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DGAC Bolivia Private Pilot (PPA) study materials
DGAC Bolivia Private Pilot (PPA) study resources

DGAC Bolivia Private Pilot (PPA) practice questions

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Question 1Air Law and DGAC Regulations

Under DGAC Bolivia regulations, which document certifies that a pilot has met the knowledge, experience and medical requirements to act as pilot in command of a private aircraft?

  1. The radio station authorisation
  2. The pilot licence issued by the civil aviation authority Correct answer.
  3. The aircraft registration certificate
  4. The airworthiness certificate of the aircraft

Explanation

The pilot licence is the personal document issued by the civil aviation authority confirming that its holder has satisfied the required knowledge, experience and medical standards. Aircraft documents such as the airworthiness and registration certificates belong to the aircraft, not to the pilot, and the radio station authorisation concerns the installed equipment.

Question 2Air Law and DGAC Regulations

What is the primary purpose of the medical certificate held by a private pilot?

  1. To record the pilot's total flight hours
  2. To demonstrate that the pilot meets the medical fitness standards required to exercise licence privileges Correct answer.
  3. To authorise the pilot to carry passengers for hire
  4. To confirm the pilot has paid current licensing fees

Explanation

The medical certificate is issued after examination by an authorised medical examiner and confirms that the holder meets the fitness standards set for the licence privileges being exercised. It is a health document, so it neither records flight experience nor grants commercial privileges.

Question 3Air Law and DGAC Regulations

Before flight, which set of documents must normally be carried on board the aircraft?

  1. The maintenance workshop invoices and the insurance policy only
  2. The aircraft flight manual alone
  3. Only the pilot's logbook and personal identification
  4. Certificate of registration, certificate of airworthiness and the aircraft radio station licence Correct answer.

Explanation

Bolivian regulations follow the common international practice of requiring the aircraft's registration, airworthiness and radio station documents to be on board during flight, together with the crew licences. These documents allow inspectors to verify that the aircraft is legally airworthy and properly equipped for the operation.

Question 4Air Law and DGAC Regulations

Which authority in Bolivia is responsible for issuing and enforcing civil aviation regulations and for certificating pilots and aircraft?

  1. The Directorate General of Civil Aviation (DGAC) Correct answer.
  2. The national meteorological service
  3. The airport fire and rescue service
  4. The national customs agency

Explanation

The Directorate General of Civil Aviation is the state body that regulates, oversees and enforces civil aviation activity in Bolivia, including licensing of personnel and certification of aircraft. Other agencies may support aviation indirectly, but they do not hold regulatory authority over pilots or airworthiness.

Question 5Air Law and DGAC Regulations

An aircraft is being operated with a valid certificate of airworthiness. What does this certificate indicate?

  1. That the aircraft conforms to its approved type design and is maintained in an airworthy condition Correct answer.
  2. That the aircraft has been flown by a qualified pilot recently
  3. That the aircraft's owner has paid all airport charges
  4. That the aircraft has sufficient fuel for the planned flight

Explanation

A certificate of airworthiness confirms that the aircraft meets its approved design standards and is maintained according to the required programme, so it is considered safe for flight. It is a technical document and does not attest to recent use, fuel state or payment of fees.

Question 6Air Law and DGAC Regulations

What is the purpose of a pre-flight briefing for passengers before take-off?

  1. To record the passengers' weights for the load sheet
  2. To familiarise passengers with safety equipment, exits and emergency procedures Correct answer.
  3. To verify the passengers' pilot licences
  4. To collect payment for the flight

Explanation

The pre-flight briefing ensures that passengers know how to use seat belts, locate exits and understand emergency procedures, which improves survival chances in an abnormal situation. It is a safety obligation of the pilot in command, not an administrative or financial step.

Question 7Air Law and DGAC Regulations

Who has final authority over the operation of an aircraft during flight?

