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NCAA PPL (Helicopter) Theory Exam study materials
NCAA PPL (Helicopter) Theory Exam study resources

NCAA PPL (Helicopter) Theory Exam practice questions

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Question 1Air Law and Operational Procedures

Under NCAA regulations, a private pilot licence (helicopter) holder may act as pilot-in-command of an aircraft carrying passengers only if the pilot has made at least how many take-offs and landings within the preceding 90 days?

  1. One take-off and one landing
  2. Five take-offs and five landings
  3. Ten take-offs and ten landings
  4. Three take-offs and three landings Correct answer.

Explanation

NCAA general operating rules require recent flight experience: to carry passengers, the pilot must have performed at least three take-offs and three landings within the preceding 90 days. For helicopters these take-offs and landings must be in the same category and class. The requirement is a recency rule, not a currency on the licence itself.

Question 2Air Law and Operational Procedures

What is the primary purpose of a pre-flight briefing to passengers before a helicopter sightseeing flight?

  1. To familiarise passengers with safety equipment, emergency exits and rotor hazards Correct answer.
  2. To record the passengers' body weights for loading calculations
  3. To confirm that each passenger holds a valid medical certificate
  4. To satisfy the insurance company's paperwork requirements

Explanation

The passenger safety briefing exists so that people unfamiliar with helicopters know how to behave around rotors, how to fasten harnesses, where exits are and how to react in an emergency. It is a safety requirement, not an administrative or commercial formality. A briefing given before boarding reduces the risk of rotor-strike and evacuation injuries.

Question 3Air Law and Operational Procedures

In helicopter operations, the term 'height-velocity diagram' (dead man's curve) is used to define which region?

  1. The maximum altitude at which the helicopter may hover out of ground effect
  2. The airspeed range in which retreating-blade stall occurs
  3. The wind velocity at which the helicopter must be grounded
  4. The combination of height and airspeed from which a safe autorotative landing is unlikely Correct answer.

Explanation

The height-velocity diagram marks the low-height, low-airspeed combinations where, after an engine failure, the pilot has neither enough height to establish autorotation nor enough speed to cushion the landing. Operations in the shaded area are avoided unless the task demands it. It is a performance and safety envelope, not a wind or altitude limit.

Question 4Air Law and Operational Procedures

For a helicopter flight under visual flight rules in controlled airspace, which document is the primary authority for the flight and must be carried on board?

  1. The aircraft maintenance schedule only
  2. The pilot's logbook only
  3. The certificate of registration and certificate of airworthiness Correct answer.
  4. The passenger manifest only

Explanation

The certificate of registration and the certificate of airworthiness establish the legal status of the aircraft and must be on board for the flight. The maintenance schedule and logbook are records kept elsewhere. The manifest is an operational document but does not establish airworthiness or registration.

Question 5Air Law and Operational Procedures

What does a red light signal directed at a helicopter on the ground from the aerodrome control tower mean?

  1. Taxi clear of the landing area
  2. Return to the apron for parking
  3. Stop Correct answer.
  4. Cleared for take-off

Explanation

In the standard light-signal table, a steady red light shown to an aircraft on the ground means stop. A green light would mean cleared for take-off, and a flashing white light would mean return to the starting point. Light signals are used when radio communication fails.

Question 6Air Law and Operational Procedures

Which of the following is the correct action when a helicopter is being refuelled with passengers on board?

  1. Refuelling may proceed with engines running if a fire extinguisher is present
  2. Passengers may remain on board provided no smoking occurs and engines are shut down Correct answer.
  3. Passengers must be disembarked and the rotors stopped before refuelling begins
  4. Refuelling is prohibited whenever passengers are on board regardless of circumstances

Explanation

Refuelling with passengers on board is permitted only under strict conditions: engines and rotors stopped, no smoking, and firefighting equipment positioned. The intent is to control ignition sources. Simply having an extinguisher does not allow refuelling with engines running.

Question 7Air Law and Operational Procedures

What is the standard meaning of a flashing red light directed at a helicopter in flight?

  1. Cleared to land
  2. Land at this aerodrome and proceed to apron
  3. Airport unsafe, do not land
  4. Give way to other aircraft and continue circling Correct answer.

