C-17FuelControl_TestInstruction.pdf.pdf

T.O. 2G-GTCP331-3-2

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Figure 1-1. Functional Schematic

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Figure 1-2. Fuel Control Layout, Front View

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Figure 1-3. Fuel Control Layout, Bottom View

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Figure 1-4. Fuel Control Layout, Top View

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Figure 1-5. Fuel Control Layout, Right Side View

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3 TESTING AND FAULT ISOLATION

3.1. Refer to Table 3-1 for a list of required test equipment and materials. Equivalent substitutes may be used.

Table 3-1. Test Materials and Equipment

Material/Equipment Manufacturer Information

Oil Seal, CR7440 Chicago Rawhide

Part of TE3310507-1 900 N. State Street

Elgin, Illinois 60123

Phone: (800) 882-0008 www.chicago-rawhide.com

Packing, M25988/1-036 Commercially Available

281600-7 Fuel Accessories Test Stand Honeywell

Aerospace Support Equipment

717 North Bendix Drive

South Bend, IN 46628

Bearing, 60355K92 McMaster-Carr

Part of TE3310507-1 9630 Norwalk Blvd.

Santa Fe Springs, CA 90670

Phone: (562) 692-5911 www.mcmaster.com

Turbine Oil, MIL-L-2075, MIL-PRF-7808 British Petroleum

Or MIL-L-23699 333 South Hope Street

Los Angeles, CA 90071

Phone: (310) 549-6204

URL: www.bp.com

TE3310507-1 Test Adapter Triumph Air Repair

TE3310510-1 Hookup Kit 4010 S. 43P rd P Place

TE3310519-1 Test Cable Phoenix, AZ 85040

TE0000248-1 Test Fitting Phone: (602) 437-1144

TE0000249-1 Test Fitting URL: www.triumphairrepair.com

TE0000250-1 Test Fitting

TE0000246-1 Adjusting Tool

TE3310618-1 Test Cable

TE3310727-1 Test Plug T3310725-1 Special Wrench

TE0000242-3 Restrictor

V-Band Clamp Clampco Products Inc.

V0233100N-316-H PO Box 72226

Part of TE3310507-1 Cleveland, OH 44192

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3.2. General test information:

MIL-PRF-7024 Type II Calibration Fluid – Reference Number: 8

CAUTION

Do not energize the fuel solenoid valve for more than 1 minute continuously without the drive shaft rotating. Fuel flow is required to cool the solenoid valve coils.

3.2.1. Maintain a fuel inlet temperature within 85 + 15°F throughout the test procedure.

3.2.2. The test procedure is intended to verify the airworthiness of the unit using the least number of test steps necessary. During testing it may be necessary to repeat test steps or perform test steps out of sequence in order to obtain necessary adjustments. However, for final acceptance test steps must be performed in the sequence provided.

NOTE

Verify that the Fuel Control Unit (FCU), once removed from the engine, has been modified and noted prior to return to service, as follows:

“S” modification configuration incorporates gearshaft P/N 3882697-5, fuel seal P/N 3883891-1, and rotor P/N

3883248-2. This is a partial modification that shall be annotated in the lower right corner with the “S” modification letter.

“C” modification configuration incorporates housing racetrack gear pockets, bushings P/N 3883529-1 and P/N

3883529-2, fuel seal P/N 3883891-1, rotor P/N 3883248-2, Carrier P/N 3882490-3, bolts P/N AS3236-22, washers P/N 3883722-1, gearshaft P/N 3883490-3, high pressure filter P/N 3883496-2, and plug P/N AN814-

8DL. This is a complete modification that shall be annotated in the lower right corner with the “C” modification letter.

3.2.3. This manual contains instructions for two different types of tests. The continued service test (see Step 3.4) is intended to determine the condition of a unit as removed from service. Units that pass this test are acceptable for continued service. Units that fail this test should be repaired or overhauled as necessary. The overhaul test

(see Step 3.5) is intended to verify the airworthiness of a unit after repair or overhaul has been performed.

The overhaul test may also be helpful for troubleshooting units that fail the continued service test.

3.2.4. All readings and measurements are to be made using the automated test software in the 281600-7-1 Fuel

Accessory Test Stand unless otherwise specified.

3.2.5. Test hook-up diagrams (Figure 3-1, Figure 3-2, and Figure 3-3) indicate hose and fitting sizes in 16ths of an inch (i.e. -4 means 4/16 or ¼ inch). Hoses and fittings shall be at least as large as the indicated size.

3.2.6. When test hook-up #3 is used (see Figure 3-3), the automated test stand should provide backpressure on FUEL

RETURN as shown in Figure 3-4 (within +/- 2%) unless otherwise specified.

3.2.7. Throughout this test procedure, changes to torque motor current should be made only in the increasing or decreasing direction as specified. If the desired value is missed, return to the previous test condition and try again.

3.2.8. At certain times during the test procedure, it is necessary to perform a current cycle. A current cycle is defined as follows:

3.2.8.1. Set drive speed to zero RPM.

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3.2.8.2. Energize torque motor with approximately 150 milliamps.

3.2.8.3. Cycle the torque motor current from 150 milliamps to 0 milliamps and back to 150 milliamps within one half second or less. Repeat this cycle at least two more times.

3.2.8.4. Adjust torque motor current to zero milliamps.

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3.3. Test preparation:

WARNING

For flexible pneumatic lines, use a hose capable of withstanding 400 psig pressure. For a flexible hydraulic line, use a medium hose suitable for fuel system service and capable of withstanding 2000 psig pressure.

NOTE

Refer to T.M. SE-876-03-1053 for operation and maintenance of the 281600-7-1 Fuel

Accessory Test Stand.

3.3.1. Install TE3310507-1 Test Adapter onto 281600-7-1 Fuel Accessory Test Stand.

Do not over-tighten clamp nut. Damage to equipment may result if nut is over-tightened.

3.3.2. Install fuel control unit onto TE3310507-1 Test Adapter with M25988/1-036 packing and secure with clamp.

Tighten clamp nut to 20 inlbf maximum.

3.3.3. Inspect fuel filter element (IPB Figure 11-3, View D, Item 50) for contamination or foreign particles. Replace filter element if contaminated.

3.3.4. Inspect strainer element (IPB Figure 11-3, Detail N or Detail T, Item 470 or 470A) for contamination or foreign particles. Clean strainer element if contaminated.

3.3.5. Fill TE3310507-1 Test Adapter with turbine oil. Connect ADAPTOR AIR SUPPLY and ADAPTOR GAGE as shown in Figure 3-1.

