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ANAC Private Pilot Helicopter (PPH) study materials
ANAC Private Pilot Helicopter (PPH) study resources

ANAC Private Pilot Helicopter (PPH) (ANAC) practice questions

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Question 1Air Law and Regulations

Under ANAC rules, who is ultimately responsible for determining that a helicopter is airworthy before flight?

  1. The pilot in command Correct answer.
  2. The owner of the aircraft
  3. The ANAC-certificated mechanic who last signed the logbook
  4. The maintenance organisation's quality manager

Explanation

The pilot in command is responsible for deciding whether the aircraft is in condition for safe flight before each departure, which includes confirming that required inspections and maintenance have been completed. A mechanic may certify work, but that certification does not transfer the pre-flight airworthiness decision to the mechanic, the owner, or the maintenance organisation.

Question 2Air Law and Regulations

A private pilot helicopter licence holder wants to carry passengers. Which condition must be met for the flight to be lawful?

  1. The pilot must file a flight plan with ANAC before departure
  2. The pilot must hold a valid medical certificate appropriate to the privileges exercised Correct answer.
  3. The pilot must have logged at least 500 total helicopter hours
  4. The helicopter must be certified for commercial air transport

Explanation

Exercising the privileges of a private pilot licence requires a valid medical certificate of the appropriate class, and the pilot must also be current. Total flight hours beyond the licensing minimum, commercial certification of the aircraft, and flight-plan filing are not general conditions for carrying passengers on a private flight.

Question 3Air Law and Regulations

What is the standard validity period of a Class 2 medical certificate for a pilot under 40 years of age engaged in private operations?

  1. 12 months
  2. 36 months
  3. 24 months Correct answer.
  4. 6 months

Explanation

For private pilots under 40, the Class 2 medical certificate is normally valid for 24 months. Shorter validity applies to older pilots and to holders exercising commercial privileges, where 12 months or less is typical.

Question 4Air Law and Regulations

Before operating a helicopter in controlled airspace, what must a private pilot normally obtain?

  1. Written authorisation from the local police authority
  2. A special permit issued by the aircraft manufacturer
  3. Approval from the nearest flight school
  4. A clearance from the responsible air traffic control unit Correct answer.

Explanation

Entry into controlled airspace requires an ATC clearance issued by the unit responsible for that airspace, and the pilot must comply with the clearance and any instructions given. Police authorities, manufacturers, and flight schools have no role in granting airspace access.

Question 5Air Law and Regulations

What minimum fuel reserve must a helicopter operated under visual flight rules by day normally carry?

  1. Enough fuel to fly for 45 minutes at cruising speed Correct answer.
  2. Enough fuel to reach the destination with no reserve
  3. Enough fuel for the entire planned route plus 5 minutes
  4. Enough fuel to fly for 20 minutes at cruising speed

Explanation

Day VFR helicopter operations normally require a fuel reserve sufficient for 45 minutes of flight at cruising speed, in addition to the fuel needed for the planned route. This reserve protects against unexpected headwinds, diversions, or holding.

Question 6Air Law and Regulations

Which document must be carried on board a helicopter during flight?

  1. The pilot's personal logbook
  2. The certificate of airworthiness Correct answer.
  3. The maintenance workshop's internal manual
  4. The aircraft purchase invoice

Explanation

The certificate of airworthiness is among the documents that must be on board during flight, together with the certificate of registration and other specified papers. Personal logbooks, internal maintenance manuals, and purchase invoices are not required on board.

Question 7Air Law and Regulations

A pilot holds a private helicopter licence and wants to be compensated for flying a passenger to a business meeting. How does ANAC treat this?

  1. It is permitted if the flight stays within 50 nautical miles
  2. It is prohibited because private pilots may not receive remuneration for carrying passengers Correct answer.
  3. It is permitted because the passenger is not paying the pilot directly
  4. It is permitted if the pilot holds a valid Class 2 medical certificate

Explanation

A private pilot licence does not allow the holder to receive remuneration for transporting passengers or property; such activity requires a commercial licence and an operator certificate. The medical class or the distance flown does not change this limitation.