Explanation

For an aircraft in flight, a flashing red light means give way to other aircraft and continue circling. A steady red light means give way and continue circling as well, but the flashing red specifically warns of conflicting traffic. A steady green light means cleared to land.

Question 8Air Law and Operational Procedures

A pilot operating a helicopter under VFR must maintain a minimum flight visibility and cloud clearance in controlled airspace. Which of the following best describes the general principle behind these minima?

  1. They ensure that the helicopter remains within gliding distance of an aerodrome
  2. They ensure that radio communication is always possible
  3. They ensure the pilot can see and avoid other traffic and remain clear of cloud Correct answer.
  4. They guarantee that the helicopter can autorotate safely

Explanation

VFR visibility and cloud-clearance minima exist so that the pilot can see and avoid other aircraft and maintain visual reference with the surface. They are not guarantees of radio coverage, autorotation performance, or glide distance. The minima are expressed in terms of visibility and distance from cloud.

Question 9Air Law and Operational Procedures

A helicopter pilot is planning a flight and the destination aerodrome has no published instrument approach and the weather is marginal. Which action best reflects sound operational decision-making under the NCAA rules?

  1. Obtain a forecast and, if conditions are below VFR minima, delay or cancel the flight Correct answer.
  2. Depart and divert only if weather deteriorates en route
  3. Depart and rely on special VFR clearance at the destination
  4. Depart and maintain VFR at all times by flying lower if cloud is encountered

Explanation

The pilot-in-command must ensure that the flight can be conducted in accordance with the applicable minima before departure. If the forecast indicates conditions below VFR minima at the destination, the flight should be delayed or cancelled. Relying on an en-route diversion or descending below cloud is not an acceptable substitute for pre-flight planning.

Question 10Air Law and Operational Procedures

A pilot holds a PPL(H) and wishes to carry a passenger on a flight that will cross an international border. Which statement is correct regarding licence validity?

  1. The PPL(H) is valid only within the national territory and cannot be used for international flight
  2. An international flight requires an ATPL regardless of the aircraft used
  3. The PPL(H) is valid for international flight provided the pilot meets recency and medical requirements and the aircraft is properly documented Correct answer.
  4. An international flight requires a separate endorsement on the licence for each country overflown

Explanation

A PPL(H) issued in accordance with ICAO Annex 1 standards may be used for international flight provided the pilot meets recency, medical and documentation requirements. No separate endorsement for each country is required. The licence is not restricted to domestic flight by its nature.

Question 11Air Law and Operational Procedures

When a helicopter is operated in accordance with the minimum equipment list (MEL), which principle governs the dispatch decision?

  1. The MEL applies only to commercial operations, not to private flights
  2. Only items listed in the MEL may be deferred, and the associated operational conditions must be met Correct answer.
  3. Any inoperative item may be deferred indefinitely provided the pilot accepts the risk
  4. The MEL allows the pilot to defer any defect that does not affect the engine

Explanation

The MEL is an approved document that identifies which equipment may be inoperative for dispatch, together with the conditions and limitations that apply. Items not listed in the MEL must be serviceable before flight. The pilot cannot extend the MEL by personal judgement.

Question 12Air Law and Operational Procedures

A pilot is planning a flight over a congested area of a city at low level. Which rule applies to minimum heights over congested areas?

  1. The helicopter must maintain a height that allows a safe forced landing without undue hazard to persons or property on the surface Correct answer.
  2. The helicopter may fly at any height provided it remains clear of obstacles
  3. The helicopter must maintain at least 1,500 ft above the highest obstacle
  4. The helicopter may descend below the minimum height only if the pilot holds an instrument rating

Explanation

Over congested areas, the rule requires the pilot to maintain a height from which, if the engine fails, a safe forced landing can be made without undue hazard to persons or property on the surface. The precise numeric minima vary with the state's rules, but the underlying principle is the same. A fixed 1,500 ft figure is not the general rule for helicopters.

Question 13Air Law and Operational Procedures

Which of the following is the correct interpretation of the term 'controlled airspace' in relation to a VFR helicopter flight?