  1. The operator's maintenance chief
  2. The aircraft owner, even if not on board
  3. The pilot in command Correct answer.
  4. The air traffic controller handling the flight

Explanation

The pilot in command is responsible for the safe conduct of the flight and holds final authority over decisions affecting the aircraft while it is in operation. Controllers provide clearances and information, but responsibility for the safe operation remains with the pilot.

Question 8Air Law and DGAC Regulations

What is the standard unit used in Bolivian aviation for reporting horizontal visibility and runway visual range?

  1. Nautical miles
  2. Metres Correct answer.
  3. Kilometres
  4. Feet

Explanation

Visibility and runway visual range in aviation reports are normally expressed in metres, which allows precise and consistent interpretation by pilots and controllers. Other units such as feet are used for altitude, while nautical miles are used for distances in navigation.

Question 9Air Law and DGAC Regulations

A private pilot plans a flight and the destination aerodrome forecast indicates conditions below the pilot's personal minimums but above the published legal minima. What is the most appropriate action?

  1. Ask the tower to lower the legal minima for this flight
  2. Depart without further consideration because legal minima are met
  3. Reassess the plan and consider delaying or altering the route to stay within personal minimums Correct answer.
  4. Reduce the fuel load to compensate for the weather

Explanation

Legal minima are the outer limit permitted by regulation, while personal minimums are a self-imposed safety buffer that should be respected. A prudent pilot reviews the plan and adjusts timing or routing rather than pressing on simply because the flight is technically legal.

Question 10Air Law and DGAC Regulations

During a cross-country flight the pilot becomes aware that a required onboard document has expired. What is the correct course of action?

  1. Ignore the expiry because the aircraft is still airworthy
  2. Continue to the destination and renew the document after landing
  3. Report the matter only at the next annual inspection
  4. Land at the nearest suitable aerodrome and resolve the deficiency before continuing Correct answer.

Explanation

Operating without valid documents makes the flight non-compliant, so the pilot should land at the nearest suitable aerodrome and correct the deficiency before proceeding. Continuing the flight knowingly would compound the regulatory breach and could invalidate insurance coverage.

Question 11Air Law and DGAC Regulations

How is night defined for the purpose of applying night flight rules and logging night experience?

  1. The period between sunset and sunrise
  2. The period between the end of evening civil twilight and the beginning of morning civil twilight Correct answer.
  3. Any time the runway lights are switched on
  4. The period between 18:00 and 06:00 local time

Explanation

Aviation regulations define night by reference to civil twilight, running from the end of evening civil twilight to the beginning of morning civil twilight. This definition is more precise than simple sunset and sunrise because it reflects the actual light conditions relevant to flight.

Question 12Air Law and DGAC Regulations

A pilot holds a private pilot licence and wishes to carry passengers who will share the direct costs of the flight. Under what condition is this normally permitted?

  1. Provided the pilot does not receive any remuneration and the costs are shared proportionally Correct answer.
  2. Provided the flight remains within 50 nautical miles
  3. Provided the pilot holds a commercial licence
  4. Provided the passengers sign a liability waiver

Explanation

A private pilot may share the direct operating costs of a flight with passengers, but may not receive remuneration or profit from carrying them. The costs must be genuinely shared, which preserves the non-commercial character of the flight.

Question 13Air Law and DGAC Regulations

What is the purpose of the aircraft weight and balance calculation before flight?

  1. To confirm the aircraft's radio frequencies
  2. To calculate the landing fees at the destination
  3. To determine the aircraft's fuel consumption rate
  4. To ensure the aircraft remains within certified weight and centre of gravity limits throughout the flight Correct answer.

Explanation

The weight and balance computation confirms that the aircraft does not exceed its maximum structural weights and that the centre of gravity stays within the approved envelope for all phases of flight. Exceeding these limits degrades performance and controllability, so the check is a mandatory safety task.

Question 14Air Law and DGAC Regulations

An aircraft's certificate of registration shows the name of the previous owner, and ownership was recently transferred. What must the new owner do?

