Airworthiness Directive · Amendment 39-18267 · Fuel
The Boeing Company
This AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 757 airplanes. This AD was prompted by reports of latently failed fuel shutoff valves discovered during fuel filter replacement. This AD requires revising the maintenance or inspection program to include new airworthiness limitations. We are issuing this AD to detect and correct latent failures of the fuel shutoff valve to the engine and auxiliary power unit (APU), which could result in the inability to shut off fuel to the engine and APU and, in case of certain fires, an uncontrollable fire that could lead to structural failure.
Within 30 days after the effective date of this AD, revise the maintenance or inspection program, as applicable, to add airworthiness limitations Nos. 28-AWL-ENG and 28-AWL-APU, by incorporating the information specified in figure 1 and figure 2 to paragraph (g) of this AD into the Airworthiness Limitations Section of the Instructions for Continued Airworthiness. The initial compliance time for accomplishing the actions specified in figure 1 and figure 2 to paragraph (g) of this AD is within 10 days after accomplishing the maintenance or inspection program revision required by this paragraph.
| AWL No. | Task | Interval | Applicability | Description |
|---|---|---|---|---|
| 28-AWL-ENG | ALI | DAILY INTERVAL NOTE: Not required on days when the airplane is not used in revenue service. The check must be done before further flight once the airplane is returned to revenue service | ALL APPLICABILITY NOTE: Only applies to airplanes with an MA20A2027 (S343T003-56) or MA30A1001 (S343T003-66) actuator installed at the engine fuel spar valve position | Engine Fuel Shutoff Valve (Fuel Spar Valve) Position Indication Operational Check. Concern: The fuel spar valve actuator design can result in airplanes operating with a failed fuel spar valve actuator that is not reported. A latently failed fuel spar valve actuator could prevent fuel shutoff to an engine. In the event of certain engine fires, the potential exists for an engine fire to be uncontrollable. Perform one of the following checks/inspection of the fuel spar valve position (unless checked by the flightcrew in a manner approved by the principal operations inspector). A. Operational check during engine shutdown |
| 1. Do an operational check of the left engine fuel spar valve actuator. | ||||
| a. As the L FUEL CONTROL switch on the quadrant control stand is moved to the CUTOFF position, verify the left SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| b. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| 2. Do an operational check of the right engine fuel spar valve actuator. | ||||
| a. As the R FUEL CONTROL switch on the quadrant control stand is moved to the CUTOFF position, verify the right SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| b. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| B. Operational check during engine start | ||||
| 1. Do an operational check of the left engine fuel spar valve actuator. | ||||
| a. As the L FUEL CONTROL switch on the quadrant control stand is moved to the RUN position, verify the left SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| b. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| 2. Do an operational check of the right engine fuel spar valve actuator. | ||||
| a. As the R FUEL CONTROL switch on the quadrant control stand is moved to the RUN position, verify the right SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| b. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| C. Operational check without engine operation | ||||
| 1. Supply electrical power to the airplane using standard practices. | ||||
| 2. Make sure all fuel pump switches on the Overhead Panel are in the OFF position. | ||||
| 3. If the APU is running, open and collar the L FWD FUEL BOOST PUMP (C00372) circuit breaker on the Main Power Distribution Panel. | ||||
| 4. Make sure LEFT and RIGHT ENG FIRE switches on the Aft Aisle Stand are in the NORMAL (IN) position. | ||||
| 5. Make sure L and R Engine Start Selector Switches on the Overhead Panel are in the OFF position. | ||||
| 6. Do an operational check of the left engine fuel spar valve actuator. | ||||
| a. Move L FUEL CONTROL switch on the quadrant control stand to the RUN position and wait approximately 10 seconds. | ||||
| NOTE: It is normal under this test condition for the ENG VALVE disagreement light on the quadrant control stand to stay illuminated. | ||||
| b. Move L FUEL CONTROL switch on the quadrant control stand to the CUTOFF position. | ||||
