Aviation Exam

Airframes

The structure of an aircraft that supports its components and withstands aerodynamic forces, ensuring that all parts work together effectively during flight.

The strength in truss built airframes comes primarily from the stressed skin covering.

False

- In reality, while the stressed skin does contribute to strength, the primary support comes from the framework of the truss itself.

  • Composite airframes: These utilize materials such as carbon fiber and fiberglass, which provide high strength-to-weight ratios, improving overall efficiency and performance.

The formers in a semi-monocoque airframe are held in place by:

  • ribs.

    • structural components in aircraft design used to provide shape and support for the airframe skin. They work in conjunction with other components like formers and stringers to maintain the structural integrity of the aircraft under various aerodynamic forces.

  • rivets.

    • mechanical fasteners used in aircraft construction to hold structural components together. They are typically made of metal and are installed by deforming the end of the rivet to create a tight bond, providing strength and durability to the airframe.

  • stringers.

    • These components work together to provide structural integrity and support the skin of the aircraft, ensuring it can withstand various aerodynamic forces.

  • the fabric covering.(Note: Formers are structural elements used in aircraft design to provide shape and support.)

Composite construction is typically lighter than metal but not as strong.

False

- Composite materials often have high strength-to-weight ratios, making them both lightweight and strong, which is why they are commonly used in modern aircraft construction.

In a truss the lengthwise tubes are called:

  • stringers.

  • Longerons.

  • Struts.

  • Forms.(Note: Longerons refer specifically to the longitudinal members that provide structural support in a truss design.)

If the stringer were eliminated from a semi-monocoque airframe we would have a:

A. truss type airframe.

B. monocoque type airframe.

C. steel type airframe.

D. composite type airframe.

  • (Note: A monocoque structure relies on the external skin to support most of the load.)

Engines

The most common engines used in general aviation are air-cooled.

True - Air-cooled engines are prevalent in general aviation due to their simple design and effectiveness.

When doing a run-up, a failure to see the RPM drop while on the right magneto position is an indication:

  • the timing is correct.

  • the left magneto will be live when the mags are turned OFF.

  • of a normal check.

  • the magneto will be OFF when the mags are turned OFF.(Note: The run-up is a pre-flight check to test the engine and magnetos.)

One cycle in a piston engine is defined as the time taken for the piston to travel from bottom dead center to top dead center.

False - A complete cycle includes both upward and downward motion of the piston, encompassing all four strokes of the engine.

The strokes of a piston engine in order are:

  • power, exhaust, compression, and intake.

  • intake, power, compression, and exhaust.

  • compression, power, intake, and exhaust.

  • intake, compression, power, and exhaust.(Note: The correct order is intaking the air-fuel mixture, compressing it, igniting it for power, and then expelling exhaust.)

The spark plug fires just before the piston reaches top dead center.True - This timing ensures optimal combustion of the air-fuel mixture.

During the exhaust stroke in a piston engine both valves remain opened for the duration of the stroke.

False - Typically, during the exhaust stroke, the exhaust valve opens while the intake valve remains closed.

A method of cooling used in a piston engine aircraft is by:

  • installing fins on the cylinders.

  • using an oil cooler.

  • directed airflow.

  • All the above.(Note: Proper cooling is crucial to prevent overheating and maintain engine efficiency.)

The primary disadvantage of the magneto system is that without electrical power the engine will stop running.

False - A magneto generates its own electrical power independently from the aircraft's electrical system, ensuring engine operation even if the electrical system fails.

Dual ignition implies that:

  • a single spark plug for each cylinder is driven from either the left magneto or the right for backup purposes.

  • a single spark plug for each cylinder is driven by both the left magneto and the right magneto combined.

  • two separate spark plugs are fired in each cylinder but driven by a single magneto.

  • two separate spark plugs are fired in each cylinder and driven by its own magneto.(Note: Dual ignition enhances engine reliability and performance.)

The mixture controls the fuel to air ratio by volume.False - The mixture controls the ratio of fuel to air by weight, which is critical for optimal combustion efficiency.

Running an engine with the mixture set too lean may cause:

  • rough engine operation.

  • overheating.

  • back firing.(Note: Lean mixture ratios mean less fuel, which can lead to engine performance issues.)

The reason carburetor heat is turned off while taxiing is because carburetor ice is less likely to form at such low RPM.

False - Carburetor heat is typically used during low throttle settings to prevent ice formation; it should be applied when there is a risk of ice.

The turbocharger takes power from the exhaust and the supercharger takes power by being geared off the engine.

True - Turbochargers utilize exhaust gases to increase intake air pressure, while superchargers are mechanically driven.

The vacuum pump is driven by the electrical system in the aircraft and will continue to provide suction to the instruments despite an engine failure.

False - Vacuum pumps are typically engine-driven and will lose suction if the engine fails.

Critical Surface Contamination

Any accumulations of frost, snow, or ice on the wings will:

  • have no effect on the stall speed.