  1. Apply to the authority to have the registration updated to reflect the new owner Correct answer.
  2. Wait until the next certificate of airworthiness renewal
  3. Nothing, because the aircraft continues to fly legally
  4. Simply write the new name on the certificate by hand

Explanation

Registration records must reflect the actual owner of the aircraft, so a transfer of ownership requires a formal application to the civil aviation authority for the record to be updated. Handwritten amendments or delay leave the official record inaccurate and the operation potentially non-compliant.

Question 15Air Law and DGAC Regulations

Which of the following best describes the role of the aircraft flight manual in operations?

  1. It is an optional reference used only during training
  2. It replaces the certificate of airworthiness
  3. It lists the air traffic control frequencies for each country
  4. It contains the operating limitations, procedures and performance data approved for the aircraft type Correct answer.

Explanation

The flight manual is the approved document that establishes the operating limitations, normal and emergency procedures and performance data for the specific aircraft. Pilots must comply with it, and it complements but never replaces the certificate of airworthiness.

Question 16Air Law and DGAC Regulations

A pilot is planning a flight and the departure aerodrome has no published instrument approach. Which consideration is most relevant to regulatory compliance?

  1. Verifying the number of parking stands available
  2. Confirming that the aerodrome has a control tower
  3. Ensuring the planned operation and alternate selection satisfy the applicable weather and fuel rules for the flight Correct answer.
  4. Checking whether the aerodrome has a duty-free shop

Explanation

When an aerodrome lacks an instrument approach, the pilot must ensure the flight can be conducted and, if required, an alternate selected in accordance with the applicable weather and fuel rules. Commercial or infrastructural features of the aerodrome have no bearing on these regulatory requirements.

Question 17Air Law and DGAC Regulations

What does an airworthiness directive require an operator to do?

  1. Retrain the pilot in emergency procedures only
  2. Change the aircraft's radio call sign
  3. Carry out specified inspections or modifications to correct an unsafe condition Correct answer.
  4. Recalculate the aircraft's registration fees

Explanation

An airworthiness directive is a mandatory instruction issued when an unsafe condition is identified, requiring specific inspections, modifications or operating limitations to restore an acceptable level of safety. Compliance is obligatory and is normally recorded in the aircraft maintenance records.

Question 18Air Law and DGAC Regulations

A pilot operating a Bolivian-registered aircraft intends to cross into a neighbouring country. Which requirement is most directly related to air law?

  1. Changing the aircraft's tyres before departure
  2. Painting the aircraft a different colour
  3. Obtaining the necessary overflight or landing permission and ensuring the flight is conducted under the applicable bilateral arrangements Correct answer.
  4. Hiring an additional mechanic for the return leg

Explanation

International flights require appropriate permissions and must be conducted in accordance with the bilateral or multilateral arrangements between the states concerned. Cosmetic or maintenance choices do not satisfy these legal prerequisites for crossing a border.

Question 19Air Law and DGAC Regulations

What is the significance of the aircraft nationality and registration marks displayed on the aircraft?

  1. They identify the state of registry and the individual aircraft Correct answer.
  2. They show the pilot's licence number
  3. They display the aircraft's cruising speed
  4. They indicate the aircraft's maximum take-off weight

Explanation

The nationality mark identifies the state in which the aircraft is registered, and the registration mark identifies the individual aircraft within that register. Together they allow the aircraft to be legally identified in flight and on the ground.

Question 20Air Law and DGAC Regulations

A pilot discovers during pre-flight inspection that a required instrument is unserviceable but the flight could be conducted under visual flight rules in daylight. What should the pilot do?

  1. Ask a passenger to monitor the instrument
  2. Determine whether the applicable minimum equipment provisions permit the flight without that instrument Correct answer.
  3. Fly anyway because the weather is good
  4. Remove the instrument and fly immediately

Explanation

The pilot must check whether the operator's approved minimum equipment provisions allow dispatch with the particular item unserviceable under the planned conditions. If the item is not covered by such provisions, the aircraft must not fly until it is repaired.

Question 21Air Law and DGAC Regulations

How does the regulatory concept of 'commercial operation' differ from a private flight under Bolivian rules?

