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ANAC Commercial Pilot Helicopter (PCH) study materials
ANAC Commercial Pilot Helicopter (PCH) study resources

ANAC Commercial Pilot Helicopter (PCH) practice questions

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Question 1Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Under the Brazilian RBAC framework, which document establishes the minimum requirements that a commercial pilot helicopter licence holder must satisfy to exercise the privileges of the licence?

  1. The RBAC that regulates the licensing of aeronautical personnel Correct answer.
  2. The RBAC that addresses aerodrome physical characteristics
  3. The RBAC that regulates commercial air transport operations
  4. The RBAC that governs airworthiness certification of aircraft

Explanation

Licensing requirements for flight crew, including the commercial pilot helicopter licence, are consolidated in the RBAC dedicated to licensing of aeronautical personnel. That regulation defines prerequisites, privileges and validity conditions for each licence and rating. Airworthiness, transport operations and aerodrome standards are addressed in separate regulations.

Question 2Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A commercial pilot helicopter licence holder wants to carry passengers for remuneration. Which condition is fundamental to exercise that privilege lawfully?

  1. Holding only a private pilot licence with a current flight review
  2. Holding the appropriate licence with valid medical certificate and ratings Correct answer.
  3. Holding a flight instructor certificate regardless of aircraft category
  4. Holding a maintenance technician certification for the helicopter type

Explanation

To carry passengers for remuneration the pilot must hold the commercial licence, a valid medical certificate appropriate to the privilege, and the required ratings for the aircraft and operation. The licence alone is not sufficient if medical validity or ratings lapse. Other certificates do not substitute for the commercial licence.

Question 3Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Regarding the validity of the medical certificate required for commercial pilot helicopter operations, which statement reflects the ANAC approach?

  1. The certificate is required only for international flights, not domestic ones
  2. The certificate has a defined validity period that depends on the pilot's age and privilege level Correct answer.
  3. The certificate validity is determined solely by the operator's internal policy
  4. The certificate remains valid indefinitely once issued after the initial examination

Explanation

Medical certificates for commercial pilots have validity periods set by regulation, and those periods vary with the age of the holder and the type of privilege exercised. Operators may apply stricter internal limits but cannot extend regulatory validity. Domestic and international operations both require a valid medical certificate.

Question 4Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A pilot's class 1 medical certificate expires while the pilot is away from base. What is the correct regulatory understanding of the pilot's status?

  1. The pilot may not exercise commercial privileges until the certificate is renewed or revalidated Correct answer.
  2. The pilot may continue as long as the licence itself has not expired
  3. The pilot may continue if the chief pilot grants a verbal authorisation
  4. The pilot may continue for 30 days because the renewal examination was already scheduled

Explanation

Commercial privileges depend on a valid medical certificate, so once it expires the pilot cannot exercise those privileges. Scheduling an examination or obtaining an internal authorisation does not extend validity. The licence validity does not substitute for medical validity.

Question 5Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which of the following best describes the purpose of a type rating on a commercial pilot helicopter licence?

  1. It authorises the pilot to act as pilot in command on a specific aircraft type requiring one Correct answer.
  2. It grants the pilot authority to certify the aircraft as airworthy
  3. It certifies the pilot's total flight experience for airline recruitment purposes
  4. It replaces the need for recurrent proficiency checks on that aircraft

Explanation

A type rating is a crew qualification that authorises operation of a specific aircraft type that the regulation identifies as requiring one. It is issued after appropriate training and testing. It does not replace recurrent checks nor confer maintenance certification authority.

Question 6Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A helicopter pilot holds a commercial licence but has not flown the relevant type for several months. Which regulatory concept most directly governs the return to passenger-carrying operations?

  1. Recent flight experience and proficiency requirements Correct answer.
  2. The aircraft's certificate of airworthiness renewal cycle
  3. The aerodrome's operating hours of service
  4. The operator's fuel policy revision schedule

Explanation

Regulations impose recent experience and proficiency requirements that must be met before a pilot resumes carrying passengers. These requirements ensure currency of skills after a period without flying. Aircraft certification, fuel policy and aerodrome hours are unrelated to pilot currency.

