MH-60R - Systems - Fuel Flashcards
(45 cards)
What does the prime/boost pump do?
The prime/boost pump is used to prime the engine or APU fuel lines and provides fuel under pressure to the APU during starting and operations at pressure altitudes above 8,000 feet.
Briefly describe the fuel system
The fuel system is a crashworthy, suction-type system with a self-sealing main tank. The system is capable of pressure refueling, gravity refueling, and Helicopter In-Flight Refueling (HIFR). It has provisions for priming the engines, dumping fuel, indicating fuel quantity, and warning of low fuel levels.
Describe the fuel lines
All lines include self-sealing breakaway valves that stop fuel flow in the event of fuel system damage.
What is the note regarding fuel filters and water?
The fuel filters are not sensitive to water contamination. Water-contaminated fuel may cause fluctuations/surges in one or both engines with no associated FUEL PRESS or FUEL FLTR BYPASS caution.
What is the capacity of the main fuel tanks?
590 gallons (4,012 lbs of JP-5)
Briefly describe the main fuel tanks
The main tank system is composed of two cells interconnected to form one tank. The cells are located behind the cabin in the transition section. The left main cell has provisions for single-point refuel/defuel, gravity refuel, and HIFR. It also contains two high-level shutoff floats, a check valve, a sump drain, and a vent. The right cell contains two check valves, a sump drain, a vent, an APU fuel line, and a fuel dump system. The lower one third of the tank is self-sealing. The main cells’ interconnect level is approximately 270 to 600 pounds per side.
Briefly describe the aux tanks
120-gallon external fuel tanks may be installed on the two inboard pylons to extend the endurance/range of the helicopter (240 gallons total). Management is provided through the Fuel Management Control Panel (FMCP). Each inboard weapons pylon is configured to accept a crashworthy, ballistically hardened 120-gallon capacity external auxiliary fuel tank. The tank has self-sealing breakaway valves so that no fuel will be spilled in the event of separation of the tank. The tank is jettisonable and incorporates provisions for gravity fueling, pressure fueling and HIFR, and defueling through the basic fuel system.
How is the fuel level sensed in the aux tanks?
The fuel level of each auxiliary fuel tank is internally monitored by a single gauge probe. Each probe provides a fuel quantity signal to the Mission Displays (MDs)/Flight Displays (FDs) and FMCP. Each auxiliary tank contains a low-level thermistor sensor that is exposed only when the tank is empty and then sends a signal to the FMCP.
How is overflow sensed in the auxiliary tanks?
Each external auxiliary tank contains an overflow thermistor sensor that sends a signal to the FMCP if fuel is sensed in the external tank vent line. When fuel is sensed, a signal is sent to illuminate the EXT FUEL OVERFLOW caution.
How does the FMCP determine if there is an aux tank present?
If an auxiliary tank gauge and low-level switch signal are absent, FMCP commands automatically bypass that tank station and go to the next occupied tank station.
What causes illumination of the PUMP/VALVE FAIL caution? What happens?
When a single valve or pump fails, the PUMP/VALVE FAIL caution will illuminate and the alternate pump or valve will supply fuel transfer capabilities.
What causes the illumination of the AUX FUEL XFER FAULT caution?
This indicates a total failure of dual transfer/shutoff valves, dual transfer pumps, or FMCP logic.
What must be done if the automatic mode of fuel transfer fails?
Manual mode must be used.
Briefly describe the fuel transfer system
The fuel transfer system is controlled by the FMCP and consists of two transfer/dump pumps that provide the capability to transfer fuel from external tanks to the main tank. When fuel transfer is manually selected (TRANSFER, MANUAL OVRD), the selected external tank shutoff valve (L INBD, R INBD) is energized open and fuel transfer occurs until the fuel level reaches the high-level shutoffs of the main tanks, at which point the flow sensor will shut off the pumps. The pumps may also be secured manually.
What are the indications of fuel transfer?
- FUEL MGT panel R INB, L INB, or INTL FLOW light illuminates on the FMCP.
- Tank quantity changes on the mission display fuel graphics for the respective fuel tanks. If the fuel quantity indicators on the flight display or mission display fuel graphic do not change during manual transfer, the fuel transfer system is inoperative.
What is the caution associated with the right tank filling faster than the left tank during fuel transfer?
During transfer of auxiliary fuel, if right cell fills faster than left cell, monitor the fuel quantity gauges closely. If difference in cell quantities persists, stop transferring fuel before right cell is full (approximately 1,700 pounds).
What is e caution regarding unmonitored manual fuel transfer?
Do not initiate unmonitored manual transfer to the main tank from auxiliary tanks until main tank is below 3,200 pounds. During manual auxiliary tank transfer, the main tank high-level sensor (float valves) should prevent overflow of the main fuel tanks.
When should a manual fuel transfer check be accomplished?
After main tank fuel quantity has decreased 300 lbs. One short manual transfer will exercise both transfer pumps and transfer valves to ensure proper operation.
How can the aux tanks be jettisoned? When?
The external auxiliary fuel tanks can be jettisoned individually or simultaneously via the Emergency Jettison Panel (EJP) using either All Stores Jettison or Selective Jettison. Emergency jettison of external fuel tanks via the ALL STORE JETT pushbutton is inhibited when less than 40 gallons (approximately 272 lbs.) remain in the tank. SEL JETT must be used to jettison when less than 40 gallons remain in the tank. The fuel gauge for the external fuel tank reads in 50 lbs. increments. If the external fuel tank requires jettison and the fuel gauge reads 300 lbs. or less, SEL JETT should be utilized.
What does TRANSFER on the FMCP master switch do?
The FMCP control logic enables the MODE SWITCH and transfer operation.
What does STOP FLOW on the FMCP master switch do?
Power is removed from all FMCP switches, control logic is disabled, and auxiliary fuel system control is stopped, which closes all external tank shutoff valves.
What does REFUEL on the FMCP master switch do?
For power on refueling, the sequencing logic turns off all FMCP switches except precheck switches. All external tank shutoff valves close until the main internal tank is filled and then open one at a time to selectively fill the external tanks. The tank fill sequence is main tank, right external tank (if installed), and left external tank (if installed).
What does AUTO on the mode switch do?
The fuel management logic is not initiated until the main fuel tank fuel level depletes to approximately 2,640 pounds. This fuel transfer management sequence repeats until contents of both external tanks are transferred to the main tanks. During automatic fuel transfer, fuel transfer sequence is reverse of fill.
What does MANUAL OVRD on the mode switch do?
Both transfer valves are open and both Dump/Transfer pumps are ON. External tank fuel is immediately transferred to the main tanks until the high-level switch is reached, STOP FLOW is selected, or until the external tanks are empty.