Question 8Air Law and Regulations

A pilot's Class 2 medical certificate expired two weeks ago and the pilot feels healthy. What is the correct course of action?

  1. Fly only during daylight hours
  2. Fly only as pilot in command on local flights
  3. Fly if accompanied by a flight instructor
  4. Refrain from exercising licence privileges until a valid medical certificate is obtained Correct answer.

Explanation

The privileges of the licence may only be exercised while a valid medical certificate is held; feeling healthy does not substitute for the document. Local flights, instructor accompaniment, and daylight restrictions do not create an exception to the medical validity requirement.

Question 9Air Law and Regulations

A helicopter has been involved in an accident causing serious injury. What is the pilot's primary obligation regarding notification?

  1. Wait until the insurance company completes its assessment
  2. Notify the nearest ANAC office or authority without delay Correct answer.
  3. Send a written report within 90 days
  4. Report the event only if the helicopter was destroyed

Explanation

Accidents involving serious injury or substantial damage must be notified to the competent authority without delay so that investigation can begin and evidence preserved. Waiting for insurers, applying a damage threshold, or delaying to a written report conflicts with the prompt notification duty.

Question 10Air Law and Regulations

During a cross-country flight, the pilot notices a passenger becoming agitated and attempting to open the door. What authority does the pilot in command hold?

  1. The pilot must land immediately at the nearest aerodrome in all cases
  2. The pilot may take reasonable measures to ensure safety, including restraining the passenger Correct answer.
  3. The pilot must consult ANAC by radio before acting
  4. The pilot has no special authority over passengers in flight

Explanation

The pilot in command has final authority over the aircraft and may take reasonable measures, including restraint, to protect the safety of the flight and its occupants. Immediate landing or prior consultation is not always required if safety can be restored on board.

Question 11Air Law and Regulations

Which of the following best describes the minimum visibility requirement for a helicopter operating under VFR in uncontrolled airspace below 900 metres?

  1. Visibility may be reduced to 800 metres if the pilot is instrument rated
  2. Visibility may be reduced to zero if the helicopter stays below 50 feet
  3. Visibility must be at least 1,500 metres Correct answer.
  4. Visibility must be at least 5 kilometres

Explanation

Below 900 metres in uncontrolled airspace, VFR helicopter operations generally require a minimum flight visibility of 1,500 metres and clear of cloud with surface in sight. Instrument rating, extreme low altitude, or a five-kilometre standard do not replace this value.

Question 12Air Law and Regulations

A pilot plans a flight over a congested area of a city at low altitude. What rule applies?

  1. The pilot must maintain a height that allows a safe emergency landing without undue hazard to persons or property Correct answer.
  2. No minimum height applies over cities
  3. The pilot must fly at exactly 500 feet above the highest obstacle
  4. The pilot may descend to rooftop level if the helicopter is light

Explanation

Over congested areas, the pilot must maintain a height that permits a safe forced landing without undue hazard to persons or property on the ground, and must remain clear of obstacles. A fixed 500-foot figure or rooftop-level flight does not satisfy this performance-based rule.

Question 13Air Law and Regulations

What is the purpose of the certificate of registration carried on board a helicopter?

  1. It identifies the aircraft and its registered owner and establishes nationality Correct answer.
  2. It proves the aircraft's maintenance status
  3. It authorises the pilot to fly commercially
  4. It records the aircraft's fuel consumption

Explanation

The certificate of registration identifies the aircraft, its registered owner, and its nationality, and must be carried on board. Maintenance status is shown by the certificate of airworthiness, commercial authority comes from the operator certificate, and fuel records are separate.

Question 14Air Law and Regulations

A pilot receives a clearance to enter a control zone but the radio fails before entering. What is the appropriate action?

  1. Land immediately wherever possible
  2. Enter the zone and proceed as planned
  3. Remain outside the control zone and follow the published lost-communication procedure Correct answer.
  4. Squawk 7600 and continue without change

Explanation

If communication is lost before entering controlled airspace, the pilot should remain clear of the zone and comply with the published lost-communication procedure, which may include attempting re-establishment and landing at a suitable aerodrome. Continuing as planned without a valid clearance is not acceptable.