Question 7Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

What is the principal function of the aircraft flight manual in commercial helicopter operations under RBAC?

  1. It serves as the operator's commercial contract with charter customers
  2. It establishes the approved operating limitations and procedures for that specific aircraft Correct answer.
  3. It records the pilot's flight hours for licensing purposes
  4. It lists the maintenance workshops approved for the operator

Explanation

The flight manual contains the approved limitations, performance data and normal and emergency procedures for the specific aircraft. Pilots must operate within those limitations. It is not a commercial contract, a workshop list, or a personal logbook.

Question 8Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

In the context of RBAC operations, what does the minimum equipment list (MEL) allow an operator to do?

  1. Operate without a certificate of airworthiness for short periods
  2. Defer all maintenance indefinitely until the next major inspection
  3. Dispatch an aircraft with specified equipment inoperative under defined conditions Correct answer.
  4. Reduce the required crew complement for night operations

Explanation

An approved minimum equipment list permits operation with particular items of equipment inoperative, subject to specified conditions and limitations. It does not authorise indefinite deferral of maintenance or operation without airworthiness certification. It also does not change crew complement requirements.

Question 9Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which regulation set primarily governs the conduct of commercial air transport operations by helicopter in Brazil?

  1. The RBAC addressing private pilot licensing only
  2. The RBAC addressing commercial air transport operations Correct answer.
  3. The RBAC addressing airport slot allocation
  4. The RBAC addressing unmanned aircraft systems

Explanation

Commercial air transport operations, including helicopter operations, are governed by the RBAC specific to commercial air transport. That regulation covers operator certification, operational control and flight rules. Licensing, unmanned aircraft and slot allocation are covered elsewhere.

Question 10Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

An operator wishes to begin commercial helicopter passenger operations. Which element is normally required before such operations may commence?

  1. Approval from the aircraft manufacturer's sales department
  2. A verbal agreement with the local aerodrome operator
  3. Registration of the company with a foreign aviation authority
  4. An operational certificate or authorisation issued by ANAC for the intended operations Correct answer.

Explanation

Commercial air transport requires an authorisation or certificate from the civil aviation authority covering the intended operations and specifications. This ensures the operator meets organisational, training and operational requirements. Local agreements or manufacturer approvals do not substitute for that authority.

Question 11Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

What is the role of the operations manual in a certified helicopter operator's organisation?

  1. It sets out the procedures and policies personnel must follow to comply with regulations Correct answer.
  2. It is an optional reference used only during initial training
  3. It is submitted only to insurers and not to the authority
  4. It replaces the aircraft flight manual for operational limitations

Explanation

The operations manual translates regulatory requirements into company procedures that flight and ground personnel must follow. It is a controlled document accepted or approved by the authority. It does not replace the flight manual's limitations and is not merely an optional training aid.

Question 12Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A commercial helicopter pilot is offered a charter flight that would exceed the aircraft's maximum certified takeoff mass. What is the correct action?

  1. Accept the flight and record the excess in the technical log
  2. Accept the flight if the customer signs a liability waiver
  3. Accept the flight if the sector is short and weather is good
  4. Refuse the flight or reduce load so that all certified limits are respected Correct answer.

Explanation

Certified mass limits are hard limitations in the flight manual and cannot be exceeded for commercial convenience. The pilot must adjust the load or decline the flight. Weather, sector length or customer waivers do not authorise exceeding certification limits.

Question 13Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

How does Brazilian regulation typically treat the use of alcohol by flight crew before and during flight?

  1. Consumption is permitted in small quantities if the pilot feels unaffected
  2. Consumption is permitted only on flights longer than four hours
  3. Consumption is regulated only by the operator's internal social policy
  4. Consumption is prohibited within a specified period before flight and during duty Correct answer.