3.3.6. Connect TE3310519-1 Test Cable as follows:

3.3.6.1. Connect cable labeled TM to fuel control unit torque motor connector.

3.3.6.2. Connect cable labeled SOL to fuel control unit solenoid valve connector.

3.3.6.3. Connect cable labeled E10A to test stand fixed 28 Vdc supply.

3.3.6.4. Connect cable labeled E10B to test stand 0-300 mA dc supply.

3.3.7. Remove retainer (IPB Figure 11-3, Detail K, Item 290) and install TE0000250-1 Test Fitting.

3.4. Continued service test:

The continued service test procedure is intended to determine the condition of a unit as removed from service. Units that pass this test are acceptable for continued service.

Units that fail this test should be repaired or overhauled as necessary.

The mechanical indicator tests identified in this procedure only apply to differential pressure indicator P/N’s 3883154-1 and E3310340-1. When testing differential pressure indicator P/N E3311028-1, omit steps 3.4.1.6, 3.4.1.8, 3.4.1.11, and 3.4.1.15 as indicated because the mechanical indicator has been removed from this differential pressure indicator.

3.4.1. Perform differential pressure indicator test as follows:

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3.4.1.1. Construct test hookup as shown in Figure 3-1. Note the following:

3.4.1.1.1. Install caps on the IGV actuator supply and return ports.

3.4.1.1.2. Remove strainer element and plug (IPB Figure 11-3, Detail N or Detail T, items 470 and 480, or item 470A) and install TE0000249-1 Test Fitting.

3.4.1.1.3. Remove cap from TE0000249-1 Test Fitting and leave open to ambient pressure.

3.4.1.2. Remove filter body and filter element (IPB Figure 11-3, View D, items 50 and 90).

3.4.1.3. Lubricate packing (IPB Figure 11-3, View E, items 60 and 170) with petrolatum and install on

TE3310727-1 Test Plug.

3.4.1.4. Install TE3310727-1 Test Plug in place of filter element.

3.4.1.5. Connect TE3310618-1 Test Cable as follows:

3.4.1.5.1. Connect cable labeled UNIT to differential pressure indicator electrical connector.

3.4.1.5.2. Connect cable labeled PIN 1 to the positive terminal of a digital multimeter.

3.4.1.5.3. Connect cable labeled Pin 2 to the negative terminal of a digital multimeter.

3.4.1.5.4. Leave remaining cables disconnected at this time.

3.4.1.6. Verify that differential pressure indicator (IPB Figure 11-3, Detail F, item 100) is not extended. If extended, reset indicator. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.4.1.7. Slowly adjust FUEL SUPPLY to apply 10 + 2 psig.

3.4.1.8. Observe differential pressure indicator. Differential pressure indicator shall extend. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.4.1.9. Observe digital multimeter. Digital multimeter shall indicate closed circuit (resistance less than 2 ohms between pins 1 and 2).

3.4.1.10. Adjust FUEL SUPPLY to apply 0 psig.

3.4.1.11. Reset differential pressure indicator. This step is not applicable for differential pressure indicator P/N

E3311028-1.

3.4.1.12. Remove TE3310727-1 Test Plug and re-install filter element (IPB Figure 11-3, View D, item 50). Re-install filter body.

3.4.1.13. Cap TE0000249-1 Test Fitting installed in strainer element port.

3.4.1.14. Slowly adjust FUEL SUPPLY to apply 10 + 2 psig.

3.4.1.15. Observe differential pressure indicator. Differential pressure indicator shall not extend. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.4.1.16. Observe digital multimeter. Digital multimeter shall indicate open circuit (resistance greater than 1K ohms between pins 1 and 2).

3.4.1.17. Record results on test data sheet (see Figure 3-5).

3.4.2. Perform internal leakage test as follows:

3.4.2.1. Verify test hookup as shown in Figure 3-1. Note the following:

3.4.2.1.1. Cap TE0000249-1 Test Fitting installed in strainer element port.

3.4.2.1.2. Provide graduated beakers for measuring leakage from discharge port and seal drain port.

3.4.2.2. Adjust FUEL SUPPLY to obtain 40 + 4 psig.

3.4.2.3. Bleed off trapped air from the IGV actuator supply and return ports.

3.4.2.4. Energize the fuel solenoid with 28 VDC.

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3.4.2.5. Observe leakage rate from the fuel discharge port. Leakage shall not exceed 50 cc per minute. If leakage is excessive, proceed as follows:

3.4.2.5.1. Remove and inspect pressurizing valve components (IPB Figure 11-3, Detail P, Items 510 thru

550). Replace defective components and re-assemble.

3.4.2.5.2. Remove and inspect solenoid valve components (IPB Figure 11-3, Detail G, Items 130 thru 160).

Replace defective components and re-assemble.

3.4.2.6. Observe leakage rate from the seal drain port. Leakage shall not exceed 1 drop in 8.5 minutes. If leakage is excessive, proceed as follows:

3.4.2.6.1. If leaking fluid is oil, replace oil seal (IPB Figure 11-2, Item 240).

3.4.2.6.2. If leaking fluid is fuel, replace fuel seal (IPB Figure 11-2, Item 180) and packing (IPB Figure

11-2, Item 210).

3.4.2.7. Record results on test data sheet (see Figure 3-5).

3.4.2.8. De-energize the fuel solenoid.

3.4.2.9. Adjust FUEL SUPPLY pressure to zero.

3.4.3. Perform an initial flow test as follows:

NOTE

Some fuel controls experience low or no flow during testing. It has been identified that differential pressure valve plug P/N 3882546-2 (IPB Figure 11-3, item 450) can be received from supply in two lengths. If this low or no flow condition is encountered, verify differential pressure valve plug length is between 0.365” and 0.375”. If plug length is between 0.413” to 0.415”, rework plug to desired length of 0.365” to 0.375” before proceeding with test procedure.

3.4.3.1. Construct test hookup as shown in Figure 3-3. Note the following:

3.4.3.1.1. Remove TE0000249-1 Test Fitting and re-install strainer element and plug (IPB Figure 11-3, Detail N or Detail T, items 470 and 480, or item 470A).

3.4.3.1.2. Remove plug (IPB Figure 11-3, Detail P, Item 550) and install TE0000248-1 Test Fitting into pressurizing valve port.

3.4.3.1.3. Note direction of flow arrow on TE0000242-3 Restrictor.

3.4.3.2. Energize the fuel solenoid valve.

3.4.3.3. Perform a current cycle as described in step 3.2.8.

3.4.3.4. Adjust FUEL SUPPLY to apply 20 to 25 psig.

3.4.3.5. Adjust drive speed to 3320 + 10 RPM.

3.4.3.6. Energize the torque motor with 200.0 + 0.2 milliamps.

Do not operate the fuel control unit for more than 1 minute continuously without adequate fuel flow indicated. Fuel flow is required to cool internal components. Damage may results from operating unit without adequate fuel flow.

