UK CAA PPL(H) Principles of Flight (082) — Information & Free Practice

About UK CAA PPL(H) Principles of Flight (082)

UK CAA PPL(H) Principles of Flight (082) · GB

Key exam facts

Provider

UK Civil Aviation Authority (CAA) owns and administers the GA theoretical knowledge e-Exams. Training organisations manage local bookings; CAA-authorised Ground Examiners conduct the examinations.

Format

Computer-delivered multiple-choice theoretical knowledge examination through the CAA GA e-Exams system, conducted at the training organisation under a Ground Examiner.

Time limit

The examination time limit is confirmed by the Ground Examiner in the pre-examination briefing (Standards Document 11, 9.1.17(b)). The checked public CAA subject outline, candidate/organisation guides and examination procedures do not publish a numeric duration for subject 082; confirm the actual answering time with the training organisation.

Passing score

At least 75% of the marks allocated to the examination paper; no penalty marking (FCL.025(b)(1)).

Exam fee

GBP £14.28 per online PPL examination paper is payable to the CAA by the approved training school under ORS5 No. 446, section 6.3, effective 1 April 2026. This is the CAA paper charge, not a published all-inclusive candidate price; ask the training organisation for its total charge, including any local administration or resit charges.

Topics covered

• Subsonic aerodynamics

  • Basic concepts, laws and definitions
  • Conversion of units
  • Definitions and basic concepts about air: (a) the atmosphere and International Standard Atmosphere; (b) density; (c) influence of pressure and temperature on density.
  • Newton’s laws: (a) Newton’s second law: Momentum equation; (b) Newton’s third law: action and reaction.
  • Basic concepts about airflow: (a) steady airflow and unsteady airflow; (b) Bernoulli’s equation; (c) static pressure, dynamic pressure, total pressure and stagnation point; (d) TAS and IAS; (e) two-dimensional airflow and three-dimensional airflow; (f) viscosity and boundary layer.
  • Two-dimensional airflow
  • Aerofoil section geometry: (a) aerofoil section; (b) chord line, thickness and thickness to chord ratio of a section; (c) camber line and camber; (d) symmetrical and asymmetrical aerofoils sections.
  • Aerodynamic forces on aerofoil elements: (a) angle of attack; (b) pressure distribution; (c) lift and lift coefficient (d) relation lift coefficient: angle of attack; (e) profile drag and drag coefficient; (f) relation drag coefficient: angle of attack; (g) resulting force, centre of pressure and pitching moment.
  • Stall: (a) boundary layer and reasons for stalling; (b) variation of lift and drag as a function of angle of attack; (c) displacement of the centre of pressure and pitching moment.
  • Disturbances due to profile contamination: (a) ice contamination; (b) ice on the surface (frost, snow and clear ice).
  • The three-dimensional airflow round a wing and a fuselage
  • The wing: (a) planform, rectangular and tapered wings; (b) wing twist.
  • Airflow pattern and influence on lift: (a) span wise flow on upper and lower surface; (b) tip vortices; (c) span-wise lift distribution.
  • Induced drag: causes and vortices
  • The airflow round a fuselage: (a) components of a fuselage; (b) parasite drag; (c) variation with speed.

• Transonic aerodynamics and compressibility effects

  • Airflow velocities
  • Airflow speeds: (a) speed of sound; (b) subsonic, high subsonic and supersonic flows.
  • Shock waves: (a) compressibility and shock waves; (b) the reasons for their formation at upstream high subsonic airflow; (c) their effect on lift and drag.
  • Influence of wing planform: sweep-angle

• Rotorcraft types

  • Rotorcraft
  • Rotorcraft types: (a) autogyro; (b) helicopter.
  • Helicopters
  • Helicopters configurations: the single main rotor helicopter
  • The helicopter, characteristics and associated terminology: (a) general lay-out, fuselage, engine and gearbox; (b) tail rotor, fenestron and NOTAR; (c) engines (reciprocating and turbo shaft engines); (d) power transmission; (e) rotor shaft axis, rotor hub and rotor blades; (f) rotor disc and rotor disc area; (g) teetering rotor (two blades) and rotors with more than two blades; (h) skids and wheels; (i) helicopter axes and fuselage centre line; (j) roll axis, pitch axis and normal or yaw axis; (k) gross mass, gross weight and disc loading.