  1. Commercial operations are flights carrying more than two passengers
  2. Commercial operations are flights performed only at night
  3. Commercial operations involve the transport of persons or goods for remuneration or hire, which a private licence does not authorise Correct answer.
  4. Commercial operations are any flights longer than two hours

Explanation

The defining element of a commercial operation is the carriage of persons or goods for remuneration or hire, which requires appropriate licensing and operational approval. Flight duration, time of day or the number of passengers do not by themselves convert a private flight into a commercial one.

Question 22Air Law and DGAC Regulations

An operator wishes to use an aircraft for a flight that will carry cargo for payment. Which statement is correct under the licensing framework?

  1. The flight is permitted if no passengers are on board
  2. The flight is permitted if it stays within national airspace
  3. Any private pilot may conduct the flight if the cargo is light
  4. The operation requires the appropriate commercial licensing and operational authorisation Correct answer.

Explanation

Carrying cargo for payment constitutes a commercial operation and therefore requires the appropriate commercial licensing of the operator and crew together with the relevant operational authorisation. The absence of passengers or the lightness of the load does not remove the commercial character of the flight.

Question 23Air Law and DGAC Regulations

A pilot's medical certificate carries a limitation requiring the use of corrective lenses. What is the correct operational consequence?

  1. The pilot must wear the corrective lenses while exercising the privileges of the licence Correct answer.
  2. The limitation expires automatically after one year of flight
  3. The limitation applies only to night flights
  4. The pilot may fly without lenses if visibility is good

Explanation

A limitation printed on a medical certificate is a condition of the licence privileges and must be complied with whenever those privileges are exercised. Ignoring the limitation renders the flight non-compliant regardless of weather or time of day.

Question 24Air Law and DGAC Regulations

Why do aviation regulations require the pilot in command to ensure that a flight is not commenced unless the aircraft is properly maintained and all required inspections are current?

  1. To standardise the colour scheme of the fleet
  2. To increase the commercial value of the aircraft
  3. To reduce the workload of air traffic controllers
  4. To preserve the assumed level of safety on which the certification of the aircraft and the licensing framework depend Correct answer.

Explanation

Certification and licensing are built on the assumption that continuing maintenance and inspections keep the aircraft at the safety level established at type certification. If that assumption fails, the legal basis for operating the aircraft is undermined and the risk to occupants and third parties rises sharply.

Question 25Air Law and DGAC Regulations

Under Bolivian regulations, what is the minimum age at which a person may first apply for a private pilot licence?

  1. 21 years
  2. 18 years
  3. 17 years Correct answer.
  4. 16 years

Explanation

Bolivian licensing rules follow the common international practice that a private pilot applicant must have reached 17 years of age before the licence can be issued. Applicants may begin training earlier, but the licence itself is granted only once that age is attained.

Question 26Air Law and DGAC Regulations

A private pilot has not flown as pilot in command for several months. Which statement best describes the recency requirement before carrying passengers?

  1. No recency requirement applies to private pilots once the licence is issued
  2. The pilot must complete a specified number of take-offs and landings within the preceding period Correct answer.
  3. The pilot must pass a new written examination with the DGAC
  4. The pilot must renew the aircraft certificate of airworthiness

Explanation

Private pilots must maintain recent flight experience, typically expressed as a minimum number of take-offs and landings, usually including full-stop landings, within the preceding period before acting as pilot in command with passengers. Currency is separate from licence validity.

Question 27Air Law and DGAC Regulations

Before flight, the pilot in command must be satisfied that the aircraft's mass and centre of gravity remain within approved limits. Which document normally provides the empty mass and moment data used for this computation?

  1. The air traffic services route manual
  2. The aircraft mass and balance report or equipment list Correct answer.
  3. The pilot's personal logbook
  4. The aerodrome obstacle chart

Explanation

The mass and balance report, together with the equipment list, records the empty mass and the moment arm of the aircraft as weighed, allowing the pilot to add fuel, crew, passengers and baggage and confirm the centre of gravity stays inside the approved envelope. Other documents do not contain aircraft-specific weighing data.

