Robinson R22 Student Study Guide. Contents Page R22 COCKPIT LAYOUT 3. EXERCISE 1 a FAMILIARISATION WITH THE HELICOPTER 4

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1 Contents Page R22 COCKPIT LAYOUT 3 EXERCISE 1 a FAMILIARISATION WITH THE HELICOPTER 4 EXERCISE 1b EMERGENCY PROCEDURES EXERCISE 2 PREPARATION FOR AND ACTION AFTER FLIGHT 5 EXERCISE 3 AIR EXPERIENCE 6 EXERCISE 4 EFFECTS OF CONTROLS 7 EXERCISE 5 POWER AND ATTITUDE CHANGES 12 EXERCISE 6 & 9 STRAIGHT & LEVEL AND TURNING 15 EXERCISE 7 & 8 CLIMBING & DESCENDING EXERCISE 10 BASIC AUTOROTATION 18 EXERCISE 11 a) HOVERING, b) HOVER TAXI, c) EMERGENCIES 21 EXERCISE 12 TAKE OFF & LANDING 26 EXERCISE 13 TRANSITIONS 29 EXERCISE 14 a) CIRCUITS & b) CIRCUIT EMERGENCIES 33 EXERCISE 15 FIRST SOLO 36 EXERCISE 16 SIDEWAYS & BACKWARD HOVER MANOEUVRING 37 EXERCISE 17 SPOT TURNS 39 EXERCISE 18 HOVER OUT OF GROUND EFFECT & VORTEX RING 40 EXERCISE 19 SIMULATED ENGINE OFF LANDINGS 42 EXERCISE 20 ADVANCED AUTOROTATION 45 EXERCISE 21 PRACTICE FORCED LANDINGS 47 EXERCISE 22 STEEP TURNS 50 Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 1

2 EXERCISE 23 PRECISION TRANSITIONS 51 EXERCISE 24 QUICKSTOPS 52 EXERCISE a) NAVIGATION, b) LOW LEVEL NAV, c) RADIO NAV. EXERCISE 26 ADVANCED TAKE OFF & LANDINGS 60 EXERCISE 27 SLOPING GROUND 62 EXERCISE 28 LIMITED POWER 64 EXERCISE 29 CONFINED AREAS 67 EXERCISE 30 BASIC INSTRUMENT FLIGHT 73 EXERCISE 31 a) NIGHT FLYING b) NIGHT NAVIGATION 76 APPENDIX A POWER REQUIRED VS POWER AVAILABLE 80 APPENDIX B HEIGHT VELOCITY DIAGRAM 81 APPENDIX C ABBREVIATIONS 82 APPENDIX D GLOSSARY OF TERMS 84 Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 2

3 Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 3

4 EXERCISE 1A FAMILIARISATION WITH THE HELICOPTER The following points will be covered: External Features Cockpit Layout Helicopter Systems Checklists, procedures and controls Exercise 1b Emergency Procedures The following points will be covered Position and use of safety equipment Emergency evacuation procedures By the time you are ready for solo, you should be familiar with: The main and tail rotor systems The fuel and oil systems The electrical system and radio equipment Appropriate emergency procedures Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 4

5 EXERCISE 2: PREPARATION FOR AND ACTION AFTER FLIGHT INTRODUCTION Your instructor will run through the following detail: Helicopter authorisation Helicopter acceptance Serviceability documentation External checks Internal checks Seat harness and control adjustments Starting and warm up checks Engaging rotor Running down and stopping engine Leaving the helicopter, parking and security Completion of authorisation and helicopter documents Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 5

6 EXERCISE 3: AIR EXPERIENCE INTRODUCTION The flight will take approximately 30 minutes and is intended to familiarise you with the new sensations of helicopter flight. Additionally, the main features of the local area will be pointed out to you. You will be given the opportunity to feel the nature of the controls, although no attempt will be made to explain their effects in any detail. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 6

7 EXERCISE 4: EFFECTS OF CONTROL INTRODUCTION This exercise introduces you to the helicopter controls and their functions. If you have flown fixed wing aircraft you will see that there is a resemblance to some of those you have already used, whilst others will be unfamiliar to you. In addition, you will be shown the indications and uses of the instruments and avionics. AIRMANSHIP LOOKOUT Although the exercise itself will absorb most of your concentration, it is important to develop a good lookout. You will also need to keep a check on your position and regularly check fuel remaining, engine temperatures and pressures (T s and P s) The clock code system is used, plus high or low (i.e. above or below the horizon). Therefore Aircraft 12 o clock high means an aircraft is dead ahead and above the horizon. HANDING OVER CONTROLS During the demonstrations you will be asked to follow through on the controls. It is important that you don t override your instructor. When the instructor wants you to take control he will say You have control. You will then take hold of the nominated control(s) and acknowledge, I have control. The reverse is true when the instructor requires to re-take control. The controls The Cyclic Stick: The cyclic controls the helicopter in the horizontal plane. Movement of the cyclic in any direction changes the rotor disc attitude in that direction followed by a similar change in the helicopter attitude. Forward cyclic causes the rotor disc to tilt forward and the helicopter to adopt a nose down attitude. The helicopter will accelerate. Only small movements are required. You will find it convenient to rest your forearm on your leg or hip in order to damp out unnecessary control movements. The cyclic stick is not self-centring, and in cruise flight a slight pressure to the right needs to be applied to maintain the helicopter laterally level. To offset this force, a pull-up trim knob is on the centre console and when selected applies a small spring pressure to the cyclic. This trim is used in cruising flight above 65 knots. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 7