| c. Verify the left SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| d. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| 7. Do an operational check of the right engine fuel spar valve actuator. | ||||
| a. Move R FUEL CONTROL switch on the quadrant control stand to the RUN position and wait approximately 10 seconds. | ||||
| NOTE: It is normal under this test condition for the ENG VALVE disagreement light on the quadrant control stand to stay illuminated. | ||||
| b. Move R FUEL CONTROL switch on the quadrant control stand to the CUTOFF position. | ||||
| c. Verify the right SPAR VALVE disagreement light on the quadrant control stand illuminates and then goes off. | ||||
| d. If the test fails (light fails to illuminate), before further flight, repair faults as required (refer to Boeing AMM 28-22-11). | ||||
| 8. If the L FWD FUEL BOOST PUMP circuit breaker was collared in step 3, remove collar and close. | ||||
| D. Perform an inspection of the fuel spar valve actuator position | ||||
| NOTE: This inspection may be most useful whenever the SPAR VALVE light does not function properly. | ||||
| 1. Make sure the L FUEL CONTROL switch on the quadrant control stand is in the CUTOFF position. | ||||
| NOTE: It is not necessary to cycle the FUEL CONTROL switch to do this inspection. | ||||
| 2. Inspect the left engine fuel spar valve actuator located in the left rear spar. | ||||
| NOTE: Access is through access panel 551EBX. | ||||
| a. Verify the manual override handle on the engine fuel spar valve actuator is in the CLOSED position. | ||||
| b. Repair or replace any actuator that is not in the CLOSED position (refer to Boeing AMM 28-22-11). | ||||
| 3. Make sure the R FUEL CONTROL switch on the quadrant control stand is in the CUTOFF position. | ||||
| NOTE: It is not necessary to cycle the FUEL CONTROL switch to do this inspection. | ||||
| 4. Inspect the right engine fuel spar valve actuator located in the right rear spar. | ||||
| NOTE: Access is through access panel 651EBX. | ||||
| a. Verify the manual override handle on the engine fuel spar valve actuator is in the CLOSED position. | ||||
| b. Repair or replace any actuator that is not in the CLOSED position (refer to Boeing AMM 28-22-11). |
| AWL No. | Task | Interval | Applicability | Description |
|---|---|---|---|---|
| 28-AWL-APU | ALI | 10 DAYS | ALL | APU Fuel Shutoff Valve Position Indication Operational Check. |
| INTERVAL NOTE: Not required on days when the airplane is not used in revenue service. Must be done before further flight with an operational APU if it has been 10 or more calendar days since last check. | APPLICABILITY NOTE: Only applies to airplanes with an MA20A2027 (S343T003-56) or MA30A1001 (S343T003-66) actuator installed at the APU fuel shutoff valve position. | Concern: The APU fuel shutoff valve actuator design can result in airplanes operating with a failed APU fuel shutoff valve actuator that is not reported. A latently failed APU fuel shutoff valve actuator could prevent fuel shutoff to the APU. In the event of certain APU fires, the potential exists for an APU fire to be uncontrollable. Perform the operational check of the APU fuel shutoff valve position indication (unless checked by the flightcrew in a manner approved by the principal operations inspector). A. Do an operational check of the APU fuel shutoff valve position indication. 1. If the APU is running, unload and shut down the APU using standard practices. | ||
| 2. Supply electrical power to the airplane using standard practices. | ||||
| 3. Make sure the APU FIRE switch on the Aft Aisle Stand is in the NORMAL (IN) position. | ||||
| 4. Make sure there is at least 700 lbs (300 kgs) of fuel in the Left Main Tank. | ||||
| 5. Move APU Selector switch on the Overhead Panel to the ON position and wait approximately 10 seconds. | ||||
| 6. Move APU Selector switch on the Overhead Panel to the OFF position. | ||||
| 7. Verify the APU FAULT light on the Overhead Panel illuminates and then goes off. | ||||
| 8. If the test fails (light fails to illuminate), before further flight requiring APU availability, repair faults as required (refer to Boeing AMM 28-25-11). | ||||
| NOTE: Dispatch may be permitted per MMEL 28-25-2 if APU is not required for flight. |
After accomplishment of the maintenance or inspection program revision required by paragraph (g) of this AD, no alternative actions (e.g., inspections) or intervals may be used unless the actions or intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (i)(1) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
Appliances and equipment
