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bakers oral powerplant questions.
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bakers oral powerplant questionsHow are reciprocating engines classified? - ANS-1) Cylinder Arrangement w/ respect to
crankshaft (in-line, V-type, radial and opposed)
2) Method of cooling (liquid cooled, or air cooled)
what are the different types of piston rings - ANS-compression rings, oil control rings
and scraper rings
what are the main causes of a cylinder having low compression - ANS-broken piston
rings, rings that are not seated properly, burnt valves and poorly seating valves
what is the purpose of the oil control rings? - ANS-they are used to control the thickness
of the oil film on the cylinder walls
what may be the result of installing piston rings incorrectly - ANS-excessive oil
consumption
what type of piston rods are commonly found in radial engines - ANS-a master and
articulating rod assembly
what type of bearings are in general use in reciprocating engines - ANS-plain, roller and
ball bearings
what is the indication of valve blowby - ANS-a hissing or whistle when pulling the
propeller through by hand
what is the purpose of using more than one spring for valve closing - ANS-valve springs
will resonate (or surge) at certain engine speeds.
what is the purpose of valve overlap - ANS-better volumetric efficiency and lowers the
cylinder operating temperatures
describe the inspection you would give the valve springs during engine overhaul -
ANS-they should be cleaned thoroughly, then visually inspected for evidence of
overheating, cracks, broken ends, and compression strengh
,what is the purpose of using valves with sodium filled stems - ANS-because it is an
excellent heat conductor
what causes engine sudden stoppage - ANS-Striking an object or engine seizure due to
internal damage.
What type inspection must be made after sudden stoppage of an engine? - ANS-a
complete engine tear down and inspection
what is the purpose of the crankshaft dynamic dampers used in aircraft engines -
ANS-to overcome forces which cause deflection of the crankshaft and torsional vibration
How would you make a "runout" check on a crankshaft that is still installed in the
engine? - ANS-remove the propeller from the crankshaft and attach a dial indicator
gauge to the front of the crankcase. adjust the position of the gauge needle so that it is
touching the shaft. rotate the crankshaft and check for misalignment
what is detonation? - ANS-The instantaneous explosive burning of the last portion of the
charge
what cylinder is engine to magneto timing based on? - ANS-the number one cylinder
what is engine sudden speed reduction - ANS-This occurs when the propeller strikes an
object but continues to run.
What can be learned about the condition of an engine by studying the results of a
compression check? - ANS-if the valves, piston rings, and pistons are adequately
sealing the combustion chamber
How can a cold cylinder be located on a double row radial engine? - ANS-with a cold
cylinder indicator, sometimes called a "magic wand"
what instrument can be used to check bore for out of roundness - ANS-a dial indicator,
telescopic gauge and outside micrometer or inside mircrometer
what would a cold cylinder indicate - ANS-no combustion inside the cylinder
where is a crack most likely to occur on a piston - ANS-where the piston pin/wrist pin
connects
, what should be done to a nose wheel airplane before removing the engine -
ANS-support the tail of the airplane
what are the major components of a typical gas turbine engine - ANS-an air inlet,
compression section, combustion section, turbine section, exhaust section and
accessory section
what are the two principle types of compressors used in turbojet aircraft -
ANS-centrifugal flow and axial flow types
what are the four combustion chamber systems - ANS-can, can-annular, annular, and
reverse flow annular types
what is the purpose of the interconnector tubes between can types combustion
chambers - ANS-to spread the flame to the combustion chambers that are not equipped
with igniter plugs during engine starting
what prevents burning of the liner walls in can type combustion chambers - ANS-louvers
What types of damage may be found when inspecting compressor blades? -
ANS-dents, scratches, gouges, galling, burns, burrs, pitting and cracks
what is the location and function of the diffuser section in a turbine engine - ANS-the
diffuser is the divergent section of the engine located between the compressor section
and burner cans. its function is to change the high velocity compressor discharge air to
static pressure
where are stress rupture cracks most likely to occur on turbine blades - ANS-on or
across the leading or trailing edge of the blades
how are compressor blades attached to a disk-type rotor - ANS-by either bulb-type,
fir-tree or dove tail type roots. they are then locked by means of screws, peening,
locking wires, pins or keys
what is the purpose of the nozzle diaphragm, or turbine nozzle - ANS-the turbine nozzle
prepares the combustion mass airflow to drive the turbine rotor. first they change a
portion of the heat and pressure energy to velocity energy. the fixed vanes are shaped
and set at such an angle that they form a number of small nozzles that discharge the
gases at extremely high speeds. the second purpose of the turbine nozzle is the deflect
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