Question 15Air Law and Regulations

Which of the following flights would require the pilot to hold a commercial pilot licence rather than a private licence?

  1. Carrying a friend on a sightseeing flight where the pilot pays an equal share of costs
  2. Training with an instructor for a rating renewal
  3. Flying to another city for personal business
  4. Transporting cargo for hire on behalf of a company Correct answer.

Explanation

Carrying cargo for hire is a commercial operation and requires a commercial licence together with the appropriate operator certification. Cost-shared private flights, personal travel, and instructional flights do not constitute commercial carriage.

Question 16Air Law and Regulations

A pilot is asked to fly a helicopter that has just returned from maintenance with a signed release. What should the pilot verify before flight?

  1. That the maintenance organisation has a valid insurance policy
  2. That the release covers the work performed and that the aircraft is within inspection limits Correct answer.
  3. That the work was completed during daylight hours
  4. That the mechanic holds a private pilot licence

Explanation

The pilot should confirm that the maintenance release is properly completed, covers the work done, and that all required inspections remain valid. Insurance of the workshop, the mechanic's pilot qualifications, and the time of day are irrelevant to the airworthiness verification.

Question 17Air Law and Regulations

Under what circumstances may a helicopter be operated at night by a private pilot?

  1. Whenever the pilot carries a flashlight
  2. Only if the flight remains within 10 nautical miles of the departure aerodrome
  3. Whenever the pilot has more than 100 hours of total flight time
  4. Only if the pilot holds the appropriate night rating and the helicopter is suitably equipped Correct answer.

Explanation

Night operations require the pilot to hold the appropriate night qualification and the helicopter to be equipped for night flight, including lighting and instruments as prescribed. Total hours, proximity to the departure point, or a flashlight alone do not satisfy these requirements.

Question 18Air Law and Regulations

A pilot operating a helicopter in a wildlife protection area is asked to fly lower than the published minimum. What is the correct response?

  1. Comply only during daylight hours
  2. Comply if the helicopter is certified for low-level flight
  3. Refuse unless a specific authorisation or exemption applies Correct answer.
  4. Comply if the passenger requests it

Explanation

Published minimum heights and environmental restrictions apply unless a specific authorisation or legal exemption has been granted. Passenger requests, aircraft certification, or daylight conditions do not override those restrictions.

Question 19Air Law and Regulations

A pilot discovers after landing that a required periodic inspection had actually expired before the flight. What is the most accurate statement of the pilot's position?

  1. The responsibility lies solely with the maintenance organisation
  2. The pilot is protected because the logbook was not checked
  3. No violation occurred because the flight ended safely
  4. The pilot committed an infraction by operating an aircraft without valid inspections Correct answer.

Explanation

Operating an aircraft when a required inspection has expired is an infraction attributable to the pilot in command, who is responsible for confirming airworthiness before flight. A safe outcome, delegation to maintenance staff, or failure to check records does not eliminate that responsibility.

Question 20Air Law and Regulations

Two pilots share a helicopter for a private trip and each pays an equal share of fuel and aerodrome fees. How is this treated under ANAC rules?

  1. As prohibited remuneration for the pilot flying
  2. As commercial air transport requiring an operator certificate
  3. As a charter operation requiring a commercial licence
  4. As an acceptable cost-sharing arrangement under private privileges Correct answer.

Explanation

Private pilots may share the direct costs of a flight with passengers provided no profit is generated and the pilot does not receive remuneration beyond an equal share. Commercial transport, charter operations, and prohibited remuneration all involve payment for the service itself.

Question 21Aircraft General Knowledge – Helicopter

In a helicopter, what is the primary purpose of the swashplate assembly?

  1. To measure rotor RPM for the tachometer
  2. To store rotational energy for autorotation landings
  3. To reduce engine torque before it reaches the main rotor
  4. To transfer pilot control inputs into blade pitch changes while the rotor turns Correct answer.

Explanation

The swashplate has a stationary ring that follows the control inputs and a rotating ring that turns with the mast. Tilting or raising the swashplate changes blade pitch cyclically or collectively, allowing control of the turning rotor. It does not store energy, reduce torque, or sense RPM.

