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86 Cards in this Set
- Front
- Back
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"An unbalanced force on a body produces or trends to produce acceleration in the direction of the force and the acceleration, if any, is directly proportional to the force and inversely proportional to the mass of the body." Which law of motion is this? |
Newton's second law of motion |
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Which type of duct decreases air velocity and increases pressure as it passes through? |
Divergent |
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What does fuel for an engine represent? |
Potential energy |
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Which section of a jet engine continually supplies air and maintains pressure? |
Compressor |
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Which section of a jet engine introduces and burns fuel? |
Combustion |
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Which section of a jet engine keeps the compressor rotating? |
Turbine |
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Through which section of a jet engine is energy expanded into the atmosphere, resulting in thrust? |
Exhaust |
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How many British thermal units (Btu) does the heat content per pound of kerosene produce? |
18,500 |
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To measure barometric pressure, use a _ |
Barometer |
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What is the sea-level atmospheric pressure in psi at "standard day" conditions? |
14.7 |
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What effect does moisture content/humidity have on air density? |
Moisture lowers density |
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How do divergent ducts affect air pressure? |
Increase pressure |
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The air temp of a jet engine gradually rises across the compressor to the diffuser outlet as a result of what? |
Compression |
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What engine section is the hottest? |
Combustion |
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Which jet engine component meters fuel for combustion? |
Fuel control |
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What is required of air velocity for a jet engine to work? |
Greater velocity exciting than entering |
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What is the general flow of gases from the combustion chamber of the jet engine? |
Parallel to the axis of the rotor shaft |
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What directs gases onto the first-stage turbine wheel blades in a jet engine? |
Turbine stator |
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When two or more turbine wheels are used in a jet engine, which component is placed directly in front of each turbine wheel? |
Turbine stator (nozzle diaphragm) |
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The operation of any gas turbine, regardless of type, requires the provisions to be made for three major functions. What are they? |
Compression of air, expansion of air by burning fuel, and extraction of power from gases for driving the compressor and engine-driven accessories. |
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The 3 major sections of all jet engines are compressor, combustion, and what? |
Turbine |
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Vane-type fuel pumps used in jet engines are similar to |
Sliding-vane air compressors |
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Which condition reduces the efficiency of a centrifugal compressor? |
Pressure pulsations |
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A constructional feature of the centrifugal compressor is that the impeller _ |
Is forged as a single unit |
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In a dual-spool compressor, N2 rpm is determined by the |
Fuel control |
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The jet engine compressor that is cheaper to manufacture is the |
Centrifugal type, because of its fewer parts |
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Which is a constructional feature of an axial-flow compressor casing? |
Split horizontal centerline |
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The percentage of combustion efficiency of a gas turbine is usually between _ |
95 and 100 |
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Which facet of jet engine design helps prevent igniter plug fouling? |
Directing air around the plug |
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Carbon monoxide gas is poisonous odorless, and _ |
had no color |
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What is the most chemically correct ratio for burning fuel in a combustion chamber of a jet engine? |
15:1 |
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The excess airflow that is not burned in the combustion chamber of a jet engine is used to _ |
Cool the burner surfaces |
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The inner and outer surfaces of an annular-type combustion chamber are formed by _ |
Interlocking stainless-steel bands |
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Fuel that accumulates after a failed engine start is _ |
Drained overboard by a drain system |
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The parts on a can-annular combustion section must be removed in a specific order because of the |
Combustion chamber crossover tubes |
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What is the most common type of fuel nozzle system? |
Pressure-atomizing |
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Three types of turbine and vane assemblies used in jet engines are impulse, reaction, and |
Reaction-impulse |
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In the reaction type turbine, what in the design causes the rotor to turn? |
Reduced pressure and increased velocity of exhaust gases between rotor blades |
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The "fir tree" method of attaching turbine blades (buckets) to the turbine rotor disc is preferred because of |
The temperature differential between turbine rotor disc and the blades |
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What method of attaching the turbine blades to the rotor disc is used most frequently? |
Series of grooves/notches broached in the rim of the turbine rotor disc |
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The exhaust duct connects the turbine outlet and the _ |
Jet nozzle |
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The design of an exhaust duct straightens the exhaust gases as they leave the last stage of the turbine section to provide for _ |
Larger thrust, more efficiently |
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The rear opening if the exhaust duct on the jet engine is referred to as the _ |
Exhaust nozzle |