Explanation

Regulations prohibit alcohol consumption within a defined period before flight and during duty, and impose blood alcohol limits. The restriction is a safety rule, not a matter of personal judgement or company social policy. Feeling unaffected does not make consumption lawful.

Question 14Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A pilot is prescribed a medication that may impair alertness. What does the regulatory framework require before the pilot resumes commercial flying?

  1. Approval from the operator's scheduling department alone
  2. Confirmation from an authorised medical assessor that the medication permits safe flight Correct answer.
  3. No action, provided the dose is below the package recommendation
  4. A self-assessment that the pilot feels alert after the first dose

Explanation

When medication may affect fitness, the pilot must obtain clearance from an authorised medical assessor before exercising licence privileges. Self-assessment or scheduling approval is insufficient because the assessor evaluates the specific effect on flight safety. The package dose does not determine aeromedical acceptability.

Question 15Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

What is the purpose of the pilot logbook in the regulatory context?

  1. It replaces the need for proficiency checks
  2. It documents the operator's commercial revenue per flight
  3. It provides a verifiable record of flight experience used to support licensing and currency Correct answer.
  4. It serves as the aircraft's technical maintenance record

Explanation

The logbook records flight time and conditions of flight so that experience, recency and licensing requirements can be verified. It is distinct from the aircraft technical log. It does not record commercial revenue and cannot replace proficiency checks.

Question 16Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

In commercial helicopter operations, what does the technical log primarily record?

  1. The pilot's duty and rest periods
  2. The fuel price at each refuelling location
  3. The passenger manifest for each flight
  4. Defects, maintenance actions and release to service information for the aircraft Correct answer.

Explanation

The technical log documents aircraft defects, the maintenance actions taken, and certification of release to service. It forms part of the aircraft's continuing airworthiness records. Duty periods, manifests and fuel prices are recorded in other documents.

Question 17Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which statement accurately describes the relationship between the certificate of airworthiness and commercial flight operations?

  1. The certificate is required only for the first flight after manufacture
  2. The certificate may be replaced by a manufacturer's statement of conformity
  3. The certificate is issued by the pilot in command before each flight
  4. The aircraft must hold a valid certificate of airworthiness for the flight to be lawful Correct answer.

Explanation

A valid certificate of airworthiness is a precondition for lawful flight, and it remains valid only while maintenance and airworthiness requirements are met. It is issued by the authority, not by the pilot, and is not limited to the first flight. A manufacturer statement does not replace it.

Question 18Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

What is the regulatory significance of the weight and balance computation before a commercial helicopter flight?

  1. It verifies that mass and centre of gravity remain within approved limits for the planned flight Correct answer.
  2. It replaces the performance calculation for the takeoff
  3. It determines the maintenance interval for the next inspection
  4. It establishes the fare to be charged to each passenger

Explanation

Weight and balance calculations confirm that the aircraft's mass and centre of gravity stay within the limits approved in the flight manual. Exceeding either limit compromises performance and controllability. The computation is unrelated to fares or maintenance intervals and does not replace performance planning.

Question 19Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A pilot operating a commercial helicopter is asked to fly into an area where a temporary flight restriction has been published. What is the correct regulatory response?

  1. Comply with the restriction unless an authorisation has been obtained from the issuing authority Correct answer.
  2. Treat the restriction as advisory with no legal effect
  3. Ignore the restriction because it applies only to private flights
  4. Ignore the restriction if the flight is conducted under visual flight rules

Explanation

Published flight restrictions are legally binding and apply to the operations described in the notice. A flight may enter the area only when the appropriate authorisation has been granted. The restriction is not limited to private flights, is not waived by visual flight rules, and is not merely advisory.

Question 20Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which of the following is a standard responsibility of the pilot in command of a commercial helicopter flight?

  1. Approval of the operator's annual maintenance budget
  2. Negotiation of the company's insurance premiums
  3. Certification of the operator's financial statements
  4. Final authority for the operation and safety of the aircraft during flight time Correct answer.