Question 28Air Law and DGAC Regulations

An aircraft is parked on a Bolivian aerodrome and the pilot intends to start the engine. Which action is required before engine start at an uncontrolled aerodrome?

  1. File a new flight plan for each engine start
  2. Broadcast the intended movement on the appropriate aeronautical frequency Correct answer.
  3. Wait for a signal from the aerodrome fire service
  4. Obtain a written clearance from the DGAC office

Explanation

At an uncontrolled aerodrome the pilot announces intentions on the designated frequency so that other traffic in the vicinity is aware of the activity. No written authority or fire service signal is required for a routine engine start.

Question 29Air Law and DGAC Regulations

Which of the following is the primary purpose of the DGAC requirement that aircraft carry liability insurance for third-party damage?

  1. To replace the need for a certificate of airworthiness
  2. To cover the cost of fuel for the flight
  3. To guarantee that the aircraft will be maintained in airworthy condition
  4. To protect persons and property on the ground and in the air who are not parties to the flight Correct answer.

Explanation

Third-party liability insurance exists so that innocent persons suffering injury or damage caused by the aircraft can be compensated. It does not certify airworthiness, fund maintenance, or pay operating costs.

Question 30Air Law and DGAC Regulations

A pilot operating under visual flight rules in controlled airspace finds that the aircraft's radio fails in flight. Which course of action best reflects the regulatory principle for such a failure?

  1. Continue the flight without any change because radio is not required under visual flight rules
  2. Immediately shut down the engine and land in the nearest field
  3. Climb into cloud to obtain better reception
  4. Continue while squawking the communication failure code and comply with the published communication failure procedures Correct answer.

Explanation

Published communication failure procedures exist so that the pilot follows a predictable sequence, including setting the designated transponder code and conforming to the applicable rules for the airspace. Deviating without following those procedures removes the protection they are designed to provide.

Question 31Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

Which main structural component of a semi-monocoque airplane fuselage carries the primary bending and shear loads along its length?

  1. The cabin upholstery
  2. The fabric covering
  3. The longerons and stringers Correct answer.
  4. The wing struts

Explanation

In semi-monocoque construction the skin carries part of the load, but the longitudinal members called longerons and stringers give the structure its stiffness and carry most of the bending and shear loads along the fuselage. The skin alone would buckle without this internal framework.

Question 32Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the primary function of the vertical stabilizer and rudder assembly?

  1. To house the fuel tanks
  2. To provide lift at low speed
  3. To control yaw about the vertical axis Correct answer.
  4. To control pitch about the lateral axis

Explanation

The vertical stabilizer provides a fixed surface that resists sideways disturbance, and the hinged rudder attached to it produces yaw about the vertical axis. Pitch is controlled by the horizontal tail and elevator, so the two surfaces serve distinct purposes.

Question 33Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

A wing is described as cantilever. What does this mean?

  1. It is supported at the root without external bracing Correct answer.
  2. It is designed to fold for storage
  3. It carries floats instead of wheels
  4. It is braced by external struts and wires

Explanation

A cantilever wing carries all its bending loads internally at the wing root and needs no external struts or bracing wires. This reduces drag compared with braced designs, which rely on struts or wires for support.

Question 34Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

Which flight control surface is normally mounted on the trailing edge of the horizontal stabilizer?

  1. The elevator Correct answer.
  2. The rudder
  3. The flap
  4. The aileron

Explanation

The elevator is hinged to the trailing edge of the horizontal stabilizer and changes pitch by altering the tail downforce. Ailerons and flaps are wing surfaces, while the rudder is on the vertical fin.

Question 35Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

In a four-stroke reciprocating engine, during which stroke does the piston move upward with both valves closed, compressing the fuel-air mixture?

