WHY MUST A FLOAT TYPE CARBURETOR SUPPLY A RICH MIXTURE DURING IDLE? because of reduced mechanical efficiency during idle engine operation at idle results in higher than normal volumetric efficiency because at idling speeds the engine may not have enough airflow around the cylinders to provide proper cooling.
IF A FIRE STARTS IN THE INDUCTION SYSTEM DURING THE ENGINE STARTING PROCEDURE, WHAT SHOULD THE OPERATOR DO? continue cranking the engine turn off the fuel switches to stop the fuel turn off all switches.
DIRECT MECHANICAL PUSH PULL CARBURETOR HEAT CONTROL LINKAGES SHOULD NORMALLY BE ADJUSTED SO THAT THE STOP LOCATED ON THE DIVERTER VALVE WILL BE CONTACTED: before the stop at the control lever is reached in both HOT and COLD positions after the stop at the control lever is reached in both HOT and COLD positions before the stop at the control lever is reached in the HOT position and after the stop at the control lever is reached in the COLD position.
WHAT DOES VALVE OVERLAP PROMOTE? a backflow of gasses across the cylinder better scavenging and cooling characteristics lower intake manifold pressure and temperatures.
IF A FULL FLOW OIL FILTER IS USED ON AN AIRCRAFT ENGINE, AND THE FILTER BECOMES COMPLETELY CLOGGED, THE: oil supply to the engine will be blocked oil will be bypassed back to the oil tank hopper where larger sediments and foreign matter will settle out prior to passage through the engine bypass valve will open and the oil pump will supply unfiltered oil to the engine.
(1)WELDING AND STRAIGHTENING OF TURBINE ENGINE ROTATING AIRFOILS DOES NOT REQUIRE SPECIAL EQUIPMENT. (2)WELDING AND STRAIGHTENING OF TURBINE ENGINE ROTATING AIRFOILS IS COMMONLY RECOMMENDED BY THE MANUFACTURER.
REGARDING THE ABOVE STATEMENTS: only no.1 is true neither no.1 nor no.2 is true only no.2 is true.
SHARP BENDS SHOULD BE AVOIDED IN IGNITION LEADS PRIMARILY BECAUSE: weak points may develop in the insulation through which high tension current can leak ignition lead wire conductor material is brittle and may break ignition lead shielding effectiveness will be reduced.
THE FUNCTION OF THE EXHAUST CONE ASSEMBLY OF A TURBINE ENGINE IS TO: straighten and collect the exhaust gases into a solid exhaust jet swirl and collect the exhaust gases into a single exhaust jet collect the exhaust gases and act as a noise suppressor.
WHAT TYPE OF TURBINE BLADE IS MOST COMMONLY USED IN AIRCRAFT JET ENGINES? impulse-reaction reaction impulse.
On a carburetor without an automatic mixture control as you ascend to altitude, the mixture will:
be leaned. be enriched. not be affected.
Under which of the following conditions would an engine run lean even though there is a normal amount of fuel present?
The use of too high an octane rating fuel. The carburetor air heater valve in the HOT position. Incomplete fuel vaporization.
Augmenter tubes are part of which reciprocating engine system?
Fuel. Exhaust. Induction.
Apparent engine roughness is often a result of propeller unbalance. The effect of an unbalanced propeller will usually be:
greater at low RPM. greater at high RPM. approximately the same at all speeds.
If a spark plug lead becomes grounded, the:
distributor rotor finger will discharge to the next closest electrode within the distributor. capacitor will break down. magneto will not be affected.
The purpose of a sonic venturi on a turbocharged engine is to:
increase the velocity of the fuel/air charge. increase the amount of air that can flow from the turbocharger into the cabin for pressurization. limit the amount of air that can flow from the turbocharger into the cabin for pressurization.
What is the basic operational sequence for reducing the power output of an engine equipped with a constant speed propeller?
Reduce the manifold pressure, then retard the throttle to obtain the correct RPM. Reduce the manifold pressure, then the RPM. Reduce the RPM, then the manifold pressure.
Which statement is true regarding jet engines?
At the lower engine speeds, thrust increases rapidly with small increases in RPM. At the higher engine speeds, thrust increases rapidly with small increases in RPM. The thrust delivered per pound of air consumed is less at high altitude than at low altitude.
