Ground Operations & Servicing

Question 1

What is the proper way to extinguish an induction system fire that occurs when starting a reciprocating engine?

Answer 1

Keep the engine running and blow the fire out. If this does not work, use a COz fire extinguisher directed into the carburetor air inlet.

Question 2

What type of fire extinguisher is best suited for extinguishing an induction fire in a reciprocating engine?

Answer 2

Carbon dioxide.

Question 3

What must be done if a hung start occurs when starting a turbojet engine?

Answer 3

Terminate the starting operation and find the reason the engine would not accelerate as it should.

Question 4

What is meant by a liquid lock in the cylinder of an aircraft engine, and how is one cleared?

Answer 4

Oil accumulates in the cylinders below the centerline of the engine and prevents the piston moving to the top of its stroke. To clear a liquid lock, remove one of the spark plugs and turn the engine crankshaft until all of the oil is forced out of the cylinder.

Question 5

What special precautions should be taken when towing an aircraft that is equipped with a steerable nose-wheel?

Answer 5

Be sure that the nosewheel does not try to turn past its stops. Some aircraft must have the torsion links on the nose wheel strut disconnected when they are being towed.

Question 6

When starting an aircraft engine that is equipped with a float carburetor, in what position should the carburetor heat control be placed?

Answer 6

In the “Cold” position.

Question 7

How far ahead of an idling turbojet engine does the danger area extend?

Answer 7

25 feet.

Question 8

Why is it important that turbine fuel not be mixed with aviation gasoline that is used in an aircraft reciprocating engine?

Answer 8

The turbine engine fuel will cause the engine to detonate.

Question 9

What grade of aviation gasoline is dyed blue?

Answer 9

Low-lead 100-octane.

Question 10

What damage is likely to occur if an aircraft reciprocating engine that is designed to use 100-octane fuel is operated with 80-octane fuel?

Answer 10

Detonation will occur, which will cause such things as bent connecting rods, burned pistons and cracked cylinder heads.

Question 11

What is meant by detonation in an aircraft reciprocating engine?

Answer 11

Detonation is an uncontrolled burning of the fuel in the cylinder of an engine. It is an explosion, rather than a smooth burning.

Question 12

What is the danger of using a fuel that vaporizes too readily?

Answer 12

Vapor lock can occur in the fuel lines. This will shut off the flow of fuel to the engine.

Question 13

What type of fuel is Jet-A fuel?

Answer 13

A fuel with a heavy kerosine base, a flash point of 110-150°F, a freezing point of -40°F, and a heat energy content of 18,600 Btu/pound.

Question 14

What is the significance of the two numbers, 100/130, in the dual rating of aviation gasoline?

Answer 14

The first number is the octane rating or performance number of the fuel when operating with a lean mix-ture, and the last number is the octane rating or performance number when operating with a rich mix-ture.

Question 15

What are two functions of tetraethyl lead that is added to aviation gasoline?

Answer 15

It increases the critical pressure and temperature of the fuel, and it acts as a lubricant for the valves.

Question 16

What information must be located near the fuel tank filler opening in an aircraft powered by a reciprocating engine?

Answer 16

The word “Avgas,” and the minimum fuel grade.

Question 17

What information must be located near the fuel tank filler opening in an aircraft powered by a turbine engine?

Answer 17

The words “Jet Fuel,” the permissible fuel designa-tions, or references to the AFM for permissible fuel designations. For pressure fueling systems, the maximum permissible fueling supply pressure and the maximum permissible defueling pressure.

Question 18

What action should a mechanic take while taxiing an aircraft on a runway if the tower shines a flashing red light at him?

Answer 18

Taxi the aircraft clear of the runway in use.

Question 19

What publication lists the standard hand signals that are used for directing a taxiing aircraft?

Answer 19

Aeronautical Information Manual.

Question 20

What should be done to a reciprocating engine fuel system if turbine fuel is inadvertently put into the tanks and the engine is run?

Answer 20

The entire fuel system must be drained and flushed with gasoline, the engine given a compression check and all of the cylinders given a borescope inspec-tion. The oil must be drained and all of the filters and strainers checked. After the aircraft is properly fueled, the engine must be given a proper run-up and check.