Storage GENERAL 28-10: STORAGE 1. General A. Fuel Storage System The fuel storage system consists primarily of a vented integral 149.25-gallon (1009-liter) capacity main fuel tank in each wing, an integral fuel collector tank/sump in each wing, 2-position (LEFT/RIGHT) electric fuel control valves, a motive fuel-driven ejector (jet) fuel pump, an electric fuel pump, an electric fuel shutoff valve, and four fuel drains. Each wing contains an integral fuel tank bounded by the upper and lower wing skins, main spar web, aft wing shear web, and the inboard and outboard fuel tank ribs. The wing skins and fuel ribs are of carbon composite with foam core sandwich construction. Three fuel baffle ribs are integral to each outboard fuel tank bay to reduce fuel slosh. Fuel flows by gravity from each fuel tank to the corresponding integral collector tank. Access panels in the lower surface of each wing allow access to the associated wet-bay for inspection and maintenance. Fuel tank fittings and screens are accessible through the wing access panels. (Refer to 6-00) Sump/drain valves are installed at the lowest point of each main and collector tank to permit fuel sumping and draining. Fuel from each wing tank gravity feeds through forward and aft strainers and hinge valves to the associated collector tank in each wing. The hinge check valves minimize fuel from flowing outboard from the collector during lateral acceleration. Vent/overflow lines connect the airspaces of the main and collector tanks. WARNING Wet-bay access panels must be fillet-sealed during installation. (Refer to 20-10) A 1/4 inch mesh strainer is installed on each of the two ports in each integral fuel tank. The strainers are accessible by removing the inboard fuel tank access cover. The fuel strainers in the fuel tanks should always be cleaned after the airplane has been in storage. If any damage or restrictions are noted during inspection, the strainers must be replaced. Each integral wing fuel tank has a filler cap in the upper surface of each wing for fuel servicing. The fuel cap assembly has a viton o-ring which seals the fitting in the upper wing skin. The fuel cap is grounded by conductive sealant to the aircraft lightning protection. Fuel tabs are integrated into the fuel filler necks and indicate a range of fuel levels from 85 to 130 gallons at 15 gallon increments. The airplane may be serviced to a reduced capacity to permit heavier cabin loading. The reduced fuel load is accomplished by filling each tank to the graduation level marking on the fuel tab visible below the fuel filler. Internal tank pressures are maintained through a vent line from each wing tank. Venting is accomplished independently in each tank by a vent line leading to a ramp-type vent inlet 1
GENERAL mounted underneath the wing aft of the ice impingement zone. Each collector tank incorporates a forward and aft vent/overflow to the associated fuel tank. Four drain valves at the system low points allow draining the system for maintenance and for examination of fuel in the system for contamination. The fuel must be sampled after each fueling and prior to each flight. A sampler cup is provided to drain a small amount of fuel from the wing tank drains and the collector tank drains. If takeoff weight limitations for the next flight permit, the fuel tanks should be filled after each flight to minimize condensation. (Refer to 12-10) All fuel grounding points are connected to each other through the aircraft structure and provide lightning protection. 2
2. Maintenance Practices A. Fuel Cap Assembly (See Figure 28-10-1) (1) Removal - Fuel Cap Assembly WARNING Never attempt to remove the fuel cap assembly with pressure in the fuel system. (b) Unlock fuel cap with key and remove. Rotate fuel cap external flange counter-clockwise to remove from wing. (2) Disassembly - Fuel Cap (b) (c) (d) Remove nut and washer securing fuel cap stem. Remove clip securing lock core. Remove outer o-ring. Remove stem o-ring. (3) Reassembly - Fuel Cap Install stem o-ring. (b) Install outer o-ring. (c) Install clip securing lock core. (d) Loosely Install nut and washer securing fuel cap stem. (e) Verify lever is in closed position. Nut torque rises rapidly. (f) Torque the nut to 8 inch-lb (0.90 Nm). (Refer to 20-60) 3
