Homework Exercise to prepare for Class #2. Answer these on notebook paper then correct or improve your answers (using another color) by referring to the answer sheet. 1. Identify the major components depicted in the following illustration: 2. When you move the control wheel to the left (turn it counter-clockwise), will the left aileron move up or down? 3. True/false. The rudder is located on the horizontal stabilizer. 4. What is the purpose of trim devices? 5. An airplane with its third wheel mounted on the tail (instead of the front as depicted above) is equipped with what type of landing gear? 6. In addition to providing power to turn the propeller, what other functions does the engine in a typical training airplane perform? 7. Select the true statement(s) regarding the four forces of flight. a. During accelerated flight, thrust and drag are equal. b. The four forces are in equilibrium during unaccelerated flight. a. In straight and level unaccelerated flight, all four forces are equal in magnitude. 2012 Joseph J. Zubay 10/31/12 Page 1 of 5 Pages
8. Refer to the following illustration and identify aerodynamic terms associated with airfoils and the airflows interacting with them. 9. Describe how Newton s law of motion and Bernoulli s principle explain the generation of lift by an airfoil. 10. True/False. As airspeed increases, the angle of attack at which an airfoil stalls also increases. 11. Identify three methods you can use to control lift during flight. 12. Will the wings angle of attack increase or decrease when trailing edge flaps are lowered? 13. Is it more desirable for the wing root or wingtips to stall first and why? 14. List the three kinds of parasite drag and provide examples of aircraft features that reduce parasite drag. 15. Explain why induced drag increases as airspeed decreases. 16. The reduction in induced drag due to ground effect is most noticeable when the airplane is within what distance from the earth s surface? 17. True/False. When landing in gusty winds, airspeed should be increased above normal to help guard against a stall. 18. List the basic steps for stall recovery 19. List the general procedures for recovery from an inadvertent spin. 20. What relative airspeed, power, and angle of attack conditions produce the most noticeable left-turning tendencies common to single-engine, propeller-driven aircraft? 2012 Joseph J. Zubay 10/31/12 Page 2 of 5 Pages
21. Name three airplane design elements (things the manufacturer does) that are used to help offset the left-turning tendencies of an airplane. 22. What causes an airplane to turn? 23. If angle of bank and altitude are held constant, what can be done to increase the rate of turn? 24. Given a wings-level, 1G stall speed of 55 knots, use Figure 1-37 (Page 1-19 of The Complete Private Pilot) and a calculator to determine the stall speed under the following conditions. a. Bank angle, 30 b. Bank angle, 45 c. Bank angle, 75 25. True/False. Maneuvering speed (Va) increases with an increase in gross weight. Optional Research Problem: Who is the manufacturer of the airplane that you use (or will use) for training? What is the model number of the airplane that you use (or will use) for training? What is this airplane s maneuvering speed range and the associated weight range? Where did you find these data? Is the maneuvering speed range marked on this airplane s airspeed indicator? 2012 Joseph J. Zubay 10/31/12 Page 3 of 5 Pages
ANSWERS to the Homework Exercise to prepare for Class #2. Do Not View this until all questions are answered. Use the following to correct or improve your answers. Correct or append your answers using another color pencil or pen. Do not erase incorrect answers strike them out so the incorrect data are still readable. 1. a. Fuselage b. Wing c. Power Plant d. Tail e. Tricycle Landing Gear (not Conventional Landing Gear) 2. Up. 3. False. It is located on the vertical stabilizer. 4. Trim devices aerodynamically help move a control surface, or maintain a surface in a desired position in order to reduce the flight control forces a pilot must maintain. 5. Conventional landing gear. 6. Accessories mounted on or connected to the engine generate electrical power to meet the electrical needs of all of the aircraft s systems (except of the engine s ignition system which runs on self-contained magnetos), provided a vacuum source for some of the flight instruments, and, in most single-engine airplanes, provide a source of cabin heat for the pilot and passengers. 7. B 8. a. Upwash b. Leading Edge c. Trailing Edge d. Downwash e. Flight Path f. Relative Wind g. Camber h. Chord Line i. Angle of attack 9. According to Bernoulli s principle, the increase in speed of the air over the top of an airfoil produces a drop in pressure and this lowered pressure is a component of total lift. Newton s third law of motion explains how the airstream striking the lower surface of the wing and being deflected downward (i.e. downwash) results in a reaction that also is a component of total lift. The majority of the lift is produced by the upper surface usually approximately 60%. 10. False. 11. You can control lift by changing airspeed, changing angle of attack, or by deploying high-life devices such as leading edge cuffs or trailing edge flaps. 12. Increase. 2012 Joseph J. Zubay 10/31/12 Page 4 of 5 Pages
13. It is preferable for the wing root to stall first. If the wingtips stall before the root, the disrupted airflow near the wingtip can reduce aileron effectiveness to such an extent that it may be impossible to control the airplane s roll motion. 14. There are three types of parasite drag: form drag, interference drag, and skin friction drag. Streamlining decreases form drag, and design features, such as wheel fairings and retractable landing gear, can reduce both form and interference drag. Skin friction drag can be minimized by eliminating protruding rivet heads, and employing a clean glossy flat finish to airplane surfaces. 15. Induced drag is caused by the creation of wingtip vortices formed as the wing is generating lift. As the air pressure differential between the upper and lower surfaces of the wing becomes greater with an increase in angle of attack, stronger vortices are formed and induced drag is increased. Since the wing is usually at a low angle of attack at high airspeeds, and a high angle of attack at low airspeeds, a relationship between induced drag and speed can be observed. Induced drag is inversely proportional to the square of the speed. 16. Less than one wingspan. 17. True. 18. For stall recovery: Decrease the angle of attack to less than the critical angel of attack. Smoothly apply maximum power. Once the airplane recovers, adjust the power as necessary while maintaining coordinated flight. 19. For spin recovery: Throttle to idle. Neutralize the ailerons. Determine the direction of rotation. Apply full opposite rudder. Briskly apply elevator (or stabilator) to neutral or slightly forward of neutral to assure that the angle of attack is lower than the critical angel of attack. As rotation stops, neutralize the rudder. Gradually apply aft elevator (or stabilator) to return to level flight without exceeding the critical angel of attack. 20. Low airspeed, high power settings, and high angles of attack. 21. Left turning tendencies are usually corrected for by the designer/manufacturer, in part, by the offset vertical stabilizer, offset mounting of the power plant and the increased angle of incidence of the left wing. 22. When an airplane is banked, lift is comprised of two components a vertical component and a horizontal component. The airplane turns because the horizontal component of lift creates a force directed inward toward the center of the turn. 23. Decrease airspeed. 24. a. 59 knots. b. 66 knots. c.110 knots. 25. True 2012 Joseph J. Zubay 10/31/12 Page 5 of 5 Pages