  1. Airspace of defined dimensions within which air traffic control service is provided to controlled flights Correct answer.
  2. Airspace in which only commercial air transport may operate
  3. Airspace in which radio communication is optional
  4. Airspace in which all flights must be conducted under instrument flight rules

Explanation

Controlled airspace is airspace of defined dimensions within which an air traffic control service is provided to controlled flights in accordance with the applicable classification. VFR flights may operate in some classes of controlled airspace subject to clearance and equipment requirements. It is not reserved exclusively for IFR or commercial transport.

Question 14Air Law and Operational Procedures

A pilot is conducting a flight and the radio fails in controlled airspace. Which action is most consistent with standard procedures?

  1. Immediately descend below controlled airspace and continue visually
  2. Continue the flight while squawking the appropriate communication-failure code and following the published lost-communication procedure Correct answer.
  3. Land at the nearest available site and abandon the flight
  4. Turn back to the departure aerodrome without notifying anyone

Explanation

On radio failure in controlled airspace, the pilot should set the transponder to the designated communication-failure code where the aircraft is so equipped and follow the published lost-communication procedure for the airspace. This allows ATC to identify the aircraft and manage traffic. Immediate descent or unauthorised diversion increases collision risk.

Question 15Air Law and Operational Procedures

What is the significance of the 'certificate of airworthiness' for a helicopter operated on a private flight?

  1. It certifies that the helicopter conforms to its type design and is in a condition for safe operation Correct answer.
  2. It certifies that the operator holds an air operator certificate
  3. It certifies that the pilot is competent to fly the helicopter
  4. It certifies that the helicopter has been insured for the flight

Explanation

The certificate of airworthiness attests that the aircraft conforms to its approved type design and is maintained in a condition for safe operation. It is issued following type certification and continued maintenance. It does not certify pilot competence, insurance, or operator status.

Question 16Air Law and Operational Procedures

A pilot is planning a flight that will pass through airspace where a transponder is required. The helicopter is not equipped with a serviceable transponder. What is the correct course of action?

  1. Proceed and inform ATC on first contact that the transponder is unserviceable
  2. Proceed only if the flight can be conducted without entering that airspace or a specific exemption is obtained Correct answer.
  3. Proceed and squawk the emergency code throughout the flight
  4. Proceed and switch off all electrical equipment to avoid interference

Explanation

Where a transponder is mandated for the airspace, an aircraft without a serviceable unit may not enter unless an exemption or specific authorisation applies. The pilot should plan a route that avoids the airspace or obtain the required approval. Simply informing ATC does not remove the requirement.

Question 17Air Law and Operational Procedures

Which of the following best describes the pilot-in-command's responsibility regarding the carriage of dangerous goods on a private helicopter flight?

  1. Dangerous goods may be carried only if the pilot holds a commercial licence
  2. Dangerous goods may be carried freely on private flights
  3. Dangerous goods may be carried only in accordance with the applicable regulations and with the pilot's awareness of the associated risks Correct answer.
  4. Dangerous goods may never be carried on any helicopter flight

Explanation

Carriage of dangerous goods is governed by the applicable regulations, which set out permitted items, packaging, stowage and notification requirements. The pilot must be aware of what is on board and the associated risks. Private flights are not exempt from these rules, and a blanket prohibition is incorrect.

Question 18Air Law and Operational Procedures

A helicopter pilot is asked to operate a flight for which the calculated mass and balance places the centre of gravity outside the approved limits. What is the correct action?

  1. Operate the flight and note the deviation in the aircraft log
  2. Operate the flight and adjust the cyclic trim to compensate
  3. Operate the flight and reduce airspeed to remain within limits
  4. Do not operate the flight until the loading is adjusted to bring the centre of gravity within limits Correct answer.

Explanation

The centre of gravity must remain within the approved limits for the entire flight; exceeding them can degrade controllability and performance. The correct action is to adjust the loading, fuel or passengers until the centre of gravity is within limits. Trim or airspeed changes cannot compensate for an out-of-limits loading condition.

Question 19Air Law and Operational Procedures

What is the purpose of the 'authority of the pilot-in-command' provision in the regulations?