(4) Installation - Fuel Cap Assembly Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Sealant PR-2200, Class B PRC-Desoto International Seal cap. Dry Film Lubricant LPS 1 LPS Laboratories Lubricate lock, lever, and center pin. (b) (c) (d) (e) Apply sealant to fuel cap external flange threads. When fuel cap external flange is correctly oriented, fuel cap lock is positioned forward and tab on fuel cap stem folds aft. Position external flange to wing and rotate clockwise to secure. Hand tighten external flange, and then rotate counter-clockwise up to 1/4 turn for correct orientation. Insert fuel cap and lock with key. Lightly lubricate lock, lever, and center pin with petroleum jelly. (5) Functional Test - Fuel Cap Assembly Ground Resistance Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Ohmmeter Model 115/EFSP True RMS Fluke Check resistance. (b) Measure resistance from LH landing gear ground tab. (See Figure 12-10-1) 1 Connect one lead of ohmmeter to LH landing gear ground tab. 4
At fuel cap ring, measure resistance from the point where the fuel nozzle contacts the aircraft. 2 Measure and record resistance from LH landing gear ground tab to LH fuel cap ring. 3 Verify ground resistance to LH fuel cap ring is less than 10 ohms. 4 Measure and record resistance from LH landing gear ground tab to RH fuel cap ring. 5 Verify ground resistance to RH fuel cap ring is less than 10 ohms. (c) Measure resistance from RH landing gear ground tab. (See Figure 12-10-1) 1 Connect one lead of ohmmeter to RH landing gear ground tab. (d) At fuel cap ring, measure resistance from the point where the fuel nozzle contacts the aircraft. 2 Measure and record resistance from RH landing gear ground tab to LH fuel cap ring. 3 Verify ground resistance to RH fuel cap ring is less than 10 ohms. 4 Measure and record resistance from RH landing gear ground tab to RH fuel cap ring. 5 Verify ground resistance to RH fuel cap ring is less than 10 ohms. If any measured ground resistance exceeds maximum values, contact Cirrus Aircraft for disposition. 5
Figure 28-10-1: Fuel Cap Assembly 1 2 3 4 5 A 6 7 8 11 WING SKIN (REF) 9 11 10 LEGEND 1. Fuel Cap Stem 2. Lock 3. Fuel Cap 4. O-Ring 5. Fuel Cap Saddle 6. Washer 7. Nut 8. External Flange 9. Internal Flange 10. Fuel Level Tab 11. Rivet DETAIL A SF50_MM28_0009 6 21 Dec 2016
B. Collector Tank Hinge Valves (1) Removal - Collector Tank Hinge Valves De-fuel corresponding wing fuel tank. (Refer to 12-10) (b) Remove access panel FB2L or FB2R. (Refer to 6-00) (c) Remove bolts and washers securing hinge valve to fuel line flange on inner collector tank wall. (2) Installation - Collector Tank Hinge Valves Acquire necessary tools, equipment, and supplies. (b) Inspect hinge valve contact area for any contaminants. Remove contaminants as necessary to obtain a clean contact area. (c) Position and wet install hinge valve to fuel line flange on inner collector tank wall with washers and bolts. (Refer to 20-10) (d) Verify entire contact area of hinge valve makes contact with fuel line flange. (e) Install access panel FB2L or FB2R. (Refer to 6-00) (f) Re-fuel airplane. (Refer to 12-10) (g) Description P/N or Spec. Supplier Purpose Sealant, Fuel Bay AMS 3277 Type 2, B-1/2 Any Source Seal fuel bay. Inspect fuel tank for any signs of leakage. Service as required. C. Collector Tank Drain Valve (See Figure 28-10-2) (1) Removal - Collector Tank Drain Valve De-fuel corresponding wing fuel tank. (Refer to 12-10) (b) Remove access panel FB2L or FB2R. (Refer to 6-00) 7 21 Dec 2016
(c) (d) Remove nut securing fuel drain valve to access panel. Remove and discard o-ring from fuel drain valve. (2) Installation - Collector Tank Drain Valve Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Fuel Sampler Cup Refer to IPC, Fly Away Kit for approved cup Cirrus Aircraft Drain and collector tanks. Fuel Drain Valve O-Ring Refer to IPC, Fuel System - Storage for approved o-ring Any Source Replace o-ring for fuel drain valve. (b) (c) CAUTION To maintain lightning protection, the drain valves must be installed onto a clean, bare metal surface. Ensure entire base of drain valve makes contact with the access panel and no paint or contaminants exist between the surfaces. Failure to do so may result in potential ignition sources in the collector tank due to lightning. Inspect drain valve contact area for any paint or other contaminants. Remove contaminants as necessary to obtain a clean and bare metal contact area. Install new o-ring to fuel drain valve. CAUTION Ensure o-ring fits securely in valve body groove. (d) Secure fuel drain valve to access panel with nut. (e) Torque nut 80 to 100 in-lb (9.0 to 11.3 Nm). (Refer to 20-60) (f) Verify entire base of fuel drain valve makes contact with access panel. (g) Install access panel FB2L or FB2R. (Refer to 6-00) (h) Re-fuel airplane. (Refer to 12-10) (i) Place fuel sampler cup under fuel drain valve and test valve for proper operation. Inspect fuel for any contaminants. (j) Inspect complete fuel system for any signs of leaks and service as required. 8