Propeller blade stations are measured from the:
index mark on the blade shank. hub centerline. blade base.
A safety feature usually employed in pneumatic starters that is used to prevent the starter from reaching burst speed if inlet air does not terminate on schedule is the:
stator nozzle design that chokes airflow and stabilizes turbine wheel speed. spring coupling release. drive shaft shear point.
Engine pressure ratio is the total pressure ratio between the:
aft end of the compressor and the aft end of the turbine. front of the engine inlet and the aft end of the compressor. front of the compressor and the rear of the turbine.
The resistance of the current return path through the aircraft is always considered negligible, provided the:
voltage drop across the circuit is checked. voltage drop across the circuit is checked. structure is adequately bonded.
Which of the following engine variables is the most critical during turbine engine operation?
Compressor RPM. Compressor inlet air temperature. Turbine inlet temperature.
What could cause a lean mixture and high cylinder head temperature at sea level or low altitudes?
Defective accelerating system. Automatic mixture control stuck in the extended position. Mixture control valve fully closed.
What is the purpose of a safety gap in some magnetos?
To ground the magneto when the ignition switch is off. To prevent flashover in the distributor. To discharge the secondary coil's voltage if an open occurs in the secondary circuit.
Basically, the indicator of a tachometer system is responsive to change in:
voltage. current flow. frequency.
The amount of voltage generated in any magneto secondary coil is determined by the number of windings and by the:
rate of collapse of the magnetic field around the primary coil. amount of charge released by the capacitor. rate of buildup of the magnetic field around the primary coil.
The EGT gauge used with reciprocating engines is primarily used to furnish temperature readings in order to:
obtain the best mixture setting for engine cooling. prevent engine overtemperature. obtain the best mixture setting for fuel efficiency.
An oil separator is generally associated with which of the following?
Engine driven vacuum pump. Engine driven oil pressure pump. Cuno oil filter.
At what RPM is a reciprocating engine ignition switch check made?
1,500 RPM. The slowest possible RPM. Full throttle RPM.
Which of the following will decrease volumetric efficiency in a reciprocating engine?
1. Full throttle operation.
2. Low cylinder head temperatures.
3. Improper valve timing.
4. Sharp bends in the induction system.
5. High carburetor air temperatures.
2, 4, and 5. 3, 4, and 5. 1, 2, 3, and 4.
Reduced air density at high altitude has a decided effect on carburetion, resulting in a reduction of engine power by:
reducing fuel vaporization. excessively leaning the fuel/air mixture. excessively enriching the fuel/air mixture.
Which type valve prevents oil from entering the main accessory case when the engine is not running?
Relief. Check. Bypass.
When engine power is increased, the constant speed propeller tries to function so that it will:
maintain the RPM, increase the blade angle, and maintain a low angle of attack. increase the RPM, decrease the blade angle, and maintain a low angle of attack. maintain the RPM, decrease the blade angle, and maintain a low angle of attack.
A nine cylinder engine with a bore of 5.5 inches and a stroke of 6 inches will have a total piston displacement of:
1,283 cubic inches. 1,425 cubic inches. 740 cubic inches.
Which of the following fire detection systems will detect a fire when an element is inoperative but will not test when the test circuit is energized?
The thermocouple system and the Lindberg system. The Kidde system and the thermocouple system. The Kidde system and the Fenwal system.
(Refer to Figure 1 .) Determine which portion of the AD is applicable for Model O-690 series engine, serial No. 5863-40 with 283 hours' time in service. (B), (2). (A). (B), (1).
What indications may shift when a turbofan engine anti-icing (bleed air) system is turned on?
1, 2, and 3. 1 and 2. 2 and 3.
The two types of centrifugal compressor impellers are:
impeller and diffuser. single entry and double entry. rotor and stator.
How does the aerodynamic twisting force affect operating propeller blades?
It tends to turn the blades to a low blade angle. It tends to bend the blades forward. It tends to turn the blades to a high blade angle.
Engine crankshaft runout is usually checked:
1. during engine overhaul.
2. during annual inspection.
3. after a "prop strike" or sudden engine stoppage.
4. during 100-hour inspection.
1, 2 and 3. 1 and 3. 1, 3, and 4.