  1. To allow the pilot to delegate responsibility to a passenger
  2. To allow the pilot to operate without a valid licence in an emergency
  3. To allow the pilot to deviate from rules when necessary in the interests of safety Correct answer.
  4. To allow the pilot to ignore ATC instructions at any time

Explanation

The pilot-in-command has final authority over the aircraft and may deviate from the rules to the extent necessary in an emergency to preserve safety. This authority is not a licence to disregard ATC or to delegate responsibility. It exists to cover situations not anticipated by the rules.

Question 20Air Law and Operational Procedures

A helicopter pilot intends to land at an aerodrome where the tower is in operation. Which of the following is required before entering the aerodrome traffic circuit?

  1. Only a radio call announcing the intention to land
  2. A filed flight plan
  3. A written permission from the aerodrome operator
  4. A clearance from the tower and two-way radio communication Correct answer.

Explanation

At a controlled aerodrome, entry into the traffic circuit requires a clearance from the tower and established two-way radio communication. A radio call announcing intentions is not a substitute for a clearance. A flight plan or written permission is not the controlling requirement.

Question 21Air Law and Operational Procedures

In the context of helicopter operations, what does the term 'operations manual' typically contain for a commercial operator?

  1. The aircraft maintenance schedule only
  2. The aerodrome's rescue and firefighting plan
  3. The pilot's personal logbook entries
  4. The instructions and information necessary for the conduct of operations, including procedures and limitations Correct answer.

Explanation

The operations manual sets out the procedures, limitations and instructions necessary for the conduct of operations, and it must be approved where required. It is distinct from the maintenance schedule, the pilot's logbook and the aerodrome emergency plan. It provides the operational framework for the operator's flights.

Question 22Air Law and Operational Procedures

A pilot is planning a flight at night under VFR. Which additional equipment is generally required for night operations in a helicopter?

  1. A serviceable landing light and navigation lights Correct answer.
  2. A weather radar
  3. A flight data recorder
  4. A second altimeter only

Explanation

Night VFR operations require serviceable navigation lights and, for helicopters, a landing light to illuminate the landing area. A flight data recorder or weather radar is not generally required for private night flights. A second altimeter is not the defining night requirement.

Question 23Air Law and Operational Procedures

A helicopter is operating under VFR in class G airspace. Which statement best describes the pilot's obligations regarding traffic separation?

  1. The pilot must file a flight plan before entering the airspace
  2. The pilot is responsible for collision avoidance and must maintain a listening watch on the appropriate frequency where required Correct answer.
  3. The pilot may enter the airspace only if equipped with a serviceable transponder
  4. The pilot must obtain a clearance from ATC before entering the airspace

Explanation

In class G airspace, separation is not provided by ATC, so the pilot is responsible for see-and-avoid and collision avoidance. A listening watch on the appropriate frequency is required where the airspace rules specify it. A clearance, flight plan or transponder is not a general condition for entry into class G.

Question 24Air Law and Operational Procedures

A pilot is operating a helicopter on a flight where the destination aerodrome's weather is reported as below VFR minima, but the pilot holds a valid instrument rating and the helicopter is instrument-equipped. Which statement is most accurate?

  1. The pilot may land visually by reducing speed and descending through cloud
  2. The pilot may conduct an instrument approach and land provided the approach and aerodrome are approved for the operation and the required minima are met Correct answer.
  3. The pilot may descend below VFR minima at any aerodrome without an instrument approach procedure
  4. The pilot may not conduct the flight at all because the destination is below VFR minima

Explanation

An instrument-rated pilot in an appropriately equipped helicopter may conduct an instrument approach at an aerodrome approved for such operations, provided the applicable approach minima and any required authorisations are met. Descending through cloud without an approved procedure is not permitted. A blanket prohibition is incorrect where the rating and equipment allow the operation.

Question 25Air Law and Operational Procedures

A pilot is considering whether a flight can be conducted under 'special VFR'. Which condition is most consistent with the purpose of special VFR?

