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Gas Turbine Engines Aviation Fuel   Types of  Aviation Fuel The fuel used in Gas turbine engine is called the Jet fuel or simply Aviation Turbine Fuel. In 1950s, when commercial jet Industry was developing, Kerosine type fuel was chosen as it showed the best properties. Following are the three types of Fuels used in the aviation industry. 1. Jet A 2. Jet A-1 3. Jet B Jet A is used in the United States while rest of the world uses Jet A-1. The important difference between the two fuels is that Jet A-1 has a lower maximum freezing point of -47°C than Jet A fuel having  freezing point of –40°C. Jet A-1 also contains mandatory anti-static additives. The lower freezing point makes Jet A-1 more suitable for long international flights, especially on polar routes during the winter. Jet B fuel is used in some industry in Alaska and Canada as this type of fuel is best suited in cold weathers. Fuel Performance Properties Since the primary function of aviation turbine fuel (jet fuel) is to power a

 EASA PART 66 Aircraft Maintenance Engineering Module 7 Oscilloscopes: The oscilloscope, or scope for short, is a device for drawing calibrated graphs of voltage vs time very quickly and conveniently. Such an instrument is obviously useful for the design and repair of circuits in which voltages and currents are changing with time. There are also many devices, called transducers, which convert some non-electrical quantity such as pressure, sound, light intensity, or position to a voltage. By using a transducer the scope can make a plot of the changes in almost any measurable quantity. This capability is widely used in science and technology.   The heart of the oscilloscope is a cathode ray tube or CRT. Looking at the face of the instrument, you are viewing the screen that the electron beam strikes. Electronic circuits in the scope apply voltages to one set of deflection plates to sweep the beam across the screen from left to right at a constant rate, thereby providing the time axis. Oth

EASA PART 66 Module 7 Electrical Wiring Interconnection System Lets take this quiz and check your knowledge about Electrical Wiring Interconnection System. Loading…

Classes Of Fire   Fire results from the chemical reaction that occurs when oxygen combines rapidly with fuel to produce heat, (and light). Three essentials of this process form the ‘Fire Triangle’. A fire requires three components to burn, and the removal of any one of these components will extinguish the fire. The requirements of the three components, forming the ‘Fire Triangle’, are: Fuel: a combustible material, which may be a solid, liquid or gas Oxygen: in sufficient volume to support the process of combustion Heat: of sufficient intensity to raise the temperature of the fuel to its ignition (or kindling) point. Classes of Fire There are a number of types of portable fire extinguishers. Each type of extinguisher may be rated for one or more classes of fire. In some cases, particular extinguishers are not only considered ineffective against certain classes of fire, they can be dangerous if used in those circumstances. The classes of fire in  European system are: Class A: Ordinary C

EASA PART 66 MODULE 7 MAINTENANCE PRACTICES Material Safety Data Sheets (MSDS) A material safety data sheet (MSDS) is a document provided by the material manufacturer or subsequent material processor that contains information related to the material hazard and includes safe handling and disposal procedures. The format of these sheets must be consistent with the requirements of the Hazard Communications Standard. MSDSs should be provided by the manufacturer for each hazardous material supplied by them. The Material Safety Data Sheet is the primary source of information about hazardous chemicals used in your work site. Your employer is required to have an MSDS for every hazardous chemical used or stored at your work site, and to make it available for review on request. Let's attempt this quiz and see how much do we know about MSDS. Loading…    

 EASA / SARI MODULE 7 SUB MODULE 7.18 AIRCRAFT DISASSEMBLY, INSPECTION, REAPIR AND ASSEMBLY TECHNIQUES FAULT DIAGNOSIS - TROUBLE SHOOTING Aircraft maintenance schedules have been developed so that the amount of time an aircraft spends on the ground for routine inspection and servicing is kept to a minimum. However, aircraft might also “grounded” by equipment defects; it is most important that these are rectified efficiently. One of the factors governing maintenance efficiency is the initial fault diagnosis, generally known as Trouble Shooting. Unfortunately defect rectification is sometimes attempted without prior fault diagnosis, or after only a limited attempt to narrow the field of possible causes. Such rectification usually deteriorates into a succession of component changes aimed a eliminating the fault by trial and error. This type of approach causes unnecessary work, waste of aircraft spares and excessive delays before the aircraft can be returned to service. All of this can be

EASA PART 66 / SARI MODULE 7 NON-DESTRUCTIVE TESTING (NDT): Nearly all inspection operations on aircraft structures are carried out visually at intervals specified in the Approved Maintenance Schedule. Sometimes visual examination is not practicable, or there may be some uncertainty about the serviceability of a part and one of the methods of nondestructive examination may be used to determine its condition. Non-destructive tests seek to detect defects such as cracks or corrosion either at the surface of below it and a number of methods are presently in use. In each case the part being tested is not harmed in any way.  The selection of the method to be used will depend on the design of the structure, its accessibility and the nature of the suspected defect. 1. VISUAL INSPECTION Visual inspection is the oldest of the non-destructive methods of testing. It is a quick and economical method of detecting various types of cracks before they progress sufficiently to cause failure. Its reliabi

CORROSION REMOVAL, ASSESSMENT AND REPROTECTION:   Due to the high cost of modern aircraft, operators are expecting them to last much longer than perhaps even the manufacturer anticipated. As a result, the manufacturers have taken more care in the design of the aircraft, to improve the corrosion resistance of aircraft. This improvement includes the use of new materials and improved surface treatments and protective finishes. The use of preventative maintenance has also been emphasised more than previously. Preventative maintenance, relative to corrosion control, should include the:  Adequate and regular cleaning of the aircraft  Periodic lubrication (often after the cleaning) of moving parts  Regular and detailed inspection for corrosion and failure of protective treatments  Prompt treatment of corrosion and touch-up of damaged paint  Keeping of drain holes clear  Draining of fuel cell sumps  Daily wiping down of most critical areas  Sealing of aircraft during foul weather and ventilati

 EASA PART 66 MODULE 7 Aircraft Disassembly, Inspection, Repair and Assembly Techniques Tyres: Tyres have their serviceability indicated by the depth of the groove in the tyre tread. The AMM gives information of what constitutes a worn or damaged tyre. Apart from normal wear, other defects, that can affect a tyre, are cuts, blisters, creep and low pressure. Most tyres can be re-treaded a number of times after they have reached their wear limits, but the re-treaded can only be completed if the complete tyre has not been damaged badly.  Creep is the movement of a cover around the rim, in very small movements, due to heavy braking action. This movement is dangerous if the tyre is fitted with a tube, as the movement can tear the charging valve out of the tube, causing a rapid loss of pressure. To provide an indicator, small white marks are painted across the wheel rim and the tyre side wall cover so, if creep takes place, the marks will split in half and indicate clearly that the tyre cove

EASA MODULE 7 SUB MODULE 7.3 TOOLS Lubrication Methods:   Solid surfaces are never perfectly smooth, as the actual rubbing contact (the friction), between two moving surfaces, is concentrated on a number of high spots on the respective surfaces. Any load between the two surfaces tends to wear away these high spots until the area of contact is large enough to support the load without further deformation.   During the wearing action fragments of the surface are broken away and high local temperatures are generated. The effects are potentially dangerous, in that the fragments can cause serious damage to the surfaces while excess heat leads to expansion of the materials.   The expansion is likely to cause higher frictional forces, leading to further damage (due to more particles breaking from the surface) and can possibly result in eventual ‘seizure’ and stoppage of movement. Seizure could have disastrous results in any moving mechanism.   Lubrication is a process for reducing friction and