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your responsibility to ensure the aircraft is in an airworthy condition.In preparation for flight, the use of a checklist is importantso that no item is overlooked. Follow the manufacturer’ssuggested outline for both the inside and outside inspection. This ensures that all the items the manufacturerfeels are important are checked. Obviously, if there areother items you feel might need attention, inspectthem as well.MINIMUM EQUIPMENT LISTS (MELS) ANDOPERATIONS WITH INOPERATIVEEQUIPMENTThe Code of Federal Regulations (CFRs) requires thatall aircraft instruments and installed equipment beoperative prior to each departure. However, when theFAA adopted the minimum equipment list (MEL)concept for 14 CFR part 91 operations, flights wereallowed with inoperative items, as long as the inoperative items were determined to be nonessential for safeflight. At the same time, it allowed part 91 operators,without an MEL, to defer repairs on nonessentialequipment within the guidelines of part 91.There are two primary methods of deferring maintenanceon rotorcraft operating under part 91. They are the deferral provision of 14 CFR part 91, section 91.213(d) and anFAA-approved MEL.The deferral provision of section 91.213(d) is widelyused by most pilot/operators. Its popularity is due tosimplicity and minimal paperwork. When inoperativeequipment is found during preflight or prior to departure, the decision should be to cancel the flight, obtainmaintenance prior to flight, or to defer the item orequipment.Maintenance deferrals are not used for in-flight discrepancies. The manufacturer's RFM/POH procedures areto be used in those situations. The discussion thatMinimum Equipment List (MEL)—An inventory of instruments andequipment that may legally be inoperative, with the specific conditionsunder which an aircraft may be flown with such items inoperative.9-2follows assumes that the pilot wishes to defer maintenance that would ordinarily be required prior to flight.Using the deferral provision of section 91.213(d), thepilot determines whether the inoperative equipment isrequired by type design, the CFRs, or ADs. If the inoperative item is not required, and the helicopter can besafely operated without it, the deferral may be made.The inoperative item shall be deactivated or removed andan INOPERATIVE placard placed near the appropriateswitch, control, or indicator. If deactivation or removalinvolves maintenance (removal always will), it must beaccomplished by certificated maintenance personnel.For example, if the position lights (installed equipment)were discovered to be inoperative prior to a daytimeflight, the pilot would follow the requirements of section 91.213(d).The deactivation may be a process as simple as the pilotpositioning a circuit breaker to the OFF position, or ascomplex as rendering instruments or equipment totallyinoperable. Complex maintenance tasks require a certificated and appropriately rated maintenance person toperform the deactivation. In all cases, the item or equipment must be placarded INOPERATIVE.All rotorcraft operated under part 91 are eligible to usethe maintenance deferral provisions of section 91.213(d).However, once an operator requests an MEL, and a Letterof Authorization (LOA) is issued by the FAA, then theuse of the MEL becomes mandatory for that helicopter.All maintenance deferrals must be accomplished inaccordance with the terms and conditions of the MEL andthe operator-generated procedures document.The use of an MEL for rotorcraft operated under part 91also allows for the deferral of inoperative items orequipment. The primary guidance becomes the FAAapproved MEL issued to that specific operator andN-numbered helicopter.The FAA has developed master minimum equipmentlists (MMELs) for rotorcraft in current use. Upon written request by a rotorcraft operator, the local FAA FlightStandards District Office (FSDO) may issue the appropriate make and model MMEL, along with an LOA, andthe preamble. The operator then develops operationsand maintenance (O&M) procedures from the MMEL.This MMEL with O&M procedures now becomes theoperator's MEL. The MEL, LOA, preamble, and procedures document developed by the operator must be onboard the helicopter when it is operated.The FAA considers an approved MEL to be a supplemental type certificate (STC) issued to an aircraft byserial number and registration number. It thereforebecomes the authority to operate that aircraft in a condition other than originally type certificated.With an approved MEL, if the position lights were discovered inoperative prior to a daytime flight, the pilotwould make an entry in the maintenance record or discrepancy record provided for that purpose. The item isthen either repaired or deferred in accordance with theMEL. Upon confirming that daytime