Questions & Answers - Gliding Questions on basic theory 1. Why and what are you checking under “Ballast” in the Pre Takeoff check? 2. What happens to the glider's stall speed in a turn? 3. What is the “safe speed near the ground” in a 10 kt breeze in your glider? 4. What is aileron drag and how do you and the glider's designer compensate for it? 5. Why is it important to clean the glider prior to flight? 6. What happens to the glider's stall speed with the brakes out? 7. What are the symptoms of the Basic Stall? 8. What is the primary function of the airbrakes? 9. How does airspeed affect control effectiveness and response? 10. What force turns the glider? 11. What affects the landing performance of a glider? 12. What is adverse yaw and how is it corrected? 13. What is “Induced Drag” and when is it greatest? 14. What is the significance of the “Minimum Cockpit Load” for your glider? 15. What is the method of checking the glider is trimmed for flight? 16. What is the secondary effect of rudder? 17. What causes the pre stall buffet warning? 18. Why is any damage to the “D” nose section of the wing critical to airworthiness of the glider? 19. On a glider fitted with an elevator trim tab, which way will the tab move if the trim lever is moved forward? 20. If the glider's wing drops at the stall, what is the correct action on the part of the pilot? 21. A glider flying at 60 kts into a 10 kt headwind will have a ground speed of what? 22. What are the 3 primary flight controls and the axis of movement they operate about? 23. What is the correct recovery action from a fully developed spin? 24. What action is necessary to unstall a glider? 25. What 3 forces act on the glider in flight? 26. What is the difference between slip and skid? 27. Why does the glider want to over bank when set in a turn? 28. What is the difference between Indicated Air Speed (IAS) and Groundspeed (G/S)? 29. Why does the nose of the glider pitch down at the stall? 30. Why is there a Maximum Aero Tow and a Maximum Winch Launch speed?
Model answers for basic theory questions
1. To ensure the cockpit loading is within the Minimum to Maximum allowable weight range so that the glider is operated within its certified Centre of Gravity (CofG) range. We check that if ballast weights are required, that the correct amount has been properly fitted and secured. If not required, we check that they are not fitted. 2. It increases, because of the increase in effective weight due to an increase in the “G” loading. 3. Stall speed for your glider at your weight, plus 10, plus half the wind velocity; so for a glider that stalls at 38 kts, add 10 plus 5 and you get 53 kts as a safe speed in this example. 4. A down-going aileron causes an increase in induced drag, resulting in yaw away from the direction of intended turn. This is called adverse yaw. The most common fix designers use is differential ailerons that have more upward travel than downward travel. The pilot is still left with the task of ensuring sufficient rudder is applied in coordination with the aileron application when rolling into a turn. Look at the types of aileron control on gliders at your site. 5. Cleaning removes any surface irregularities like dust, bugs, dirt etc that will create unwanted airflow disturbances that reduce lift and increase drag (and increase the gliders stall speed). All of this reduces the lift/drag ratio…your glide performance. 6. It increases by 2 to 5 knots, depending on the type of glider and amount of brake extended. 7. Slightly higher nose attitude than the normal glide, with reducing airspeed as a result; reducing control effectiveness, because of the reduced airflow over them; change in the sound of the airflow, usually getting quieter as less flow around the cockpit as speed reduces; light buffet as turbulent airflow separates from the wing and strikes the fuselage and tailplane surfaces. 8. To control rate of descent, by increasing it when required; ie. on approach. 9. As speed increases, control effectiveness increases. ie. for the same amount applied the response is greater, so less input is required to get the same response as that of a slower speed. The controls also feel heavier when applied at higher speed. 10. Lift. When the glider is banked, using aileron to roll it, the lift force is tilted in the direction of the turn. 11. Approach speed flown; amount of airbrake used; wind strength and direction; surface condition ie. grass short or long, wet or dry, ground hard or soft; tyre inflation; wheel braking. 12. Yaw in the opposite direction to the intended direction of turn, caused by aileron drag. Countered by the coordinated application of rudder and aileron when rolling into a turn. 13. Drag induced whenever the wing is generating lift. It is greatest when lift is greatest, ie. at high angles of attack, at low speed. 