• Main rotor aerodynamics

  • Hover flight outside ground effect
  • Airflow through the rotor discs and round the blades: (a) circumferential velocity of the blade sections; (b) induced airflow, through the disc and downstream; (c) downward fuselage drag; (d) equilibrium of rotor thrust, weight and fuselage drag; (e) rotor disc induced power; (f) relative airflow to the blade; (g) pitch angle and angle of attack of a blade section; (h) lift and profile drag on the blade element; (i) resulting lift and thrust on the blade and rotor thrust; (j) collective pitch angle changes and necessity of blade feathering; (k) required total main rotor-torque and rotor-power; (l) influence of the air density.
  • Anti-torque force and tail rotor: (a) force of tail rotor as a function of main rotor- torque; (b) anti-torque rotor power; (c) necessity of blade feathering of tail rotor blades and yaw pedals.
  • Maximum hover altitude OGE: (a) total power required and power available; (b) maximum hover altitude as a function of pressure altitude and OAT.
  • Vertical climb
  • Relative airflow and angles of attack: (a) climb velocity VC, induced and relative velocity and angle of attack; (b) collective pitch angle and blade feathering.
  • Power and vertical speed: (a) induced power, climb power and profile power; (b) total main rotor power and main rotor torque; (c) tail rotor power; (d) total power requirement in vertical flight.
  • Forward flight
  • Airflow and forces in uniform inflow distribution: (a) assumption of uniform inflow distribution on rotor disc; (b) advancing blade (90°) and retreating blade (270°); (c) airflow velocity relative to the blade sections, area of reverse flow; (d) lift on the advancing and retreating blades at constant pitch angles; (e) necessity of cyclic pitch changes; (f) compressibility effects on the advancing blade tip and speed limitations; (g) high angle of attack on the retreating blade, blade stall and speed limitations; (h) thrust on rotor disc and tilt of thrust vector; (i) vertical component of the thrust vector and gross weight equilibrium; (j) horizontal component of the thrust vector and drag equilibrium.
  • The flare (power flight): (a) thrust reversal and increase in rotor thrust; (b) increase of rotor RPM on non governed rotor.
  • Power and maximum speed: (a) induced power as a function of helicopter speed; (b) rotor profile power as a function of helicopter speed; (c) fuselage drag and parasite power as a function of forward speed; (d) tail rotor power and power ancillary equipment; (e) total power requirement as a function of forward speed; (f) influence of helicopter mass, air density and drag of additional external equipment; (g) translational lift and influence on power required.
  • Hover and forward flight in ground effect
  • Airflow in ground effect and downwash: rotor power decrease as a function of rotor height above the ground at constant helicopter mass
  • Vertical descent
  • Vertical descent, power on: (a) airflow through the rotor, low and moderate descent speeds; (b) vortex ring state, settling with power and consequences.
  • Autorotation: (a) collective lever position after failure; (b) up flow through the rotor, auto-rotation and anti- autorotation rings; (c) tail rotor thrust and yaw control; (d) control of rotor RPM with collective lever; (e) landing after increase of rotor thrust by pulling collective and reduction in vertical speed.
  • Forward flight: Autorotation
  • Airflow through the rotor disc: (a) descent speed and up flow through the disc; (b) the flare, increase in rotor thrust, reduction of vertical speed and ground speed.
  • Flight and landing: (a) turning; (b) flare; (c) autorotative landing; (d) height or velocity avoidance graph and dead man’s curve.