Explanation

The pilot in command holds final authority and responsibility for the aircraft and its occupants during flight time. This authority supports safety decisions even when they conflict with commercial pressure. Financial, budgetary and insurance matters fall outside that role.

Question 21Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A pilot suspects that a colleague is about to fly while unfit for duty. Which action best reflects the regulatory and safety culture expected under RBAC?

  1. Say nothing because fitness is a purely personal matter
  2. Report the concern through the operator's established safety reporting channel before the flight Correct answer.
  3. Record the concern only in the pilot's personal logbook
  4. Wait until after the flight and mention it informally

Explanation

Safety management principles require personnel to report fitness concerns promptly through established channels so that the flight can be prevented or reassessed. Fitness is not purely personal because it affects the safety of the operation. Delaying or ignoring the concern leaves the risk unaddressed.

Question 22Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

What does the concept of operational control mean for a helicopter operator conducting commercial flights?

  1. The pilot in command alone decides all commercial scheduling without company involvement
  2. The aircraft manufacturer controls where the aircraft may be flown
  3. The operator exercises authority over flight planning, dispatch and supervision of each flight Correct answer.
  4. The aerodrome operator authorises each individual flight

Explanation

Operational control means the operator has the authority and responsibility for initiating, conducting and terminating flights, including dispatch and supervision. It complements rather than removes the pilot in command's authority. Manufacturers and aerodrome operators do not exercise operational control over the flight.

Question 23Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

How should a commercial helicopter pilot treat the performance data in the flight manual when planning a flight to a high-altitude helipad on a hot day?

  1. Use sea-level hover data because altitude differences are negligible for helicopters
  2. Apply the approved performance data for the actual conditions to confirm the flight can be conducted safely Correct answer.
  3. Assume a margin of 10 percent over the maximum mass to cover the heat
  4. Rely on the pilot's previous experience at the same site instead of the charts

Explanation

Approved performance data must be applied to the actual pressure altitude and temperature to confirm that the planned operation stays within limits. Sea-level data and personal experience are not substitutes for the approved charts. Adding a margin above maximum mass is not permitted.

Question 24Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

An operator's helicopter is involved in a serious incident. Which regulatory obligation applies to the pilot in command?

  1. Wait for the next scheduled audit before reporting
  2. Discuss the event only with the insurance company
  3. Notify the appropriate authority and preserve evidence as required by the investigation rules Correct answer.
  4. Complete repairs before reporting so the aircraft can return to service

Explanation

Serious incidents trigger notification duties and obligations to preserve evidence for the investigation authority. Repairing the aircraft before reporting can destroy evidence and is not permitted. Reporting is owed to the authority, not only to insurers.

Question 25Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which statement best describes how RBAC requirements apply to a commercial helicopter operation conducted under visual flight rules at night?

  1. Night operations are governed by the same requirements as day operations with no additions
  2. Night operations require no instrument or lighting equipment
  3. Night visual flight rules impose additional equipment, currency and planning requirements Correct answer.
  4. Night operations are permitted only for private pilots

Explanation

Night visual flight rules operations carry additional requirements, such as specific equipment, pilot night currency and more conservative planning. They are not identical to day operations. Night flight is not restricted to private pilots, and lighting and instrument equipment are typically required.

Question 26Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Under RBAC, what is the validity period of a Class 1 medical certificate for a commercial helicopter pilot who is 40 years old?

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

Explanation

RBAC 67 establishes that a Class 1 medical certificate is valid for 12 months for pilots under 40 and for 6 months for pilots aged 40 or older. Since the pilot is 40, the shorter 6-month period applies. This ensures more frequent medical oversight as pilots age.

Question 27Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

For a commercial helicopter operation under RBAC 135, what is the minimum recent flight experience required for a pilot to carry passengers at night?

  1. Five takeoffs and five landings within the preceding 6 months
  2. Three takeoffs and three landings within the preceding 90 days Correct answer.
  3. Two takeoffs and two landings within the preceding 60 days
  4. One takeoff and one landing within the preceding 30 days

Explanation

RBAC 135 requires that a pilot carrying passengers at night must have performed at least three takeoffs and three landings within the preceding 90 days. These takeoffs and landings must be accomplished during the night period to satisfy the recency requirement. This ensures the pilot remains proficient in night operations.

