PRINCIPLES OF FLIGHT [Main Title]

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  • Title: PRINCIPLES OF FLIGHT [Main Title]
  • Film Number: AMY 27
  • Other titles:
  • Summary: Fourteen-part instructional series focusing on the various principles of flight.
  • Description: Reel 1: “Airflow” - Example of how water and air flow are similar and how water can be used to demonstrate the flow of air. Wind tunnel using smoke to show flow of air. “Alice Through The Looking Glass” - young girl sat in front of mirror demonstrating warm air rising from her arm with the help of an optical device – same effect can be obtained by using a heated element. Demonstration of heated air being blow along wind tunnel and effect of a plate being raised into airflow. Spark gap demonstrated and the ripple effect on the airflow. Slow motion film of air flowing over a plate to show turbulent air over plate. Lift and drag demonstrated. “Stalling” - Stalling angle explained. Unstalling explained. Reel 2: Explanation of the effect of air on a body moving through it – every action has an equal and opposite reaction principle. Diagram to show angle of attack. “Resultant Air Force” - direction of airflow, direction of motion, angle of attack produces resultant air force. “Lift and Drag” - explanation of lift and drag and effect of varying the angle of attack. “Pressure Distribution On An Aerofoil” - explanation of the effect of lift on an aerofoil/wing. Comparison of diagrams of a flat plate v aerofoil for lift. Reel 3: “Streamlining” - The effect of streamlining an object to reduce the drag and turbulence caused as it passes through the air. “Fineness ratio” explained and it's effect on reducing turbulence. “Radial Engine Cowling” - effect of a radial engine on the wake and turbulence of an streamlined nacelle and placement of a Townend Ring to reduce turbulence. Townend Ring compared with a NACA cowl. Reel 4: “Cambered Wings” - use of cambered wing to increase the stall angle of a surface. Stalling and unstalling different thickness of cambered wing in wind tunnel. Real life demonstration of stalling on an aircraft wing in flight, fitted with wool tufts over wing area and on vertical rods on leading and trailing edge of wing. How ice build-up affects airflow over wing. Reel 5: “Lift and Drag Coefficients” - summary of the aerofoil and lift and drag explained and the effect of the size of a wing on it's performance. The force on a wing is found to be proportional to the square of its velocity. Explanation of lift and drag, with diagrams of stalling angle. “Stalling Speed” - explanation. “Landing Speed” - explanation. “The Handley-Page Slat” - explanation of effect of additional slat to leading edge to reduce stall/unstall of wing section. Reel 6: “Scale Effect” - “Airflow, Initial Motion” - “Effect of Varying The Wind Speed” - increase of wind speed increases the amount of turbulence flowing over wing section. “Effect Of Size” - increase size of aerofoil reduces stall at similar angle. “Effect Of Air Density” - increase in air density decreases stalling effect.. Reel 7: Drag coefficient of aerofoil and effect of increase of angle of attack. Wind tunnel models. Wind tunnel full scale aircraft. High pressure wind tunnel. “Scale Effect on Skin friction. Increased importance of a smooth surface at high speed.” Boundary layer explained. Reel 8: “Aspect Ratio” - Span, Chord, and aspect ratio. Wing tip vortices explained. Induced drag explained. Section drag explained. Total Drag calculated by adding Skin Friction and Form Drag and Induced Drag together. “Downwash” - explained. “Biplanes and Interference” - effect of biplane aerofoils on each other relative to their proximity. Effects of drag. “Stagger” - effect of forward and backward stagger. “Monoplanes and Tapered Wings” - reasons for use of monoplanes wings. Reel 9: “Equilibrium and Stability” - principles of equilibrium. Principles of stability explained. “The Centre Of Pressure Of An Aeroplane” - explained. “Instability Of Cambered Wings” - explained. “Various Wing Sections” - Reel 10: “Methods Of Representing The Air Forces on An Aeroplane” - explanation of the various forces affecting the aeroplane.. “Level Flight” - elements required to be over come to achieve level flight. Reel 11: “”Weather-Cock” Or Static Stability” - demonstration, using model aeroplane, of lift, drag, thrust and weight effects on steady level flight. Damped oscillations explained. Reel 12: “The Effect of a Tail plane in Obtaining Equilibrium in Steady Level Flight” - effect of adding a tail plane to the aeroplane fuselage. Reel 13: “Directional Stability in Level Flight” - effect of the tail plane and fin on directional stability in level flight. “Lateral Stability in Level Flight” - dihedral angle of wings introduces lateral stability. Reel 14: “Fore and Aft Control” - (G-AFHI) Adjusting elevator and effect on flight. “Directional Control” - effect on flight by operating the rudder. “Lateral Control” - effect of the ailerons on flight. “Banked Turns” - horizontal and vert component of lift explained in banked turn. Reel 15: “Balance control”: Effect of the air-stream on rudder when turning. Strong force tending to push rudder back, which must be overcome by the pilot. “Horn balance control”: Horn balance is applied by placing a portion of the control surface in front of its hinge line. A similar process is applied to the elevator. “Balance tabs”: A balance tab is fitted to the trailing edge of the elevator and is linked to the elevator by an operating rod. The balance tab moves in the opposite direction to the elevator. The same principle seen applied to the rudder and the wing ailerons. Actuating rod and mass balance attached to aileron. “Servo tabs”: Servo tab (small auxiliary rudder) is attached to rear edge of rudder. Pilot first moves the servo in the opposite direction he wishes to move the main rudder, then moves the rudder in opposite direction. The three types of balance control are reviewed on a night bomber. Reel 16: “Aileron drag”: Pilot turns to port, by putting port aileron up and starboard aileron down. The air forces on each wing are explained. The unbalanced forces on the wings tend to form another couple opposing the turn to port (yaw). This is aileron drag. To overcome this effect, the ailerons are interconnected differentially so the upward moving aileron moves to a higher angle than the downward moving aileron. Demonstrated on an aircraft. “Frise ailerons”: The up-going edge of the specially shaped aileron protrudes beneath the underside of the wing whist preserving continuity of the upper surface of the wing. Purpose of frise ailerons is to overcome aileron drag artificially by increasing the drag of the up-going aileron.“Interceptors”: Another method of overcoming aileron drag, used in conjunction with the Handley Page slat. “Trimming tabs. Adjustable on the ground only”: Trimming tabs fitted on the rudder and elevator provide fine adjustments to trim and control on air surfaces where necessary.“Trimming tabs adjustable in flight. Tail trimming and rudder bias gear”: The six tabs may be adjusted by the pilot to maintain the aircraft in longitudinal and directional trim to suit his chosen speed.
  • Alternative Title:
  • Colour: B&W
  • Digitised:
  • Object_Number: AMY 27
  • Sound: Sound
  • Access Conditions:
  • Featured Period: 1919-1938
  • Production Date: 1935
  • Production Country: GB
  • Production Details: ROYAL AIR FORCE (Production sponsor) NK (Production company)
  • Personalities, Units and Organisations:
  • Keywords:
  • Physical Characteristics: Colour format: B&W Sound format: Sound
  • Technical Details: Format: 35mm Number of items/reels/tapes: 14
  • HD Media:
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    AMY 27

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