3.4.3.7. Verify that at least 30 pounds per hour of fuel flow is indicated. If adequate fuel flow is not indicated, proceed as follows:

3.4.3.7.1. Remove and inspect solenoid valve components (IPB Figure 11-3, Detail G, Items 130 thru 160).

Replace defective components and re-assemble.

3.4.3.7.2. Remove and inspect torque motor components (IPB Figure 11-3, Detail H, Items 180 thru 220).

Replace defective components and re-assemble.

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3.4.3.7.3. Remove and inspect differential pressure valve components (IPB Figure 11-3, Detail M, Items

400 thru 460). Replace defective components and re-assemble.

3.4.3.7.4. Remove and inspect IGV regulator components (IPB Figure 11-3, Detail K, Items 230 thru 300).

Replace defective components and re-assemble.

3.4.3.7.5. Remove and inspect pressurizing valve components (IPB Figure 11-3, Detail P, Items 510 thru

550). Replace defective components and re-assemble.

3.4.3.8. Operate at this condition for a minimum of 4 minutes to stabilize fuel control temperature.

3.4.3.9. Adjust drive speed to zero.

3.4.3.10. Perform a current cycle as described in step 3.2.8.

3.4.3.11. Adjust drive speed to 1660 + 10 RPM.

3.4.3.12. Increase torque motor current from zero to 17.0 + 0.2 milliamps.

3.4.3.13. Fuel flow shall be 41 to 45 pounds per hour. If fuel flow is not within range, proceed as follows:

3.4.3.13.1. If fuel flow is out of range by less than 3 pounds per hour, adjust thickness of shims (IPB Figure

11-3, Detail M, Item 440). Increasing shim thickness by 0.010 inch increases fuel flow by approximately 0.7 pound per hour. Do not adjust shim thickness by more than 0.040 inch.

Use caution when using TE0000246-1 Adjusting Tool. Connect tool to torque motor threads by 2 or 3 turns only. Do not wrench tighten. Make small incremental adjustments (approximately 0.010 inch at a time), then repeat test step before making further adjustments. The application of excessive force can cause damage to torque motor.

3.4.3.13.2. If fuel flow is out of range by more than 3 pounds per hour, but less than 10 pounds per hour, remove cover (IPB Figure 11-3, Detail H, Item 185) using T3310725-1 Special Wrench and adjust torque motor using TE0000246-1 Adjusting Tool. Driving the torque motor armature in

(towards fuel control unit) increases flow. Driving torque motor armature out (away from fuel control unit) decreases flow.

3.4.3.13.3. If fuel flow is out of range by more than 10 pounds per hour, proceed as follows:

3.4.3.13.3.1. Remove and inspect torque motor components (IPB Figure 11-3, Detail H, Items 180 thru

220). Replace defective components and re-assemble.

3.4.3.13.3.2. Remove and inspect differential pressure valve components (IPB Figure 11-3, Detail M, Items 400 thru 460). Replace defective components and re-assemble.

3.4.3.13.3.3. Perform a pump performance test in accordance with step 3.5.5. If unit fails, repair or overhaul is required.

3.4.3.14. PUMP DISCHARGE PRESSURE shall be 115 psig minimum. If PUMP DISCHARGE PRESSURE is not within range, proceed as follows:

3.4.3.14.1. Adjust thickness of special washers (IPB Figure 11-3, Detail P, Item 510) as necessary to achieve

115 psig minimum pump discharge pressure.

3.4.3.14.2. Remove and inspect pressurizing valve components (IPB Figure 11-3, Detail P, Items 510 thru

550). Replace defective components and re-assemble.

3.4.3.15. NOZZLE PRESSURE shall be 10 psig minimum. If NOZZLE PRESSURE is not within range, proceed as follows:

3.4.3.15.1. Remove and inspect solenoid valve components (IPB Figure 11-3, Detail G, Items 130 thru 160).

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3.4.3.15.2. Verify 281700-6 test stand is providing backpressure in accordance with Figure 3-4. If not, correct cause before proceeding.

3.4.3.16. REGULATED PRESSURE shall be 115 psig minimum. If REGULATED PRESSURE is not within range, proceed as follows:

3.4.3.16.1. Remove and inspect IGV regulator components (IPB Figure 11-3, Detail K, Items 230 thru 300).

Replace defective components and re-assemble.

3.4.3.17. Record results on test data sheet (see Figure 3-5).

3.4.3.18. Maintain this test condition for the next test step.

3.4.4. Perform a start flow test in the increasing direction as follows:

3.4.4.1. With test condition as previously established, increase torque motor current to 25.0 + 0.2 milliamps.

3.4.4.2. Fuel flow shall be 57 to 63 pounds per hour.

3.4.4.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.4.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.4.4.5. REGULATED PRESSURE shall be 115 psig minimum.

3.4.4.6. Record results on test data sheet (see Figure 3-5).

3.4.4.7. Maintain this test condition for the next test step.

3.4.5. Perform a start flow test in the decreasing direction as follows:

3.4.5.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 25.0 + 0.2 milliamps.

3.4.5.2. Fuel flow shall be 57 to 70 pounds per hour.

3.4.5.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.5.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.4.5.5. REGULATED PRESSURE shall be 115 psig minimum.

3.4.5.6. Record results on test data sheet (see Figure 3-5).

3.4.5.7. Maintain this test condition for the next test step.

3.4.6. Perform altitude performance test at 55 milliamps in the increasing direction as follows:

3.4.6.1. With test condition as previously established, adjust drive speed to 8300 + 10 RPM.

3.4.6.2. Increase torque motor current to 55.0 + 0.2 milliamps.

3.4.6.3. Fuel flow shall be 124 to 159 pounds per hour.

3.4.6.4. PUMP DISCHARGE PRESSURE shall be 130 to 230 psig.

3.4.6.5. Record results on test data sheet (see Figure 3-5).

3.4.6.6. Maintain this test condition for the next test step.

3.4.7. Perform altitude performance test at 55 milliamps in the decreasing direction as follows:

3.4.7.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 55.0 + 0.2 milliamps.

