ATA 28 Fuel Systems - Bombardier DHC 8-400 (PWC PW150) Issue 6 January 2023 PDF

BOMBARDIER DHC 8-400 (PWC PW150) ATA 28 - FUEL SYSTEMS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY B1/B2 MAINTENANCE TRAINING MANUAL Issue 6 - January 2023 Page 1 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM No electrical power is required for normal engine feed operation. In the...

BOMBARDIER DHC 8-400 (PWC PW150) ATA 28 - FUEL SYSTEMS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY B1/B2 MAINTENANCE TRAINING MANUAL Issue 6 - January 2023 Page 1 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM No electrical power is required for normal engine feed operation. In the event of an ejector pump failure, the auxiliary AC electrical pump in the collector bay is selected ON to supply engine fuel feed. PURPOSE Four scavenge ejector pumps transfer fuel inboard to the collector bay. The fuel system provides: • • • • • • • This maintains a constant level in the collector bay to ensure engine fuel feed regardless of aircraft attitude and minimizes the quantity of unusable fuel. A low fuel level sensor is located in each collector bay to provide a caution indication to the crew. Indicating Storing Venting Fuel feeding Fuel scavenging Refuelling/defuelling Fuel transferring Pressure refuelling and defuelling is accomplished through a single point refuel/defuel adaptor located in the right engine nacelle and is controlled through an adjacent refuel/defuel control panel. Both automatic and manual refuelling modes are possible. NOTE: Only tank to tank transfer is available; there is no engine cross-feed capability. Selected and actual fuel tank quantities are displayed on the control panel. The Fuel Quantity Computer (FQC), located under the centre aisle floorboards, controls the logic during the automatic refuel/defuel process. Refuel operations can be accomplished using aircraft battery power. A high level sensor shutoff system ensures the maximum allowable tank capacity is not exceeded. The aircraft may be gravity or pressure refuelled. GENERAL DESCRIPTION Fuel is contained in two integral main wing tanks designated No.1 (Left) and No.2 (Right). As an alternative to pressure refuelling and defuelling, each tank can be filled through an over-wing filler point or drained through a fitting installed in the auxiliary pump canister when its element is removed. Each wing tank includes a surge bay and a collector bay. The left tank supplies fuel to the left engine and the optional Auxiliary Power Unit (APU). The right tank supplies fuel to the right engine. There are three drain valves located at the low points of each tank to permit checks for water accumulation and to drain residual fuel from the tanks when required. Normal engine feed is by means of an ejector pump in each collector bay. The engine Fuel Metering Unit (FMU) supplies the motive flow. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 2 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL SYSTEM BLOCK DIAGRAM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 3 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM GENERAL DESCRIPTION Each fuel tank is vented through a surge bay located in the outboard section of the main tank. Fixed vent lines and float vent valves between the fuel tanks and the surge bays provide adequate capacity for in flight venting. During pressure refuelling, tank venting is supplemented by a high capacity vent valve which is opened by refuel pressure. The Fuel Quantity Gauging System (FQGS) accurately measures the quantity of fuel in the main tanks. It supplies the fuel quantity data to the flight compartment and the refuel/defuel panel for display. Fuel quantity may also be checked on the ground by use of the magnetic dipsticks located on the lower surface of the wing. The maximum usable fuel capacity of the aircraft is approximately 5,338 kgs/11,724 lbs. A wing to wing fuel transfer system is provided to correct lateral fuel imbalance or to fully utilize the fuel after an engine failure. The auxiliary pump in the donor tank transfers the fuel to the receiving tank. The FUEL CONTROL TRANSFER panel in the flight compartment controls the operation of the fuel transfer system. The maximum allowable tank to tank imbalance is 272 kgs/600 lbs. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 4 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL SYSTEM SYNOPTIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 5 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM The fuel tanks are formed by the front and rear wing spars and the upper and lower wing skins. The inboard end of the main fuel tank is the wing rib at WS 42 and the outboard end is the wing rib at WS 407. FUEL STORAGE PURPOSE The fuel tanks contain the fuel to be used by the aircraft engines and optional Auxiliary Power Unit (APU). The main tanks and the collector bays are the storage areas for the fuel. The total volume of each wing tank is approximately 3391 L/896 US gallons. The high level shut off is set at 3300 L/872 US gallons to ensure that a minimum of 2% of the total volume is maintained for expansion of the fuel. The fuel tanks have the necessary components to move the fuel from the main tanks to the collector bays for use by the fuel distribution system. Fuel is stored in two wing tanks which are integral parts of the wing structure. The left No.1 tank supplies fuel to the left No.1 engine and the APU. The right No.2 tank supplies fuel to the right No.2 engine. Each wing tank has a surge bay and a collector bay. There are vent lines in the fuel storage system to prevent over-pressurization of the fuel tanks. GENERAL DESCRIPTION Each fuel tank is formed by the structure of the wing itself. This is known as an integral wet wing tank. The fuel tanks include the components that follow: • • • • • • • • • • Flapper Check Valves Motive Flow Lines Motive Flow Check Valves Scavenge Flow Lines Forward Scavenge Ejector Aft Scavenge Ejector Mid Wing Scavenge Ejector Outboard Scavenge Ejector Gravity Refill Cap Water Drain Valve TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 6 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL TANKS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 7 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM Rib baffles at WS 117, WS 191 and WS 280 slow the flow of fuel to the outboard end of the wing tank during uncoordinated manoeuvres or accelerated rolls. At WS 117 and WS 191, the joints between the skin and the ribs are sealed except for small water passage holes. One-way flapper valves installed near the bottom of the ribs allow the fuel to flow inboard only. This allows the scavenge ejectors to maximize the amount of fuel they can scavenge at low fuel and wing down conditions. FUEL STORAGE SYSTEM DESCRIPTION The wet wing tanks are prevented from leaking by sealing all the ribs, stringer