  1. It allows an IFR flight to cancel its instrument flight plan without notifying ATC
  2. It allows a pilot to depart without any weather information
  3. It allows a helicopter to operate in class A airspace without a clearance
  4. It allows a VFR flight to operate within a control zone when the weather is below VFR minima, subject to an ATC clearance and specified conditions Correct answer.

Explanation

Special VFR is a clearance that permits a VFR flight to operate within a control zone when the reported weather is below the normal VFR minima, subject to conditions such as remaining clear of cloud and in sight of the surface, and to ATC clearance. It does not apply to class A airspace, which is IFR only. It is not a substitute for weather information.

Question 26Air Law and Operational Procedures

Under ICAO Annex 2 rules, a helicopter pilot on a private flight is required to submit a flight plan before departing on a flight that will cross an international boundary. Which statement best describes the pilot's obligation in this situation?

  1. A flight plan must be filed and, unless the flight is conducted under a repetitive plan, activated before departure Correct answer.
  2. A flight plan is required only when the flight will enter controlled airspace
  3. A flight plan is only recommended and may be filed after departure by radio
  4. A flight plan is not required because private flights are exempt from international notification

Explanation

Annex 2 requires that a flight plan be submitted for any flight crossing an international border, and it must be filed before departure so that search and rescue and border authorities are informed. A repetitive flight plan may substitute for individual filing, but the plan must still be activated in accordance with the prescribed procedures.

Question 27Air Law and Operational Procedures

A helicopter pilot is preparing to depart from an aerodrome and the latest reported surface wind is 210 degrees at 12 knots. The pilot intends to use a runway with a magnetic bearing of 240 degrees. Which statement correctly describes the wind component affecting the take-off?

  1. It is a headwind component of approximately 11 knots with a crosswind of about 6 knots Correct answer.
  2. It is a direct crosswind of 12 knots with no headwind component
  3. It is a tailwind component of approximately 11 knots with a crosswind of about 6 knots
  4. It is a headwind component of approximately 6 knots with a crosswind of about 11 knots

Explanation

The wind is 30 degrees off the runway heading, so the headwind component equals 12 times the cosine of 30 degrees, about 10.4 knots, and the crosswind equals 12 times the sine of 30 degrees, about 6 knots. Because the wind direction is within 90 degrees of the runway heading, the component along the runway is a headwind.

Question 28Air Law and Operational Procedures

A pilot of a helicopter with a maximum certificated take-off mass of 2,000 kg is planning a flight and must determine the applicable minimum fuel requirement. Which statement best reflects the general regulatory principle for a VFR private flight?

  1. Fuel must be sufficient to reach the destination plus a reserve of 20 minutes at maximum continuous power
  2. Fuel must be sufficient for the planned flight plus a reserve of 45 minutes at holding speed
  3. Fuel must be sufficient to fly to the destination and then for a further 30 minutes at cruising speed Correct answer.
  4. Fuel must be sufficient only for the planned trip with no additional reserve

Explanation

For VFR flights in this class, the standard planning reserve is fuel for a further 30 minutes at normal cruising speed after reaching the destination. This reserve covers unforeseen delays such as weather or traffic without compromising safety.

Question 29Air Law and Operational Procedures

A helicopter pilot is operating at an aerodrome with an operating control tower and receives a clearance to land on a runway that the pilot considers unsafe because of standing water. Which action is most consistent with the authority of the pilot-in-command?

  1. The pilot may decline the clearance and request an alternative, because the PIC retains final authority for the safety of the flight Correct answer.
  2. The pilot must land as cleared and report the unsafe condition after landing
  3. The pilot must cancel the flight and land at another aerodrome without informing ATC
  4. The pilot must accept the clearance because ATC has responsibility for runway selection

Explanation

The pilot-in-command has final authority over the operation of the aircraft and may deviate from a clearance when safety requires it, notifying ATC as soon as practicable. ATC issues clearances but does not relieve the pilot of responsibility for accepting a safe landing surface.

Question 30Air Law and Operational Procedures

A helicopter pilot is planning a flight that will transit airspace where a Mode C transponder is required. The helicopter is fitted with a serviceable transponder but the altitude encoding function has failed. Which statement best describes the correct operational decision?

