuel sample logs indicate that contaminates are being identified prior to aircraft/engine use. The most common contaminant was water with all types of contamination detected.

Recent Aviation Maintenance Management Team visits to activities have identified only minor program administrative related discrepancies. The activities’ compliance with program requirements has been satisfactory. The requirements of the NA 01-1A-35 and the specific publications/directives are sufficient enough to maintain fuel systems/equipment in satisfactory condition. The fuel samples are taken as required by the Type/Model/Series (T/M/S) MRCs. Completion of the daily inspection and the amount of fuel in the tank is recorded on the Aircraft Inspection and Acceptance Record (OPNAV 4790/141). Completion of the MRC card requiring the fuel sample as part of the daily/turnaround inspection is documented on the Daily/Turnaround Maintenance Record (OPNAV 4790.38). These records have proven to be sufficient for trending purposes at the activity level.

The Navy Safety Center compiled data for aircraft mishaps provided below indicates that the emphasis on safety of flight in this and all NAMP programs has resulted in a declining number of aircraft mishaps fleet wide over the last decade.

NAVY/MARINE

CLASS A FLIGHT MISHAPS

FY89 – FY99*

ALL MODELS

YEAR EXPOSURE # EVTS RATE

FY 89 2,306,414 51 2.21

FY 90 2,201,634 66 3.00

FY 91 2,154,079 60 2.79

FY 92 1,962,943 55 2.80

FY 93 1,865,702 53 2.84

FY 94 1,675,241 28 1.67

FY 95 1,656,450 34 2.05

FY 96 1,650,026 36 2.18

FY 97 1,523,507 27 1.77

FY 98 1,518,109 36 2.37

FY 99 1,527,186 22 1.44

TOTAL 20,041,291 468 2.34

The effectiveness of the Fuel Surveillance Program is measured in the mishap program data. Specific data on the mishaps in which contaminated fuel was shown as a possible contributor is outlined below. The data shows only those hazards where contamination was discovered when fuel samples were taken.

|Class of | |

|The Maintenance Officer (MO): |Manhours expended |

|-Designate, in writing, a Fuel Surveillance Program Manager. The Line/Power Line Division Officer or |Admin: ................
................

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