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35 Cards in this Set
- Front
- Back
What is the main advantage of a horizontally opposed engine over a radial engine for powering modern aircraft? |
horizontally opposed has smaller frontal area and is easier to streamline than a radial
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How many throws are there in the crankshaft of a six–cylinder horizontally opposed engine?
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Six |
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What kind of connecting rod arrangement is used in a radial engine?
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A master rod |
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Of what material are most piston rings made
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Gray cast iron. |
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What is the reason for using hydraulic valve lifters in an aircraft engine?
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keeps clearance out of the valve operating mechanism. |
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At what speed does the camshaft turn, relative to the crankshaft speed in a horizontally opposed engine?
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one half of the crankshaft speed.
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What kind of main bearings are used in a horizontally opposed engine?
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Steel–backed, lead–alloy bearing |
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On what stroke is the piston of a reciprocating engine when the intake valve begins to open? |
exhaust stroke |
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On what stroke is the piston of a reciprocating engine when the exhaust valve begins to open?
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power stroke |
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Why are both the hot and cold valve clearances given for most radial engines? |
The hot clearance is given for valve timing in cylinder number one. When the timing is set, all the valves are adjusted to their cold clearance. |
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Where is the piston in a reciprocating engine when the ignition spark occurs?
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30 degrees of crankshaft before top center on the compression stroke. |
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Why do most aircraft reciprocating engines use more than one spring on each valve?
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By using more than one spring, valve float is minimized. |
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Would excessive valve clearance cause the valves to open early or late?
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valve will open late and close early. |
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What is the purpose of valve overlap in a reciprocating engine?
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Allows the exhaust gases leaving the cylinder to help the fresh induction air to start flowing into the cylinder. |
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What type of piston rings are installed on the pistons of an aircraft reciprocating engine?
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Compression rings Oil control rings Oil scaper rings. |
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Why are some exhaust valves partially filled with metallic sodium? |
transfers heat from the valve head to the valve stem. |
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What causes detonation in an aircraft engine?
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too much heat and pressure in the cylinder |
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Why is a compression check important for determining the condition of an aircraft reciprocating engine?
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Determines how well the piston rings are sealing against the cylinder walls, and the seal between the intake and exhaust valves. |
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What is meant by the compression ratio of a reciprocating engine?
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The ratio of the volume of the cylinder with the piston at the bottom of its stroke to the volume with the piston at the top of its stroke. |
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In What position should the crankshaft be when a magneto is being timed to the engine?
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Piston in cylinder no.1 should be about 30 degrees before top dead center on the compression stroke |
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What is the purpose of a cold cylinder check?
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Indicates if a cylinder is not firing. |
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What is checked on engine runup to determine the operational condition of the engine?
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Idling RPM Manifold pressure. Engine acceleration. Maximum RPM/manifold pressure. Magneto drop. Prop feathering. Oil pressure and Fuel pressure |
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What are two main causes of a cylinder having low compression?
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Piston rings not seating, worn or broken, and valves not seating |
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What is a hydraulic lock in a aircraft engine?
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Oil has drained past piston rings and filled combustion chamber. |
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How is hydraulic lock removed from an engine?
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Remove a spark plug from the locked cylinder and drain all oil out and rotate the crankshaft. Replace spark plug |
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Why is valve clearance adjusted on radial engines, but not on most horizontally opposed engines?
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Horizontally opposed engines have hydraulic valve lifters. Radial engines have solid lifters. |
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What must be inspected to determine the airworthiness of an engine installation?
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The propeller Lube system Ignition system Fuel metering system Cooling and exhaust systems |
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Where can you find the correct grade of fuel and amount of engine lube oil for an engine?
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Type Certificate Data Sheet for the aircraft |
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What are the basic steps in troubleshooting an engine installation?
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Know how the system operates |
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Where do you find the procedures to follow when correcting a defective condition in an aircraft engine?
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Engine maintenance manual |
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Where do you find instructions for removing an engine?
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Aircraft maintenance manual |
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What must normally be done to a nose–wheel airplane before removing an engine?
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Tail of the aircraft should be supported
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What should be done to the cylinders to protect them from rust and corrosion when preparing the engine for long storage?
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Spray a preservative oil inside the cylinders and replace the spark plugs with desiccant plugs |
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What is meant by a QEC engine assembly?
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The engine is on its mounts and all accessories are installed. All it needs are the controls, wiring, and fluid lines to be connected. |
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What is meant by rigging the engine controls so they have some "cushion"?
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The control on the engine component must contact its stop before the control handle in the cockpit reaches its stop. This causes the control handle to spring back |