  1. The flight may proceed only if the pilot remains clear of all controlled airspace for the entire route
  2. The flight may not proceed under any circumstances until the encoding function is repaired
  3. The flight may proceed because a transponder is fitted, regardless of the encoding capability
  4. The flight may proceed provided ATC grants an exemption and the pilot advises of the equipment status Correct answer.

Explanation

Where altitude encoding is required, an aircraft without a serviceable encoding function may generally operate only with prior permission from the controlling authority, and the pilot should inform ATC of the limitation. The requirement is about capability, not merely the presence of a transponder.

Question 31Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

In a semi-rigid (teetering) two-blade main rotor head, what component allows the blades to flap about a common hinge while equalising lift between the two sides?

  1. A swashplate with three servo inputs
  2. A teetering hinge with an underslung or trunnion arrangement Correct answer.
  3. A freewheeling unit in the transmission
  4. A lead-lag damper on each blade grip

Explanation

Semi-rigid heads use a single teetering hinge about which both blades flap together, and the hub is usually underslung so the rotor can also feather for control. This arrangement equalises lift because when one blade flaps up the other flaps down about the same hinge. Lead-lag dampers and swashplates serve different functions and do not provide the teetering freedom.

Question 32Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

Which statement best describes the function of the swashplate assembly in a helicopter control system?

  1. It absorbs rotor torque during an autorotation
  2. It limits the maximum rotor RPM during engine failure
  3. It transfers non-rotating control inputs from the servos to the rotating blade pitch links Correct answer.
  4. It converts collective lever movement into tail rotor pitch changes only

Explanation

The swashplate has a stationary ring moved by the cyclic and collective servos and a rotating ring that turns with the mast, transferring pitch inputs through the pitch links to each blade. Tilting the plate produces cyclic pitch change while raising or lowering it produces collective pitch change. It does not absorb torque or govern RPM.

Question 33Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

During a steady autorotation, what provides the driving force that keeps the main rotor turning?

  1. Tail rotor thrust acting through the fuselage
  2. Residual torque from the freewheeling unit
  3. Upward airflow through the rotor disc producing an autorotative driving region Correct answer.
  4. Engine idle power transmitted through the clutch

Explanation

In autorotation the upward relative airflow through the descending rotor produces an inboard driving region where the resultant aerodynamic force has a forward component that sustains rotation. The freewheeling unit disconnects the engine so no torque is transmitted. Engine idle, clutch, and tail rotor thrust do not drive the main rotor.

Question 34Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the primary purpose of the freewheeling unit (sprag clutch) in a helicopter transmission?

  1. To allow the rotor to rotate faster than the engine during autorotation Correct answer.
  2. To provide a second power path if the main gearbox fails
  3. To reduce tail rotor drive shaft vibration
  4. To synchronise the main and tail rotor RPM

Explanation

The freewheeling unit transmits engine torque to the rotor in one direction only, so when engine power is lost the rotor can overrun the engine and continue turning. This is essential for entering autorotation. It does not synchronise rotors, damp vibration, or provide a redundant power path.

Question 35Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

A pilot lowers the collective lever while keeping the throttle matched. What is the immediate effect on main rotor blade pitch and lift?

  1. Blade pitch decreases and lift decreases Correct answer.
  2. Blade pitch increases and lift increases
  3. Blade pitch decreases but lift stays constant
  4. Blade pitch increases but lift stays constant

Explanation

Lowering the collective reduces the pitch angle of all main rotor blades simultaneously, which reduces the angle of attack and therefore the lift produced. The rotor thrust decreases and the helicopter descends or accelerates depending on attitude. Pitch and lift change together because they are directly linked.

Question 36Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What causes dissymmetry of lift on a single main rotor helicopter in forward flight?

  1. The advancing blade sees higher relative airspeed than the retreating blade Correct answer.
  2. The rotor turns at a different RPM on each side of the mast
  3. The tail rotor produces a rolling moment on the fuselage
  4. The retreating blade has a larger chord than the advancing blade

Explanation

In forward flight the advancing blade moves into the airflow and the retreating blade moves away from it, so the advancing blade experiences a higher relative airspeed and produces more lift. Blade flapping and cyclic feathering equalise lift across the disc. Blade chord and rotor RPM are the same on both sides.