  1. Exhaust stroke
  2. Compression stroke Correct answer.
  3. Power stroke
  4. Intake stroke

Explanation

The compression stroke begins with both valves closed and the piston moving toward top dead center, squeezing the mixture and raising its pressure and temperature before ignition. The power stroke follows ignition, when the burning gases push the piston down.

Question 36Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the purpose of the magnetos on a light aircraft piston engine?

  1. To generate the high-voltage spark for ignition Correct answer.
  2. To charge the battery in flight
  3. To regulate oil pressure
  4. To supply pressurized fuel to the carburetor

Explanation

Magnetos are engine-driven ignition devices that generate high voltage and deliver it to the spark plugs at the correct moment, independent of the aircraft battery. This independence is why the engine keeps running even if the electrical system fails.

Question 37Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What does the airspeed indicator actually measure directly?

  1. Ground speed
  2. Vertical speed
  3. Dynamic pressure converted to a speed indication Correct answer.
  4. True airspeed

Explanation

The airspeed indicator compares ram air pressure from the pitot tube with static pressure and displays the resulting dynamic pressure as a speed. Because it responds to pressure rather than to actual motion over the ground, its indication must be corrected for density and position error to obtain true airspeed.

Question 38Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

Which instrument is connected to the static pressure source only?

  1. The tachometer
  2. The airspeed indicator
  3. The altimeter Correct answer.
  4. The turn coordinator

Explanation

The altimeter operates solely from static pressure, which decreases as altitude increases, and it displays that pressure as an altitude. The airspeed indicator needs both pitot and static pressure, and the turn coordinator is gyroscopic and needs no pressure source.

Question 39Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

A pilot notices that the ammeter shows a continuous discharge in flight with the alternator switch on. What is the most appropriate initial interpretation?

  1. The fuel mixture is too rich
  2. The engine oil pressure is too high
  3. The alternator is not supplying current and the battery is being drained Correct answer.
  4. The battery is fully charged and no action is needed

Explanation

A sustained discharge indication means the electrical load exceeds the output reaching the bus, so the battery is supplying the deficit and will eventually be depleted. The pilot should reduce electrical load and plan to land, because continued flight will end in loss of electrical power.

Question 40Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

During a run-up magneto check, the engine RPM drops excessively when switching to the right magneto and runs roughly. What is the most likely cause?

  1. A spark plug or lead in the right magneto circuit is malfunctioning Correct answer.
  2. The left magneto is faulty
  3. The altimeter setting is incorrect
  4. The carburetor heat is stuck on

Explanation

When the right magneto is selected, only the right magneto fires; excessive drop or rough running points to a fault in that magneto, its leads, or its plugs. Normal drop is small and smooth, so a large or rough drop calls for maintenance before flight.

Question 41Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What happens to indicated airspeed and true airspeed as an aircraft climbs at a constant indicated airspeed into less dense air?

  1. True airspeed decreases while indicated airspeed stays constant
  2. True airspeed remains equal to indicated airspeed
  3. Both true and indicated airspeed decrease
  4. True airspeed increases while indicated airspeed stays constant Correct answer.

Explanation

The airspeed indicator responds to dynamic pressure, so holding a constant indication while air density falls means the aircraft must move faster through the air. True airspeed therefore rises above indicated airspeed as altitude increases.

Question 42Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

Why must a pilot avoid abrupt control movements at high speed near the never-exceed speed?

  1. Because the engine will overheat
  2. Because control forces become too light to feel
  3. Because dynamic pressure loads on the structure can exceed design limits Correct answer.
  4. Because the compass will become unreliable

Explanation

Dynamic pressure increases with the square of speed, so at high speed even a small deflection produces very large aerodynamic loads on the wing and tail. Abrupt inputs can then overstress the structure, which is why maneuvering must be smooth near Vne.

Question 43Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the function of the carburetor heat system in a float-type carburetor engine?

  1. To pressurize the fuel tanks
  2. To supply warmed air to the carburetor to prevent or clear ice Correct answer.
  3. To cool the fuel before it enters the venturi
  4. To increase the octane rating of the fuel

Explanation

Carburetor heat routes air heated by the exhaust or a heat exchanger into the carburetor intake, raising the air temperature so that ice in the venturi cannot form or melts if already present. Applying heat typically causes a slight power loss because warm air is less dense.