3.4.7.2. Fuel flow shall be 124 to 159 pounds per hour.

3.4.7.3. PUMP DISCHARGE PRESSURE shall be 130 to 230 psig.

3.4.7.4. Record results on test data sheet (see Figure 3-5).

3.4.7.5. Maintain this test condition for the next test step.

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3.4.8. Perform altitude performance test at 100 milliamps in the increasing direction as follows:

3.4.8.1. With test condition as previously established, increase torque motor current to 100.0 + 0.2 milliamps.

3.4.8.2. Fuel flow shall be 237 to 272 pounds per hour.

3.4.8.3. PUMP DISCHARGE PRESSURE shall be 200 to 310 psig.

3.4.8.4. Record results on test data sheet (see Figure 3-5).

3.4.8.5. Maintain this test condition for the next test step.

3.4.9. Perform altitude performance test at 100 milliamps in the decreasing direction as follows:

3.4.9.1. With test condition as previously established, increase torque motor current to approximately 200 milliamps, then decrease torque motor current to 100.0 + 0.2 milliamps.

3.4.9.2. Fuel flow shall be 237 to 272 pounds per hour.

3.4.9.3. PUMP DISCHARGE PRESSURE shall be 200 to 310 psig.

3.4.9.4. Record results on test data sheet (see Figure 3-5).

3.4.9.5. Maintain this test condition for the next test step.

3.4.10. Perform maximum flow test as follows:

3.4.10.1. With test condition as previously established, increase torque motor current to 250.0 + 0.2 milliamps.

3.4.10.2. Fuel flow shall be 525 to 660 pounds per hour.

3.4.10.3. PUMP DISCHARGE PRESSURE shall be 650 psig minimum.

3.4.10.4. REGULATED PRESSURE shall be 350 psig maximum.

3.4.10.5. Record results on test data sheet (see Figure 3-5).

3.4.10.6. Maintain this test condition for the next test step.

3.4.11. Perform solenoid valve test as follows:

Do not operate the fuel control unit for more than 1 minute continuously with the fuel solenoid de-energized. Fuel flow is required to cool internal components. Damage may results from operating unit without adequate fuel flow.

3.4.11.1. With test condition as previously established, de-energize fuel solenoid valve.

3.4.11.2. PUMP DISCHARGE PRESSURE shall be 625 psig maximum. Record results on test data sheet (see

Figure 3-5).

WARNING

Calibration fluid may flow from open discharge port, causing a hazardous condition.

Use caution while disconnecting hose.

3.4.11.3. Check NOZZLE PRESSURE and ensure DISCHARGE PORT is at a safe pressure then remove hose from discharge port and allow port to drain. Once port has drained, observe port for leakage. No leakage permitted. Record results on test data sheet (see Figure 3-5).

3.4.11.4. Reconnect hose to fuel discharge port.

3.4.11.5. Energize fuel solenoid valve.

3.4.11.6. Fuel flow shall be within + 10 pounds per hour of value obtained in step 3.4.10.

3.4.11.7. PUMP DISCHARGE PRESSURE shall be within + 10 psig of value obtained in step 3.4.10.

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3.4.11.8. Record results on test data sheet (see Figure 3-5).

3.4.11.9. Maintain this test condition for the next test step.

3.4.12. Perform minimum flow test as follows:

3.4.12.1. With test condition as previously established, decrease torque motor current to 0.0 + 0.2 milliamps.

3.4.12.2. Fuel flow shall be 10 to 36 pounds per hour.

3.4.12.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.12.4. REGULATED PRESSURE shall be 115 psig minimum.

3.4.12.5. Record results on test data sheet (see Figure 3-5).

3.4.12.6. Maintain this test condition for the next test step.

3.4.13. Perform a hot initial flow test as follows:

3.4.13.1. With test condition as previously established, adjust drive speed to zero.

3.4.13.2. Perform a current cycle as described in step 3.2.8.

3.4.13.3. Adjust drive speed to 1660 + 10 RPM.

3.4.13.4. Increase torque motor current from zero to 17.0 + 0.2 milliamps.

3.4.13.5. Fuel flow shall be 39 to 47 pounds per hour.

3.4.13.6. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.13.7. NOZZLE PRESSURE shall be 10 psig minimum.

3.4.13.8. REGULATED PRESSURE shall be 115 psig minimum.

3.4.13.9. Record results on test data sheet (see Figure 3-5).

3.4.13.10. Maintain this test condition for the next test step.

3.4.14. Perform a hot restart test in the increasing direction as follows:

3.4.14.1. With test condition as previously established, increase torque motor current to 25.0 + 0.2 milliamps.

3.4.14.2. Fuel flow shall be 55 to 67 pounds per hour.

3.4.14.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.14.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.4.14.5. REGULATED PRESSURE shall be 115 psig minimum.

3.4.14.6. Record results on test data sheet (see Figure 3-5).

3.4.14.7. Maintain this test condition for the next test step.

3.4.15. Perform a hot restart test in the decreasing direction as follows:

3.4.15.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 25.0 + 0.2 milliamps.

3.4.15.2. Fuel flow shall be 55 to 70 pounds per hour.

3.4.15.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.4.15.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.4.15.5. REGULATED PRESSURE shall be 115 psig minimum.

3.4.15.6. Record results on test data sheet (see Figure 3-5).

3.4.15.7. Maintain this test condition for the next test step.

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3.4.16. Perform external leakage test as follows:

This test step may be performed simultaneously with other test steps. The 5 minute minimum operating time may be accumulated from multiple steps during the test sequence.

3.4.16.1. Operate fuel control unit at 8300 + 10 RPM and maintain a PUMP DISCHARGE PRESSURE of at least 200 psig for at least 5 minutes continuously.

3.4.16.2. Observe external surfaces of fuel control for leakage. No leakage allowed.

3.4.16.3. Observe drain port for leakage. Leakage from drain port shall not exceed 1 drop in 8.5 minutes.

3.4.16.4. Record results on test data sheet (see Figure 3-5).

3.4.17. Remove fuel control unit from test hookup.

NOTE

If unit passes test verification, modification compliance shall be accomplished before FCU can be returned to service. The data plate shall have an “S” or “C” in the lower right corner. See NOTE para.3.2.2.

3.5. Overhaul test:

The overhaul test procedure is intended to verify the airworthiness of a unit after repair or overhaul has been performed. Units as returned from service should be tested in accordance with the continued service test procedure in Step 3.4.

The mechanical indicator tests identified in this procedure only apply to differential pressure indicator P/N’s 3883154-1 and E3310340-1. When testing differential pressure indicator P/N E3311028-1, omit steps 3.5.1.6, 3.5.1.8, 3.5.1.11, and 3.5.1.15 as indicated because the mechanical indicator has been removed from this differential pressure indicator.