14. This is the minimum load required in the front seat to keep the glider operating within its certified C of G range. If the loading is too light, the C of G will be aft G LIDING N EW Z EALAND 15 July 1999 6 Pilot Examinations of the limit and elevator control effectiveness will be reduced to a point where if the glider was to stall, full forward elevator may be insufficient to reduce the angle of attack required for recovery. 15. Set an attitude for the speed you wish to be flying at, then gently relax your grip on the control column. If there is any tendency for the nose to pitch up or down, you are not correctly trimmed. 16. Roll caused by the outer wing traveling faster than the inner wing. 17. Turbulent air flow striking the rear of the wing, the fuselage and tail surfaces and buffeting them. 18. The D nose section forward of the main spar provides strength to withstand the torsional twisting loads imposed on the wing in flight. Damage to this section can greatly reduce the structural integrity of the wing. 19. Up. See a K-13 and some Grob 103's 20. Stick forward and use only enough rudder to prevent yaw. 21. 50 kts. 22. Elevators pitch about the lateral axis; Ailerons roll about the longitudinal axis and Rudder yaws about the vertical axis. 23. Apply full rudder opposite to the direction of rotation, stick forward until the glider stops spinning, then centralise rudder and recover from the dive. 24. Reduce the angle of attack below the stalling angle, usually achieved by moving the stick forward. 25. Lift, Drag and Weight. 26. Slip is a sideways motion towards the lowered wing while skid is the sideways motion towards the higher wing. If the wings are level, any sideways motion is skid. 27. The outer wing is traveling faster, therefore generating more lift which wants to roll the glider further into the turn. 28. Indicated Air Speed is the actual speed of the glider through the air while Ground Speed is its speed relative to the ground. The two are only the same in still air at low level. 29. At the point of stall and beyond the critical angle of attack, the lift force acting through the centre of pressure reduces and moves aft. This change to the balance of forces acting on the wing has a net result of creating a nose down pitching moment. 30. These speeds protect the glider from forces generated by higher speeds that may overstress the release attachment structure as well as the whole glider.
Questions on airmanship
1. What do you do if you find the rope does not detach when you try to release from tow? 2. What are the cloud base and visibility requirements for flight in Visual Meteorological Conditions (VMC) at your field? 3. Who gives way when two gliders are approaching each other (a) head-on (b) on converging headings? 4. What is the “clock code” and when is it used? 5. Where should your left hand be during take-off? 6. What action do you take if running out of height in the circuit? 7. How should the glider be left after a flight if no one is ready to fly it next? 8. Who can stop a launch from proceeding? 9. On which side does a glider overtake another glider (a) when hill-soaring, (b) at all other times? 10. When doing the HASELL check prior to stalling, what do you check under the “A”? 11. Who establishes the direction of turn in a thermal? 12. What are the vectors on your home field? 13. What is the recommended minimum length of rope to be used for ground towing a glider? 14. Why should you not rely on your altimeter to judge your height in the circuit? 15. What precautions should you take when cleaning a glider canopy? 16. Why should you not fly when you have a head cold? 17. Assuming that the glider is not taking off or landing, what is the minimum height to fly over a built-up area? 18. What is the pilot's first priority immediately following a launch failure? 19. The recommended time from alcohol consumption to flying a glider is what? 20. What details of your glider flights do you have to log? 21. How do you check the serviceability of the tow rings prior to a launch? 22. What is the caution with self medication and flying? 23. What is the phonetic alphabet and how is it used for giving your gliders call-sign by radio? 24. Describe the procedure for handing over control of the glider when in flight. 25. What are you checking under the “Straps” part of the Pre Landing Checks? 26. What are your actions if your speed is too slow on a winch launch? 27. What are your actions if you are too fast on a winch launch? 28. What are your actions if a vehicle drives out onto the area you had intended to land on when you are on final approach? 29. What should you do if the towplane gives you the Rudder Waggle signal? 30. What action does a pilot take before carrying out intentional stalling, spinning, or before aerobatics?