Question 44Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

An aircraft is equipped with a fixed-pitch propeller. What happens to engine RPM as the aircraft accelerates in level flight at a constant throttle setting?

  1. RPM increases because the propeller loads up Correct answer.
  2. RPM decreases because the propeller unloads
  3. RPM increases only if the mixture is leaned
  4. RPM remains exactly constant

Explanation

With a fixed-pitch propeller the blade angle cannot change, so as airspeed rises the angle of attack of the blades and their load decrease, letting the engine turn faster. This is why RPM is highest in a dive and lowest during the takeoff roll at low speed.

Question 45Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the primary purpose of the fuel selector valve in a light aircraft?

  1. To filter water from the fuel
  2. To allow the pilot to draw fuel from a chosen tank or shut it off Correct answer.
  3. To automatically lean the mixture with altitude
  4. To measure the quantity of fuel in each tank

Explanation

The selector valve lets the pilot choose which tank supplies the engine and provides an OFF position for shutdown or emergencies. Fuel quantity is shown by gauges, and filtration is done by strainers and filters elsewhere in the system.

Question 46Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

During a preflight inspection a pilot finds the tire tread worn down to the cord on the main gear. What is the correct action?

  1. Ignore it because tires are not airworthy items
  2. Have the tire replaced before flight Correct answer.
  3. Reduce tire pressure to compensate
  4. Fly only short local flights

Explanation

Exposed cord indicates the tire has reached the end of its serviceable life and may fail on landing or takeoff, so it must be replaced before flight. Tires and brakes are airworthiness items subject to inspection standards.

Question 47Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the purpose of the vacuum or pressure system in an aircraft with gyroscopic instruments?

  1. To pressurize the cabin for oxygen
  2. To spin the gyros of the attitude and heading indicators Correct answer.
  3. To operate the flaps
  4. To inflate the tires

Explanation

Air-driven gyros in the attitude indicator and heading indicator require a steady vacuum or pressure source to keep their rotors spinning at high speed. Loss of that source causes the gyros to lose rigidity and the instruments to become unreliable.

Question 48Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

An attitude indicator is powered by a vacuum system. What indication should the pilot expect if the vacuum source fails in flight?

  1. The airspeed indicator freezes
  2. The instrument immediately shows a perfect inverted attitude
  3. The altimeter reads zero
  4. The horizon bar slowly drifts and the instrument becomes unreliable Correct answer.

Explanation

Without suction the gyro rotor loses speed and its rigidity, so the displayed horizon gradually errs and may tumble, making the instrument unreliable. The pilot should cross-check with the turn coordinator and other instruments and use partial-panel procedures.

Question 49Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

Why does the exhaust gas temperature gauge help the pilot set the mixture?

  1. It shows the cylinder head temperature directly
  2. It peaks near the stoichiometric fuel-air ratio, indicating best power mixture Correct answer.
  3. It indicates manifold pressure
  4. It measures the oil temperature

Explanation

As the mixture is leaned, exhaust gas temperature rises to a peak near the chemically correct fuel-air ratio and then falls as the mixture becomes too lean. The pilot uses that peak as a reference point for setting rich or lean of peak as desired.

Question 50Aircraft General Knowledge (Airframes, Systems, Powerplants, Instruments)

What is the effect of opening the throttle on the manifold pressure of a normally aspirated engine?

  1. Manifold pressure increases toward ambient pressure Correct answer.
  2. Manifold pressure remains fixed at 29.92 inHg
  3. Manifold pressure is unaffected by throttle position
  4. Manifold pressure decreases toward zero

Explanation

A closed throttle creates a strong depression in the intake manifold, and opening it lets the manifold pressure rise toward the ambient pressure outside the aircraft. Manifold pressure therefore indicates the power being developed, up to the limit of ambient pressure at that altitude.