joints, spars and fasteners with sealing compound. Adequate drainage paths are provided in the ribs and stringers to allow for the drainage of water by gravity to the sump areas of the tank. Each tank is divided into three sections: • • • The main tank The collector bay The surge bay The sumps are located in the areas that follow the: The inboard sections of the main tank form the collector bay. The collector bay holds a constant supply of fuel for the engine fuel feed system. The collector bay is located laterally between WS 42 and WS 79 and longitudinally between the rear wing spar and the wing box structure aft of fuselage station FS 396. The capacity of the collector bay is approximately 227 L/60 US gallons. • • • Surge bay Main tank, immediately outboard of rib at WS 191 Collector bay, close to the main ejector pump A drain valve is located in each sump area to allow for the drainage of water when the aircraft is on the ground. The surge bay is located outboard of the main tank between WS 407 and WS 425. Each surge bay is connected through integral standpipes to two separate NACA vents on the bottom of the wings. The standpipes prevent fuel spillage overboard. Vent lines routed from each surge bay to its main tank control the pressure inside the tanks. The wing box section between the WS 42 left and WS 42 right is called the dry bay. It separates the wing tanks from the fuselage. There are two 0.5 inch diameter openings in the bottom wing skin inboard of each WS 42. These openings provide overboard draining of minor fuel leaks, area ventilation and pressure relief resulting from altitude changes. These two drain lines are combined into one 0.75 inch diameter overboard drain in the wing/fuselage armpit area. The areas next to the fuel tank in the nacelle are also well ventilated. Removable rectangular panels along the top of the wing provide access to the inside of the main tank, surge bay and dry bay. The openings at the top of the wing rib structures inside the tanks minimize the amount of air pockets during refuelling and aircraft manoeuvres. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 8 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL TANKS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 9 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE FLAPPER CHECK VALVES PURPOSE The flapper check valves are simple mechanical valves that allow the fuel to flow inboard only. There are a total of 36 flapper check valves, 18 in each wing tank. They are located at the bottom of the wing ribs and along the forward and side walls of the collector bay. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 10 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FLAPPER CHECK VALVES TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 11 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE MOTIVE FLOW CHECK VALVES PURPOSE The motive flow check valve, inside an aluminium fitting, prevents any reverse flow from the fuel tank to the engine. There is one motive flow check valve in each tank. It is located in the motive flow supply line between the engine and the ejector pumps. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 12 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - MOTIVE FLOW CHECK VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 13 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE MOTIVE FLOW LINES PURPOSE Motive flow is pumped to the scavenge ejectors and to the engine fuel feed system primary ejectors through the motive flow lines. The motive flow fuel lines are located in the main wing tanks. The Fuel Metering Unit (FMU) in each engine supplies motive flow as a low volume, high pressure fuel flow. SCAVENGE FLOW LINES PURPOSE The scavenge flow lines are located in the main wing tanks. They transfer fuel from various areas of the main tanks to the inboard part of the main tanks and to the collector bays. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 14 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - MOTIVE FLOW AND SCAVENGE SYSTEMS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 15 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM DESCRIPTION FUEL STORAGE There is one forward scavenge ejector in each tank. Each ejector is located in the forward area of the wing just outboard of the closure rib at WS 42 and immediately aft of the front spar. SCAVENGE EJECTORS PURPOSE The purpose of the scavenge ejectors is to keep the collector bay full of fuel and to reduce the quantity of unusable fuel. They continuously scavenge fuel from the main tank and transfer it to the collector bay. DESCRIPTION The ejector has no moving parts and its operation is based on the venture principle. Pressurized fuel from the engine FMU is routed to the motive flow port of the ejector. The flow discharges at a high velocity from the nozzle into the throat section of the ejector. This creates a local low pressure area which draws fuel from the main tank into the suction port. This fuel is mixed with the motive flow fuel and is discharged at the outlet port. The following is common to all ejectors used in this system: • • • Motive flow fuel is pumped to the ejector through the motive flow lines The low volume, high pressure motive flow causes the ejector to discharge a high volume, low pressure flow into the scavenge lines A 250 micron filter at the motive fuel flow inlet of the ejector protects the small nozzle opening FORWARD SCAVENGE EJECTOR PURPOSE The purpose of the forward scavenge ejector is to keep the collector bay full of fuel during aircraft operation at negative pitch attitudes. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 16 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - SCAVENGE EJECTORS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 17 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM Motive flow is pumped to the scavenge ejectors through the motive flow lines. FUEL STORAGE AFT SCAVENGE EJECTOR PURPOSE The purpose of the aft scavenge ejector is to keep the collector bay full of fuel during aircraft operation with low fuel quantities in climb and/or uncoordinated roll attitudes. DESCRIPTION There is one aft scavenge ejector in each tank. The ejector is located in the aft area of the wing near the rear wing spar inboard of the baffle rib at WS 117. MID WING SCAVENGE EJECTOR PURPOSE The purpose of the mid-wing scavenge ejector is to transfer fuel inboard to the collector bay during uncoordinated roll manoeuvres. There is one mid wing scavenge ejector in each tank. The ejector is located just inboard of WS 191 at the low point of the wing. Motive flow is pumped to the ejector through the motive flow lines. OUTBOARD SCAVENGE EJECTOR PURPOSE The purpose of the single outboard scavenge ejector is to supply fuel to the area of the wing inboard of WS 191. This ensures that fuel which flows outboard during extended sideslip manoeuvres is available for engine feed. There is one outboard scavenge ejector in each tank. The ejector is located in the outboard area of the wing at the tank closure rib WS 407. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 18 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - SCAVENGE EJECTOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 19 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE GRAVITY REFILL CAP PURPOSE The gravity refill cap allows for gravity refuelling of the aircraft. There is one gravity refill cap installed at the outboard section of each wing near WS 407. It is located on the top of the wing to allow for gravity refuelling. The lightning proof refill cap mates with the refuel/defuel adaptor and is flush mounted with the skin of the wing. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 20 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - GRAVITY REFILL CAP LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 21 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE WATER DRAIN VALVE PURPOSE The water drain valves may be opened to drain any water accumulation in the tank. The valves are also used to drain residual fuel from the tanks when necessary. There are six water drain valves installed on the aircraft, three in each wing. They are located at the lowest points of the surge bay, main tank and collector bay. The drain valve is spring-loaded closed and may be locked in the open position. The secondary seal design allows the replacement of the primary sealing ‘O’ ring with the fuel still in the tank. The valve is retained and held against the lower wing skin by a non-metallic nut inside the fuel tank. Electrical grounding of the aluminium valve is through the valve mounting flange and the wing skin. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 22 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - WATER DRAIN VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 23 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE VENTS INTRODUCTION The vent system connects each fuel tank to ambient air pressure. This equalizes the pressure inside the tank with the pressure outside the tank and supplies sufficient venting of the fuel tanks for any aircraft flight attitude. Venting of the fuel tanks also prevents any structural damage to the aircraft during refuelling or defuelling. GENERAL DESCRIPTION The vent system lets air enter the fuel tanks as the fuel is supplied to the engines, or during aircraft defuelling. This prevents structural damage to the tanks from an excessively low internal pressure. The vents also let air out of the tanks when the aircraft is being refuelled to prevent the tanks from over pressurizing. The vent system includes these components: • • • • Inboard Vent Line Outboard Vent Line Vent Float Valves NACA Vent Inlet TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 24 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - VENT SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 25 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM The outboard end of the vent line extends through the tank closure rib at WS 407 and down to within 0.5 in/12.7 mm of the bottom of the surge bay. Due to the slight pressurization of the surge bay excess fuel in the bottom of the bay is scavenged back into the main tank. FUEL STORAGE VENTS CONTINUED OUTBOARD VENT LINE SYSTEM DESCRIPTION PURPOSE The vent system keeps the wing tank pressure within safe limits for all aircraft operations and flight manoeuvres. It allows unrestricted air flow between the tank and ambient air. The outboard vent lines vent the main fuel tanks to the surge bays refer to Vent Float Valves. Each fuel tank is vented to its related surge bay through an inboard vent line. The surge bay itself is vented to the outside through two NACA vents located on the underside of the wing. During normal flight, the air flowing into the NACA vents pressurize the surge bay and maintain the main tank pressure at or slightly above atmospheric pressure. The vent system operates satisfactorily if one of the NACA vents is blocked. There are two outboard vent lines in each fuel tank connecting the main fuel tank to the surge bay. Each vent line is connected to a vent float valve through its own 1.0 inch/2.54 cm hole in the tank closure rib at WS 407. The vent lines extend down to within 0.5 in/12.7 mm of the bottom of the surge bay. As the surge bay is pressurized in flight, through the NACA vents, any fuel in the surge bay is scavenged by the outboard vent lines back into the main tank. Each surge bay also has two forward and aft outboard vent lines equipped with vent float valves. The vent float valves close the outboard vent lines when the fuel level rises above the opening of the vent lines. During a climb, the aft vent float valve closes and venting is supplied by the forward outboard vent line. During a descent, the forward vent float valve closes and venting is supplied by the aft outboard vent line. INBOARD VENT LINE PURPOSE The inboard vent line supplies venting when the fuel is moving outboard or inboard in the tank, as in a climb, uncoordinated flight manoeuvres, accelerated rolls, refuelling and defuelling. The 1.0 inch/2.54 cm diameter inboard vent line runs immediately below the wing top skin from the surge bay along the forward wing spar to the inboard part of the main fuel tank. The line is completely unobstructed in order to supply continuous venting protection for the wing tank. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 26 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - VENT SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 27 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE VENTS CONTINUED VENT FLOAT VALVES PURPOSE The vent float valve has a polyurethane foam float which closes the outboard vent line if the fuel level in the tank rises above the opening of the valve. This prevents fuel from flowing into the surge bay. DESCRIPTION Two vent float valves are located near the top of the rib dividing the main tank from the surge bay (WS 407). The vent float valve located on the forward part of the rib at WS 407 supplies venting during a climb. The vent float valve located on the aft part of the rib at WS 407 supplies venting during a descent. If the fuel flows to the outboard part of the main tank and submerges both vent valves, the inboard vent line will provide adequate venting. The two vent float valves and the inboard vent line provide adequate venting for most flight attitudes. A high capacity refuel/dump vent valve on the inboard side of WS 407 provides outward relief when the main tank pressure reaches 4.0 psig. The same valve also supplements the venting of the tank during pressure refuelling. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 28 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - VENT FLOAT VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 29 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE VENTS CONTINUED INLET NACA VENTS PURPOSE The NACA vents are ice-free ram air vents which keep a slight positive pressure in the fuel tank while in flight. DESCRIPTION The surge bay is vented overboard through dual NACA vents. The vents are located on the lower front edge of each wing. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 30 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - NACA INLET VENT TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 31 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL STORAGE VENTS CONTINUED INLET NACA VENTS CONTINUED DESCRIPTION The NACA vents are connected to standpipes which extend up to the top rear of the surge bay. These standpipes prevent any fuel which may accumulate in the bottom of the surge bay from spilling overboard. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 32 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - NACA INLET VENT STANDPIPE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 33 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED PURPOSE The engine fuel feed system provides pressurized fuel from the tanks to the engines. The pressure and flow rate of the fuel is sufficient to satisfy all engine operational requirements. GENERAL DESCRIPTION Each individual tank supplies fuel to its related engine only. Each engine feed system consists of a primary ejector pump, an AC powered auxiliary pump and an emergency fuel shut-off valve. Both the primary and auxiliary pumps are installed close to the bottom of the collector bay so that, under normal aircraft operation, both pump intakes are submerged in fuel and subjected to positive fuel pressure. The left and right engine feed systems operate independently of each other so that failure of one system does not cause the loss of the other system. Each engine fuel feed system includes these components: • • • • • • Primary Ejector Pump Engine Feed Lines Inlet Strainer Engine Feed Shut-off Valve Auxiliary Pump Auxiliary Pump Pressure Switch TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 34 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - ENGINE FUEL FEED SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 35 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED SYSTEM DESCRIPTION A primary ejector pump located in each collector bay supplies fuel to its related engine. Each primary ejector pump uses high pressure motive flow fuel to transfer fuel from the collector bay to the engine. The engine driven fuel pump in the Fuel Metering Unit (FMU) of each engine supplies the motive flow fuel. An electrically powered AC auxiliary pump is installed in each collector bay. Either the primary ejector pump or the auxiliary pump can supply the required amount of engine fuel feed. The primary ejector pump supplies the fuel to the engine during normal aircraft operation. The auxiliary pump is manually controlled by selecting the TANK 1 or TANK 2 AUX PUMP switches on the FUEL CONTROL TRANSFER panel. The auxiliary pumps are selected ON for takeoff, landing and operation with minimum fuel quantities. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 36 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - ENGINE FUEL FEED SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 37 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED SYSTEM DESCRIPTION There is an engine feed shut-off valve located on the rear spar of each wing. The valve is used to stop the fuel supply to the engine in the event of a fire. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 38 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - ENGINE FUEL FEED OPERATION TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 39 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FEED LINES ENGINE FUEL FEED The engine feed lines transfer the fuel from the primary ejector pumps or the auxiliary pumps to the engines. PRIMARY EJECTOR PUMP PURPOSE The primary ejector pump makes sure that there is positive pressure to the enginedriven pump to prevent the possibility of pump cavitation. DESCRIPTION There is one primary ejector pump located in each collector bay. The primary ejector pump delivery rate is always greater than the engine driven pump demand. The primary ejector pump operates on the venturi principle and has no moving parts. The high pressure motive fuel from the Fuel Metering Unit (FMU) is fed directly into the throat of the ejector. This creates a local low pressure area which draws fuel from the collector bay into the suction port. This fuel is mixed with the motive flow fuel and discharged through a flapper check valve. The flapper check valve has a 0.031 inch diameter hole in it to allow for thermal relief after engine shut down. INLET STRAINER PURPOSE The inlet strainers help prevent foreign objects from entering the fuel flow. DESCRIPTION There are two inlet strainers, one for each primary ejector pump. Each inlet strainer is installed around the fuel inlet port of its related primary ejector pump. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 40 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - PRIMARY EJECTOR PUMP AND INLET STRAINER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 41 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM The white light comes on to show that the valve is closed. ENGINE FUEL FEED The battery bus supplies the electrical power to the engine feed shut-off valve. ENGINE FEED SHUT-OFF VALVE PURPOSE The engine feed shut-off valve is used to stop the fuel supply to the engine in the event of a fire. DESCRIPTION The valve is installed inside the tank on the rear spar. The valve has an electrically driven actuator which operates an open-closed ball valve positioned in the engine fuel feed line. The actuator is electrically powered by a 28V DC motor which is installed on the dry side of the spar and splined to the valve. The electrical wiring of the valve is duplicated and separated so that control of the valve is protected in case of a rotor burst. The actuator has physical and electrical position indication and may be replaced without changing the valve or draining the fuel tank. There are two thermal relief valves: one at the inlet and one at the outlet of the shutoff valve. They are set to open between 65 psig and 70 psig to protect the system from over pressurization when the valve is closed. The engine feed shut-off valve is controlled and operated by the PULL FUEL/HYD OFF handle located in the flight compartment, on the engine fire protection panel. One green light and one white light for each tank are located on the engine fire protection panel to show the valve position. The green light comes on to show that the valve is open. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 42 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - ENGINE FEED SHUT-OFF VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 43 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED AUXILIARY PUMP PURPOSE The auxiliary pump serves as a backup source for fuel supply to the engine if the primary ejector pump does not supply the minimum required fuel pressure for engine operation. The auxiliary pumps are used for takeoff, landing and during operation with low fuel levels. The auxiliary pump is installed on the wing lower skin inside the collector bay of each main tank, adjacent to the primary ejector pump. It is a submerged, electrically operated, centrifugal pump connected in parallel with the primary ejector pump. Each auxiliary fuel pump is powered by its related 115V AC variable frequency power bus and is protected by a 5A circuit breaker - B1 for AUX PMP1 and E1 for FUEL AUX PMP2. The canister type pumps are accessible from the bottom surface of the wing, and permit removal of the pumping element without entering or draining the tank. There are two outlet ports, one for engine feed and one for fuel transfer. There is a flapper check valve in each outlet port. A wire mesh screen protects the pump inlet from foreign object contamination. A third port is provided for pressure sensing. The pressure line from this port is connected to a pressure switch mounted on the wing rear spar (refer to Controls and Indications section). TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 44 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - AUXILIARY PUMP TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 45 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED CONTROLS AND INDICATIONS AUXILIARY PUMP When the TANK 1 or TANK 2 AUX PUMP switch-light on the FUEL CONTROL TRANSFER panel is pushed, the related auxiliary pump turns on. The auxiliary pumps start automatically for fuel transfer and for defuelling if an AC ground power source is available. After the pump starts, the related ENG FUEL PRESS caution light goes out. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 46 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - AUXILIARY PUMP SWITCHLIGHT TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 47 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED AUXILIARY PUMP PRESSURE SWITCH PURPOSE The Auxiliary Pump Pressure Switch sends a signal to the FUEL CONTROL TRANSFER panel to indicate that auxiliary pump is operating. DESCRIPTION There are two auxiliary pump pressure switches, one connected to each auxiliary pump. They are mounted on the wing rear spar. Each pressure switch closes when 4 psig (28 kPa) of fuel pressure is supplied. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 48 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - AUXILIARY PUMP PRESSURE SWITCH TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 49 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED AUXILIARY PUMP PRESSURE SWITCH CONTINUED DESCRIPTION When the auxiliary pump is producing sufficient pressure, the auxiliary pump pressure switch sends a signal which causes the TANK 1 or TANK 2 AUX PUMP indication on the MFD fuel page to turn green. If there is not sufficient fuel pressure, the MFD fuel page indication changes from green to white. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 50 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - MFD FUEL PAGE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 51 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED CAUTION LIGHTS A stainless steel pressure switch is located at the inlet of the engine boost stage pump, on the Fuel Metering Unit (FMU). If the fuel pressure from the primary ejector and/or auxiliary pump drops below 5.5 psi (38 kPa), the switch will cause the #1 ENG FUEL PRESS or #2 ENG FUEL PRESS (low pressure) caution lights to come on. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 52 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL SYSTEM CAUTION LIGHTS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 53 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM ENGINE FUEL FEED INTERFACES The two interface points between the engine and airframe fuel systems are: • • Fuel supply - at the inlet to the boost stage of the engine driven fuel pump Motive fuel supply - at the motive flow port of the Fuel Metering Unit (FMU) Both the No.1 and No.2 hydraulic systems have an oil-to-fuel hydraulic heat exchanger to provide cooling of the hydraulic fluid. The heat exchanger is installed in the collector bay. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 54 of 146 BOMBARDIER DHC 8-400 (PWC PW150) INTENTIONALLY LEFT BLANK TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 55 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM APU FUEL FEED PURPOSE The Auxiliary Power Unit (APU) fuel feed system supplies a flow of fuel from the left No.1 fuel tank to the optional APU. The APU is located in the rear equipment bay. GENERAL DESCRIPTION The APU fuel feed system includes these components: • • APU shut-off valve APU feed line TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 56 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - APU FUEL FEED SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 57 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM APU FUEL FEED SIMPLIFIED DESCRIPTION PURPOSE The Auxiliary Power Unit (APU) fuel feed system supplies fuel to the APU when the aircraft is on the ground. It supplies pressurized fuel to the APU when the left engine is running or when the left auxiliary (AUX) pump is selected on and AC ground power is available. Under all other conditions, the APU is gravity fed. The PWR switch-light on the APU CONTROL panel controls the fuel supply to the APU. The APU CONTROL panel is located in the flight compartment. The fuel system is de-energized to shutdown the APU. The system is electrically powered by 28V DC from the right main bus through a 5A APU FUEL circuit breaker. The APU fuel supply system has: • • • • A shut-off valve Related open/close indicator lights (on the Fire Protection Panel) A check valve A feed line to supply the fuel to the APU TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 58 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - APU FUEL FEED SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 59 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM The APU shut-off valve closes and stops the fuel flow to the APU under these conditions: APU FUEL FEED • • • APU SHUT-OFF VALVE • • • • • • • • • • • PURPOSE The APU shut-off valve (SOV) controls all fuel flow to the APU. The APU SOV is mounted on the tank closure rib at WS 42. The APU SOV has two parts: • • The valve body The actuator The PWR switch-light on the APU CONTROL panel is selected OFF Fire is sensed in the APU/tail cone area The APU fire extinguisher switch (EXTG) on the APU