Question 28Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

Which document must a commercial helicopter pilot have on board the aircraft during flight according to RBAC?

  1. The aircraft maintenance manual
  2. The company training syllabus
  3. The pilot's personal logbook
  4. The operations manual Correct answer.

Explanation

RBAC 135 requires that the operations manual, or the relevant parts of it, be carried on board during commercial operations. This document contains essential procedures and information for the flight crew. Other documents like the maintenance manual or logbook are not required to be on board.

Question 29Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

A commercial helicopter operator plans a flight over a congested area of a city. What minimum altitude must be maintained under RBAC, unless authorised otherwise?

  1. 500 feet above the highest obstacle within a horizontal radius of 600 metres Correct answer.
  2. 300 feet above the highest obstacle within a horizontal radius of 300 metres
  3. 1000 feet above the highest obstacle within a horizontal radius of 600 metres
  4. 2000 feet above the highest obstacle within a horizontal radius of 1000 metres

Explanation

RBAC 91 establishes that over congested areas, aircraft must maintain a height of at least 500 feet above the highest obstacle within a horizontal radius of 600 metres from the aircraft. This rule minimises risk to people and property on the ground in densely populated areas. It applies to all aircraft, including helicopters, unless special authorisation exists.

Question 30Air Law and ANAC Regulations (RBAC) for Commercial Helicopter Operations

In a commercial helicopter operation, what is the maximum allowable flight duty period for a single pilot under RBAC 135, considering the pilot has not had any extensions or reductions?

  1. 8 hours
  2. 14 hours
  3. 12 hours Correct answer.
  4. 10 hours

Explanation

Under RBAC 135, the maximum flight duty period for a single pilot is 12 hours, unless extensions are applied. This limit is set to manage fatigue and ensure safety. It can be reduced based on factors like start time and number of sectors, but the baseline maximum is 12 hours.

Question 31Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

On a single-engine helicopter, what is the primary purpose of the freewheeling unit (sprag clutch) in the transmission?

  1. To absorb torque spikes during rapid collective movements
  2. To reduce engine rpm to the rotor rpm required for flight
  3. To allow the rotor system to spin freely when engine power is lost or reduced Correct answer.
  4. To engage the starter motor to the engine output shaft

Explanation

The freewheeling unit is a one-way clutch between the engine and the main transmission. It transmits engine torque to the rotor but automatically disengages when the rotor turns faster than the engine, so the rotor can autorotate after an engine failure.

Question 32Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

In a semi-rigid (teetering) main rotor system, what is the purpose of the flapping hinge arrangement?

  1. To allow each blade to flap independently of the other
  2. To let the rotor disc tilt as a unit by teetering about a single hinge Correct answer.
  3. To damp lead-lag oscillations between blades
  4. To permit blade pitch changes through a swashplate

Explanation

A semi-rigid rotor uses a single teetering hinge that lets the two-blade assembly rock as a unit, balancing lift differences between the advancing and retreating sides. Individual blade flapping hinges are a feature of fully articulated systems.

Question 33Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

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

  1. To cool the tail boom mounted gearbox
  2. To provide additional lift during heavy loading
  3. To increase the rate of descent in autorotation
  4. To counter main rotor torque and provide directional control Correct answer.

Explanation

Main rotor rotation produces an equal and opposite torque reaction on the fuselage. The tail rotor produces thrust to counteract that torque and, by varying thrust with pedal input, gives the pilot yaw control.

Question 34Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

Which engine type is most commonly fitted to light commercial helicopters and delivers power through a free power turbine?

  1. Turbojet engine
  2. Turboshaft engine Correct answer.
  3. Horizontally opposed piston engine
  4. Radial piston engine

Explanation

Turboshaft engines are the standard powerplant for modern commercial helicopters. Their free power turbine is mechanically independent of the gas generator, which allows the rotor to overrun the engine through the freewheeling unit.