flight with inoperative position lights is acceptable in accordance with theprovisions of the MEL, the pilot would leave the positionlights switch OFF, open the circuit breaker (or whateveraction is called for in the procedures document), and placard the position light switch as INOPERATIVE.There are exceptions to the use of the MEL for deferral.For example, should a component fail that is not listedin the MEL as deferrable (the rotor tachometer, enginetachometer, or cyclic trim, for example), then repairsare required to be performed prior to departure. If maintenance or parts are not readily available at thatlocation, a special flight permit can be obtained fromthe nearest FSDO. This permit allows the helicopter tobe flown to another location for maintenance. This
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allows an aircraft that may not currently meet applicable airworthiness requirements, but is capable of safeflight, to be operated under the restrictive special termsand conditions attached to the special flight permit.Deferral of maintenance is not to be taken lightly, anddue consideration should be given to the effect an inoperative component may have on the operation of ahelicopter, particularly if other items are inoperative.Further information regarding MELs and operationswith inoperative equipment can be found in AC 91-67,Minimum Equipment Requirements for GeneralAviation Operations Under FAR Part 91.ENGINE STARTAND ROTOR ENGAGEMENTDuring the engine start, rotor engagement, and systemsground check, use the manufacturer’s checklists. If aproblem arises, have it checked before continuing.Prior to performing these tasks, however, make surethe area near the helicopter is clear of personnel andequipment. Helicopters are safe and efficient flyingmachines as long as they are operated within theparameters established by the manufacturer.ROTOR SAFETY CONSIDERATIONSThe exposed nature of the main and tail rotors deservespecial caution. You must exercise extreme care whentaxiing near hangars or obstructions since the distancebetween the rotor blade tips and obstructions is verydifficult to judge. In addition, you cannotsee the tail rotor of some helicopters from the cabin.Therefore, when hovering backwards or turning inthose helicopters, allow plenty of room for tail rotorclearance. It is a good practice to glance over yourshoulder to maintain this clearance.9-3Another rotor safety consideration is the thrust a helicopter generates. The main rotor system is capable ofblowing sand, dust, snow, ice, and water at high velocities for a significant distance causing injury to nearbypeople and damage to buildings, automobiles, and otheraircraft. Loose snow, can severely reduce visibility andobscure outside visual references. Any airborne debrisnear the helicopter can be ingested into the engine airintake or struck by the main and tail rotor blades.SAFETY IN AND AROUND HELICOPTERSPeople have been injured, some fatally, in helicopteraccidents that would not have occurred had they beeninformed of the proper method of boarding or deplaning. A properly briefed passenger should never beendangered by a spinning rotor. The simplest methodof avoiding accidents of this sort is to stop the rotorsbefore passengers are boarded or allowed to depart.Because this action is not always practicable, and torealize the vast and unique capabilities of the helicopter, it is often necessary to take on passengers or todeplane them while the engine and rotors are turning.To avoid accidents, it is essential that all persons associated with helicopter operations, including passengers,be made aware of all possible hazards and instructed asto how they can be avoided.Persons directly involved with boarding or deplaningpassengers, aircraft servicing, rigging, or hooking upexternal loads, etc., should be instructed as to theirduties. It would be difficult, if not impossible, to covereach and every type of operation related to helicopters.A few of the more obvious and common ones are covered below.RAMP ATTENDANTS AND AIRCRAFT SERVIC-ING PERSONNEL—These personnel should beinstructed as to their specific duties, and the propermethod of fulfilling them. In addition, the ramp attendant should be taught to:1. keep passengers and unauthorized persons out ofthe helicopter landing and takeoff area.2. brief passengers on the best way to approach andboard a helicopter with its rotors turning.AIRCRAFT SERVICING—The helicopter rotor bladesshould be stopped, and both the aircraft and the refueling unit properly grounded prior to any refueling operation. You, as the pilot, should ensure that the propergrade of fuel and the proper additives, when required,are being dispensed.Refueling the aircraft, while the blades are turning,known as "hot refueling," may be practical for certaintypes of operation. However, this