3.5.1. Perform differential pressure indicator test as follows:

3.5.1.1. Construct test hookup as shown in Figure 3-1. Note the following:

3.5.1.1.1. Install caps on the IGV actuator supply and return ports.

3.5.1.1.2. Remove strainer element and plug (IPB Figure 11-3, Detail N or Detail T, items 470 and 480, or item 470A) and install TE0000249-1 Test Fitting.

3.5.1.1.3. Remove cap from TE0000249-1 Test Fitting and leave open to ambient pressure.

3.5.1.2. Remove filter body and filter element (IPB Figure 11-3, View D, items 50 and 90).

3.5.1.3. Lubricate packing (IPB Figure 11-3, View E, item 60) with petrolatum and install on TE3310727-1 Test

Plug.

3.5.1.4. Install TE3310727-1 Test Plug in place of filter element.

3.5.1.5. Connect TE3310618-1 Test Cable as follows:

3.5.1.5.1. Connect cable labeled UNIT to differential pressure indicator electrical connector.

3.5.1.5.2. Connect cable labeled PIN 1 to the positive terminal of a digital multimeter.

3.5.1.5.3. Connect cable labeled Pin 2 to the negative terminal of a digital multimeter.

3.5.1.5.4. Leave remaining cables disconnected at this time.

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3.5.1.6. Verify that differential pressure indicator (IPB Figure 11-3, Detail F, item 100) is not extended. If extended, reset indicator. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.5.1.7. Slowly adjust FUEL SUPPLY to apply 10 + 2 psig.

3.5.1.8. Observe differential pressure indicator. Differential pressure indicator shall extend. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.5.1.9. Observe digital multimeter. Digital multimeter shall indicate closed circuit (resistance less than 2 ohms between pins 1 and 2).

3.5.1.10. Adjust FUEL SUPPLY to apply 0 psig.

3.5.1.11. Reset differential pressure indicator. This step is not applicable for differential pressure indicator P/N

E3311028-1.

3.5.1.12. Remove TE3310727-1. Lubricate packing of filter element with petrolatum and re-install filter element

(IPB Figure 11-3, View D, item 50). Re-install filter body.

3.5.1.13. Cap TE0000249-1 Test Fitting installed in strainer element port.

3.5.1.14. Slowly adjust FUEL SUPPLY to apply 10 + 2 psig.

3.5.1.15. Observe differential pressure indicator. Differential pressure indicator shall not extend. This step is not applicable for differential pressure indicator P/N E3311028-1.

3.5.1.16. Observe digital multimeter. Digital multimeter shall indicate open circuit (resistance greater than 1K ohms between pins 1 and 2).

3.5.1.17. Record results on test data sheet (see Figure 3-5).

3.5.2. Perform internal leakage check as follows:

3.5.2.1. Verify test hookup as shown in Figure 3-1. Note the following:

3.5.2.1.1. Cap TE0000249-1 Test Fitting installed in strainer element port.

3.5.2.1.2. Provide graduated beakers for measuring leakage from discharge port and seal drain port.

3.5.2.2. Adjust FUEL SUPPLY to obtain 40 + 4 psig.

3.5.2.3. Bleed off trapped air from the IGV actuator supply and return ports.

3.5.2.4. Energize the fuel solenoid with 28 VDC.

3.5.2.5. Observe leakage rate from the fuel discharge port. Leakage shall not exceed 50 cc per minute. If leakage is excessive, proceed as follows:

3.5.2.5.1. Remove and inspect pressurizing valve components (IPB Figure 11-3, Detail P, Items 510 thru

550). Replace defective components and re-assemble.

3.5.2.5.2. Remove and inspect solenoid valve components (IPB Figure 11-3, Detail G, Items 130 thru 160).

Replace defective components and re-assemble.

3.5.2.6. Observe leakage rate from the seal drain port. Leakage shall not exceed 1 drop in 8.5 minutes. If leakage is excessive, proceed as follows:

3.5.2.6.1. If leaking fluid is oil, replace oil seal (IPB Figure 11-2, Item 240).

3.5.2.6.2. If leaking fluid is fuel, replace fuel seal (IPB Figure 11-2, Item 180) and packing (IPB Figure

11-2, Item 210).

3.5.2.7. Record results on test data sheet (see Figure 3-6).

3.5.2.8. De-energize the fuel solenoid.

3.5.3. Perform pump run-in test as follows:

3.5.3.1. Construct hookup as shown in Figure 3-2. Note the following:

3.5.3.1.1. Install a cap on the discharge port.

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3.5.3.2. Adjust FUEL SUPPLY to obtain 15 to 25 psig.

3.5.3.3. Adjust drive speed and DISCHARGE PRESSURE to obtain each condition specified in Table 3-2.

3.5.3.4. Verify that the unit is able to operate at each condition for the duration specified in Table 3-2 without leaking or binding.

3.5.3.5. Record results on test data sheet (see Figure 3-6).

3.5.3.6. Maintain this test condition for the next test step.

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3.5.4. Perform relief valve test as follows:

Fuel flow is required to cool the internal pump components. Do not operate the fuel control unit for more than 30seconds without a fuel flow indication of at least 1000 lb/hr.

3.5.4.1. With test condition as previously established, adjust drive speed to 8300 + 10 RPM.

3.5.4.2. Adjust DISCHARGE PRESSURE to obtain 850 + 5 psig.

3.5.4.3. Record fuel flow on test data sheet (see Figure 3-6).

3.5.4.4. Slowly increase DISCHARGE PRESSURE until relief valve cracks open and fuel flow decreases to within 1000 + 20 pph1.

3.5.4.5. DISCHARGE PRESSURE shall be 900 to 1000 psig. Record results on test data sheet (see Figure 3-6).

3.5.4.6. Decrease DISCHARGE PRESSURE to 850 + 5 psig.

3.5.4.7. Fuel flow shall be within + 25 pounds per hour of the value noted in Step 3.5.4.3. Record results on test data sheet (see Figure 3-6).

3.5.4.8. If relief valve does not perform as specified, proceed as follows:

The relief valve protects internal fuel pump components in the event of a malfunction. If relief valve fails to perform as specified, correct cause before proceeding with the remaining test steps. Operating the fuel control unit without an operable relief valve can result in internal pump damage.

3.5.4.8.1. Remove and inspect relief valve components (IPB Figure 11-3, Detail L, Items 310, 380 and

390). Replace defective components and repeat test.

3.5.4.9. Maintain this test condition for the next test step.

3.5.5. Perform pump performance test as follows:

NOTE

Some fuel controls experience low or no flow during testing. It has been identified that differential pressure valve plug P/N 3882546-2 (IPB Figure 11-3, item 450) can be received from supply in two lengths. If this low or no flow condition is encountered, verify differential pressure valve plug length is between 0.365” and 0.375”. If plug length is between 0.413” to 0.415”, rework plug to desired length of 0.365” to 0.375” before proceeding with test procedure.