Question 35Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What does the term 'mast bumping' describe in a semi-rigid rotor system?

  1. Contact between the blade tips and the tail boom
  2. Rubbing of the swashplate against the drive shaft
  3. Contact between the teetering hub and the mast under low-G conditions Correct answer.
  4. Vibration caused by an out-of-balance tail rotor

Explanation

In a teetering rotor, strong flapping can drive the hub against the mast. This is most likely during low-G pushovers when rotor thrust is reduced and flapping angles become large, and it can cause mast failure.

Question 36Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

During an autorotation with the engine failed, what keeps the main rotor turning?

  1. Residual torque stored in the transmission
  2. The tail rotor driving the main gearbox
  3. Compressed air from the engine bleed system
  4. Upward airflow through the rotor as the helicopter descends Correct answer.

Explanation

With the engine disengaged by the freewheeling unit, the descending helicopter forces air upward through the rotor disc. This airflow drives the blades and sustains rotation, storing energy for the flare and landing.

Question 37Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What is the primary function of the swashplate assembly in the main rotor control system?

  1. To provide lubrication to the blade grips
  2. To measure rotor rpm for the tachometer
  3. To convert non-rotating control inputs into rotating blade pitch changes Correct answer.
  4. To support the static weight of the rotor mast

Explanation

The swashplate has a stationary ring moved by the cyclic and collective, and a rotating ring that turns with the mast. Tilting or raising the rings changes blade pitch cyclically or collectively, transferring control inputs to the rotating system.

Question 38Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

Why must the pilot monitor turbine outlet temperature (TOT/T4) closely during start and climb?

  1. It reflects the structural load on the tail boom
  2. Excessive temperature can damage turbine blades and hot section components Correct answer.
  3. It shows the charge state of the battery
  4. It indicates the quantity of fuel remaining in the tanks

Explanation

Turbine inlet and outlet temperatures reflect the heat load on the turbine section. Exceeding limits, especially during start or high-power climbs, can cause cracking, creep, or burnout of hot section components and shorten engine life.

Question 39Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

A helicopter with a fully articulated rotor is parked with blades drooping. What component limits the downward flapping angle?

  1. The droop stop Correct answer.
  2. The pitch link
  3. The lead-lag damper
  4. The scissor link

Explanation

Droop stops physically limit how far each blade can flap downward when rotor rpm is low. They prevent blades from striking the tail boom or fuselage and are released by centrifugal force as rpm increases.

Question 40Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What is the purpose of the centrifugal force acting on rotor blades, and how does it relate to coning?

  1. It has no effect on blade behaviour
  2. It stiffens the blades against flapping and balances lift to produce a stable coning angle Correct answer.
  3. It increases blade pitch automatically with rpm
  4. It pulls blades inward and reduces coning

Explanation

At operating rpm, centrifugal force is very large and tends to keep the blades in a flat plane. Lift causes the blades to cone upward until the vertical components balance, producing a stable coning angle that increases with higher lift or lower rpm.

Question 41Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What does an engine torque indication represent in a turboshaft helicopter?

  1. The power delivered to the main transmission Correct answer.
  2. The fuel pressure at the injectors
  3. The temperature of the engine oil
  4. The rotational speed of the tail rotor

Explanation

Torque indication reflects the twisting moment the engine applies to the transmission, which is proportional to the power being delivered. It is the primary power limit used by the pilot, especially in hover and climb.

Question 42Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

Why is a lead-lag (drag) hinge necessary in an articulated rotor system?

  1. To accommodate in-plane Coriolis forces as the blade flaps Correct answer.
  2. To allow the blade to change pitch about its spanwise axis
  3. To permit the blade to fold for storage
  4. To balance the blade statically

Explanation

When a blade flaps up, its centre of mass moves closer to the axis of rotation, and conservation of angular momentum tends to accelerate it in the plane of rotation. The lead-lag hinge and damper absorb this in-plane oscillation.