8 Initially you should note the helicopter attitude by reference to the horizon position on the windscreen. As the cyclic is eased forward, the helicopter pitches nose down, airspeed increases and the helicopter descends. The opposite effect occurs if the cyclic is moved backwards. Lateral movements of the cyclic causes the helicopter to roll, followed by yaw and a turn in the direction selected. In normal flight therefore, the operation of the cyclic stick produces the same effects as operation of the joystick in a fixed wing aircraft. Cyclic Forward = Nose lowers Speed increases Loss of height Cyclic aft = Nose rises Speed decreases Gain in height Cyclic left/right = Helicopter banks Turns left/right The collective lever: The lever controls the helicopter in the vertical plane. By simultaneously varying the blade pitch on both the main rotor blades, the collective lever varies the total rotor thrust. Note that if the collective is raised, not only is there an increase in total rotor thrust but there is also an increase on rotor drag. If uncorrected, this will lead to a drop in rotor revolutions per minute (RRPM). To offset this, the collective is also connected to the engine throttle butterfly valve by a linkage. This is known as correlation. When the lever is raised, engine power is increased, shown on the manifold air pressure gauge (MAP), and RRPM will remain fairly constant in the cruise power range. (See section on Governor below). Similarly, when the lever is lowered, MAP reduces, and RRPM remains fairly constant. However, the change in engine power, changes the torque force applied to the main rotor shaft. This causes the helicopter to yaw in the absence of any corrective pedal movements. Feel is proportional to amount of friction applied by a small toggle lever near the aft end of the collective. A neutrally balanced spring is incorporated in the linkage to offset the tendency for the lever to move of its own accord. Raise lever = Lower lever = Main blade pitch increases power increases lift increases helicopter yaws right nose pitches up helicopter climbs Main blade pitch decreases power decreases lift decreases helicopter yaws left nose pitches down helicopter descends NB THE FOLLOWING SECTION IS TO BE DISCUSSED IN THIS LESSON ONLY WHEN TRAINING ON THE R22 & R44 BUT MAY NOT BE DEMONSTRATED WITH GOVERNOR OFF. GOVERNOR OFF OPERATION IS PROHIBITED EXCEPT FOR DURING MALFUNCTIONS Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 8

9 TRAINING AND SHALL ONLY BE FLOWN AS PART OF EX 14c CIRCUIT EMERGENCIES. The twist grip throttle: The throttle twist grip is very sensitive and is used to adjust RRPM. Be aware that the correlation is not perfect and in a sense the throttle twist grip is used to fine tune ERPM and RRPM. When the throttle is opened (top away from you) MAP and RRPM increase, the extra torque causes a yaw to the right. Closing the throttle (top towards you) reduces MAP and RRPM and causes a yaw to the left. Little or no throttle movement is needed between 17 and 21 Map. Open throttle = Power increases RPM increase A/c yaws right Close throttle = Power decrease RPM decrease A/c yaws left Governor: A switch on the end of the pilot s collective operates an electronic governor, which controls the ERPM. It efficiently maintains ERPM and therefore RRPM at 104%. In achieving this you will notice variations in MAP and consequently yaw. You will do most of your training with the governor on, other than for certain specific exercises. It is selected on during the pre take-off checks and switched off after landing. Because the governor is so efficient, care must be taken to avoid exceeding engine boost limits. A warning light indicates when the governor is selected off. Yaw pedals: The pedals are light and sensitive. Left pedal causes the nose to yaw to the left. Right pedal has the opposite effect. In both cases you will notice a speed reduction. In forward flight however, the yaw pedals are not used to turn the helicopter, but to maintain balanced flight. Indication of yaw is achieved by two tell tale strips of wool secured to the outside of the bubble on the nose. Your helicopter may also be fitted with a slip indicator in the cockpit If the wool is deflected to the left, apply right pedal to centre it. The helicopter will then be flying most efficiently. Pedal movements change the collective pitch of the tail rotor, thus altering the power demanded by the tail rotor. Hence, application of left pedal will cause the MAP to rise and vice versa with the right pedal. Flying out of balance will cause the airspeed indication to reduce. Whenever the power (MAP) is increased, left pedal must be applied. Left pedal = A/c yaws left - MAP increase - Speed decrease Right pedal = A/c yaws right - MAP decrease - Speed decrease EFFECT OF AIRSPEED ON RRPM (Discussion only, Governor Off Flying not permitted - to be covered in Ex 14c) You will be shown how airspeed affects RRPM: Increase in airspeed = RRPM increase Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 9