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Some jet engines are trimmed/adjusted to their correct exhaust gas temperature by an alteration of what? |
Exhaust nozzle area |
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How many loads can be imposed on a jet engine bearing? |
3 |
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Before inspecting new bearings, you should |
Remove the preservative coating |
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Next to contamination and improper lubrication, what is the greatest enemy of bearings? |
Improper removal |
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The most commonly used bearing removal tools include |
Arbor presses and bearing pullers |
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Which type of defect appears on bearings as a result of bearing parts striking together? |
Nicks |
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Which type of bearing defect results from inadequate lubrication? |
Galling |
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Excessive bearing wear can usually be detected by |
Roughness of the metal |
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Before you install separable bearing halves, what should you do? |
Ensure bearings are a matched set (same serial number) |
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To cause an accessory in a jet engine to operate at its most optimum speed, design engineers must |
Change the gear ratio |
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On an F108 engine, the radial drive shaft connects the core engine to the _ |
Accessory drive assembly |
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Which F108 major engine module provides for mounting of the engine to the airframe? |
Fan major module |
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Power to drive the accessory gearbox (AGB) on the F108 engine is transmitted from which major module? |
Fan major module |
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F108 structural rigidity is obtained with a short length and by having only 2 main structures that are called _ |
Mainframes |
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Primary airflow in the F108 engine is through all major modules, except |
Accessory |
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Which type(s) of load(s) does the #2 bearing take up in the F108 engine? |
Radial |
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The F108 engine has an air duct through the inside diameter of the core compressor rotor that forms a path for _ |
Pressurizing and cooling airflow |
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On the F108 engine, the combustion chamber is of which design type? |
Annular |
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On the F108 engine, the LPT shaft assembly connects the fan shaft with what? |
LPT rotor |
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On the F108 engine, as gases flow through the convergent passageways of the LPT nozzle their pressure drops, and their axial velocity _ |
Increases |
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The F108 engine turbine frame is the engine rear main structural component, and it supports the _ |
LPT rotor rear section |
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On the F108, what connects the inlet gearbox to the transfer gearbox bevel gears? |
Radial drive shaft |
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On the F108 engine, how is the transfer gearbox mounted to the fan case? |
By a single clevis-and-link rod-mounting arrangement |
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On the TF34, the fan forward shaft is supported by what? |
The #s 1 and 2 bearings |
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The TF34 fan provides what % of the total thrust? |
85% |
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On the TF34, which strut does the fan speed pickup protrude through to the #2 locknut? |
9 o'clock strut |
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The TF34's compressor inlet temp sensor is mounted on the outer surface of the splitter nose at what "o' clock" position? |
9 o' clock |
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How many stages of compressor blades are in the TF34? |
14 |
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Why is the compressor case split horizontally? |
To allow access to the compressor rotor |
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What stages of compressor vanes are variable in the TF34? |
Stages 1-5 |
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What type of combustion liner does the TF34 have? |
Annular |
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On the TF34, the first-stage nozzle consists of 24 cast segments with how many vanes in each segment? |
2 vanes |
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What is the purpose of the LPT transition assembly? |
Funnel hot gases from the HPT rotor to the larger diameter LPT rotor. |
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On the TF34, which strut is used to port 7th stage compressor air into the C-sump area to pressurize the #6 carbon seal? |
12 o'clock strut |
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Which of these is not part of the accessories section on the TF34? PTO compressor stator Radial driveshaft Accessory gearbox |
Compressor stator |
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To facilitate borescoping the engine, what is provided for rotating the high-pressure rotor system and where is it located? |
Gearbox cranking pad, between the lube and fuel pump pads. |
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Which of these compressor section subsystems does not belong on the F117? LPC group HPT group LPC driveshaft group Intermediate case group |
HPT group |
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The HPC on the F117 consists of how many rotor stages and how many stators surrounded by a two section titanium and steel case? |
12 rotors, 12 stators |
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How many exit vanes make up the compressor exit stator assembly on the F117? |
72 |
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The combustion chamber assembly provides the optimum environment for combustion and directs the flow of what to where? |
Hot gases to the turbine nozzle |
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Which of these turbine section subsystems does not belong on the F117? Turbine nozzle group LPC nozzle group HPT module LPT module |
LPC nozzle group |
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Which one of these components is not an engine accessory component on the F117? Permanent Magnetic Alternator (PMA) Radial driveshaft Oil pump module Fuel pump/fuel control |
Radial driveshaft |
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Which of these is not an aircraft accessory component on the F117? IDG Starter Two hydraulic pumps LPT module |
LPT module |