  • produce a decrease in stall speed and an increase in stall angle of attack.

  • produce a decrease in stall speed and a decrease in stall angle of attack.

  • produce an increase in stall speed and a decrease in stall angle of attack.(Note: Stall speed increases as contamination affects the wings' lift characteristics.)

Ice accumulation with the thickness and roughness of medium to coarse grit sandpaper will decrease the lift by as much as . . . . . % while increasing the drag by as much as . . . . . %.

  • 40, 30

  • 25, 30

  • 30, 25

  • 30, 40(Note: Ice can severely impact aircraft performance.)

The clean aircraft concept is an air regulation that allows a pilot to take off only when:

  • when ATC gives permission.

  • any surface contamination found has been removed.

  • frost, ice, or snow adhering to an aircraft has been inspected by the PIC.

  • only the bottom half of the wings are frost covered.(Note: Ensures aircraft safety by mandating clean surfaces for optimal performance.)

The pilot notices that frost caused by cold-soaked fuel is sticking under the wings. The takeoff may:

  • not be carried out.

  • not be carried out unless FSS gives permission.

  • take place regardless of ice under the wing.

  • be carried out if it is conducted in accordance with the manufacturer’s instructions.(Note: Always adhere to manufacturer guidelines for safety.)

The primary danger of ice accumulation on an aircraft is the increase in weight.

False - The primary danger is the effect on lift and control, not just the weight.

Which are considered critical surfaces? 1. Wings or Rotors 2. Engine intakes 3. Propellers 4. Landing gear 5. Control surfaces 6. Tail and stabilizers:

  • 1, 2, 3, 4, 5, and 6

  • 1, 2, 4, and 5

  • 1, 3, 5, and 6

  • 1, 2, 3, and 4(Note: Critical surfaces are those that directly affect flight performance.)

Principles of flight

Bernoulli found that when air is forced through a pipe that gradually constricts, that the air traveled faster in the constricted section of the pipe and that the air pressure was found to be:

  • less than the pressure at the downwind end of the pipe.

  • more than the pressure at the ends of the pipe.

  • less than the pressure at both ends of the pipe.

  • equal to the pressure at the ends of the pipe.(Note: This principle is fundamental in understanding how lift is generated.)

According to Bernoulli, as the velocity of a fluid increases, the pressure:

  • causes an equal and opposite force to be applied.

  • experiences a drop in viscosity.

  • remains constant but the temperature will rise.

  • of the fluid will be reduced.(Note: This is often summarized as "Bernoulli's principle.")

Generation of lift through differential pressure on the top and bottom of a wing is described by:

  • Newton's third law.

  • Newton's first law.

  • the ping-pong ball experiment.

  • Bernoulli's principle.(Note: Understanding this is crucial for pilots to ensure efficient flight.)

In what way does Newton's third law explain how lift can be generated by a wing?

  • Air is forced to accelerate over the top of the wing.

  • Acceleration of air causing a downward force.

  • Air being deflected downward by a wing causing an opposite reaction.

  • A drop in pressure causing an opposite force to be applied to the wing.(Note: Newton's third law states that for every action, there is an equal and opposite reaction.)

Which would be an example of Bernoulli's principle?

  • Stepping from a boat to a dock causes the boat to move away from the dock.

  • Throwing a ball into the air causes it to follow a parabolic arc.

  • When dropping a feather and a golf ball from a roof, the golf ball reaches the ground first.

  • A truck passing you on your bicycle causing you to be deflected toward the truck.(Note: This illustrates how changes in airflow can affect lift and movement.)

Which would be an example of Newton's third law?

  • A truck passing you on your bicycle causing you to move toward the truck.

  • Throwing a ball into the air causes it to follow a parabolic arc.

  • Stepping from a boat to a dock causes the boat to move away from the dock.

  • Firing a shotgun causes you to move toward your target.(Note: This highlights the reaction force that occurs with every action.)

Fuel and SystemsMatch the following fuel types with their associated color:

  • 80 (80/87): Red

  • MOGAS (car gas): Yellow

  • Jet Fuel: Clear

  • 100/130 (High Lead): Green

  • 100LL (low lead): Blue(Note: Color coding helps in identifying the type of fuel being used.)

Which statement regarding octane rating is incorrect?

  • Using the next higher grade of fuel may cause detonation.

  • The second number of a fuel grade indicates the octane rating at the rich mixture setting.

  • The first number of the fuel grade indicates the octane rating at the lean mixture setting.

  • If the correct grade of fuel is unavailable, it is safe to use the next higher grade.(Note: Understanding octane ratings is crucial for performance; they represent a fuel's resistance to knocking.)

The component of fuel that burns slowly and possesses minimum detonating qualities is called:

  • Heptane.

  • Ethylene Dibromide.

  • Tetra Ethyl.