Model answers to airmanship questions
1. Operate the release again; advise the tow plane by radio if fitted, otherwise fly out to the left of the tug and rock your wing, await acknowledgment then return to the normal tow position; expect to be released back near the airfield, over clear land in case the rope releases when released from the tug end; try releasing again to get rid of the rope once off tow; assume you still have the rope trailing unless positively advised of it having released and plan your final approach accordingly to clear obstructions. 2. At an uncontrolled airfield: 600 ft cloud ceiling and 1500 meter visibility; At a controlled airfield: 1500 ft cloud ceiling and 8km visibility unless granted Special VFR in which case the requirements are to remain clear of clouds with at least a 600 ft ceiling and a visibility of 1500 meters. 3. Head on, both gliders turn right; converging, the glider that has the other on its right gives way. 4. Imagine an analog clock face superimposed on the glider where ahead is 12 o'clock, the right wing is at 3 o'clock, the tail is at 6 o'clock and the left wing is at 9 o'clock.. Use this to describe direction; a glider off your right wing is in your 3 o'clock; a town in front of you is in your 12 o'clock…and add an estimated distance and a relative height ie. High, low or same level, to help describe the position relative to yours. 5. Resting on your left leg in easy reach of the release should it be needed. 6. Adjust your aiming point and modify your circuit to land safely in the best available area. 7. Power off, brakes held open and canopy closed; remove off the active vector and picket securely if windy. 8. Anyone who sees a potential hazard to the launch developing. 9. When ridge soaring, overtake on the downwind side between the glider and the hill side. Pass between the glider and the ridge if at the same level or well clear above and below or to the upwind side if there is insufficient room to pass on the inside. At all other times, overtake on the right. 10. A is for Airframe and you check the configuration you want for the particular stall you intend doing; the position of flaps, brakes and undercarriage as required. 11. The first glider in the thermal unless local rules specify a direction as is often the case at a contest. 12. Determine these for your home field. Eg. Omarama is 09 / 27. 13. Half the glider's span; to ensure it can not strike the tow vehicle if it swings out of control of the wing walker. 14. The altimeter measures height above a set datum; usually above sea level. It does not measure height above the ground and is prone to errors that make it too inaccurate for total reliance in circuit height planning. 15. Use a clean soft cloth or moistened chamois, ensuring you do not have any hard objects like a ring on your finger that could scratch the canopy. 16. Any cold is likely to be accompanied by some infection and inflammation of the eustacian tube and inner ear tissues which could be further irritated and damaged by the pressure changes that occur with flying at even low levels. The inner ear balance organs may also be fiberglass affected and this will reduce the pilot's ability to remain spatially orientated in flight. 17. 1000 ft above the highest obstacle within a horizontal radius from the glider of 2000 ft. 18. Lower the nose to attain Safe Speed Near The Ground. 19. 12 hours. 20. As per the NZGA Logbook; date, registration, duration of flight, dual / solo, type of launch. 21. Inspect for cracks visually and by rattling to hear a jingle / ring. Feel for any cracks or damage and visually check ring shape is not distorted by previous overstress. Rotate the big ring through the rope to ensure any damage is not hidden by the rope. 22. Generally a no- no as most medications are for use on the ground and are not suitable for pilots as they dull the body's sensors used for orientation. Check any medication with an aviation qualified doctor ensuring he realises you are wanting to fly as pilot in command and not just as a passenger. 23. Alpha, Bravo, Charlie, Delta…. GNX is “Golf November Xray” or “Glider November Xray” 24. Pilot flying says “You have control”, waits for the other to place hands and feet on the controls and when ready says “I have control” before letting go of the controls. If a pilot wants to take control from the other, they say, “I have control” as they place hands and feet on the controls; the flying pilot then releases control saying “You have control”. 25. Straps are prone to working loose in flight, partially as a result of your “settling” in the seat and partially from your movement working against them. On longer flights, loss of body weight will also cause them to be loose. Tightening them ensures your full protection on landing. 26. Lower the nose and release if the speed does not increase. 27. Lower the nose, waggle the rudder to signal you are too fast but release if still too fast. 28. Close the brakes and re establish an approach to a new aim point in a clear area beyond the vehicle, then use the brakes again as required. 29. Check your brakes are closed; if open, close them ensuring you maintain the normal tow position. 30. Complete the Pre Maneuver Checks; Height, Airframe, Security, Engine, Location and Lookout. courtesy NZ Gliding Association |