• Main rotor mechanics

  • Flapping of the blade in hover
  • Forces and stresses on the blade: (a) centrifugal force on the blade and attachments; (b) limits of rotor RPM; (c) lift on the blade and bending stresses on a rigid attachment; (d) the flapping hinge of the articulated rotor and flapping hinge offset; (e) the flapping of the hinge less rotor and flexible element.
  • Coning angle in hover: (a) lift and centrifugal force in hover and blade weight negligible (b) flapping, tip path plane and disc area.
  • Flapping angles of the blade in forward flight
  • Forces on the blade in forward flight without cyclic feathering: (a) aerodynamic forces on the advancing and retreating blades without cyclic feathering; (b) periodic forces and stresses, fatigue and flapping hinge; (c) phase lag between the force and the flapping angle (about 90°); (d) flapping motion of the hinged blades and tilting of the cone and flap back of rotor; (e) rotor disc attitude and thrust vector tilt.
  • Cyclic pitch (feathering) in helicopter mode, forward flight: (a) necessity of forward rotor disc tilt and thrust vector tilt; (b) flapping and tip path plane, virtual rotation axis or no flapping axis and plane of rotation; (c) shaft axis and hub plane; (d) cyclic pitch change (feathering) and rotor thrust vector tilt; (e) collective pitch change, collective lever, swash plate, pitch link and pitch horn; (f) cyclic stick, rotating swash plate and pitch link movement and phase angle.
  • Blade lag motion
  • Forces on the blade in the disc plane (tip path plane) in forward flight: (a) forces due to the Coriolis effect because of the flapping; (b) alternating stresses and the need of the drag or lag hinge.
  • The drag or lag hinge: (a) the drag hinge in the fully articulated rotor; (b) the lag flexure in the hinge less rotor; (c) drag dampers.
  • Ground resonance: (a) blade lag motion and movement of the centre of gravity of the blades and the rotor; (b) oscillating force on the fuselage; (c) fuselage, undercarriage and resonance.
  • Rotor systems
  • See-saw or teetering rotor
  • Fully articulated rotor: (a) three hinges arrangement; (b) bearings and elastomeric hinges.
  • Hinge less rotor and bearing less rotor
  • Blade sailing: (a) low rotor RPM and effect of adverse wind; (b) minimising the danger; (c) droop stops.
  • Vibrations due to main rotor: (a) origins of the vibrations: in plane and vertical; (b) blade tracking and balancing.

• Tail rotors

  • Conventional tail rotor
  • Rotor description: (a) two-blades tail rotors with teetering hinge; (b) rotors with more than two blades; (c) feathering bearings and flapping hinges; (d) dangers to people and to the tail rotor, rotor height and safety.
  • Aerodynamics: (a) induced airflow and tail rotor thrust; (b) thrust control by feathering, tail rotor drift and roll; (c) effect of tail rotor failure and vortex ring.
  • The fenestron: technical lay-out
  • The NOTAR: technical lay-out
  • Vibrations: high frequency vibrations due to the tail rotors

• Equilibrium, stability and control

  • Equilibrium and helicopter attitudes
  • Hover: (a) forces and equilibrium conditions; (b) helicopter pitching moment and pitch angle; (c) helicopter rolling moment and roll angle.
  • Forward flight: (a) forces and equilibrium conditions; (b) helicopter moments and angles; (c) effect of speed on fuselage attitude.
  • Control
  • Control power (a) fully articulated rotor; (b) hinge less rotor; (c) teetering rotor.
  • Static and dynamic roll over

• Helicopter performances

  • Engine performances
  • Piston engines: (a) power available; (b) effects of density altitude.
  • Turbine engines: (a) power available; (b) effects of ambient pressure and temperature.
  • Helicopter performances
  • Hover and vertical flight: (a) power required and power available; (b) OGE and IGE maximum hover height; (c) influence of AUM, pressure, temperature and density.
  • Forward flight: (a) maximum speed; (b) maximum rate of climb speed; (c) maximum angle of climb speed; (d) range and endurance; (e) influence of AUM, pressure, temperature and density.
  • Manoeuvring: (a) load factor; (b) bank angle and number of g’s; (c) manoeuvring limit load factor.
  • Special conditions: (a) operating with limited power; (b) over pitch and over torque.

How to prepare

Work through the topics, read the explanation after each answer, and revisit the areas where you miss questions. Use the official outline and reference materials below to guide your study.

These independent practice questions are not actual exam items and do not guarantee a passing result.

Frequently asked questions

Official sources and references

• CAA CAP2090H — Principles of Flight Helicopter

  pp. 1–7, Helicopter PPL column

• CAA UK Aircrew Regulation consolidation

  p. 210, AMC1 FCL.215; FCL.235(a)(1)

• CAA UK Aircrew Regulation consolidation

  p. 79, FCL.025(b)(1)

• CAA Standards Document 11

  p. 16, 9.1.17(b)

• CAA Standards Document 11

  p. 16, 9.1.4

• CAA ORS5 No. 446 — Personnel Licensing Scheme of Charges

  p. 20, 6.3

• CAA GA Theoretical Knowledge e-Exams

  GA Theoretical Knowledge e-Exams introduction

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