Fire Protection Panel is selected ON The Weight off Wheels (WOFFW) switch is open (aircraft off ground) Oil pressure <35 psig (241 kPag) Oil temperature >275°F/135°C EGT >1890°F/1032°C on start EGT >1324°F/18°C during run Turbine speed <95% Turbine speed >105% Starter/Generator Overheat Fire (test) Loss of both EGT sensors Loss of both speed sensors The actuator opens and closes the valve. The actuator is mounted on the dry bay side of WS 42 external to the fuel tank. It is a 28V DC motor which is attached to the valve body by a splined shaft. The actuator has a lever that manually operates the valve and acts as a valve position indicator. The valve itself is an open/close ball type valve enclosed in a tee-shaped fitting located inside the fuel tank. The actuator can be replaced without removing the valve or draining the fuel tank. CONTROLS AND INDICATIONS The APU shut-off valve opens when the PWR switch-light on the APU CONTROL panel is pushed ON. The actuator part of the valve sends an electrical position signal to the APU Fire Protection Panel. The valve position is shown by a green FUEL VALVE OPEN light or a white FUEL VALVE CLOSED light on the APU Fire Protection Panel on the overhead console. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 60 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - APU SHUT-OFF VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 61 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM APU FUEL FEED APU FEED LINE The fuel for the APU is fed through a 0.5 inch/12.7 mm diameter line which is connected to the discharge line of the primary ejector pump in the left collector bay. The APU fuel line passes through an in-line motorized APU shut-off valve mounted on the tank closure rib at WS 42. From the shut-off valve the line goes to a reducer fitting at the rear wing spar. Aft of the spar, the 0.375 inch/10 mm diameter line travels to the fuselage tail cone area through the dorsal fairing. NOTE: This is a rigid line with permanent swaged type couplings. The line terminates at the APU/tailcone firewall. The connection at the firewall has a shroud with provisions for an overboard drain. A flexible hose assembly with an integral fire sleeve connects the fitting to the APU Fuel Control Unit (FCU). A check valve is installed in the APU feed line downstream of the APU shut-off valve. No part of the APU feed line is inside the pressurized portion of the fuselage. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 62 of 146 BOMBARDIER DHC 8-400 (PWC PW150) INTENTIONALLY LEFT BLANK TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 63 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER PURPOSE The fuel transfer system provides a means to transfer fuel from one wing tank to the other when AC electrical power is available. The primary purpose of the system is to correct lateral imbalance between the two wing tanks. In case of an in-flight shutdown, it allows the crew to use the remaining fuel from both tanks for sustained single engine operation. The system can empty one fuel tank for maintenance without defuelling the aircraft. GENERAL DESCRIPTION The fuel transfer system uses some of the components and protection circuits of the refuel/defuel system. Fuel transfer is accomplished using the auxiliary pump, part of the engine feed system, the refuel/defuel/transfer manifold and the fuel transfer shutoff valves. The fuel transfer system includes these components: • • • • Fuel Transfer Shut-off Valves Level Control Shut-off Valves Level Control Solenoid Fuel Control Transfer Panel TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 64 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL TRANSFER SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 65 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER SIMPLIFIED DESCRIPTION The fuel transfer system is used to correct lateral fuel imbalance, either in flight or when the aircraft is on the ground. The system is also used for fuel management with one engine inoperative. The fuel transfer system is controlled by a three position TRANSFER switch on the FUEL CONTROL TRANSFER panel in the flight compartment. The panel has a control switch and lights to indicate the correct operation of various components of the system. Fuel flows from the auxiliary pump of the donor tank through a transfer line into the receiver tank. A restrictor in the transfer line limits the fuel flow used for transfer. This makes sure there is sufficient fuel flow available for engine feed. Once selected, fuel transfer will continue until the TRANSFER switch is set to the centre position. Fuel transfer will also stop if the high level sensor unit in the receiver tank senses an overfill condition. Fuel transfer cannot occur if the FUELING ON caution light is on. This caution light comes on if the refuel/defuel access door is open. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 66 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL TRANSFER SCHEMATIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 67 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM If the high level sensor is submerged during fuel transfer, the High Level Control Unit (HLCU) will close the level control shut-off valve which stops the fuel transfer process. FUEL TRANSFER The HLCU will also send a signal to close the fuel transfer shut-off valve. FUEL TRANSFER SHUT-OFF VALVE This provides a redundant means of stopping fuel transfer in case either the TO TANK 1 or TO TANK 2 switches on the FUEL CONTROL TRANSFER panel are left in the ON position. PURPOSE The fuel transfer shut-off valves open to allow refuelling, defuelling or fuel transfer. There is one fuel transfer shut-off valve in each wing. The valve is mounted on the tank closure rib at WS 42. It consists of two parts: • • The valve body The actuator The actuator opens and closes the valve. The actuator is mounted on the dry bay side of WS 42 external to the fuel tank. It is a 28V DC motor which is attached to the valve body by a splined shaft. The actuator has a lever that manually operates the valve and acts as a valve position indicator. The valve itself is an open/close ball type valve enclosed in a tee-shaped fitting located inside the fuel tank. The actuator can be replaced without removing the valve or draining the fuel tank. The fuel transfer shut-off valve is used during: • • • Defuelling Refuelling Fuel transfer In the transfer mode, the valve is controlled by the TRANSFER switch on the FUEL CONTROL TRANSFER panel. In the automatic pre-select refuel or pre-select defuel mode, the valve is controlled by the Fuel Quantity Computer (FQC). In the manual refuel or defuel mode, the fuel transfer shut-off valve is controlled by the related TANK 1 or TANK 2 switch on the Refuel/Defuel Panel. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 68 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL TRANSFER SHUT-OFF VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 69 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER LEVEL CONTROL SHUT-OFF VALVE PURPOSE The level control shut-off valve allows fuel to flow during transfer and refuel operations. It also acts as the primary shut-off device for fuel flow into the tank. DESCRIPTION There is one level control shut-off valve in each wing. The valve is located in the refuel/ transfer line and is hydro-mechanically controlled by the level control solenoid. The level control shut-off valve has a pilot port which is connected by a pilot line to the level control solenoid. The solenoid is normally closed which maintains refuel pressure in the piston chamber of the shut-off valve. This refuel pressure keeps the spring-loaded piston in the closed position. When the level control solenoid opens, the fuel pressure is bled out through the pilot port of the shut-off valve. This allows refuelling pressure to force the spring-loaded piston back and open the valve. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 70 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - LEVEL CONTROL SHUT-OFF VALVE AND SOLENOID TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 71 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM Control Unit (HLCU), which will de-energize the level control solenoid and close the related level control SOV. FUEL TRANSFER LEVEL CONTROL SOLENOID PURPOSE The level control solenoid valve controls the opening and closing of the level control shut-off valve (SOV). There is one level control solenoid in each wing. It is mounted on the rear wing spar. A pilot line connects each level control solenoid to its related level control SOV. When the solenoid is closed, its related SOV is also closed. When the solenoid is energized open, its related SOV opens. When the manual REFUEL mode is selected, the level control solenoid is controlled by: • • The Refuel/Defuel Panel The vent/dump valve control circuit When the automatic PRESELECT mode is selected, the solenoid is controlled by: • • The Fuel Quantity Computer (FQC) The vent/dump valve circuit In the fuel transfer mode, the level control solenoid (for the receiving tank) is energized open by selecting the TRANSFER toggle switch to the TO TANK 1 or TO TANK 2 position. This action opens the related level control SOV and causes fuel transfer to proceed. The high level sensor can also control the level control solenoid. When the high level sensor is submerged in fuel, it sends a signal to the High Level TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 72 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - LEVEL CONTROL SHUT-OFF VALVE AND SOLENOID TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 73 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER CONTROLS AND INDICATIONS FUEL CONTROL TRANSFER PANEL The FUEL CONTROL TRANSFER panel is located on the centre console in the flight compartment. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 74 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL CONTROL TRANSFER PANEL LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 75 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER CONTROLS AND INDICATIONS FUEL CONTROL TRANSFER PANEL The FUEL CONTROL TRANSFER panel has a TRANSFER switch and two switchlights. The three-position toggle TRANSFER switch is used to set the direction of fuel transfer ,TO TANK 1 or TO TANK 2, the third switch position is OFF. When the TRANSFER switch is selected to the TANK 1 or TANK 2 position: • • • The auxiliary pump in the collector bay of the donor tank comes on automatically The fuel transfer shut-off valves open The level control shut-off valve in the receiving tank opens A signal from the operating auxiliary pump pressure switch causes the related ON switch-light segment to turn green. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 76 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - FUEL CONTROL TRANSFER PANEL DETAIL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 77 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM FUEL TRANSFER CONTROLS AND INDICATIONS FUEL CONTROL TRANSFER PANEL CONTINUED Fuel transfer indications are shown on the fuel page of the Multi Function Display (MFD). The TRANSFER SW segment turns white when the TRANSFER switch is selected to the TO TANK 1 or TO TANK 2 position. The triangle (white) just below the TRANSFER SW segment points to the receiving tank. If the TRANSFER switch is in the centre position, this segment will display the word OFF. The VALVE segment indicates the position of the fuel transfer shut-off valve. The word OPEN in the lower part of the segment indicates the fuel transfer shut-off valve is open. The word CLOSED in the upper part of the segment indicates the valve is closed. If the valve is in transition between the two positions the segment is blank. The TANK 1 AUX PUMP or TANK2 AUX PUMP circular segment turns green when either the left or right auxiliary pump is on and fuel pressure is sensed by the auxiliary pump pressure switch. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 78 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - MFD FUEL PAGE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 79 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM REFUEL/DEFUEL PURPOSE The refuel/defuel system is used for pressure refuelling or defuelling through a single point adapter. Gravity refuel of an individual tank is also possible. GENERAL DESCRIPTION The aircraft is refuelled or defueled through the single point pressure refuelling/ defuelling adapter located in the aft portion of the right engine nacelle. Both automatic and manual refuelling/defuelling modes are available. Selected and actual fuel tank quantities are displayed on the refuel/defuel control panel in the right engine nacelle. The Fuel Quantity Computer (FQC) controls the logic of the automatic refuelling and defuelling process. Gravity refuelling can be done through a gravity refuel adapter on the top surface of the wing. Defuelling can be done by external suction pressure, or by use of the auxiliary pumps in each collector bay. The refuel/defuel system have these components: • • • • • • • • Refuel/Defuel Control Panel Refuel/Defuel Indicator Refuel/Defuel Shut-Off Valve Refuel/Defuel Shut-Off Valve Actuator Refuel/Defuel Adapter No-Flow Pressure Switch Refuel Vent Valve High Level Sensor TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 80 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - REFUEL/DEFUEL SYSTEM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 81 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM The refuelling flow into each tank stops automatically at the pre-selected fuel level on the Refuel/Defuel Indicator (RDI). REFUEL/DEFUEL In the manual mode, the refuelling process is stopped by