(k) (l) CAUTION If fuel system is drained or a fuel tank is empty for any reason, air may enter the system. Purge air from fuel system. See Williams FJ33-5A Line Maintenance Manual. (Refer to 5-00) CAUTION To ensure proper engine operation, run the engine at idle for at least two minutes. (Refer to Airplane Flight Manual, Section 4) Reinspect complete fuel system for any signs of leaks and service as required. 9 21 Dec 2016
Figure 28-10-2: Fuel Drain Valve A B WING FUEL TANK ACCESS PANEL (REF) 1 1 COLLECTOR TANK 1 ACCESS PANEL (REF) 2 1 2 3 4 A 3 4 B 1 NOTE Torque nut to 80-100 in-lb (9.0-11.3 Nm). LEGEND 1. Nut 2. Washer 3. O-ring 4. Drain Valve SF50_MM28_0136A 10
D. Vent Baffles (1) Removal - Vent Baffles De-fuel corresponding wing fuel tank. (Refer to 12-10) (b) Remove access panel W4L or W4R. (Refer to 6-00) (c) Remove nut securing vent baffle to bulkhead fitting on fuel bay wall. Remove vent baffle from airplane. (2) Installation - Vent Baffles Acquire necessary tools, equipment, and supplies. (b) Inspect vent baffle contact area for any contaminants. Remove contaminants as necessary to obtain a clean contact area. (c) Install fuel vent baffle and tighten with nut. Torque nut 240 to 280 in-lb (27.1 to 31.6 Nm). (d) Install access panel W4L or W4R. (Refer to 6-00) (e) Re-fuel airplane. (Refer to 12-10) (f) Inspect fuel tank for any signs of leakage. Service as required. E. Fuel Strainers (See Figure 28-10-3) (1) Removal - Fuel Strainers Drain corresponding fuel tank for side being serviced. (Refer to 12-10) (b) Remove access panel W1L or W1R. (Refer to 6-00) (c) Remove bolts, washers, and spacers securing flange of fuel strainer to wing rib. Remove fuel strainer from airplane. (2) Installation - Fuel Strainers Acquire necessary tools, equipment, and supplies. 11
(b) Position fuel strainer flange to wing rib and secure with spacers, washers. and bolts. (c) Install access panel W1L or W1R. (Refer to 6-00) (d) Fill fuel tank. (Refer to 12-10) (e) Inspect fuel tank for any signs of leakage. Service as required. (3) Inspection/Check - Fuel Strainers Visually inspect fuel strainers for signs of damage or restrictions. If damage or restrictions exist, clean or replace fuel strainer. F. Fuel System Ventilation (See Figure 28-10-3) (1) Removal - Fuel System Ventilation Drain corresponding wing fuel tank. (Refer to 12-10) (b) Remove access panel W4L or W4R. (Refer to 6-00) (c) Disconnect fitting securing vent tubing to outboard wing fuel vent. (d) Disconnect fitting securing vent tubing to bulkhead fitting on wing rib. Remove vent tubing from airplane. (2) Installation - Fuel System Ventilation Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Sealant, Fuel Bay AMS 3277 Type 2, B-1/2 Any Source Seal fuel bay. (b) Position vent tubing to bulkhead fitting on wing rib and connect fitting. (c) Position vent tubing to outboard wing fuel vent and connect fitting. (d) Install access panel W4L or W4R. (Refer to 6-00) 12
(e) Fill fuel tank. (Refer to 12-10) (f) Inspect fuel tank for any signs of leakage. Service as required. (3) Inspection/Check - Fuel System Ventilation Inspect vent tubing for obstructions, kinks, chaffing, or cuts. Replace tubing if damaged. 13
Figure 28-10-3: Wing Fuel System Components A 6 5 7 4 DETAIL A 1 3 8 2 1 3 1 4 LEGEND 1. Supply Tube Assembly 2. Collector Tank 3. Fuel Overflow Line 4. Fuel Tank Strainers 5. Fuel Tank Access Panel (Underside of Wing) 6. Fuel System Vent Line 7. Vent Inlet 8. Fuel Tank, Left Integral SF50_MM28_0135A 14