3.5.5.1. With test condition as previously established, decrease DISCHARGE PRESSURE to within 800 + 5 psig.

3.5.5.2. Fuel flow shall be 1800 pounds per hour minimum. Record results on test data sheet (see Figure 3-6).

3.5.5.3. Decrease DISCHARGE PRESSURE to within 400 + 5 psig.

3.5.5.4. Fuel flow shall be 1800 pounds per hour minimum. Record results on test data sheet (see Figure 3-6).

3.5.5.5. Decrease DISCHARGE PRESSURE to within 200 + 5 psig.

3.5.5.6. Fuel flow shall be 1800 pounds per hour minimum. Record results on test data sheet (see Figure 3-6).

3.5.5.7. Adjust drive speed to obtain 1660 + 10 RPM.

3.5.5.8. Fuel flow shall be 260 pounds per hour minimum. Record results on test data sheet (see Figure 3-6).

3.5.5.9. Adjust drive speed to obtain 830 + 10 RPM.

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3.5.5.10. Decrease DISCHARGE PRESSURE to within 100 + 5 psig.

3.5.5.11. Fuel flow shall be 130 pounds per hour minimum. Record results on test data sheet (see Figure 3-6).

3.5.5.12. Adjust DISCHARGE PRESSURE to zero.

3.5.5.13. Adjust FUEL SUPPLY to zero.

3.5.5.14. Adjust drive speed to zero.

3.5.5.15. De-energize fuel solenoid valve.

3.5.5.16. If pump performance test results are not as specified, remove and inspect pump components (IPB Figure

11-2, Items 10 thru 170). Replace defective components and re-assemble.

3.5.6. Perform differential pressure valve test as follows:

Do not exceed 350 psig REGULATED PRESSURE. If REGULATED

PRESSURE exceeds 350 psig at any time, discontinue testing and correct cause before continuing.

3.5.6.1. Construct test hookup as shown in Figure 3-3. Note the following:

3.5.6.1.1. Remove TE0000249-1 Test Fitting and re-install strainer element and plug (IPB Figure 11-3, Detail N or Detail T, items 470 and 480, or item 470A).

3.5.6.1.2. Remove plug (IPB Figure 11-3, Detail P, Item 550) and install TE0000248-1 Test Fitting into pressurizing valve port.

3.5.6.1.3. Note direction of flow arrow on TE0000242-3 Restrictor.

Do not operate the fuel control unit for more than 1 minute continuously without adequate fuel flow indicated. Fuel flow is required to cool internal components. Damage may results from operating unit without adequate fuel flow.

3.5.6.2. Energize fuel solenoid valve.

3.5.6.3. Perform a current cycle as described in Step 3.2.8.

3.5.6.4. Adjust FUEL SUPPLY to apply 20 to 25 psig.

3.5.6.5. Adjust drive speed to 3320 + 10 RPM.

3.5.6.6. Energize the torque motor with 200.0 + 0.2 milliamps.

3.5.6.7. Verify that at least 30 pounds per hour of fuel flow is indicated. If adequate fuel flow is not indicated, proceed as follows:

3.5.6.7.1. Remove and inspect solenoid valve components (IPB Figure 11-3, Detail G, Items 130 thru 160).

Replace defective components and re-assemble.

3.5.6.7.2. Remove and inspect torque motor components (IPB Figure 11-3, Detail H and Detail J Items 180 thru 220). Replace defective components and re-assemble.

3.5.6.7.3. Remove and inspect differential pressure regulator components (IPB Figure 11-3, Detail M, Items 400 thru 460). Replace defective components and re-assemble.

3.5.6.7.4. Remove and inspect IGV regulator components (IPB Figure 11-3, Detail K, Items 230 thru 300).

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3.5.6.7.5. Remove and inspect pressurizing valve components (IPB Figure 11-3, Detail P, Items 510 thru

550). Replace defective components and re-assemble.

3.5.6.8. Adjust drive speed to 8300 + 10 RPM.

3.5.6.9. Adjust torque motor current to 250.0 + 0.2 milliamps.

3.5.6.10. Fuel flow shall be 525 to 660 pounds per hour. If fuel flow is not within range, proceed as follows:

Use caution when using TE0000246-1 Adjusting Tool. Connect tool to torque motor threads by 2 or 3 turns only. Do not wrench tighten. Make small adjustments

(approximately 0.010 inch at a time), then repeat test step before making further adjustments. The application of excessive force can cause damage to torque motor.

3.5.6.10.1. Remove torque motor cap using special tool T3310725-1.

3.5.6.10.2. Adjust torque motor using TE0000246-1 Adjusting Tool to obtain required fuel flow.

3.5.6.11. DIFFERENTIAL PRESSURE shall be 50 + 5 psid. If DIFFERENTIAL PRESSURE is not within range, proceed as follows:

3.5.6.11.1. Adjust thickness of shims (IPB Figure 11-3, Detail M, Item 440) to obtain required

DIFFERENTIAL PRESSURE. Increasing shim thickness by 0.010 inch increases

DIFFERENTIAL PRESSURE by approximately 1 psid.

3.5.6.12. PUMP DISCHARGE PRESSURE shall be 650 to 1000 psig. If PUMP DISCHARGE PRESSURE is not within range, proceed as follows:

3.5.6.12.1. Verify test stand is providing backpressure in accordance with Figure 3-4. If not, correct cause before proceeding.

3.5.6.13. REGULATED PRESSURE shall be 350 psig maximum. If REGULATED PRESSURE is not within range, proceed as follows:

3.5.6.13.1. Remove and inspect differential pressure regulator components (IPB Figure 11-3, Detail M, Items 400 thru 460). Replace defective components and re-assemble.

3.5.6.14. Record results on test data sheet (see Figure 3-6).

3.5.6.15. Adjust torque motor current to 100.0 + 0.2 milliamps.

3.5.6.16. Fuel flow shall be 237 to 272 pounds per hour.

3.5.6.17. DIFFERENTIAL PRESSURE shall be 50+ 5 psid.

3.5.6.18. PUMP DISCHARGE PRESSURE shall be 140 to 310 psig.

3.5.6.19. Record results on test data sheet (see Figure 3-6).

3.5.6.20. Note NOZZLE PRESSURE.

3.5.6.21. Adjust backpressure on FUEL RETURN to obtain a NOZZLE PRESSURE that is 150 + 2 psig greater that the value noted in step 3.5.6.20.