10 Decrease in airspeed = RRPM decrease EFFECTS OF DISC LOADING ON RRPM (Discussion only, Governor Off Flying not permitted - to be covered in Ex 14c) You will be shown that RRPM rise with an increase in positive G, and decay if negative G is applied. Abrupt pushovers (low G created by forward cyclic) are prohibited. FURTHER EFFECTS OF LEVER AND THROTTLE Fully lowering the lever reduces the MAP, but the governor maintains ERPM & RRPM at 104% unless the throttle is closed below 80% ERPM which disengages the governor causing a needle split on the RPM Tachometer. When the lever is lowered, a large amount of right pedal is needed to maintain balanced flight. (Known as autorotation) At 65 kts, the rate of descent is approximately 1800ft/min. If the throttle is now fully closed onto the detent, raising and lowering the lever causes the blade pitch and therefore RRPM to change, but does not affect the MAP. OTHER CONTROLS Friction Frictions are provided on the cyclic and collective controls. Generally friction is not used on the cyclic in flight, although it may well be used on the collective to maintain pitch. Mixture Control The mixture control is a push / pull knob on the lower console. It is used to lean the fuel / air mixture at high altitudes and as an idle cut-off to stop the engine after flight. A plastic collar is placed over the knob to prevent inadvertent operation in flight. Carburettor air temperature control (C.A.T.) The C.A.T. push / pull control knob is situated near base of the cyclic, and provides hot air to the carburettor to prevent induction icing. The control is used to keep the C.A.T. out of the icing band. For normal operations maintain C above 18 MAP. Manifold pressure gauge The manifold pressure (MAP) gauge indicates engine output. There is a maximum power indication on the gauge, although actual power available at any Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 10

11 specific time depends on environmental conditions. See the Limited Manifold pressure diagram in the cockpit. Rotor brake The rotor brake is used to stop the rotor after engine shutdown. The following procedures should be used. After pulling the idle cut-off, wait at least 30 seconds Pull the brake toggle (located above the pilots left shoulder) using a maximum 10 lbs force. Do not stop the rotor in less than 20 seconds from initial rotor brake application. After rotor stops retract the toggle, or if required as a parking brake, pull handle down and push the bead chain into the slot. A warning light indicates the rotor brake is on. When the rotor brake is selected on. An inhibitor prevents the pilot from starting the engine when the rotor brake is engaged. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 11

12 EXERCISE 5: POWER AND ATTITUDE CHANGES INTRODUCTION In this exercise you will learn the relationship between the attitude and airspeed and how to make attitude changes with cyclic in order to vary airspeed. You will also learn how to make power changes, control RRPM, and to co-ordinate control movements to maintain balanced flight. This will involve an introduction to the Power Required vs Power Available diagram. AIRMANSHIP Maintain a good lookout. This is especially important when turning, climbing or descending. Keep a check on your location. Your instructor will point out landmarks. Monitor the engine instruments and fuel contents regularly. Develop a regular scan sequence: LOOKOUT LOCATION INSTRUMENTS Positive handover / take over of the controls specified Limitations: Engine RPM/ Rotor RPM limits 97% - 104% Manifold Air Pressure Limit for the Day Carburettor temperature C During your briefing, your instructor will introduce you to the Power Required vs Power Available diagram which is shown in Appendix A. This diagram shows the how the power required to maintain straight and level flight varies with airspeed changes. Speed changes (cyclic and pedals) 50 90kts Speed Increase: In order to increase speed from balanced cruise flight, it is necessary to tilt the rotor disc further forward with the cyclic. This will result in the nose pitching down to a new attitude and the helicopter speeds up. As the helicopter accelerates the rotor disc will tend to flap back, so to maintain the attitude, it is necessary to move the cyclic progressively forward. When the speed is close to that required adjust the nose attitude to maintain a constant speed. On most light helicopters the nose attitude may be seen to be marginally lower for each increase in airspeed. Speed Decrease: To decrease the speed, the disc is tilted back with the cyclic. The nose rises to a more nose up attitude and the helicopter slows down. As the speed decays the disc flaps forward, and the cyclic must be moved further back to maintain the attitude. Once again, when the speed is close to that desired, the nose attitude is adjusted to that which you think will maintain the required speed. To change the speed, select the desired accelerative or decelerative nose attitude. Hold that attitude by moving the cyclic as necessary, and then adjust the nose attitude to maintain the new airspeed. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 12

13 It must be understood that it takes a certain time for speed changes to occur and attempts to hurry the process at first may lead to overcontrolling. The helicopter is maintained in balanced flight by small movement of pedals. Changing airspeed will of course lead to the helicopter climbing or descending. This can be countered by increasing or decreasing collective pitch thus power. You will have the opportunity to practice changing attitude and thus airspeed whilst maintaining level flight. Use the technique of SELECT HOLD ADJUST POWER CHANGES (Lever, throttle and pedals) 104% - RRPM The height of the helicopter is controlled by the collective lever, which controls the pitch of the rotor blades. As blade pitch is altered, the throttle will be adjusted by the governor and correlation to maintain constant RRPM, because of the changes in rotor drag. When the lever is raised the correlation linkage increases power by opening the throttle to overcome increased rotor drag. The nose yaws to the right as a result in the change of torque reaction and you will need to use left pedal to maintain heading. The reverse is true if the lever is lowered. The correlation will satisfactorily maintain the RRPM in the power range 17 to 21 MAP and no adjustment of the throttle is necessary. Outside this range, the governor maintains RPM at 104%. When you lower the lever the helicopter will start to descend. As the rotor drag is reduced, the correlation will reduce the power to prevent RRPM from rising. Unfortunately below 17 MAP, the governor maintains RRPM at 104%. The throttle must therefore be opened manually to maintain RRPM. Maintaining heading by using the left pedal. On completion of power changes, confirm correct balance by reference to the slip ball & trim strings. Following all power changes you should check to see that the carburettor air temperature (CAT) is just above the yellow sector (+10 C 15 C). It must be noted that below 18 MAP carburettor temperature gauge doesn t read correctly and full carb heat should be applied. You must maintain your scan sequence throughout: Lookout Location T s & P s Should the low RPM warning system operate, it is essential that the throttle is opened and the lever lowered to prevent a dangerous low RPM condition Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 13

14 developing. The correction should be immediate, but measured. It is important to avoid over reacting to the noise of the low RRPM horn. Fixed wing pilots should be particularly careful not to react to the horn as if it is a stall warning horn. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 14

15 EXERCISE 6 & 9: Ex 6 STRAIGHT & LEVEL, Ex 9 LEVEL TURNING INTRODUCTION The aim of this exercise is to apply the techniques of speed control and power changing learned in the previous exercise to achieve: - level balanced flight at specified airspeeds; - climbs and descents to specified altitudes ; - turns onto specified headings. You should by now have a reasonable knowledge of the local flying area. Gradually you will assume more responsibility for your own navigation. Regular checks of temperatures and pressures and fuel consumption (approx. 8 US gals / hr for an R22 Alpha, hp or Beta and 10 US gals / hr for an R22 Beta II) must become second nature. AIRMANSHIP Complete a good lookout of the surrounding area, especially the area into which the helicopter is moving. Apply full carb heat prior to reducing MAP <18. A regular attitude / instrument scan will be required to achieve precision. Exercise 6: Straight and level flight (50-80KTS) Straight and level flight: The basic rule to remember are that the lever controls height and the cyclic controls the attitude and hence speed. To achieve flight at a given airspeed, remember : SELECT HOLD ADJUST E.g. SELECT HOLD ADJUST Attitude for speed - 75kts Once the desired airspeed has been set, overcome any flap and adjust the lever to maintain height (20 MAP approx). Cross check the VSI to ensure level flight has been achieved. Adjust lever if necessary. Adjust pedals for balance. The governor controls RRPM and may produce MAP variations. Note: Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 15

16 Helicopter lag allow time for inputs to take effect. Attitude, power and yaw pedals are required to settle accurately in level flight at the correct airspeed and in balance. The attitude is not significantly different between kts once the airspeed has been stabilised. Exercise 9: Turns in level flight, climbs and descents In this exercise, turns are practiced at degrees bank. Try to use a smooth rate of roll into and out of the turn, remembering to maintain balance throughout. Height is maintained using the collective lever and speed is maintained with the cyclic as normal. You will probably need an extra ½ 1 MAP to remain level during the turn. Remember that the vertical position of the horizon in the windscreen will appear different in right and left hand turns due to the side-by-side seating in the R22. Effect of Offset Seat Position When carrying out climbing turns, the rate of climb reduces as bank increases, and for descending turns, rate of descent increases as bank angle increases. The syllabus requires you to turn onto selected headings. For this you will learn how to use the magnetic compass and the Directional Indicator (DI). You should anticipate the roll out of the turn by the same number of degrees as you have bank angle. E.g. Anticipate roll out by 20 degrees of heading when turning with 20 degrees of bank. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 16

17 EXERCISE 7 & 8 CLIMBING & DESCENDING Exercise 7 Climb (climbing configuration) Climbing configurations: Best rate of climb: Best rate of climb is achieved at the speed which gives the greatest power margin (53 kts), using maximum permitted power at +15 C at sea level. The standard climb: the standard climb is carried out at the optimum speed of 60 kts and 23 MAP. (You should not climb at max MAP for more than 5 minutes at a time.) Entry to the climb from the cruise ATTITUDE POWER TRIM Attitude: Power: Trim: Nose up attitude for 60 kts (cyclic) Set climb power (23 MAP) maintain balance. Trim adjust attitude, power and balance is required Level off from the climb to the cruise. (Anticipate level off by 10% of rate of climb) ATTITUDE POWER TRIM Attitude: Power: Trim: Set accelerative attitude until cruise speed is reached (75 kts) Set cruise power (approx. 20 ) maintain balance with pedal Adjust attitude, power and balance is required Exercise 8 Descent In this exercise you will practice the descent configuration descending at 60 kts and approximately 500ft / min rate of descent. POWER ATTITUDE TRIM Power: Attitude: Trim: Set 15 MAP Select attitude (decelerate to 60kts) Final adjustments to power, attitude and balance Entry to descent: Before descending, make sure that the airspace below is clear and select carb fully hot. From straight and level at 75kts lower the collective lever to initiate the descent and prevent any yaw. Power settling Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 17

18 is approximately 15 MAP. When the helicopter is positively descending, raise the nose to reduce airspeed to 60kts. Make adjustments as necessary to maintain speed and rate of descent. Level off from descent: POWER ATTITUDE TRIM Power Attitude Trim Set cruise power - Anticipate level off by 10% of RoD. Set attitude for cruise (75kts). Adjust power, attitude and balance as necessary. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 18

19 EXERCISE 10: BASIC AUTOROTATIONS INTRODUCTION In powered flight the rotor drag is overcome by engine power, but when the engine fails or is deliberately disengaged from the rotor system, some other means must be adopted to maintain the rotor RPM. Lowering the collective lever and allowing the helicopter to descend achieves this. The airflow resulting from the rate of descent strikes the blades in such a manner that the airflow itself provides the driving force to turn the blades. When the helicopter descends in this manner the rate of descent airflow becomes the power equivalent, and is known as the autorotative force. The helicopter is now said to be in a state of autorotation. AIRMANSHIP Before practicing autorotations you must perform the following HASEL checks: H A S E L Height sufficient to allow recovery by 500ft agl (away from the airfield) Area suitable Security Harnesses, doors, no loose articles. Engine temperatures and pressures, Carb heat fully hot. Lookout all round and especially below for other aircraft. Lookout above on recovery is also very important. Check wind velocity (W/V): The aim of the exercise is to be able to enter autorotation and turn into wind so that, in an emergency situation (which will be practiced in later exercises) a successful engine off landing could be carried out. It must become instinctive to recognise the general wind direction by reference to smoke, patterns on water, crops, or by assessing the helicopter drift. Verbal warning: A verbal warning should preface all autorotations. Precede the manoeuvre with the phrase: PRACTICE AUTOROTATION GO Rotor RPM limitations % RPM. BASIC AUTOROTATION Entry into autorotation (from S to L at 75 kts) into wind. Select a reference point ahead of the helicopter and on the horizon, to assist in attitude control. Smoothly but firmly lower the lever to the bottom stop without reducing the throttle. At the same time prevent yaw by applying right pedal. During entry maintain wings level and raise the nose slightly. Your instructor will close the throttle and the RPM needles will split. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 19

20 There is a tendency to pitch nose down due to the effect of the horizontal stabiliser, and roll slightly to the left as a result of compensating for tail rotor drift. At high weights it will be necessary to raise the lever slightly to maintain RRPM at the top of the green sector. Now that the autorotation is established speed can be reduced to 65kts. Just before the speed reaches the desired figure adopt the attitude, which you think, will maintain it. Then adjust as necessary and check balance. The speed for minimum rate of descent in autorotation is 53kts. Effects in Autorotation In autorotation at 65kts at normal AUW and density attitude, the rate of descent will be approximately 1800ft / min and RRPM should be maintained at about 100%. If a nose down attitude is adopted, rate of descent will increase. RRPM will initially drop as disc loading reduces, then rise as airspeed increases. If the helicopter is flared, the rate of descent will decrease markedly. RRPM will initially increase as disc load increases then decrease as airspeed reduces. In a turn, both rate of descent and RRPM will increase with bank angle. Avoid exceeding the maximum RRPM limit (110%) by raising the collective a small amount. However, once the manoeuvre is completed don t forget to lower the lever again or RRPM may drop below the lower limit (90%). It may be that raising the lever to control RRPM will cause the needles to rejoin. If so reduce the throttle slightly. When the manoeuvre is complete and the lever is fully lowered, reset the ERPM to 80%. RECOVERY FROM AUTOROTATION The height loss during recovery will depend on several factors, but as a rough guide it will be in the order of 200ft. Recovery action should therefore be initiated at least 700 ft agl when away from the airfield. To recover from the autorotation:- ensure that the RRPM needle is within the permitted power on range of %; open the throttle to above 80% ERPM, the governor will rejoin the needles; smoothly raise the lever to max power (5 min rating); Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 20

21 prevent yaw with the left pedal. During the recovery, maintain attitude in pitch and roll. There will be a tendency to pitch up and roll slightly right; check the area is clear in the direction of climb and check instrument indications. Reset carb. heat to +10 C 15 C. NB: climb should be at 5 min rating, 104% RRPM 60kts During the recovery phase, two of the requirements for Vortex Ring are present, namely, high rate of descent and power applied. However, providing the airspeed is not allowed to fall below 30kts, there is no danger of entering the Vortex Ring state (see ex. 15). Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 21

22 EXERCISE 11: a) HOVERING, b) HOVER TAXIING & c)hover EMERGENCIES Exercise 11a: Hovering INTRODUCTION The aim of this exercise is to teach how to hover: i.e. to maintain a given position relative to the ground at a constant height, heading and RRPM. The hover is a basic requirement in helicopter flying, since it is the pre-requisite to safe landings. It is also the basic factor in many operational functions. AIRMANSHIP Lookout a good lookout all round must be maintained. A large clear area should be selected without any obstructions. The wind D/V should be noted. Temperatures and pressures should be monitored frequently. Care must be taken not to exceed the helicopter power limitations. The procedure for handing over control must be strictly observed. HOVER ATTITUDE If both seats are occupied, the R22 will normally hover with the left skid 1 or 2 inches lower than the right. This is caused by tail rotor roll. The amount by which the left skid hangs low is also dependant on two other factors: 1. The lateral centre of gravity 2. The wind strength and direction relative to the helicopter If only the right hand seat is occupied, the helicopter will be laterally level. WIND EFFECT At this stage in your training you will only be hovering with your heading into wind. The helicopter will tend to drift downwind if no corrective action is taken. Therefore to maintain a position relative to the ground, the disc must be tilted into wind, this will change the hover attitude due to slightly forward cyclic. The effect of wind on hover power will be demonstrated. Less power is required to hover in a strong wind. Since the helicopter is in effect in forward flight relative to the air, it therefore experiences translational lift. If the wind velocity changes, then this will cause variation in the amount of drift and will need to be corrected by cyclic. There will also be variations in Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 22

23 translational lift, which would cause the helicopter to climb or descend. This is corrected by use of the collective lever. In general, the helicopter will tend to climb and move away from any gust of wind. In the hover the helicopter is statically stable in all planes since it will return to it s original position if displaced by an outside force, e.g. a gust of wind, However, it will continue through this position and then continue to oscillate about it in increasing amounts. Thus the helicopter is said to be dynamically unstable in all three planes in the hover. GROUND EFFECT In still air conditions, a ground cushion is formed. The benefit of this is that less power is needed to hover. This can be appreciated by making small power reductions when in a high hover. The helicopter will settle, ground effect will build and the helicopter will stabilise in a lower hover at a lower power. The intensity of the ground cushion depends on several factors including the hover height, and the nature of the ground. It should also be noted that the slightly increased air pressure under the rotor disc will affect the altimeter and VSI readings. ENGINE FAILURE IN THE HOVER In the unlikely event of an engine failure in the hover, there will be rapid yaw to the left, a loss of RRPM and height plus a tendency to drift to the left. The action therefore is to stop the yaw with right pedal, pause, and then cushion the touchdown by raising the lever whilst preventing drift with cyclic. If the engine failure occurs at greater than 5ft agl, it is desirable to lower the lever fully before raising it to cushion the touchdown. THE AIR EXERCISES The exercise will take place heading into wind, 5ft skid clearance and at 104% RPM. The function of each control is as follows: Cyclic: By controlling the disc attitude and hence helicopter attitude, the cyclic controls the position of the helicopter over the ground. Only small control inputs are required. Remember there is lag between selecting an attitude and resultant helicopter movement Collective: This controls the height of the helicopter and only small movements of the lever are required. It is important to check the manifold pressure gauge to avoid exceeding maximum power. Throttle: the governor maintains ERPM and RRPM at 104% through small automatic throttle movements and MAP variations may be noticed. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 23

24 Ensure manifold pressure limit is not exceeded. Do not inhibit throttle movements. Yaw Pedals: These are used to control the helicopter s direction. Heading changes tends to occur either through wind effects or as a result of yaw caused by collective and/or throttle movements. Application of the left pedal will cause the MAP to increase whilst with right pedal applications you will notice MAP reduction. N.B: the ball in the slip indicator has no function in the hover. In order to maintain an accurate hover, a good scan is required which should include the following points: The visual horizon for attitude and heading. A mid-distance object area some 30 metres ahead to gain a general perspective. Close ahead and to the side, to determine accurate position and height. Monitor RRPM, manifold pressure and temperatures and pressures. In the hover, there is a common tendency to stare at a fixed point thus denying yourself the other reference points that help maintain a hover. A good scan monitors external references for the vast majority of the time with brief but regular glances at the instruments. At times it may seem that the helicopter is moving away from the hover and several things are changing at once. To return to a stable hover: Reselect the hover attitude. Correct height errors with the lever (the governor will maintain RPM). Correct yaw with pedals. Once the situation has stabilised, return to the normal hover, SLOWLY Learning to hover is not easy, you will need considerable time, effort and patience to acquire this skill. Exercise 11b: Hover Taxiing, Spot Turns This exercise will begin with revision of hover techniques. Hover taxiing is the process of moving the helicopter forward at a fast walking pace, at a normal hover height in a given direction. The control functions are as follows: Cyclic: controls direction and speed. Taxiing is forward flight and flapback will be encountered. Only a minimal acceleration attitude is required so delicate cyclic control will produce better results. Directional control is achieved by lateral attitude control with the cyclic. Therefore turns are carried out using a very Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 24

25 modest back angle, and any temptation to use the pedals to steer the helicopter should be avoided. Left or right drift is corrected by lateral cyclic. To slow the helicopter to a hover, select a slightly decelerative attitude, anticipating the stopping distance, and then re-select the hover attitude as the helicopter comes to a halt. Collective: Controls height. Because the rotor thrust will be tilted forward the lever is raised to maintain height. With forward speed translational lift will increase and lowering of the lever may be necessary to maintain hover height. The opposite happens with reduction in speed. These effects will need to be anticipated and collective inputs applied accordingly. Yaw Pedals: Used to keep the fuselage pointing in the same direction as the disc is travelling (and not to steer the helicopter). During turns a little pro turn pedal will be required to keep the fuselage in line with the path of the turn. Throttle: The governor controls RPM, and throttle movements may be felt. Also MAP will fluctuate and the MAP limit must not be exceeded. Effects of wind: Allowances must be made to prevent wind causing undesired drift, speed and height changes. Into Wind: In the hover the helicopter will already be taxiing in relation to wind direction. Ground effect will be reduced or even negligible. Wind from Left: Left skid lower, use some right pedal, raise lever. Wind from the right: Fuselage towards level or right skid low, use more left pedal, watch MAP limit, raise lever. Downwind: Nose high attitude, Translational lift from behind, keep groundspeed low. More lever required watch MAP limit. Wind Strength: In light wind the above effects will be minimal. In strong wind they will be more pronounced. Attention should be paid to control limits and it should be remembered that application of left pedal will increase MAP. A maximum demonstrated crosswind operation is stated in the flight manual. HOVER TAXI PROCEDURE Airmanship Lookout Area clear Wind velocity Monitor: Warning Lights, RRPM, MAP, T&P's,Fuel, Carb Air Temp MAP limit Handovers To taxi forward: Look ahead aiming point Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 25

26 Cyclic accelerative attitude - expect lag before helicopter moves Lever raised as required to maintain hover height Pedals - left pedal As helicopter moves forward Cyclic further forward to counteract flapback Lever down as translational lift increases Lever down, pedal to maintain fuselage heading. During Taxi: Control speed and direction with cyclic Height with lever Fuselage heading with pedals Maintain good lookout, ensure taxi path remains clear. To Stop: Looking ahead; lower lever, apply right pedal. Select decelerative attitude with cyclic. As helicopter approaches hover; Select hover attitude with cyclic. Raise lever, apply left pedal. When hover established; lookout and checks. Exercise 11c Hover Emergencies Engine Failure in the hover - NB Demonstration only at this stage An engine failure in the hover will be indicated by a sharp yaw to the left accompanied by the low RPM horn. Reaction from the pilot must be immediate and relies largely on ingrained muscle memory to react in time. Control inputs are as follows:- Yaw pedals - Sufficient right pedal to stop the yaw left, Cyclic - Sufficient right cyclic to stop drift to the left caused by decaying tail rotor thrust, Collective - Pausing to allow the helicopter to descend to approx 2 feet, the raise collective to cushion touchdown, If time permits, a small amount of forward cynic applied as the collective is raised will reduce the impact and help the helicopter stay straight, reducing the chances of rollover. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 26

27 EXERCISE 12: TAKE OFF AND LANDING INTRODUCTION This is the first practical application of the skills acquired during hovering. As with hovering, the area should be level and free from obstruction. You will be expected to know the following checks before the exercise commences: Pre-take off checks After take off checks Pre-landing checks After landing checks AIRMANSHIP Lookout Fuel and engine instrument checks Recovery actions in the event of: mislanding, onset of ground resonance, dynamic rollover. Throughout the landing and take-off sequence, continue to use the external hover references and do not be tempted to concentrate on references that are too close to the helicopter. Once again, small control movements are essential to achieve a smooth performance. Remember that a good landing can only be achieved from a stable hover. LANDING Having established a stable 5ft hover, gently lower the collective lever very slightly at the same time preventing left yaw by reducing pressure on the left pedal. The helicopter will sink slightly and stabilise at a lower hover height. Maintain the ground position with cyclic. If this process is repeated, the helicopter will eventually touch the ground normally with the left skid first when dual. Once this position has been reached, lower the collective lever further and allow the right skid to come into contact with the ground. All that remains is to gently and progressively lower the collective lever to the fully down position. At the same time smoothly set the neutral position for the yaw pedals. The governor will maintain RPM at 104%. The cyclic stick may then be centralised and the post landing checks carried out. N.B DO NOT ALLOW THE HELICOPTER TO DRIFT SIDEWAYS OR BACKWARDS DURING LANDING Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 27

28 RECOVERY FROM A MIS LANDING SITUATION It is important when landing to prevent yaw, sideways and rearward movement. Should such errors exist, it is essential that the landing be discontinued by smoothly raising the collective lever to return the helicopter to a safe hover height. Once the hover is re-established, make a conscious effort to relax, assess the cause of the error and continue with another landing. Any attempt to continue a landing when the helicopter is moving laterally may result in a dynamic rollover, i.e. the helicopter will pivot around the skid which touches first and cyclic correction will not control the subsequent rollover. TAKE OFF First carry out Pre Take Off Checks, noting the following: Wind D/V. Warning lights out, E/RRPM & MAP T s and P s in the green, CAT +10 C to +15 C. Fuel sufficient. Hatches and harnesses secure. Cyclic and collective frictions off. Area clear (including above). Look to ensure the immediate vicinity is clear and that it is safe to takeoff. Level the disc using cyclic stick and anticipate yaw with left pedal. Look well ahead of the helicopter and then gently begin to raise the collective lever to approx 17 MAP. Check the governor is maintaining RPM at 104% Look ahead, correcting the tendency for the helicopter to yaw (pedals) or roll (cyclic). As the helicopter begins to lift off, adjust the cyclic stick position very slightly to achieve the hover attitude. Maintain heading with pedals. It is important to ensure the helicopter makes a smooth, clean break with the ground and continues to climb to 5ft. During the climb maintain ground position (cyclic) and heading, (pedals), establishing the hover with small control movements. When a stable hover is achieved carry out the after takeoff checks. DYNAMIC ROLLOVER Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 28

29 If the rotor disc is incorrectly positioned before take-off the helicopter will tend to roll around one skid. If this happens (and it can happen quickly), do not continue raising the lever as the cyclic will not control the rollover. The correct action is to lower the lever, which will cause the helicopter to roll back level again, readjust the disc attitude and try another takeoff. GROUND RESONANCE The R22 is not prone to ground resonance, but the risk does exist during landing and takeoff, when the skids are lightly in contact with the ground. Prolonged operation in this condition should therefore be avoided. Once the skids are on the ground, gently lower the collective lever to the bottom stop. The symptoms of ground resonance are large fuselage oscillations, which increase in amplitude. The recovery must be immediate and positive. Lift the helicopter to the hover and wait for the oscillations to cease before attempting to land again. Blades out of track or balance and over controlling aggravate the onset of ground resonance. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 29

30 EXERCISE 13: TRANSITIONS INTRODUCTION The term transition covers all flight from and to the hover. Although not specifically included in this exercise, you will also be practicing hover taxiing. This is really no more than hovering with slow forward movement. The constant angle approach & transition is particularly important; as it is not only used during circuits but also in future advanced exercises. AIRMANSHIP Lookout turn 90 left or right Area clear of obstructions and reasonably level Check fuel and engine instruments Monitor the Wind Pre take-off / pre landing checks Where possible, ensure that all transitions track parallel to the duty runway/into wind Understanding of the height / velocity diagram in the flight manual TRANSITION EFFECTS To initiate a transition into forward flight, select a slightly nose down attitude. However, in addition to accelerating, there are several noticeable effects, which must be corrected if the transition is to be carried out as demonstrated. Initial height loss: There will be an initial height loss as the nose is lowered since the rotor thrust vector has been inclined forward. Also in light winds, as the helicopter starts to move forward, there will be a loss of ground effect. Flapback and Inflow Roll: Shortly after the helicopter has begun to move forward, there will be a tendency for the helicopter to pitch nose up (flap back) and roll slightly to the right (inflow roll). Translational Lift: At approximately knots airspeed, the helicopter will tend to climb away from the ground with no additional power being applied. In calm conditions, this effect is accompanied by slight airframe buffet. The helicopter must not be allowed to climb away from the ground too far, (not more than 10 feet until 45 knots) to remain outside the avoid area on the height/velocity diagram. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 30

31 Increase in RRPM: During the transition particularly in light wind conditions, the RRPM may try to increase above normal limits. This will be controlled by the governor which will cause small MAP variations. TRANSITIONS FROM THE HOVER TO FORWARD FLIGHT Lookout Turn: This manoeuvre requires a clearing turn of 90 degrees to check the airspace behind, ahead, above and on the approach is clear of other aircraft. The helicopter should then be turned to establish a steady into wind hover and a suitable point on the horizon chosen for a heading reference. Gently accelerate forward, using a small cyclic movement, preventing sink with collective. As flapback takes effect, the cyclic must be moved progressively further forward to maintain the required accelerative attitude. During this phase, heading should be maintained with the pedals, using your chosen heading reference. As translational lift is gained, lower the collective to maintain height at approximately 10 feet. This will ensure that the helicopter remains outside the avoid area on the height/velocity diagram. A common fault is to let the helicopter climb too quickly initially which will put it into the avoid area. Your instructor will explain why this is undesirable. Refer to the Height / Velocity diagram at Appendix B. With the extra lift you can increase the rate of acceleration, and power can now be increased to 23 inches MAP at 104% RRPM. Keep the helicopter straight. At 45 knots ensure that the helicopter is in balance with the pedals, and raise the nose to the attitude for 60 knots. Your instructor will show you two slightly different techniques for the transition. You may find a particular technique easier to use in certain conditions. As you encounter flapback and translational lift there will be a tendency for the helicopter to climb. One technique involves lowering the collective to maintain height requiring the input of right pedal to keep straight. Another technique is to use further forward cyclic to counter any increase in height. This will lead to further acceleration which may be desirable in certain circumstances but must not be used excessively so that the helicopter starts to sink again or exceed engine limitations. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 31

32 TRANSITION FROM LEVEL FLIGHT TO THE HOVER The aim of this part of the exercise is to fly a constant angle approach to the hover. The angle of the approach will be varied in later exercises, but at the moment you will be taught the approach at approximately 10 degrees. Fly the helicopter level at 500 feet, 60 knots, check rotor rpm is at 104% and that the governor is working normally. Apply full carb heat and when the sight picture indicating the correct approach angle is achieved, gently lower the collective to commence a decent of ideally 500 fpm. Throughout the approach, you will need to maintain a constant apparent groundspeed to achieve a zero groundspeed hover over the aiming point. This will require a slightly nose up attitude to reduce airspeed. Adjustments to the sight picture approach are made using the collective. If the sight picture changes: e.g. you are getting low, the perspective of the aiming point will flatten out, therefore you will need to raise the collective. If you are too high, the perspective of the aiming point deepens, therefore you will need to lower the collective. All this will be demonstrated to you. In the latter stages of the approach, the aiming point should appear to slide down the canopy and disappear under the nose. In order to ensure you arrive over the aiming point in the hover it is necessary to use lateral markers. NB If a constant angle of approach is correctly maintained, the perspective of the aiming point will not alter. At 200 feet, select carb heat to the hover setting. The correct rate of closure to the landing point must be judged visually, rather than by reference to the ASI. As height and speed are lost it should be noted, that for most of the approach, the apparent ground speed remains constant. On the final stage of the approach, the indicated airspeed must not be allowed to drop below 30 knots until the rate of descent is less than 300 feet per minute. At this point outside references should be used to continue the approach to the 5 hover. THE APPROACH PICTURE Sight Picture Correct Sight Picture Too Steep Sight Picture Too shallow Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 32

33 VORTEX RING In order to avoid a Vortex Ring condition (see Ex 18), it is important to ensure that the airspeed reduces on the final stages of the approach and that the rate of descent does not exceed 300 feet per minute. As translational lift is lost, collective must be applied to prevent the helicopter from sinking. HOVER You should aim to bring the helicopter to the hover with the minimum possible attitude change, and with a smooth increase in collective as translational lift is lost. Maintain a heading with pedals and monitor RRPM THE GO AROUND Assuming that there are no external reasons requiring you to abandon the approach, there are two areas of potential mis-judgement, which would prove hazardous if the approach were continued: Excessive ground speed in the latter stages: In this situation, you would be faced with rapid transition to the hover, which is probably beyond your present capabilities. Excessive rate of descent with low airspeed: Although groundspeed is the main pre-occupation, airspeed cannot be totally ignored, as doing so, could lead to the onset of vortex ring. If this situation develops, you must go-around. The Go around procedure is to select an accelerative attitude, apply climbing power preventing yaw and reposition for another approach. Advise ATC as necessary and maintain a good look out. Other common mistakes are: Not maintaining a constant angle of approach Late application of power when establishing hover from the approach with resultant heading loss Forcing too high a rate of descent to make the desired hover point. Initially you may experience some difficulty in flying accurate transitions to the hover. With practice however, you will find that your judgement steadily improves. Cambridge City Airport, Newmarket Road, Cambridge CB5 8RX 33