Question 22Aircraft General Knowledge – Helicopter

What happens to the collective pitch and the throttle as the collective lever is raised?

  1. Pitch stays constant and only the throttle opens
  2. Pitch increases and the throttle opens to maintain rotor RPM Correct answer.
  3. Pitch increases while the throttle stays fixed at idle
  4. Pitch decreases and the throttle closes

Explanation

Raising the collective increases the pitch angle of all blades, which increases drag and power required. The interconnected throttle opens to keep rotor RPM within limits. Lowering the collective reverses both effects.

Question 23Aircraft General Knowledge – Helicopter

Which statement correctly describes cyclic control in a helicopter?

  1. It changes the pitch of all blades equally to control climb
  2. It controls only the tail rotor thrust
  3. It changes the pitch of each blade cyclically to tilt the rotor disc and move the helicopter Correct answer.
  4. It sets the engine power directly

Explanation

The cyclic varies blade pitch through each revolution, producing a tilt of the rotor thrust vector. This tilts the rotor disc in the desired direction of travel. Collective, not cyclic, changes pitch equally on all blades.

Question 24Aircraft General Knowledge – Helicopter

What is the function of the tail rotor on a conventional single-main-rotor helicopter?

  1. To provide most of the lift in forward flight
  2. To counter main rotor torque and provide directional control Correct answer.
  3. To reduce vibration from the main rotor
  4. To increase engine power during hover

Explanation

Main rotor rotation produces a torque reaction on the fuselage. The tail rotor produces thrust to oppose that torque, and pedal inputs vary its thrust for yaw control. It provides little or no lift.

Question 25Aircraft General Knowledge – Helicopter

During an autorotation, what drives the main rotor?

  1. Tail rotor thrust through the drive shaft
  2. Upward airflow through the rotor as the helicopter descends Correct answer.
  3. Stored hydraulic pressure
  4. The engine through a freewheeling unit

Explanation

In autorotation the engine is disconnected and the rotor is driven by air flowing upward through it as the helicopter descends. Rotor RPM is controlled by collective pitch and airspeed. Engine drive is intentionally removed by the freewheeling unit.

Question 26Aircraft General Knowledge – Helicopter

What is the purpose of the freewheeling unit in a helicopter drivetrain?

  1. To engage the starter motor
  2. To let the rotor turn independently of the engine when engine power drops Correct answer.
  3. To lock the rotor to the engine during autorotation
  4. To reduce tail rotor RPM in cruise

Explanation

The freewheeling unit, usually an overrunning clutch, transmits engine power to the rotor in one direction only. If engine RPM falls below rotor RPM, the rotor disengages and can autorotate. This protects the drivetrain and enables safe autorotation.

Question 27Aircraft General Knowledge – Helicopter

Which instrument directly indicates main rotor RPM in most light helicopters?

  1. The dual tachometer showing rotor and engine RPM Correct answer.
  2. The manifold pressure gauge
  3. The altimeter
  4. The vertical speed indicator

Explanation

A dual tachometer displays rotor RPM and engine RPM so the pilot can monitor both and keep them in the normal range. Manifold pressure indicates power output, while the altimeter and VSI show altitude and climb rate.

Question 28Aircraft General Knowledge – Helicopter

What does translational lift refer to?

  1. The loss of lift caused by settling with power
  2. Extra lift gained as the rotor moves out of its own downwash into undisturbed air Correct answer.
  3. Lift gained by increasing collective while hovering
  4. Lift produced only by the tail rotor in forward flight

Explanation

At a low forward speed, roughly fifteen to twenty knots, the rotor encounters cleaner air and produces more lift for the same power. This efficiency gain is translational lift. It explains why helicopters accelerate and climb more easily once moving forward.

Question 29Aircraft General Knowledge – Helicopter

A helicopter is hovering with a left crosswind. Which control input will most likely be needed to hold position?