  • Octane.(Note: Octane is the measure of fuel's ability to resist knocking during combustion.)

Refer to the Fuel Weight Table. The weight of 120 liters of AVGAS at -20°C is:

  • 230 lb.

  • 345 lb.

  • 198 lb.

  • 154 lb.(Note: Understanding fuel weight is essential for weight and balance calculations.)

Using fuel with a higher octane than specified for the engine could result in:

  • an engine failure.

  • fouling of the spark plugs.

  • knocking.

  • a mixture that is too rich.(Note: Higher octane fuels are often not necessary for all engines and can lead to undesirable effects.)

The most commonly recommended practice for preventing condensation in the fuel tanks is to:

  • drain a pint of fuel from the tank sumps each night.

  • strain all fuel as it is put into the tanks.

  • install a quick drain gascolator.

  • fill each fuel tank after every flight.(Note: Preventing condensation is critical for fuel quality and aircraft safety.)

When liquid water is found in a sample of fuel after straining the tanks it would:

  • sink to the bottom of the sample of AVGAS.

  • appear to be clear if the sample contained only AVGAS.

  • be straw in color if the sample contained only water.

  • appear as a separate layer above the sample of AVGAS.(Note: Water is denser than fuel, so it will settle at the bottom.)

Detonation is caused by using a fuel octane rating that is too low for the aircraft.

True - Low octane fuels can lead to premature ignition of the fuel-air mixture, causing detonation, which is damaging to the engine.

Rapid fuel combustion, loss of power, engine overheating, and engine damage are all symptoms of:

  • vapor lock.

  • detonation.

  • pre-ignition.

  • hot spots.(Note: Each of these can lead to significant engine issues if not addressed.)

Blockage of the fuel vents could result in:

  • fuel starvation.

  • high fuel pressure.

  • vapor lock.

  • high cylinder head temperature.(Note: Fuel venting is critical for maintaining proper fuel flow.)

The fuel gauges are always reliable and should be the primary indicator of how much fuel is on board.

False - Fuel gauges can be inaccurate, and pilots should use other means to confirm fuel levels.

The dangers associated with handling fuel can be minimized by:

  • attaching a ground wire between the fuel pump or truck to an unpainted part of the aircraft.

  • touching the fuel nozzle to the side of the fuel filler hole before starting fueling.

  • stop fueling before breaking contact with the side of the fuel filler hole.(Note: This practice prevents static discharge during fueling.)

Bonding to prevent static electricity is not required when refueling from fuel drums.False - Bonding is necessary to prevent static sparks which can ignite fuel vapors.

Forces acting on an Airplane

Lift is the component of aerodynamic force that is:

  • perpendicular to the chord of the wing.

  • perpendicular to the angle of attack.

  • perpendicular to the relative airflow.

  • parallel to the chord of the wing.(Note: Understanding lift is essential for maintaining flight.)

Drag is the component of aerodynamic force that is parallel to the:

  • chord of the wing but in opposite direction.

  • relative airflow and in the same direction.

  • relative airflow but in opposite direction.

  • chord of the wing and in the same direction.(Note: Drag counteracts thrust and affects flight efficiency.)

Not a form of parasite drag is:

  • interference drag.

  • skin drag.

  • form drag.

  • induced drag.(Note: Parasite drag includes components that resist forward motion without contributing to lift.)

The type of drag caused by the effect of one part on another is known as:

  • skin drag.

  • induced drag.

  • form drag.

  • interference drag.(Note: Understanding drag types is crucial for aircraft design and performance.)

The shape of an object that causes it to resist forward motion refers to induced drag.

False - This definition better describes form drag, which arises from the body shape affecting airflow.

The performance of an aeroplane is best determined by:

  • power setting.

  • pitch.

  • angle of attack.

  • pitch and power setting.(Note: Performance metrics are vital for optimizing flight operations.)

As the speed of an aircraft increases:

  • parasite drag remains unchanged.

  • parasite drag increases.

  • induced drag remains unchanged.

  • induced drag increases.(Note: The dynamics of drag change with speed.)

The force acting vertically toward the center of the earth that results from gravity is known as:

  • mass.

  • center of gravity.

  • momentum.

  • weight.(Note: Understanding weight is crucial for flight safety.)

For an aircraft to fly straight and level at a constant airspeed:

  • thrust must be equal to drag.

  • drag must exceed thrust.

  • thrust must exceed drag.

  • lift must exceed weight.(Note: Balance between thrust and drag is necessary for level flight.)

Airplane Parts

Locate Parts:

  • Engine

  • Fuel Tank

  • Right aileron

  • Radio Antenna

  • Elevator trim tab

  • Vertical Stab

  • Beacon flashing

  • Rudder

  • Elevator

  • Horizontal stab

  • Flaps

  • Navigation light

  • Landing Gear

  • Fuselage

  • Propeller(Note: Familiarity with these parts is essential for understanding aircraft operation and maintenance.)