3.5.6.22. Fuel flow shall be within + 10 pounds per hour of value obtain in Step 3.5.6.16.

3.5.6.23. DIFFERENTIAL PRESSURE shall be 50 + 5 psid.

3.5.6.24. PUMP DISCHARGE PRESSURE shall be 270 to 450 psig.

3.5.6.25. Record results on test data sheet (see Figure 3-6).

3.5.6.26. Maintain this test condition for the next test step.

3.5.7. Perform IGV regulator test as follows:

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3.5.7.1. With test condition as previously established, adjust torque motor current to 200.0 + 0.2 milliamps.

3.5.7.2. DIFFERENTIAL PRESSURE shall be 50 + 5 psid.

3.5.7.3. PUMP DISCHARGE PRESSURE shall be 500 to 825 psig.

3.5.7.4. REGULATED PRESSURE shall be 250 + 25 psig.

3.5.7.5. Record results on test data sheet (see Figure 3-6).

3.5.7.6. Maintain this test condition for the next test step.

3.5.8. Perform pressurizing valve test as follows:

3.5.8.1. With test condition as previously established, adjust drive speed to 830 + 10 RPM.

3.5.8.2. Adjust torque motor current to 20.0 + 0.2 milliamps.

3.5.8.3. Fuel flow shall be 35 to 65 pounds per hour.

3.5.8.4. PUMP DISCHARGE PRESSURE shall be 115 to 155 psig. If PUMP DISCHARGE PRESSURE is not within range, proceed as follows:

3.5.8.4.1. Adjust thickness of shims (IPB Figure 11-3, Detail P, Item 510) to achieve required pump discharge pressure.

3.5.8.5. NOZZLE PRESSURE shall be 18 psig minimum.

3.5.8.6. REGULATED PRESSURE shall be 115 psig minimum.

3.5.8.7. Record results on test data sheet (see Figure 3-6).

3.5.8.8. Adjust drive speed to zero.

3.5.9. Perform an initial flow test as follows:

NOTE

Some fuel controls experience low or no flow during testing. It has been identified that differential pressure valve plug P/N 3882546-2 (IPB Figure 11-3, item 450) can be received from supply in two lengths. If this low or no flow condition is encountered, verify differential pressure valve plug length is between 0.365” and 0.375”. If plug length is between 0.413” to 0.415”, rework plug to desired length of 0.365” to 0.375” before proceeding with test procedure.

3.5.9.1. Perform a current cycle as described in Step 3.2.8.

3.5.9.2. Adjust FUEL SUPPLY to apply 20 to 25 psig.

3.5.9.3. Adjust drive speed to 3320 + 10 RPM.

3.5.9.4. Energize the torque motor with 200.0 + 0.2 milliamps.

3.5.9.5. Operate at this condition for a minimum of 4 minutes to stabilize fuel control temperature.

3.5.9.6. Adjust drive speed to zero.

3.5.9.7. Perform a current cycle as described in Step 3.2.8.

3.5.9.8. Adjust drive speed to 1660 + 10 RPM.

3.5.9.9. Increase torque motor current from zero to 17.0 + 0.2 milliamps.

3.5.9.10. Fuel flow shall be 41 to 45 pounds per hour.

3.5.9.11. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.9.12. NOZZLE PRESSURE shall be 10 psig minimum.

3.5.9.13. REGULATED PRESSURE shall be 115 psig minimum.

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3.5.9.14. Record results on test data sheet (see Figure 3-6).

3.5.9.15. Maintain this test condition for the next test step.

3.5.10. Perform a start flow test in the increasing direction as follows:

3.5.10.1. With test condition as previously established, increase torque motor current to 25.0 + 0.2 milliamps.

3.5.10.2. Fuel flow shall be 57 to 63 pounds pr hour.

3.5.10.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.10.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.5.10.5. REGULATED PRESSURE shall be 115 psig minimum.

3.5.10.6. Record results on test data sheet (see Figure 3-6).

3.5.10.7. Maintain this test condition for the next test step.

3.5.11. Perform a start flow test in the decreasing direction as follows:

3.5.11.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 25.0 + 0.2 milliamps.

3.5.11.2. Fuel flow shall be 57 to 67 pounds per hour.

3.5.11.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.11.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.5.11.5. REGULATED PRESSURE shall be 115 psig minimum.

3.5.11.6. Record results on test data sheet (see Figure 3-6).

3.5.11.7. Maintain this test condition for the next test step.

3.5.12. Perform altitude performance test at 55 milliamps in the increasing direction as follows:

3.5.12.1. With test condition as previously established, adjust drive speed to 8300 + 10 RPM.

3.5.12.2. Increase torque motor current to 55.0 + 0.2 milliamps.

3.5.12.3. Fuel flow shall be 124 to 159 pounds per hour.

3.5.12.4. PUMP DISCHARGE PRESSURE shall be 130 to 230 psig.

3.5.12.5. Record results on test data sheet (see Figure 3-6).

3.5.12.6. Maintain this test condition for the next test step.

3.5.13. Perform altitude performance test at 55 milliamps in the decreasing direction as follows:

3.5.13.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 55.0 + 0.2 milliamps.

3.5.13.2. Fuel flow shall be 124 to 159 pounds per hour.

3.5.13.3. PUMP DISCHARGE PRESSURE shall be 130 to 230 psig.

3.5.13.4. Record results on test data sheet (see Figure 3-6).

3.5.13.5. Maintain this test condition for the next test step.

3.5.14. Perform altitude performance test at 100 milliamps in the increasing direction as follows:

3.5.14.1. With test condition as previously established, increase torque motor current to 100.0 + 0.2 milliamps.

3.5.14.2. Fuel flow shall be 237 to 272 pounds per hour.

3.5.14.3. PUMP DISCHARGE PRESSURE shall be 200 to 310 psig.

3.5.14.4. Record results on test data sheet (see Figure 3-6).

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3.5.14.5. Maintain this test condition for the next test step.

3.5.15. Perform altitude performance test at 100 milliamps in the decreasing direction as follows:

3.5.15.1. With test condition as previously established, increase torque motor current to approximately 200 milliamps, then decrease torque motor current to 100.0 + 0.2 milliamps.