  1. Collective reduction to stop drift
  2. Cyclic into the wind to counter drift Correct answer.
  3. More right pedal to counter drift
  4. Aft cyclic to increase airspeed

Explanation

In a hover the cyclic tilts the rotor disc, and thrust tilts with it. To counter drift from a crosswind, the pilot tilts the disc slightly into the wind. Pedals control heading, not lateral position, and collective controls height.

Question 30Aircraft General Knowledge – Helicopter

Why does a helicopter require more power to hover in ground effect removal conditions at high altitude?

  1. The engine produces more power in thin air
  2. The tail rotor becomes more efficient with altitude
  3. Rotor RPM increases automatically with altitude
  4. Thinner air reduces rotor efficiency and the ground effect cushion is lost Correct answer.

Explanation

High altitude lowers air density, so each blade produces less lift for a given pitch and power must increase. Leaving ground effect removes the cushion that reduces induced flow and improves lift efficiency. Together these raise the power required to hover.

Question 31Aircraft General Knowledge – Helicopter

What is the primary cause of retreating blade stall?

  1. Low rotor RPM during autorotation
  2. A failed tail rotor drive shaft
  3. Excessive airspeed combined with high blade pitch and high load factor Correct answer.
  4. Too little collective pitch in a descent

Explanation

The retreating blade sees lower relative airflow, so it must operate at a higher angle of attack to produce lift. At high airspeed, high gross weight, high pitch, or high load factor, that angle exceeds the stall angle. The result is a pitch-up and roll toward the retreating side.

Question 32Aircraft General Knowledge – Helicopter

A pilot notices the helicopter tends to drift right during a hover. Which factor most directly explains this tendency?

  1. The vertical fin generates lift in a hover
  2. Tail rotor thrust produces a sideways force that must be offset with cyclic Correct answer.
  3. The main rotor turns counterclockwise in all helicopters
  4. The engine torque increases as fuel burns off

Explanation

Tail rotor thrust acts sideways at the tail boom, pushing the fuselage laterally. The pilot compensates by tilting the rotor disc slightly, which is why hovering often requires a small cyclic input. Direction depends on tail rotor thrust direction and rotor rotation.

Question 33Aircraft General Knowledge – Helicopter

What is the effect of raising the collective too quickly during a hover?

  1. Rotor RPM will increase beyond limits
  2. Rotor RPM may droop and the engine may be over-torqued Correct answer.
  3. The helicopter will enter autorotation
  4. The tail rotor will lose thrust entirely

Explanation

A rapid collective increase demands more power than the engine can deliver instantly, so rotor RPM can droop while torque and manifold pressure spike. The pilot should raise collective smoothly and monitor both RPM and torque limits.

Question 34Aircraft General Knowledge – Helicopter

Which condition is most likely to cause settling with power?

  1. A climb at best rate of climb speed
  2. A steep descent with low airspeed, high power, and high descent rate Correct answer.
  3. A shallow approach with high airspeed and low power
  4. A hover taxi into a strong headwind

Explanation

Settling with power occurs when the helicopter descends into its own downwash, typically with low airspeed, a high rate of descent, and high power applied. Recovery involves lowering collective and gaining forward airspeed to escape the vortex ring state.

Question 35Aircraft General Knowledge – Helicopter

Why is a magneto check performed during the run-up?

  1. To test the tail rotor pedals for full travel
  2. To confirm each magneto circuit operates and the engine runs acceptably on either one Correct answer.
  3. To check the fuel quantity indicators
  4. To verify the rotor brake releases properly

Explanation

Switching from both magnetos to each individually verifies that both ignition circuits fire and that the RPM drop stays within limits. An excessive drop or rough running indicates a faulty magneto or plug. This check is done before flight at specified RPM.

Question 36Aircraft General Knowledge – Helicopter

What does a carburetor heat application typically do to engine power in a piston helicopter engine?

  1. It reduces power because warmer, less dense air enters the engine Correct answer.
  2. It increases manifold pressure without changing mixture
  3. It increases power because warm air burns faster
  4. It has no effect on power at any altitude

Explanation

Carburetor heat routes warmed air into the induction system, lowering air density and therefore power output. It is used to prevent or clear carburetor ice, and the resulting power loss should be anticipated. The mixture may also need adjustment.