G. Fuel Tanks (Wing and Collector) (1) Adjustment/Test - Wing Fuel Tank Pressure Test Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Rubber Tubing OD less than 0.25 inch and length at least 35 ft (11 m) - Any Source Test fuel system. Putty, Temporary Adhesive - Any Source Test fuel system. Cap (2) AN929-6D, -12D Any Source Pressure-Regulating Test Tool T13583 Cirrus Aircraft Verify pressure. Compressed Air - Any Source Apply pressure. (b) (c) Connect LH and RH tank vent inlets. 1 Wrap adhesive putty around one end of tube, leaving about 0.5 inch (1.27 cm) of bare tube protruding. 2 Insert bare end of tube into LH wing tank vent port on lower wing skin and mold putty against vent inlet surface to create airtight seal. 3 Wrap adhesive putty around opposite end of tube, leaving about 0.5 inch (1.27 cm) of bare tube protruding. 4 Insert bare end of tube into RH wing tank vent port on lower wing skin and mold putty against vent inlet surface to create airtight seal. Disconnect fuel system from engine. 1 Disconnect fuel supply flex line and motive flex line from firewall bulkhead fittings. CAUTION Do not torque caps; tighten only until snug. Leak check involves very low pressures, and stainless bulkhead fittings are prone to galling. If caps leak during test, they can be tightened incrementally until leakage stops. 2 Install caps on bulkhead fittings where flex lines were disconnected. 15 21 Dec 2016
(d) (e) (f) Connect pressure test tool to system. 1 Remove LH fuel filler cap. 2 Verify outlet port of pressure test tool is connected to supplied test fuel cap. 3 Install test fuel cap. Position of Fuel Control Valves is not relevant to this procedure; LH and RH tanks are pressurized via flexible tubing installed previously at tank vent inlets. 4 Verify main lever on test tool is in OFF position. 5 Connect compressed air supply to inlet port of pressure test tool. CAUTION Never connect compressed air supply directly to fuel system. Using pressure test tool ensures that system is pressurized in a slow, controlled manner. Unregulated compressed air can quickly overpressure system, leading to aircraft structural damage. Pressurize system and check for leaks. 1 Move pressure test tool valve to ON position and monitor both pressure gauges as system pressurizes. 2 When system pressure has reached 1.5 ±0.1 psig, move valve to OFF position. If either pressure gauge reads 2.0 psig or higher at any point, terminate test, depressurize system, and contact Cirrus for disposition. 3 Allow pressure to stabilize for up to 10 minutes. 4 Make note of current time and system pressure from digital readout. 5 After 30 minutes, check digital readout and compare to previously noted system pressure. Changes in ambient or internal tank temperature during test may result in detectable pressure changes. 6 Test is passed if there is no change in pressure over 30 minute period. At LH fuel filler, remove test fuel cap and install fuel filler cap. 16
(g) (h) At firewall, remove caps and connect fuel supply flex and motive flex lines to firewall bulkhead fittings. At LH and RH wing tank vent ports, remove tubes and putty from wing tank vent ports. (2) Inspection/Check - Wing Fuel Tank (Fuel Contaminants) No detectable fuel leaks are allowed after repair procedure has been performed. (Refer to 28-10) (b) (c) (d) Drain quart of fuel from main tank drain valve into clean, clear container. Visually inspect fuel sample for evidence of contaminants. Drain pint of fuel from collector tank drain valve. Visually inspect fuel sample for evidence of contaminants. If no contaminants are found, no further action is required. Make an entry in airplane logbook stating inspection was performed. If contaminants are found, fuel tank must be drained and cleaned. (Refer to 12-10) (3) Inspection/Check - Wing Fuel Tank (Leakage) The approved jet fuels do not contain dyes, but leaks may collect dirt or debris to cause staining. A wet or stained spot on the wing can be an indication of a fuel leak. Not all fuel leaks require immediate repair. Fuel leaks which do not constitute a flight hazard can be repaired at the next scheduled servicing. Fuel leaks that do not constitute a flight hazard are stains, seeps, and heavy seeps which are not in an enclosed area. Fuel tanks are sealed with AMS3277 or MIL-S-8802 Type ll sealant. Repairs that break the fuel tank access panel seal will necessitate resealing of that fuel tank. All repairs made within the fuel tank must be fay surface sealed and fillet sealed. All boundaries and any other place that could leak must be sealed. Stains and seeps which are not immediately repaired must be inspected prior to and immediately after each flight until they have been repaired. (b) Stain - 3/4 of an inch in size or less. Seep - 3/4 of an inch up to 1 1/2 inches. 17 21 Dec 2016
