Principles of Flight for pilots
Why an airplane flies and how it behaves: lift and drag, the stall, high-speed flight, stability and control, flight controls and the loads on the airframe, as EASA ATPL subject 081 examines them.
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Aircraft Axes and Stability Fundamentals
The three axes of rotation and the basic ideas of static and dynamic stability, damping, controllability and relaxed stability.
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Airflow and Bernoulli's Principle
The basic behavior of moving air, covering streamlines, continuity, Bernoulli's principle, static, dynamic and total pressure, the venturi, the stagnation point, relative airflow and air density.
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Airfoil Geometry
The terms used to describe an airfoil section and the angles that define how it meets the airflow, from chord line and camber to angle of attack, angle of incidence and pitch attitude.
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Asymmetric Flight
Flight with one engine inoperative, the yawing and rolling moments, the critical engine, identifying the failed engine and controlling sideslip.
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Boundary Layer
The thin layer of slowed air next to the aircraft skin, laminar and turbulent flow, the transition point, adverse pressure gradient and separation, laminar flow airfoils and vortex generators.
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Buffet and Buffet Margin
Low-speed and high-speed buffet, the buffet onset boundary, the buffet margin required at cruise and the coffin corner at high altitude.
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Control Balance, Tabs and Trim
How hinge moments set control forces, the aerodynamic balances and tabs used to lighten or weight them, and the trim systems that remove steady forces.
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Drag
The types of drag, how parasite and induced drag vary with speed, the drag coefficient, the total drag curve and minimum drag speed, the drag polar and the lift-to-drag ratio.
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Dutch Roll
The coupled yawing and rolling oscillation of swept-wing aircraft: why it happens, what makes it worse, how yaw dampers suppress it and how pilots recover.
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Flutter and Aeroelasticity
How airframe flexibility interacts with aerodynamic loads to cause wing twist, control reversal, flutter and buzz, and how mass balancing prevents them.
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High-Lift Devices
Trailing-edge flaps and leading-edge slats, slots and Krueger flaps: how each works and how they change CLmax, stall angle, drag and pitch.
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High-Speed Flight
Compressibility and Mach number, the transonic and supersonic regimes, shock and expansion waves, shock stall, wave drag and the design features that delay them.
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Induced Drag and Wingtip Vortices
How spanwise flow creates wingtip vortices and downwash, why that produces induced drag, what it depends on, and how elliptical lift, winglets and ground effect reduce it.
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Lateral and Directional Stability
Stability in roll and yaw: sideslip, the fin and weathercocking, dihedral effect and its sources, and the Dutch roll and spiral modes.
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Lift
How a wing produces lift, the lift equation and lift coefficient, the lift curve and CLmax, and the center of pressure, aerodynamic center and pitching moment.
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Load Factor and Flight Envelope
Load factor in maneuvers and gusts, structural limit and ultimate loads, and how the V-n diagram defines the safe flight envelope.
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Longitudinal Stability
Stability in pitch: the tailplane's role, CG, neutral point and static margin, stick forces, maneuver margin and the phugoid and short-period modes.
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Newton's Laws and the Four Forces
Newton's laws applied to flight, the four forces of lift, weight, thrust and drag, and how they balance as forces and couples in steady flight.
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Power Curves and Speed Stability
Thrust and power required and available, the minimum drag and minimum power speeds, excess thrust and power, speed stability and the back of the drag curve.
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Primary Flight Controls
The elevator, ailerons and rudder, combined control surfaces such as stabilators, ruddervators and elevons, and the secondary effects of each control.
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Propeller Aerodynamics
How a propeller blade produces thrust, blade angle, helix angle and pitch, efficiency and power, variable pitch, twisting moments and windmilling.
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Propeller Torque and Slipstream Effects
The left-turning tendencies of a propeller aircraft, torque reaction, spiraling slipstream, P-factor and accelerated slipstream, and how contra-rotation removes them.
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Roll Control, Adverse Yaw and Spoilers
How ailerons and spoilers roll the aircraft, why adverse yaw occurs and how differential and Frise ailerons, interconnects and roll spoilers counter it.
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Spins and Spiral Dives
How a stall becomes a spin, the phases and types of spin, the recovery technique, and how a spiral dive differs.
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Stall
What happens at the critical angle of attack, how stall speed changes with weight, load factor and power, stall warning and wing drop, and how to recover.
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Swept Wings
Why wings are swept, the low-speed penalties of sweep, tip stall and pitch-up, and the fences, vortilons and saw-tooth leading edges used to control them.
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Tail Configurations
Horizontal and vertical stabilizers, conventional, T, H, cruciform and canard layouts, and the deep stall, tailplane stall and fin stall risks they bring.
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Turning Flight
The forces in a turn, how bank angle sets rate and radius of turn, coordination, slips and skids, and steep-turn behavior.
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Wing Planform and Design
How span, area, aspect ratio, taper, sweep, washout and planform shape affect lift, drag, stall behavior and wing loading, and what a hard wing is.
Test yourself on Principles of Flight
The v1prep banks cover this topic in Principles of Flight (081), with a worked explanation for every answer.
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