Question 37Aircraft General Knowledge – Helicopter

A pilot is flying at maximum gross weight on a hot day. Which performance consideration is most critical?

  1. Lower fuel consumption during climb
  2. Reduced hover ceiling and longer takeoff distance Correct answer.
  3. Increased rotor efficiency and shorter takeoff distance
  4. Higher allowable manifold pressure

Explanation

High density altitude from heat and high gross weight both reduce excess power. This lowers the hover ceiling and increases the distance and time needed to clear obstacles. The pilot should consult performance charts before departure.

Question 38Aircraft General Knowledge – Helicopter

What is the purpose of the cyclic trim or force trim system in some helicopters?

  1. To reduce the steady control forces a pilot must hold Correct answer.
  2. To limit engine torque output
  3. To control the tail rotor pitch
  4. To automatically level the helicopter after a disturbance

Explanation

Force trim uses magnetic brakes or springs to hold the cyclic in a chosen position, reducing fatigue during cruise. It does not fly the helicopter or provide automatic recovery. The pilot still makes all control inputs.

Question 39Aircraft General Knowledge – Helicopter

Which statement best explains why the rotor blades are twisted along their span?

  1. To keep the angle of attack more uniform despite varying airflow along the blade Correct answer.
  2. To reduce the need for a tail rotor
  3. To make the blade heavier at the tip for stability
  4. To allow the blade to fold for storage

Explanation

Airflow speed increases toward the blade tip, so a constant pitch would create uneven lift and stall risk near the root. Twist gives a higher pitch near the root and lower pitch near the tip, balancing lift distribution. This improves efficiency and delays stall.

Question 40Aircraft General Knowledge – Helicopter

What is the coning angle of a main rotor blade?

  1. The upward angle the blade takes as lift bends it above the hub plane Correct answer.
  2. The angle between the blade and the vertical mast in a hover
  3. The angle at which the blade folds for storage
  4. The angle of the tail rotor blade to the horizontal

Explanation

As lift is generated, centrifugal force and lift balance to bend the blade upward into a shallow cone. The coning angle increases with lift and decreases with higher rotor RPM. Flapping hinges or flexible elements allow this motion.

Question 41Aircraft General Knowledge – Helicopter

During a power-off autorotative descent, which control primarily manages rotor RPM?

  1. Collective pitch Correct answer.
  2. Throttle
  3. Cyclic trim
  4. Anti-torque pedals

Explanation

With the engine disengaged, rotor RPM is controlled by the balance of blade pitch and airflow. Lowering collective reduces angle of attack and allows RPM to rise, while raising it slows the rotor. The throttle is closed and does not govern RPM in this state.

Question 42Aircraft General Knowledge – Helicopter

A helicopter with a teetering two-blade rotor is in forward flight. What does flapping accomplish?

  1. It equalizes lift between the advancing and retreating sides by varying blade angle of attack Correct answer.
  2. It eliminates the need for cyclic pitch changes
  3. It prevents coning in a hover
  4. It keeps rotor RPM constant regardless of power

Explanation

The advancing blade sees higher airflow and tends to produce more lift, so it flaps upward and reduces its angle of attack. The retreating blade flaps downward and increases its angle of attack. This flapping balances lift across the disc and reduces hub stresses.

Question 43Aircraft General Knowledge – Helicopter

Why can a loss of tail rotor effectiveness occur in certain wind conditions?

  1. The tail rotor may operate in disturbed airflow or a vortex state, reducing its thrust Correct answer.
  2. The cyclic becomes locked in position
  3. The engine automatically shuts down
  4. The main rotor stops producing lift

Explanation

In certain relative wind directions and yaw rates, the tail rotor can enter disturbed airflow or a vortex ring state that reduces thrust. The pilot may need to change airspeed or yaw rate to restore effective anti-torque. Main rotor lift and engine operation are not directly lost.

Question 44Aircraft General Knowledge – Helicopter

A pilot must decide whether a confined-area takeoff is feasible. Which combination most improves performance margin?

  1. Higher gross weight, higher altitude, and a tailwind
  2. Higher density altitude and calm wind
  3. Full fuel and a downsloping surface with a tailwind
  4. Lower gross weight, cooler temperature, and a headwind Correct answer.