Question 43Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What is the consequence of a stuck or failed freewheeling unit that remains engaged?

  1. The rotor cannot autorotate freely if the engine stops Correct answer.
  2. The rotor cannot be driven by the engine
  3. The swashplate cannot tilt
  4. The tail rotor loses drive

Explanation

If the freewheeling unit jams engaged, the rotor remains mechanically connected to the engine. In an engine failure the rotor would be dragged down with the engine, preventing normal autorotation and creating a serious emergency.

Question 44Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

Which condition is most likely to cause compressor surge or stall in a turboshaft engine?

  1. Rapid throttle movement or a distorted inlet airflow Correct answer.
  2. Cold ambient temperature at sea level
  3. Steady cruise at moderate power
  4. High oil pressure at idle

Explanation

Compressor surge occurs when airflow separates from the blades, often caused by abrupt power changes, inlet distortion, or foreign object damage. The result is a loud bang, power loss, and high exhaust temperature requiring immediate corrective action.

Question 45Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

In a helicopter with a rigid rotor head, what primarily provides flapping freedom?

  1. Blade flexibility and elastomeric bearings Correct answer.
  2. A teetering hinge at the hub
  3. The swashplate bearing assembly
  4. A separate drag hinge for each blade

Explanation

Rigid rotors have no conventional flapping hinge. Blade bending flexibility and elastomeric or composite bearings accommodate the small flapping and lead-lag motions while the hub remains structurally stiff, giving good control response.

Question 46Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What is the purpose of the tail rotor drive shaft hanger bearings?

  1. To disconnect the tail rotor in autorotation
  2. To change the direction of drive by ninety degrees
  3. To measure tail rotor rpm
  4. To support the drive shaft and damp vibration along the tail boom Correct answer.

Explanation

Long tail rotor drive shafts are divided into segments supported by hanger bearings mounted on the tail boom. They maintain shaft alignment, absorb vibration, and prevent whirling or flexing of the shaft.

Question 47Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What does a chip detector in the transmission or engine oil system indicate?

  1. The oil filter bypass status
  2. The oil level in the reservoir
  3. The presence of metallic particles in the oil Correct answer.
  4. The oil pressure differential

Explanation

Chip detectors are magnetic plugs that attract ferrous metal particles circulating in the oil. An indication warns of possible component wear or failure and requires inspection before further flight.

Question 48Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

Why is it important that the main rotor blades be tracked and balanced correctly?

  1. To allow the helicopter to fly faster than VNE
  2. To lower the fuel consumption in autorotation
  3. To increase the engine's compression ratio
  4. To reduce vibration and prevent excessive loads on the mast and transmission Correct answer.

Explanation

Blades that are out of track or balance produce vertical and lateral vibration that stresses the mast, hub, and transmission and degrades ride quality and control. Correct tracking and balancing keep these loads within design limits.

Question 49Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

What is the primary role of the engine bleed air system on a turboshaft helicopter?

  1. To cool the main transmission oil
  2. To drive the main rotor through pneumatic nozzles
  3. To supply fuel to the combustion chamber
  4. To provide cabin heating and pressurisation or anti-ice functions Correct answer.

Explanation

Compressed air extracted from the engine compressor is used for environmental control, heating, and anti-ice protection of engine inlets. Using bleed air reduces available engine power, so it is a consideration for performance planning.

Question 50Aircraft General Knowledge - Helicopter Airframe, Rotor Systems, and Engines

During a low-G pushover in a teetering rotor helicopter, why is abrupt cyclic input dangerous?

  1. It can drive the hub into the mast and cause mast failure Correct answer.
  2. It causes the engine to overspeed
  3. It causes the tail rotor to lose thrust
  4. It disengages the freewheeling unit

Explanation

In low-G flight, rotor thrust and flapping damping are reduced, so the teetering hub can contact the mast with large flapping excursions. Smooth, gentle control inputs avoid this mast bumping hazard.