can be hazardous ifnot properly conducted. Pilots should remain at theflight controls; and refueling personnel should beknowledgeable about the proper refueling proceduresand properly briefed for specific helicopter makes andmodels.Refueling units should be positioned to ensure adequate rotor blade clearance. Persons not involved withthe refueling operation should keep clear of the area.Smoking must be prohibited in and around the aircraftduring all refueling operations.EXTERNAL-LOAD RIGGERS—Rigger training ispossibly one of the most difficult and continuallychanging problems of the helicopter external-loadoperator. A poorly rigged cargo net, light standard, orload pallet could result in a serious and costly accident.It is imperative that all riggers be thoroughly trained tomeet the needs of each individual external-load operation. Since rigging requirements may vary severaltimes in a single day, proper training is of the utmostimportance to safe operations.PILOT AT THE FLIGHT CONTROLS—Many helicopter operators have been lured into a "quick turnaround" ground operation to avoid delays at airportterminals and to minimize stop/start cycles of theengine. As part of this quick turnaround, the pilot might
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leave the cockpit with the engine and rotors turning.Such an operation can be extremely hazardous if a gustof wind disturbs the rotor disc, or the collective flightcontrol moves causing lift to be generated by the rotorsystem. Either occurrence may cause the helicopter toroll or pitch, resulting in a rotor blade striking the tailboom or the ground. Good operating procedures dictatethat pilots remain at the flight controls whenever theengine is running and the rotors are turning.EXTERNAL-LOAD HOOKUP PERSONNEL—There are several areas in which these personnelshould be knowledgeable. First, they should know thelifting capability of the helicopters involved. Sincesome operators have helicopter models with almostFigure 9-1. Exercise extreme caution when hovering nearbuildings or other aircraft.9-4identical physical characteristics but different liftingcapabilities, this knowledge is essential. For example,a hookup person may be working with a turbochargedhelicopter on a high altitude project when a non-turbocharged helicopter, which looks exactly the same tothe ground crew, comes to pick up a load. If thehookup person attaches a load greater than thenon-turbocharged helicopter can handle, a potentiallydangerous situation could exist.Second, know the pilots. The safest plan is to standardize all pilots in the manner in which sling loadsare picked up and released. Without pilot standardization, the operation could be hazardous. The operatorshould standardize the pilots on operations whilepersonnel are beneath the helicopter.Third, know the cargo. Many items carried via sling arevery fragile, others can take a beating. The hookup person should always know when a hazardous article isinvolved and the nature of the hazard, such as explosives, radioactive materials, and toxic chemicals. Inaddition to knowing this, the hookup person should befamiliar with the types of protective gear or clothingand the actions necessary to protect their own safetyand that of the operation.Fourth, know appropriate hand signals. When directradio communications between ground and flight personnel are not used, the specific meaning of handsignals should be coordinated prior to operations.Fifth, know emergency procedures. Ground and flightpersonnel should fully agree to and understand theactions to be taken by all participants in the event ofemergencies. This prior planning is essential to avoidinjuries to all concerned.PASSENGERS—All persons who board a helicopterwhile its rotors are turning should be instructed in thesafest means of doing so. Naturally, if you are at thecontrols, you may not be able to conduct a boardingbriefing. Therefore, the individual who arranged for thepassengers' flight or is assigned as the ramp attendantshould accomplish this task. The exact procedures mayvary slightly from one helicopter model to another, butin general the following should suffice.When boarding—1. stay away from the rear of the helicopter.2. approach or leave the helicopter in a crouchingmanner.3. approach from the side or front, but never out ofthe pilot's line of vision.4. carry tools horizontally, below waist level, neverupright or over the shoulder.5. hold firmly to hats and loose articles.6. never reach up or dart after a hat or other objectthat might be blown off or away.7. protect eyes by shielding them with a hand or bysquinting.8. if suddenly blinded by dust or a blowing object,stop and crouch lower; or better yet, sit down andwait for help.9. never grope or feel your way toward or awayfrom the helicopter.Since few helicopters carry