Term
| Units operated by hydraulics on aircraft |
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Definition
| Landing gear, wing flaps, control surfaces, wing folding mechanisms, bomb-bay doors, brakes. |
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Term
| Disadvantages of hydraulics |
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Definition
| Leakage and contamination |
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Term
| Characteristics of hydraulics |
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Definition
1)Extremely efficient, 2)favorable weight,
3)"smooth, flexible, uniform action without vibration", 4)maintenance is relatively simple |
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Term
| State parts of a BASIC hydraulic jack, and in order starting with pump. |
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Definition
| Pump to check valve, then to actuating cylinder, passes manual bypass valve, then to reservoir, passes another check valve, back to pump |
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Term
| Determine the FAP triangle |
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Definition
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Term
| SAFETY: Before working on any hydraulics system, make sure..... |
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Definition
| All pressure has been relieved |
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Term
| List 5 basic components that makeup a HYD system |
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Definition
Pump, actuating unit, reservoir, selector valve, and hydraulic lines
**BASIC FOR HYDRAULIC SYSTEMS** |
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Term
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Definition
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Term
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Definition
Hold supply of fluid and has *space for thermal expansion*
**CAN BLEED AIR FROM THE SYSTEM** |
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Term
| The selector valve does what? |
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Definition
| Directs flow of fluid to the actuating unit and *determines which direction it will be moved* |
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Term
| What does the actuating cylinder do? |
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Definition
| Converts fluid energy in to mechanical motion |
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Term
| What is hydraulic contamination? |
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Definition
| Presence of undesirable foreign matter that May or may not be visible to the unaided eye. |
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Term
| What is the objective of the HYD fluid contamination control program? |
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Definition
| *To achieve and maintain a satisfactory level of purity in HYD systems* = *providing safe and efficient operation of naval aircraft and support equipment.* |
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Term
| Two GRAND classifications of contamination |
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Definition
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Term
| 3 types of PARTICULATE contamination |
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Definition
Organic
Metallic solid
Inorganic solid |
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Term
| PARTICULATE, organic definition |
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Definition
Solids or semi solids that come from wear or chemical reactions of O-rings, seals, or gaskets.
When lots of particles from, it creates **SLUDGE** |
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Term
| PARTICULATE, metallic solid definition |
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Definition
| Almost always present in HYD systems. Mostly come from HYD pumps due to continuous high speed internal movement |
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Term
| PARTICULATE, inorganic solid definition |
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Definition
Dust, paint particles, dirt, and **glass particles(silicates)**
EXTREMELY UNDESIRABLE |
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Term
| FLUID, air contamination definition |
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Definition
May be introduced through improper maintenance. Creates **FOAM**
**^^ENTRAINED^^** |
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Term
| FLUID, water contamination |
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Definition
| Separates from HYD fluid and collects in filter bowls and at other critical locations. May result in formation of ice or corrosion from oxidation. May clog filters |
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Term
| FLUID, solvent contamination definition |
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Definition
| Fluid that is a chlorinated solvent, if introduced with any water in a HYD system, could form highly corrosive acids. |
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Term
| FLUID foreign fluids contamination definition |
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Definition
| Rare, generally a result of lube oil, engine fuel, or incorrect HYD fluid having been introduced during servicing. Can be verified once suspected with a chemical analysis of a fluid sample |
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Term
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Definition
Millionths of a meter, one micron is **equivalent to 0.0000394 inch.**
**25,400 microns = to 1 inch.** |
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Term
| Preferred method of testing contamination... |
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Definition
| Particle counting= sample sent to a lab (I level) or NOAP lab. A report will be sent back from the lab |
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Term
| Alternate contamination testing |
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Definition
Patch test. Through an analysis kit reference the NAVAIR 01-1A-17
The maximum level of acceptability for contamination is 200 parts per million |
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Term
| What is the maximum acceptability for contamination using the patch test method? |
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Definition
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Term
| Name 4 methods of decontamination |
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Definition
1)recirculating
2)purifying
3)flushing
4)purging |
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Term
| What are the desired characteristics for HYD fluid? |
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Definition
Low viscosity
Lubricating qualities
Corrosion stability |
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Term
| Name two types of HYD the military uses |
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Definition
(MIL-PRF-83282)- fire resistant and is primary fluid.
(MIL-H-46170 TYPE II)- preservative for HYD system in storage and used in testing. |
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Term
| Name the two types of reservoirs |
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Definition
| Pressurized and non-pressurized |
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Term
For reservoir maintenance--
Procedures and precautions must be observed in the ____ and on the _____ or________. |
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Definition
| MIMs, placard, information plate |
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Term
| What is a primary concern when servicing HYD reservoirs? |
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Definition
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Term
| Where can the pressurized reservoir be located on an aircraft? |
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Definition
| Anywhere before the pump in a HYD sys. |
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Term
| Purpose of a HYD pump and where is it located? |
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Definition
Purpose: to create locate flow of fluid.
Location: determined by the source of power |
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Term
**Location of HYD pump continued**
Where is it located when the source of power is the 1)aircraft engine, 2) electric motor, 3) emergency ram-air turbine |
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Definition
1) mounted on the engine accessory-drive section
2) anywhere In the aircraft
3) located on the emergency power package or mounted to the ram-air turbine. |
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Term
| Name the 4 types of HYD pumps |
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Definition
| 1)Gear pump, 2)piston pump, 3)vickers seven-piston, 4) vickers nine-piston |
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Term
| What are the two classifications of HYD pumps |
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Definition
Constant displacement
(Gear pump or piston pump)
Or
Variable displacement
(Vickers 7-9 piston pump) |
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Term
| With HYD pumps, where is maintenance done? |
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Definition
Pump repair is done at I level.
Gasket replacement can be done at O level. |
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Term
| **What is the purpose of shear shaft in the drive shaft? ** |
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Definition
| **To prevent damage to the power source of the pump in the event of pump binding** |
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Term
| HYD filters purpose and location. |
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Definition
Purpose: to filter the fluid of the HYD system of foreign particles.
Location: placed as needed throughout the system |
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Term
| List the 3 parts that makeup a HYD filter. |
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Definition
| Head assembly, bowl, and element. |
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Term
| What are the 3 pubs for HYD filter maintenance |
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Definition
MIMs: servicing filters
MRCs: inspection info
Aviation Hydraulics Manual: cleaning and testing info for elements |
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Term
| State the purpose of a hydraulic relief valve |
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Definition
| To protect the HYD system from damage that could result from excessive pressure caused by failure of the pump regulating devices, thermal expansion, and pressure surges. |
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Term
| Name two types of relief valves. |
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Definition
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Term
| How do main system relief valves work and where are they located? |
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Definition
They release HYD fluid from the pressure line into a return line.
Located in the pressure line after the regulator, and if *no regulator then after the pump* |
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Term
| How do thermal relief valves work and where are they located? |
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Definition
They relieve excessive pressure caused by thermal expansion .
Located where a check valve or selector valve prevents pressure from being relieved.
**in subsystem or unit system** |
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