3.5.15.2. Fuel flow shall be 237 to 272 pounds per hour.

3.5.15.3. PUMP DISCHARGE PRESSURE shall be 200 to 310 psig.

3.5.15.4. Record results on test data sheet (see Figure 3-6).

3.5.15.5. Maintain this test condition for the next test step.

3.5.16. Perform maximum flow test as follows:

3.5.16.1. With test condition as previously established, increase torque motor current to 250.0 + 0.2 milliamps.

3.5.16.2. Fuel flow shall be 525 to 660 pounds per hour.

3.5.16.3. PUMP DISCHARGE PRESSURE shall be 650 psig minimum.

3.5.16.4. REGULATED PRESSURE shall be 350 psig maximum.

3.5.16.5. Record results on test data sheet (see Figure 3-6).

3.5.16.6. Maintain this test condition for the next test step.

3.5.17. Perform solenoid valve test as follows:

Do not operate the fuel control unit for more than 1 minute continuously with the fuel solenoid de-energized. Fuel flow is required to cool internal components. Damage may results from operating unit without adequate fuel flow.

3.5.17.1. With test condition as previously established, de-energize fuel solenoid valve.

3.5.17.2. PUMP DISCHARGE PRESSURE shall be 625 psig maximum. Record data in the automated test software.

3.5.17.3. Check NOZZLE PRESSURE and ensure DISCHARGE PORT is at a safe pressure then remove hose from discharge port and allow port to drain. Once port has drained, observe port for leakage. No leakage permitted. Enter pass or fail in the automated test software.

3.5.17.4. Reconnect hose to fuel discharge port.

3.5.17.5. Energize fuel solenoid valve.

3.5.17.6. Fuel flow shall be within + 10 pounds per hour of value obtained in step 3.5.16.

3.5.17.7. PUMP DISCHARGE PRESSURE shall be within + 10 psig of value obtained in Step 3.5.16.

3.5.17.8. Record results on test data sheet (see Figure 3-6).

3.5.17.9. Maintain this test condition for the next test step.

3.5.18. Perform minimum flow test as follows:

3.5.18.1. With test condition as previously established, decrease torque motor current to 0.0 + 0.2 milliamps.

3.5.18.2. Fuel flow shall be 10 to 36 pounds per hour.

3.5.18.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.18.4. REGULATED PRESSURE shall be 115 psig minimum.

3.5.18.5. Record results on test data sheet (see Figure 3-6).

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3.5.18.6. Maintain this test condition for the next test step.

3.5.19. Perform a hot initial flow test as follows:

3.5.19.1. With test condition as previously established, adjust drive speed to zero.

3.5.19.2. Perform a current cycle as described in Step 3.2.8.

3.5.19.3. Adjust drive speed to 1660 + 10 RPM.

3.5.19.4. Increase torque motor current from zero to 17.0 + 0.2 milliamps.

3.5.19.5. Fuel flow shall be 41 to 45 pounds per hour.

3.5.19.6. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.19.7. NOZZLE PRESSURE shall be 10 psig minimum.

3.5.19.8. REGULATED PRESSURE shall be 115 psig minimum.

3.5.19.9. Record results on test data sheet (see Figure 3-6).

3.5.19.10. Maintain this test condition for the next test step.

3.5.20. Perform a hot restart test in the increasing direction as follows:

3.5.20.1. With test condition as previously established, increase torque motor current to 25.0 + 0.2 milliamps.

3.5.20.2. Fuel flow shall be 57 to 63 pounds per hour.

3.5.20.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.20.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.5.20.5. REGULATED PRESSURE shall be 115 psig minimum.

3.5.20.6. Record results on test data sheet (see Figure 3-6).

3.5.20.7. Maintain this test condition for the next test step.

3.5.21. Perform a hot restart test in the decreasing direction as follows:

3.5.21.1. With test condition as previously established, increase torque motor current to approximately 100 milliamps, then decrease torque motor current to 25.0 + 0.2 milliamps.

3.5.21.2. Fuel flow shall be 57 to 67 pounds per hour.

3.5.21.3. PUMP DISCHARGE PRESSURE shall be 115 psig minimum.

3.5.21.4. NOZZLE PRESSURE shall be 35 psig minimum.

3.5.21.5. REGULATED PRESSURE shall be 115 psig minimum.

3.5.21.6. Record results on test data sheet (see Figure 3-6).

3.5.21.7. Maintain this test condition for the next test step.

3.5.22. Perform external leakage test as follows:

This test step may be performed simultaneously with other test steps. The 5 minute minimum operating time may be accumulated from multiple steps during the test sequence.

3.5.22.1. Operate fuel control unit at 8300 + 10 RPM and maintain a PUMP DISCHARGE PRESSURE of at least 200 psig for at least 5 minutes continuously.

3.5.22.2. Observe external surfaces of fuel control for leakage. No leakage allowed.

3.5.22.3. Observe drain port for leakage. Leakage from drain port shall not exceed 1 drop in 8.5 minutes.

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3.5.22.4. Record results on test data sheet (see Figure 3-6).

3.5.23. Remove fuel control unit from test hookup.

3.6. Post Test Procedure:

3.6.1. Adjust drive speed to zero.

3.6.2. Adjust FUEL SUPPLY to zero.

3.6.3. Adjust torque motor current to zero.

3.6.4. De-energize fuel solenoid valve.

3.6.5. Disconnect TE3310519-1 Test Cable.

3.6.6. Disconnect all hoses.

3.6.7. Remove TE0000248-1 Test Fitting. Re-install plug (IPB Figure 11-3, Detail P, Item 550) with packing (IPB

Figure 11-3, Detail P, Item 560).

3.6.8. Remove TE0000250-1 Test Fitting. Re-install retainer (IPB Figure 11-3, Detail K, Item 290) with packing

(IPB Figure 11-3, Detail K, Item 300).

3.6.9. Remove filter body (IPB Figure 11-3, View D, item 90) and drain fluid then reinstall filter body.

3.6.10. Remove unit from TE3310507-1 Test Adapter.

3.6.11. Remove TE3310507-1 Test Adapter from 281600-7-1 Fuel Accessory Test Stand.

3.6.12. Replace any lockwire that was removed during testing. Refer to 8.3.4.

NOTE

If unit passes test verification, modification compliance shall be accomplished before FCU can be returned to service. The data plate shall have an “S” or “C” in the lower right corner. See NOTE para.3.2.2.

Table 3-2. Pump Run-In Test

Cond. No. Drive Speed (+ 10 RPM) GP5 Press. (+ 10 PSIG) Time at Cond. (minutes minimum)

1 830 50 2

2 830 100 1

3 1660 200 1

4 3320 400 1

5 5810 600 1

6 8300 850 1

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Figure 3-1. Test Hook-up #1

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Figure 3-2. Test Hook-up #2

3-24

Figure 3-3. Test Hook-up #3

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Figure 3-4. Backpressure Curve

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Figure 3-5. Test Data Sheet, Continued Service Test

3-27

Figure 3-6. Test Data Sheet, Overhaul Test

2G-GTCP331-3-2_changes.pdf