Question 37Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

Why does a helicopter with a counter-clockwise rotating main rotor (viewed from above) require left cyclic input in forward flight to prevent a roll to the right?

  1. The tail rotor thrust line is above the centre of gravity
  2. Flapping of the advancing blade causes the lift vector to tilt toward the retreating side Correct answer.
  3. The horizontal stabiliser produces a downward force
  4. The engine torque reaction increases with airspeed

Explanation

As forward speed increases, the advancing blade flaps up and the retreating blade flaps down, tilting the rotor thrust vector toward the retreating side. This produces a roll toward the retreating side, so the pilot applies cyclic into the advancing side to hold attitude. Tail rotor thrust and engine torque affect yaw and lateral trim but not this flapping-induced roll.

Question 38Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is translational lift?

  1. The lift generated by the tail rotor during a pedal turn
  2. The lift produced by the horizontal stabiliser at high speed
  3. The extra lift gained as the rotor moves out of its own downwash into undisturbed air Correct answer.
  4. The lift increase caused by raising collective pitch in the hover

Explanation

As the helicopter gains forward speed, the rotor disc moves out of the recirculating downwash it created in the hover and encounters undisturbed air, improving rotor efficiency and lift. This is translational lift and it explains why less power is needed once forward speed builds. Collective pitch, stabiliser, and tail rotor do not produce it.

Question 39Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

Which condition describes effective translational lift (ETL)?

  1. The speed at which retreating blade stall begins
  2. The speed at which the helicopter first leaves the ground
  3. The speed at which the tail rotor becomes ineffective
  4. The speed at which the rotor fully escapes its downwash and needs no further power reduction Correct answer.

Explanation

Effective translational lift is reached when the rotor disc has largely moved clear of its own downwash, giving a marked improvement in efficiency beyond which little further lift gain occurs. It is typically around 16 to 24 knots depending on type and conditions. It is not a takeoff speed, tail rotor limit, or stall onset.

Question 40Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the main hazard of entering vortex ring state?

  1. Loss of tail rotor effectiveness in a crosswind
  2. Sudden increase in rotor RPM above the green arc
  3. High descent rate with reduced rotor efficiency and possible loss of control Correct answer.
  4. Rapid uncommanded yaw to the left

Explanation

Vortex ring state occurs during a powered descent at low airspeed when the rotor recirculates its own tip vortices, causing turbulence, loss of lift, and a high sink rate. Recovery requires forward cyclic to gain airspeed and exit the condition. It does not primarily cause yaw or rotor overspeed.

Question 41Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

In a helicopter, what does the term 'retreating blade stall' describe?

  1. Stall of the advancing blade at high collective settings
  2. Stall of the tail rotor blades during a hover
  3. Stall of the main blades during autorotation
  4. Stall of the retreating blade at high forward speed where its relative airspeed is low Correct answer.

Explanation

At high forward speed the retreating blade's relative airspeed falls, so to produce lift it needs a high angle of attack and can exceed the stall angle. This produces vibration and a pitch-up and roll toward the retreating side. It is a high-speed phenomenon of the retreating blade, not the advancing blade or tail rotor.

Question 42Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

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

  1. To reduce main rotor RPM during descent
  2. To provide additional lift in forward flight
  3. To counteract main rotor torque and provide directional control Correct answer.
  4. To drive the main rotor through the tail drive shaft

Explanation

Main rotor torque reaction tends to rotate the fuselage in the opposite direction to the rotor, and the tail rotor produces thrust to oppose this and to allow yaw control through the pedals. It does not provide lift, drive the main rotor, or govern RPM.

Question 43Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

Loss of tail rotor effectiveness (LTE) is most likely to occur under which combination of conditions?

  1. Autorotation with the collective fully lowered
  2. Low airspeed with a left crosswind and high power Correct answer.
  3. Steady hover into a strong headwind
  4. High forward speed with a strong headwind

Explanation

LTE arises when the tail rotor is required to produce high thrust at low airspeed, often with a crosswind from certain directions, and the tail rotor airflow is disrupted. It leads to an uncommanded yaw rate that may not be recoverable with pedal alone. High forward speed and autorotation are not the classic setup.

