Aircraft Systems

Excessively high engine temperatures will

• cause damage to heat-conducting hoses and warping of the cylinder cooling fins
• cause loss of power, excessive oil consumption, and possible permanent internal engine damage
• not appreciably affect an aircraft engine

If the engine oil temperature and cylinder head temperature gauges have exceeded their normal operating range, the pilot may have been operating with

• the mixture set too rich
• higher-than-normal oil pressure
• too much power and with the mixture set too lean

One purpose of the dual-ignition system on an aircraft engine is to provide for

• improved engine performance
• uniform heat distibution
• balanced cylinder head pressure

Float-type carburetors operate based on

• automatic metering of air at the venuri as the aircraft gains altitude
• the difference is air pressure at the venturi throat and the air inlet
• increase in air velocity in the throat of a venturi causing an increase in air pressure

The basic purpose of adjusting the fuel/air mixture at altitude is to

• decrease the amount of fuel in the mixture in order to compensate for increased air density
• decrease the fuel flow in order to compensate for decreased air density
• increase the amount of fuel in the mixture to compensate for the decrease in pressure and density of the air

During the runup at a high elevation airport, you notice a slight engine roughness that is not affected by the magneto check but grows worse during the carburetor heat check. Under these circumstances, what would be the most logical initial action?

• Check the results obtained with a leaner setting of the mixture
• Taxi back to the flight line for a maintenance check
• Reduce manifold pressure to control detonation

While cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?

• The fuel/air mixture can become excessively lean
• There can be more fuel in the cylinders than is needed for normal combustion, and the excess fuel will absorb heat and cool the engine
• The excessively rich mixture creates higher cylinder head temperature and can cause detonation

Which condition is most favorable to the development of carburetor icing?

• Any temperature below freezing and a relative humidity of less than 50 percent
• Temperature between 32 degrees F and 50 degrees F and low humidity
• Temperature between 20 degrees F and 70 degrees F and high humidity

If an aircraft is equipped with a fixed-pitch propeller and a float-type carburetor, the first indication of carburetor ice would most likely be

• a drop in oil temperature and cylinder head temperature
• engine roughness
• loss of RPM

Generally speaking, the use of carburetor heat tends to

• decrease engine performance
• increase engine performance
• have no effect on engine performance