FAA Engine Fuel and Fuel Metering Systems (1)

The primary purpose of the air bleed openings used with continuous flow fuel injector nozzles is to. provide for automatic mixture control. maintain constant fuel pressure. aid in proper fuel vaporization.

Fuel boost pumps are operated. to provide a positive flow of fuel to the engine. during takeoff only. primarily for fuel transfer to another tank.

An aircraft should be facing into the wind when trimming an engine. However, if the velocity of the wind blowing into the intake is excessive, it is likely to cause a. false low exhaust gas temperature reading. trim setting resulting in engine overspeed. false high compression and turbine discharge pressure, and a subsequent low trim.

What carburetor component limits the maximum airflow into the engine at full throttle?. Throttle valve. Venturi. Main metering jet.

Select the statement which is correct relating to a fuel level check of a float-type carburetor. Use 5 pounds fuel pressure for the test if the carburetor is to be used in a gravity fuel feed system. Block off the main and idle jets to prevent a continuous flow of fuel through the jets. Do not measure the level at the edge of the float chamber.

The device that controls the ratio of the air-fuel mixture to the cylinders is called a. throttle valve. mixture control. metering jet.

Why must a float-type carburetor supply a rich mixture 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. Because of reduced mechanical efficiency during ldle.

Excessively rich or lean idle mixtures result in. too rapid completion of combustion. incomplete combustion. incomplete cylinder scavenging.

One of the best ways to increase engine power and control detonation and preignition is to. enrich the fuel/air mixture. use water injection. lean the fuel/air mixture.

What is the relationship between the accelerating pump and the enrichment valve in a pressure injection carburetor?. No relationship since they operate independently. Unmetered fuel pressure affects both units. The accelerating pump actuates the enrichment Valve.

If an engine is equipped with a float-type carburetor and the engine runs excessively rich at full throttle, a possible cause of the trouble is a clogged. main air bleed. back-suction line. atmospheric vent line.

The function of the altitude compensating, or aneroid valve used with the Teledyne-Continental fuel injection system on many turbocharged engines is to. prevent an overly rich mixture during sudden acceleration. prevent detonation at high altitudes. provide a means of enriching the mixture during sudden acceleration.

Fuel lines are kept away from sources of heat, and sharp bends and steep rises are avoided to reduce the possibility of. liquid lock. vapor lock. positive lock.

The economizer system in a float-type carburetor. keeps the fuel/air ratio constant. functions only at cruise and idle speeas. increases the fuel/air ratio at high power settings.

The economizer system of a float-type carburetor performs which of the following functions?. It supplies and regulates the fuel required for all engine speeds. It supplies and regulates the additional fuel required for all engine speeds above cruising. It regulates the fuel required for all engine speeds and all altitudes.

Which statement is correct regarding a continuous-flow fuel injection system used on many reciprocating engines?. Fuel is injected directly into each cylinder. Fuel is injected at each cylinder intake port. Two injector nozzles are used in the injector fuel system for various speeds.

What precaution should be taken when putting thread lubricant on a tapered pipe plug in a carburetor float bowl?. Put the thread lubricant only on the first thread. Do not use thread lubricant on any carburetor fitting. Engage the first thread of the plug, then put a small amount of lubricant on the second thread ana screw the plug in.

A nine-cylinder radial engine, using a multiple-point priming system with a central spider, will prime which cylinders?. 1,2,3, 8, and 9. All cylinders. 1, 3, 5, and 7.

Under which of the following conditions will the trimming of a turbine engine be most accurate?. High wind and high moisture. High moisture and low wind. No wind and low moisture.

Which of the following turbine fuel filters has the greatest filtering action of any present day filter type?. Micron filter. Plain screen mesh filter. Wafer screen filter.

A pilot reports that the fuel pressure fluctuates and exceeds the upper limits whenever the throttle is advanced. The most likely cause of the trouble is. a ruptured fuel pump relief valve diaphragm. a sticking fuel pump relief valve. an air leak at the fuel pump relief-valve body.

During idle mixture adjustments, which of the following is normally observed to determine when the correct mixture has been achieved?. Changes in fuel/air pressure ratio. Fuel flowmeter. Changes in RPM or manifold pressure.

What corrective action should be taken when a carburetor is found to be leaking fuel from the discharge nozzle?. Replace the needle valve and seat. Adjust the mixture control. Adjust throttle linkage.

What is the purpose of the carburetor accelerating system?. Supply and regulate the fuel required for engine speeds above idle. Temporarily enrich the mixture when the throttle is suddenly opened. Supply and regulate additional fuel required for engine speeds above cruising.

The density of air is very important when mixing fuel and air to obtain a correct fuel-to-air ratio. Which of the following weighs the most?. 75 parts of dry air and 25 parts of water vapor. 100 parts of dry air. 50 parts of dry air and 50 parts of water vapor.

Boost pumps in a fuel system. operate during takeoff only. are primarily used for fuel transfer. provide a positive flow of fuel to the engine pump.

What is the final authority for the details of carburetor overhaul?. The local FAA safety inspector. The Type Certificate Data Sheets for the engine. The manufacturer's recommendations.

If the idling jet becomes clogged in a float-type carburetor, the. engine operation will not be affected at any RPM. engine will not idle. idle mixture becomes richer.

It is desirable that fuel lines have a gentle slope upward or downward and not have sharp curves or sharp rises and/or falls in order to. prevent vapor lock. prevent stagnation or 'pooling' of fuel in the fuel lines. minimize the generation of static electricity by decreasing fluid friction in the lines.

At what engine speed does the main metering jet actually function as a metering jet in a float-type carburetor?. All RPM's. Cruising RPM only. All RPM's above idle range.