Explanation

Lower weight reduces power required, cooler air increases density and power available, and a headwind shortens the distance needed to gain translational lift. Together these increase the margin over obstacles. The opposite conditions erode performance.

Question 45Aircraft General Knowledge – Helicopter

What is the main reason a helicopter pilot monitors torque and manifold pressure together?

  1. They indicate power being delivered relative to limits under varying density altitude Correct answer.
  2. They measure tail rotor thrust
  3. They show rotor blade angle directly
  4. They indicate fuel flow to the engine

Explanation

Torque and manifold pressure reflect engine power output, which changes with air density and temperature. Monitoring both helps the pilot stay within transmission and engine limits. Neither instrument directly measures blade angle or tail rotor thrust.

Question 46Aircraft General Knowledge – Helicopter

In a piston-powered helicopter, what is the primary function of the mixture control during a climb to a higher-altitude airport?

  1. It regulates the engine oil pressure delivered to the bearings
  2. It sets the ignition timing advance for the magnetos
  3. It adjusts the fuel-to-air ratio to compensate for decreasing air density Correct answer.
  4. It controls the pitch of the tail rotor blades

Explanation

As altitude increases, air density decreases, so a fixed fuel flow makes the mixture progressively richer. The mixture control leans the fuel-to-air ratio to keep combustion efficient and preserve power. Proper leaning also reduces fouling and rough running at high-altitude fields.

Question 47Aircraft General Knowledge – Helicopter

A pilot observes that the main rotor turns freely by hand with the engine off but the tail rotor does not turn. Which drivetrain component most likely explains this?

  1. The freewheeling unit is slipping under load
  2. The main rotor brake is fully engaged
  3. The clutch is in the disengaged position
  4. The tail rotor drive shaft is disconnected or failed Correct answer.

Explanation

The main and tail rotors are normally linked through the same drivetrain, so turning the main rotor by hand should also turn the tail rotor. If the tail rotor does not move, the drive path to it is interrupted, such as a failed shaft or coupling. This is a maintenance discrepancy, not a normal operating condition.

Question 48Aircraft General Knowledge – Helicopter

Why does a helicopter typically require less power to maintain altitude in forward cruise than to hover?

  1. Collective pitch is reduced to zero in cruise
  2. Translational lift improves rotor efficiency as airspeed increases Correct answer.
  3. Tail rotor thrust requirements disappear in cruise
  4. The engine produces more power at cruise airspeeds

Explanation

As airspeed increases, the rotor moves into undisturbed air and translational lift improves the efficiency of the rotor system. This reduces the induced power needed to produce the same lift, so less total power is required than in a hover. Induced velocity and downwash recirculation are greatest in the hover.

Question 49Aircraft General Knowledge – Helicopter

What is the purpose of the swashplate assembly in a helicopter rotor system?

  1. It provides the freewheeling function during autorotation
  2. It absorbs the centrifugal loads generated by the spinning rotor
  3. It measures rotor RPM for the tachometer
  4. It transfers pilot control inputs from the non-rotating controls to the rotating blades Correct answer.

Explanation

The swashplate has a stationary ring that receives inputs from the cyclic and collective and a rotating ring that turns with the mast. Tilting or raising the swashplate changes blade pitch, transmitting control inputs to the rotating blades. This allows both cyclic flapping inputs and collective pitch changes.

Question 50Aircraft General Knowledge – Helicopter

During a steady autorotation, a pilot lowers the collective slightly. What is the immediate effect on rotor RPM and descent rate?

  1. Rotor RPM increases and descent rate increases Correct answer.
  2. Rotor RPM decreases and descent rate increases
  3. Rotor RPM increases and descent rate decreases
  4. Rotor RPM decreases and descent rate decreases

Explanation

Lowering collective reduces blade pitch and the induced drag on the blades, so the airflow through the rotor accelerates the blades and RPM rises. With less blade area resisting the airflow, the helicopter descends faster for the same energy state. The pilot must therefore balance collective against the desired RPM and descent rate.