(c) (d) Heavy seep - 1 1/2 inches up to 4 inches. Running Leak - vary in size depending on location and intensity of the leak. Fuel usually will flow and immediately drip after being wiped dry. (4) Inspection/Check - Collector Tank Drain corresponding fuel and collector tank bays for side being serviced. (Refer to 12-10) (b) Remove wing fuel bay access panel. (Refer to 6-00) (c) Visually inspect collector tank bay for any signs of damage, leaks or stains. If any damage, stains or leaks are present, repair tank. (d) Install wing fuel bay access panel. (Refer to 6-00) (e) Fill fuel tank. (Refer to 12-10) (f) Inspect fuel tank, collector tank, hoses, and lines for any signs of leakage. Service as required. (5) Cleaning - Wing Fuel Tank Special precautions must be observed when using solvents for cleaning. Solvents used in cleaning are toxic and flammable. Fresh air masks and/or adequate ventilation, eye protection, and skin protection must be used in all closed areas. Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Methyl Ethyl Ketone (MEK) ASTM D-740 Type 1or 2 Any Source Clean surfaces. Acetone ASTM D-329 Any Source Clean surfaces. (b) Vacuum thoroughly to remove all chips, filings, and dirt from the tank area. CAUTION Always pour solvent on cloth to prevent contaminating solvent. Do not allow cloth to drip. Wipe surfaces with clean, 18 21 Dec 2016
(c) dry cloths until white haze disappears. Never use contaminated solvent. Solvent clean all surfaces to be sealed by wiping with a clean cloth dampened with Methyl Ethyl Ketone (MEK), acetone or similar solvent. Dry surfaces with a clean cloth before solvent evaporates. H. Fuel Tank Drain Valve (See Figure 28-10-2) Includes both the main and collector fuel tank drain valves. (1) Removal - Fuel Tank Drain Valve Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Fire Extinguisher (Type AB, or ABC) - Any Source Extinguish fire in an emergency. Fuel Drain Container 5 to 300 gallon container (min) Any Source Drain fuel. Fuel Sampler Cup Refer to IPC, Fly Away Kit for approved cup Cirrus Aircraft Drain collector tanks. (b) (c) (d) (e) (f) (g) (h) (i) Position fuel drain container under fuel drain valve. Ground fuel drain container to established fuel grounding points and airplane to a suitable earth ground. (Refer to 12-10) If removing from fuselage belly (fuel collector tank): Remove access panel FB2L or FB2R. (Refer to 6-00) If removing from wing (main fuel tank): Remove access panel W1L or W1R. (Refer to 6-00) Remove fuel drain valve from access panel. Allow all fuel and any contaminants to drain from fuel tank. To completely drain fuel system, use fuel sampler cup to remove all fuel and any contaminants from main and collector tanks. Remove and discard o-ring from fuel drain valve. 19 21 Dec 2016
(2) Installation - Fuel Tank Drain Valve Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Fuel Sampler Cup Refer to IPC, Fly Away Kit for approved cup Cirrus Aircraft Drain collector tanks. Fuel Drain Valve O-Ring Refer to IPC, Fuel System - Storage for approved o-ring Any Source Replace o-ring for fuel drain valve. (b) (c) Install new o-ring to fuel drain valve. CAUTION Ensure o-ring fits securely in valve body groove. Secure fuel drain valve to access panel with nut. The valve can be identified by the crimped (cad plated steel) or chamfered (brass) stem. (d) Torque fuel drain valve 80 to 100 in-lb (9.0 to 11.3 Nm). (Refer to 20-60) (e) If installing to wing (main fuel tank): Install access panel W1L or W1R. (Refer to 6-00) (f) If installing to fuselage belly (fuel collector tank): Install access panel FB2L or FB2R. (Refer to 6-00) (g) Re-fuel airplane. (Refer to 12-10) (h) Place fuel sampler cup under fuel drain valve and test valve for proper operation. Inspect fuel for any contaminates. (i) Inspect complete fuel system for any signs of leaks and service as required. (j) (k) CAUTION If fuel system is drained or a fuel tank is empty for any reason, air may enter the system. Purge air from fuel system. See Williams FJ33-5A Line Maintenance Manual. (Refer to 5-00) CAUTION To ensure proper engine operation, run the engine at idle for at least two minutes. (Refer to Airplane Flight Manual, Section 4) Reinspect complete fuel system for any signs of leaks and service as required. 20