Question 44Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the function of a horizontal stabiliser (stabilator) on many helicopters?

  1. To counteract main rotor torque in the hover
  2. To reduce rotor RPM in autorotation
  3. To increase tail rotor thrust at low speed
  4. To improve pitch stability and trim in forward flight Correct answer.

Explanation

The horizontal stabiliser produces a downward or trimming force at speed that improves pitch stability and reduces nose-down tendencies as airspeed changes. Some types have a movable stabilator that is scheduled with airspeed and collective. It does not counter torque or affect rotor RPM.

Question 45Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What happens to the centre of gravity limits if a helicopter is loaded beyond its aft CG limit?

  1. The rotor RPM automatically increases to compensate
  2. Cyclic authority may be insufficient and controllability is reduced Correct answer.
  3. The tail rotor becomes more effective in a hover
  4. The helicopter becomes more nose-heavy and stable

Explanation

Loading beyond the aft CG limit moves the centre of gravity rearward so the cyclic may run out of forward travel, reducing controllability and increasing the risk of a tail-low attitude. The helicopter does not become more stable, nor does RPM or tail rotor effectiveness improve.

Question 46Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

Which of the following best describes the purpose of the centrifugal force acting on main rotor blades?

  1. It pulls the blades outward and stiffens them against flapping Correct answer.
  2. It drives the blades through the autorotative region
  3. It pulls the blades inward toward the mast during rotation
  4. It produces the torque reaction that the tail rotor counters

Explanation

As the rotor turns, centrifugal force acts outward along each blade, tending to straighten and stiffen it and resisting flapping and coning. This is why blades can be relatively flexible yet hold their shape in flight. It is not an inward force, torque reaction, or the source of autorotative drive.

Question 47Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the primary cause of coning of the main rotor blades?

  1. Tail rotor thrust pulling the fuselage sideways
  2. Combination of lift acting upward and centrifugal force acting outward on each blade Correct answer.
  3. Asymmetric flapping between advancing and retreating blades
  4. Reduction of rotor RPM below the green arc

Explanation

Each blade is acted on by lift upward and centrifugal force outward, and the resultant tilts the blade upward into a cone shape. The faster the rotor turns, the greater the centrifugal force and the smaller the coning angle. Tail rotor thrust and RPM excursions do not define coning.

Question 48Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

During autorotation, what is the function of the 'driven region' of the rotor disc?

  1. It is the region where blade pitch is zero
  2. It is the region where the tail rotor provides thrust
  3. It produces the driving force that keeps the rotor turning
  4. It consumes energy and produces drag near the blade root Correct answer.

Explanation

The rotor disc in autorotation is divided into a driven region near the root where the airflow opposes rotation and drag is produced, a driving region that sustains rotation, and a stalled region near the tip. The driven region consumes energy rather than producing drive. It is not a zero-pitch region or a tail rotor function.

Question 49Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the effect of increasing density altitude on helicopter performance?

  1. Only the tail rotor is affected
  2. Rotor efficiency and engine power both decrease Correct answer.
  3. Only the engine is affected, rotor efficiency is unchanged
  4. Rotor and engine performance improve because air is thinner

Explanation

Higher density altitude means thinner air, which reduces both the lift the rotor can produce and the power the engine can develop. This degrades hover ceiling, climb rate, and payload capability. Both rotor and engine are affected, not just one component.

Question 50Helicopter General Knowledge (Airframe, Systems, Rotor Dynamics, Powerplant)

What is the purpose of the engine governor (throttle correlator) in a piston helicopter?

  1. To limit the maximum altitude the helicopter can reach
  2. To control tail rotor pitch during pedal turns
  3. To engage the freewheeling unit during autorotation
  4. To maintain rotor RPM by adjusting throttle as collective pitch changes Correct answer.

Explanation

The governor or correlator adjusts engine throttle automatically as collective pitch changes so that rotor RPM remains within limits. This reduces pilot workload and prevents RPM droop or overspeed. It does not limit altitude, control tail rotor pitch, or engage the freewheeling unit.