cabin attendants, you, asthe pilot, will have to conduct the pre-takeoff and prelanding briefings. The type of operation dictates whatsort of briefing is necessary. All briefings shouldinclude the following:1. The use and operation of seatbelts for takeoff, enroute, and landing.2. For overwater flights, the location and use offlotation gear and other survival equipment thatmight be on board. You should also include howand when to abandon the helicopter should aditching be necessary.3. For flights over rough or isolated terrain, alloccupants should be told where maps and survival gear are located.4. Passengers should be instructed as to whatactions and precautions to take in the event of anemergency, such as the body position for bestspinal protection against a high vertical impactlanding (erect with back firmly against the seatback); and when and how to exit after landing.Ensure that passengers are aware of the locationof the fire extinguisher and survival equipment.5. Smoking should not be permitted within 50 feetof an aircraft on the ground. Smoking could bepermitted, at the discretion of the pilot, exceptunder the following conditions:• during all ground operations.• during, takeoff or landing.• when carrying flammable or hazardousmaterials.When passengers are approaching or leaving a helicopter that is sitting on a slope with the rotors turning, they
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should approach and depart downhill. This affords thegreatest distance between the rotor blades and theground. If this involves walking around the helicopter,they should always go around the front, never the rear.9-5VERTICAL TAKEOFF TO A HOVERA vertical takeoff, or takeoff to a hover, is a maneuverin which the helicopter is raised vertically from the surface to the normal hovering altitude (2 to 5 feet) with aminimum of lateral or longitudinal movement.TECHNIQUEPrior to any takeoff or maneuver, you should ensurethat the area is clear of other traffic. Then, head the helicopter into the wind, if possible. Place the cyclic in theneutral position, with the collective in the full downposition. Increase the throttle smoothly to obtain andmaintain proper r.p.m., then raise the collective. Usesmooth, continuous movement, coordinating the throttle to maintain proper r.p.m. As you increase the collective, the helicopter becomes light on the skids, andtorque tends to cause the nose to swing or yaw to theright unless sufficient left antitorque pedal is used tomaintain the heading. (On helicopters with a clockwisemain rotor system, the yaw is to the left and right pedalmust be applied.)As the helicopter becomes light on the skids, make necessary cyclic pitch control adjustments to maintain alevel attitude. When airborne, use the antitorque pedalsto maintain heading and the collective to ensure continuous vertical assent to the normal hovering altitude.When hovering altitude is reached, use the throttle andcollective to control altitude, and the cyclic to maintaina stationary hover. Use the antitorque pedals to maintain heading. When a stabilized hover is achieved,check the engine instruments and note the powerrequired to hover. You should also note the position ofthe cyclic. Cyclic position varies with wind and theamount and distribution of the load.Excessive movement of any flight control requires achange in the other flight controls. For example, ifwhile hovering, you drift to one side, you naturallymove the cyclic in the opposite direction. When you dothis, part of the vertical thrust is diverted, resulting in aloss of altitude. To maintain altitude, you must increasethe collective. This increases drag on the blades andtends to slow them down. To counteract the drag andmaintain r.p.m., you need to increase the throttle.Increased throttle means increased torque, so you mustadd more pedal pressure to maintain the heading. Thiscan easily lead to overcontrolling the helicopter.However, as your level of proficiency increases, problems associated with overcontrolling decrease.COMMON ERRORS1. Failing to ascend vertically as the helicopterbecomes airborne.2. Pulling through on the collective after becomingairborne, causing the helicopter to gain too muchaltitude.3. Overcontrolling the antitorque pedals, which notonly changes the handling of the helicopter, butalso changes the r.p.m.4. Reducing throttle rapidly in situations whereproper r.p.m. has been exceeded. This usuallyresults in exaggerated heading changes and lossof lift, resulting in loss of altitude.HOVERINGHovering is a maneuver in which the helicopter is maintained in a nearly motionless flight over a referencepoint at a constant altitude and on a constant heading.The maneuver requires a high degree of concentrationand coordination.TECHNIQUETo maintain a hover over a point, you should look forsmall changes in the helicopter’s attitude and altitude.When you note these changes, make the necessary control inputs before the helicopter starts to move from thepoint. To detect small variations in altitude or position,your main area of visual attention needs to be somedistance from the aircraft, using various points on thehelicopter or the tip-path plane as a reference. Lookingtoo close or looking down leads to overcontrolling.Obviously, in order to remain over a certain point, youshould know where the point is, but your attentionshould not be focused there.As with a takeoff, you control altitude with the collective and maintain a constant r.p.m. with the throttle.Use the cyclic to maintain the helicopter’s position andthe pedals to control heading. To maintain thehelicopter in a stabilized hover, make small, smooth,coordinated corrections. As the desired effect occurs,remove the correction in order to stop the helicopter’smovement. For example, if the helicopter begins tomove rearward, you need to apply a small amount offorward cyclic pressure. However, neutralize this pressure just before the helicopter comes to a stop, or it willbegin to move forward.After you gain experience, you will develop a certain“feel” for the helicopter. You will feel and see smalldeviations, so you can make the corrections before thehelicopter actually moves. A certain relaxed loosenessdevelops, and controlling the helicopter becomes second nature, rather than a mechanical response.COMMON ERRORS1. Tenseness and slow reactions to movements ofthe helicopter.2. Failure to allow for lag in cyclic and collectivepitch, which leads to overcontrolling.9-63. Confusing attitude changes for altitude changes,
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which result in improper use of the controls.4. Hovering too high, creating a hazardous flightcondition.5. Hovering too low, resulting in occasional touchdown.HOVERING TURNA hovering turn is a maneuver performed at hoveringaltitude in which the nose of the helicopter is rotatedeither left or right while maintaining position over areference point on the surface. The maneuver requiresthe coordination of all flight controls and demands precise control near the surface. You should maintain aconstant altitude, rate of turn, and r.p.m.TECHNIQUEInitiate the turn in either direction by applying antitorque pedal pressure toward the desired direction. Itshould be noted that during a turn to the left, you needto add more power because left pedal pressureincreases the pitch angle of the tail rotor, which, in turn,requires additional power from the engine. A turn to theright requires less power. (On helicopters with a clockwise rotating main rotor, right pedal increases the pitchangle and, therefore, requires more power.)As the turn begins, use the cyclic as necessary (usuallyinto the wind) to keep the helicopter over the desiredspot. To continue the turn, you need to add more andmore pedal pressure as the helicopter turns to the crosswind position. This is because the wind is striking thetail surface and tail rotor area, making it more difficultfor the tail to turn into the wind. As pedal pressuresincrease due to crosswind forces, you must increase thecyclic pressure into the wind to maintain position. Usethe collective with the throttle to maintain a constantaltitude and r.p.m. After the 90° portion of the turn, you need to decreasepedal pressure slightly to maintain the same rate ofturn. Approaching the 180°, or downwind, portion,you need to anticipate opposite pedal pressure due tothe tail moving from an upwind position to a downwind position. At this point, the rate of turn has a tendency to increase at a rapid rate due to theweathervaning tendency of the tail surfaces. Becauseof the tailwind condition, you need to hold rearwardcyclic pressure to keep the helicopter over the samespot.Because of the helicopter’s tendency to weathervane,maintaining the same rate of turn from the 180° position actually requires some pedal pressure opposite thedirection of turn. If you do not apply opposite pedalpressure, the helicopter tends to turn at a faster rate.The amount of pedal pressure and cyclic deflectionthroughout the turn depends on the wind velocity. Asyou finish the turn on the upwind heading, applyopposite pedal pressure to stop the turn. Graduallyapply forward cyclic pressure to keep the helicopterfrom drifting.Cyclic - ForwardPedal - Some left inhover, more left to startturn to left.Cyclic - RightPedal - Most leftpressure in turn.Cyclic - RearwardPedal - Changing fromleft to right pressure.Cyclic - LeftPedal - Most right pedalpressure in turn.Cyclic - ForwardPedal - Some right tostop turn, then left tomaintain heading.Collective - Powerrequired to hover atdesired height.Throttle – As necessaryto maintain r.p.m.Collective -Most powerin turn.Throttle – As necessaryto maintain r.p.m.Collective - Powerreducing.Throttle – As necessaryto maintain r.p.m.Collective - Least powerin turn.Throttle – As necessaryto maintain r.p.m.Collective - Increasingas left pedal applied.Throttle – As necessaryto maintain r.p.m.WINDFigure 9-2. Left turns in helicopters with a counterclockwise rotating main rotor are more difficult to execute because the tailrotor demands more power. This requires that you compensate with additional collective pitch and increased throttle. Youmight want to refer to this graphic throughout the remainder of the discussion on a hovering turn to the left.9-7Control pressures and direction of application changecontinuously throughout the turn. The most dramaticchange is the pedal pressure (and corresponding powerrequirement) necessary to control the rate of turn as thehelicopter moves through the downwind portion of themaneuver.Turns can be made in either direction; however, in ahigh wind condition, the tail rotor may not be able toproduce enough thrust, which means you will not beable to control a turn to the right in a counterclockwiserotor system. Therefore, if control is ever questionable, you should first attempt to make a 90° turn to theleft. If sufficient tail rotor thrust exists to turn thehelicopter crosswind in a left turn, a right turn canbe successfully controlled. The opposite applies tohelicopters with clockwise rotor systems. In thiscase, you should start your turn to the right.Hovering turns should be avoided in winds strong
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发表于 2009-3-20 23:56:31
enough to preclude sufficient aft cyclic control tomaintain the helicopter on the selected surfacereference point when headed downwind. Checkthe flight manual for the manufacturer’s recommendations for this limitation.COMMON ERRORS1. Failing to maintain a slow, constant rate of turn.2. Failing to maintain position over the referencepoint.3. Failing to maintain r.p.m. within normal range.4. Failing to maintain constant altitude.5. Failing to use the antitorque pedals properly.HOVERING—FORWARD FLIGHTYou normally use forward hovering flight to move ahelicopter to a specific location, and it is usually begunfrom a stationary hover. During the maneuver, constantgroundspeed, altitude, and heading should be maintained.TECHNIQUEBefore starting, pick out two references directly infront and in line with the helicopter. These referencepoints should be kept in line throughout the maneuver.Begin the maneuver from a normal hovering altitude byapplying forward pressure on the cyclic. As movementbegins, return the cyclic toward the neutral position tokeep the groundspeed at a slow rate—no faster than abrisk walk. Throughout the maneuver, maintain aconstant groundspeed and path over the ground withthe cyclic, a constant heading with the antitorquepedals, altitude with the collective, and the properr.p.m. with the throttle.To stop the forward movement, apply reward cyclicpressure until the helicopter stops. As forward motionstops, return the cyclic to the neutral position to prevent rearward movement. Forward movement can alsobe stopped by simply applying rearward pressure tolevel the helicopter and let it drift to a stop.COMMON ERRORS1. Exaggerated movement of the cyclic, resulting inerratic movement over the surface.2. Failure to use the antitorque pedals properly,resulting is excessive heading changes.3. Failure to maintain desired hovering altitude.4. Failure to maintain proper r.p.m.HOVERING—SIDEWARD FLIGHTSideward hovering flight may be necessary to movethe helicopter to a specific area when conditions makeit impossible to use forward flight. During the maneuver, a constant groundspeed, altitude, and headingshould be maintained.TECHNIQUEBefore starting sideward hovering flight, make sure thearea you are going to hover into is clear. Then pick twopoints of reference in a line in the direction of sidewardhovering flight to help you maintain the proper groundReferencePointsFigure 9-3. To maintain a straight ground track, use two reference points in line and at some distance in front of the helicopter.9-8track. These reference points should be kept in linethroughout the maneuver. Begin the maneuver from a normal hovering altitudeby applying cyclic toward the side in which themovement is desired. As the movement begins, returnthe cyclic toward the neutral position to keep thegroundspeed at a slow rate—no faster than a briskwalk. Throughout the maneuver, maintain a constantgroundspeed and ground track with cyclic. Maintainheading, which in this maneuver is perpendicular tothe ground track, with the antitorque pedals, and aconstant altitude with the collective. Use the throttleto maintain the proper operating r.p.m.To stop the sideward movement, apply cyclic pressure in the direction opposite to that of movementand hold