selecting the appropriate switch on the refuel/defuel control panel. SYSTEM DESCRIPTION The refuelling/defuelling fuel flow into or from each tank is through the refuel/defuel adapter and manifold. Fuel flow is controlled by the refuel/defuel shut-off valve (SOV). The pressure refuelling system also uses the two level control SOV, two level control solenoid valves and two refuelling/defuelling/transfer SOV. The maximum refuelling pressure is 50 psi (344.7 kPa), which gives a refuelling flow rate of approximately 125 US gal/min (437 L/min). A minimum of 20 psi (138 kPa) refuelling pressure is necessary for the system to operate properly. Defuelling can be done by external suction pressure or by the use of the auxiliary pumps in each collector bay. If the level control solenoid does not close the level control shut-off valve at the preselected fuel level, the refuelling process continues. When the tank is full, the high level sensor located at the high point of the tank, sends a signal to the High Level Control Unit (HLCU). The HLCU de-energizes the level control solenoid valve and causes the level control shut-off valve to close and the refuelling process stops. Operation of the HLCU shut-off feature can be checked by using the PRECHECK, OPEN, CLOSE switch, on the refuel/defuel control panel. With the switch in the PRECHECK position for the related tank, the HLCU shuts off refuelling to that tank. A no-flow pressure switch in the delivery line, located downstream of each level control shut-off valve, senses the pressure drop when the valve closes. At approximately 2 psi (13.8 kPa), the switch closes and turns on the REFUEL SHUTOFF light for the related tank on the refuel/defuel panel. In the pre-select mode, the refuelling/defuelling operation stops when the fuel content of the selected tank reaches a pre-selected level. In the manual mode, refuelling of the aircraft continues until stopped by the operator, or until the high level sensor senses a full tank and stops refuelling. During pressure refuelling, a refuel vent valve (dump valve) in each tank is kept open by fuel pressure. The DUMP VALVE OPEN TANK 1 or TANK 2 indicator light on the refuel/defuel panel comes on when the related refuel vent/dump valve is open. The refuel vent/dump valve prevents structural damage, if fuel continues to flow into full tanks. The level control solenoid valve controls the operation of the level control shut-off valve in each tank. In the pre-select mode, the Fuel Quantity Computer (FQC) signals the level control solenoid valve to close the level control shut-off valve. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 82 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - REFUEL/DEFUEL SYSTEM SCHEMATIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 83 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM When the switch is in the CLOSE position, no fuel can enter the related tank. REFUEL/DEFUEL When the switch is in the OPEN position, refuel operations can proceed. The Refuel/Defuel Indicator (RDI) is located on the refuel/defuel control panel. REFUEL/DEFUEL CONTROL PANEL The indicator shows the: PURPOSE The refuel/defuel control panel controls the pressure refuelling and defuelling operations. • • • Quantity of fuel in each wing tank Total quantity of fuel in both tanks Quantity of fuel selected in the automatic mode for refuelling/defuelling DESCRIPTION The refuel/defuel control panel is located in the right engine nacelle. The panel has: • • • • One selector switch Four toggle switches Five indicator lights Refuel/Defuel Indicator (RDI) The rotary selector switch is used to set either the pre-select or manual mode for refuelling or defuelling. The PRESELECT REFUEL or PRESELECT DEFUEL position causes the Fuel Quantity Computer (FQC) to automatically stop the refuel/defuel operation when the pre-selected levels are reached. The REFUEL or DEFUEL position causes refuelling or defuelling to continue until the select switch is set to the OFF position. The high level sensors will always stop refuelling to the related tank when a full tank is sensed. The TANK 1 and TANK 2 PRECHECK/OPEN/CLOSE toggle switches are located on the bottom right corner of the Refuel/Defuel Control Panel. The PRECHECK position tests the automatic shut-off operation of the related HLCU. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 84 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - REFUEL/DEFUEL CONTROL PANEL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 85 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM REFUEL/DEFUEL REFUEL/DEFUEL SHUT-OFF VALVE PURPOSE The refuel/defuel shut-off valve opens when the aircraft is refuelled or defueled. The refuel/defuel shut-off valve is installed in the refuel/defuel/transfer manifold and is opened when refuelling or defuelling. The valve is located on the right side aft wing spar. The refuel/defuel shut-off valve is operated by an electrically driven actuator. A thermal relief valve is installed in the valve to prevent excessive pressure build-up in the fuel system lines. The refuel/defuel shut-off valve is controlled by the five position rotary selector switch on the refuel/defuel panel. When the selector switch is in the OFF position the refuel/ defuel shut-off valve is closed. When the selector switch is in any of the other four positions, the valve is open. Regardless of the position of the rotary selector switch, the refuel/defuel shut-off valve will close when the access door to the refuel/defuel panel is closed. This ensures that refuel/defuel shut-off valve is closed in flight to isolate the refuel adapter from the rest of the fuel system. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 86 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - REFUEL/DEFUEL SHUT-OFF VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 87 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM REFUEL/DEFUEL REFUEL/DEFUEL SHUT-OFF VALVE ACTUATOR PURPOSE The refuel/defuel shut-off valve actuator opens and closes the refuel/defuel shut-off valve. The refuel/defuel shut-off valve actuator is attached to the refuel/defuel shut-off valve by a splined shaft. The actuator is installed on the dry side of the rear wing spar. The actuator has a physical and electrical position indication and may be replaced without draining fuel from the tank. The actuator has a lever that operates the valve and gives a position indication. The actuator is controlled by the rotary selector switch on the refuel/defuel control panel. The switch opens the valve and causes the MASTER VALVE CLOSED indicator light to go off when any refuel/defuel mode is selected. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 28 - FUEL SYSTEMS Issue 6 - January 2023 Page 88 of 146 BOMBARDIER DHC 8-400 (PWC PW150) FUEL SYSTEM - REFUEL/DEFUEL SHUT-OFF VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES