1. MANEUVERING YOUR SAILPLANE EFFICIENTLY CONTROL USAGE AND OTHER SUBTLETES 1.

2. INTRODUCTION: The assumption is that everyone here is a safe, competent pilot. This presentation is intended / suggested as a “Do- it-Yourself” project” for the ‘fine tuning’ of your control usage techniques. Most, if not all of you probably work hard on technique; keeping the yaw string centered, and the airspeed close to the desired value. Our discussion for the most part, will deal with maneuvering the sailplane in that thermal (speeds and bank angles) environment. To get our hands around the subject we will talk about some of the sailplane factors, some pilot factors, and then the system factors, where we combine the two. Lastly, we will relate control usage technique to some other areas such as ‘flying with water ballast’, Flying in (severe) turbulence, and low level maneuvering (ridge running and landing pattern flying). Pg. 1 Notes

3. WHY? Performance - Getting the most out of the sailplane. Safety – For yourself and those in your thermal / airspace. Better feedback - interpreting what your sailplane is telling you. 2

4. Performance: Common mistakes are over controlling (each unnecessary control surface deflection costs you), and/ or uncoordination (Keep the pointy end going forward) Safety: Don’t spin out in a gaggle. Good habits pay off in bad situations. Feedback: Your sailplane is a 15M wide ‘air sampler’, each up-set / correction is a piece of the puzzle, Poor control technique masks this information. (Consistency, including mistakes, beats erratic). I think the picture that the really good pilots paint (The Striediecks, Moffets of this world) is roughly analogous to the way the south seas islanders (before GPS) could navigate, days away from any land, by reading the waves / interference patterns caused by distant islands. Pg. 2 Notes

5. SAILPLANE FACTORS KNOW YOUR SAILPLANE CENTER OF GRAVITY AILERON DIFFERENTIAL OVER BANKING FLAPS (AND DIVE BRAKES) 3

6. CG: Some fly better with an aft CG / more neutral stability (Better climbing). Others better @ mid range (Better for cruise). A ‘forward’ CG will increase the stick (elevator) movement required, as a function of bank angle, to maintain a constant A/S. Aileron differential: The travel of the ‘up’ aileron is more than the ‘down’ aileron – usually 3 to 1 at full deflection. Because of the ‘closed loop’ nature of the control system the ‘differential’ at 0° deflection is 1/1. This means that the balance between rudder and aileron, for coordinated rolling, will vary depending on aileron deflection. For thermal maneuvering find the roll rate (range) that works best for you. Over banking: In a turn the outside wing is moving faster than the inside wing… The reason apposite aileron is required in the ‘steady state’ turn. (As stated elsewhere: When rolling into the turn before reaching the desired bank the controls should be transitioning from the ‘roll-in’ to the ‘steady state’ positions for the selected bank angle. Flaps and dive brakes: Know pitching characteristics (important for …) Increasing the flap setting (even landing flaps, momentarily) can get one through the ‘soft side’ of a thermal. Pg. 3 Notes

7. PILOT FACTORS KNOW YOURSELF HABITS & REFLEXES STRESS State of mind 4

8. Habits & Reflexes: Watch yourself when you are operating on ‘auto pilot’. (Note those areas that need improvement) and fix the ‘bad habits’. Develop the habit of self observation. Stress: Those ‘bad habits’ may reemerge in stressful situations. Can be used as indicator of physical deterioration (dehydration, fatigue, faulty O2 system.) Pg. 4 Notes

9. SYSTEM EVALUATION PILOT + SAILPLANE Thermal maneuvering (EXERCISE) Start from level, at the target airspeed. Roll into the desired bank / turn. Hold the turn only long enough to correct (as required) the yaw string, bank angle, and airspeed. When on condition, roll back though level to the same bank, opposite direction turn. 5

10. How to practice the above maneuver. – Starting from level flight and at your normal thermalling airspeed, mentally note the effects that air quality (roughness / smoothness) has on the airspeed and yaw string. These are the acceptable tolerances for same throughout the maneuver. Roll into the selected bank at the chosen rate (slow, normal, or fast). Be deliberate (slow) for the rate the ailerons are applied. This applies for rolling, both into and out of the bank. Rolling In: Observe the yaw string and A/S. If the rudder has been applied commiserate with the aileron application, and the elevator is being applied appropriate to the increase in bank angle, the yaw string and A/S will remain unchanged. Another indicator of proper elevator application (bringing the stick back as the bank increases) is pitch attitude – no change in same, if done correctly. Suggestion: If the A/S and/or the yaw string drifts from the ideal only try to arrest, or minimize, the excursion, don’t try to bring back. Make that adjustment on the next ‘roll in / roll out’ attempt). Stopping the Roll at the Desired Bank Angle: As the bank angle is approaching the target angle the controls should be moving from the ‘roll in’ application (position) to what can best be described as the ‘steady state’ (repeatable) position for the selected turn (bank angle and airspeed). Rolling Out, and into the Opposite Direction Turn: Remain in the turn long enough to get back on condition (Airspeed and coordinated). The transition to the opposite direction turn should be done at the same original roll rate. Here again the yaw string and airspeed are the measure for the quality of the maneuvering. Try different roll rates rolling into (and out of) typical thermalling turns. The yardsticks are the yaw string (should be centered throughout) and airspeed / pitch attitude (remains constant). Find the roll-rates / bank angles where this can be done successfully and work to expand the (roll rates and bank angles) envelope. Pg. 5 Notes

11. RELATED APPLICATIONS Flying (Maneuvering) with water ballast In turbulence Low level maneuvering 6

12. Water Ballast: Faster A/S’s / same pitch attitudes. Higher roll Moment of inertia (MOI) which increases sluggishness in starting and stopping the roll. Stall / spin departures will develop slower (giving a false sense of improved stability) but, in autorotation, will be slower to recover. In a thermal give the center to those W/O water and let them by. Turbulence: Correct for the ‘averages’, not each individual upset. Vertical gusts will result in the nose wanting to drop (A/S increases) in response to an ‘up-gust’ and pitch up (A/S decreases) when hitting the sink or down-gust. The elevator response should be in reestablishing the desired pitch attitude but only after the trend in airspeed change has been controlled (reversed). Side gusts don’t require much of a response (unless one is in the landing flair) as the sailplane just ‘weathervanes’ into the gust plus some secondary rolling opposite to the yawing. Small control deflections of the type to “center-the-yaw string” are in order. Low-Level Maneuvering: Extra airspeed is always in order when low – either on a ridge, or low in a landing pattern. Give up altitude as required to maintain that (A/S) margin. Low landing Patterns – When turning (hopefully to final) use more bank early (over bank) so the wings can be rolling towards level in the later stages of the turn. Ridge Running (good lift)- Stay smooth (especially pitch) brace ‘stick hand’ to minimize PIO’s. Pg. 6 Notes