it until the helicopter stops. As motionstops, return the cyclic to the neutral position toprevent movement in the opposite direction.Applying sufficient opposite cyclic pressure tolevel the helicopter may also stop sideward movement. The helicopter then drifts to a stop.COMMON ERRORS1. Exaggerated movement of the cyclic, resulting inovercontrolling and erratic movement over thesurface.2. Failure to use proper antitorque pedal control,resulting in excessive heading change.3. Failure to maintain desired hovering altitude.4. Failure to maintain proper r.p.m.5. Failure to make sure the area is clear prior tostarting the maneuver.HOVERING—REARWARD FLIGHTRearward hovering flight may be necessary to move thehelicopter to a specific area when the situation is suchthat forward or sideward hovering flight cannot be used.During the maneuver, maintain a constant groundspeed,altitude, and heading. Due to the limited visibilitybehind a helicopter, it is important that you make surethat the area behind the helicopter is cleared beforebeginning the maneuver. Use of ground personnel is recommended.TECHNIQUEBefore starting rearward hovering flight, pick out tworeference points in front of, and in line with the helicopter just like you would if you were hovering forward. The movement of the helicoptershould be such that these points remain in line.Begin the maneuver from a normal hovering altitude byapplying rearward pressure on the cyclic. After themovement has begun, position the cyclic to maintain aslow groundspeed (no faster than a brisk walk).
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Throughout the maneuver, maintain constant groundspeed and ground track with the cyclic, a constantheading with the antitorque pedals, constant altitudewith the collective, and the proper r.p.m. with the throttle.To stop the rearward movement, apply forward cyclicand hold it until the helicopter stops. As the motionstops, return the cyclic to the neutral position. Also, asin the case of forward and sideward hovering flight,opposite cyclic can be used to level the helicopter andlet it drift to a stop.COMMON ERRORS1. Exaggerated movement of the cyclic resulting inovercontrolling and an uneven movement overthe surface.2. Failure to use the antitorque pedals properly,resulting in excessive heading change.3. Failure to maintain desired hovering altitude.4. Failure to maintain proper r.p.m.5. Failure to make sure the area is clear prior tostarting the maneuver.TAXIINGTaxiing refers to operations on, or near the surface oftaxiways or other prescribed routes. In helicopters,there are three different types of taxiing.ReferencePointsFigure 9-4. The key to hovering sideward is establishing atleast two reference points that help you maintain a straighttrack over the ground while keeping a constant heading.9-9HOVER TAXIA "hover taxi" is used when operating below 25 feetAGL. Since hover taxi is just like forward,sideward, or rearward hovering flight, the technique toperform it will not be presented here.AIR TAXIAn "air taxi" is preferred when movements requiregreater distances within an airport or heliport boundary. In this case, you basically fly to yournew location; however, you are expected to remainbelow 100 feet AGL, and to avoid overflight of otheraircraft, vehicles, and personnel.TECHNIQUEBefore starting, determine the appropriate airspeed andaltitude combination to remain out of the cross-hatchedor shaded areas of the height-velocity diagram.Additionally, be aware of crosswind conditions thatcould lead to loss of tail rotor effectiveness. Pick outtwo references directly in front of the helicopter for theground path desired. These reference points should bekept in line throughout the maneuver.Begin the maneuver from a normal hovering altitudeby applying forward pressure on the cyclic. As movement begins, attain the desired airspeed with the cyclic.Control the desired altitude with the collective, andr.p.m. with the throttle. Throughout the maneuver,maintain a desired groundspeed and ground track withthe cyclic, a constant heading with antitorque pedals,the desired altitude with the collective, and properoperating r.p.m. with the throttle.To stop the forward movement, apply aft cyclic pressureto reduce forward speed. Simultaneously lower the collective to initiate a descent to hover altitude. Asforward motion stops, return the cyclic to the neutral position to prevent rearward movement. When at the properhover altitude, increase the collective as necessary.COMMON ERRORS1. Erratic movement of the cyclic, resulting inimproper airspeed control and erratic movementover the surface.2. Failure to use antitorque pedals properly, resulting in excessive heading changes.3. Failure to maintain desired altitude.4. Failure to maintain proper r.p.m.5. Overflying parked aircraft causing possible damage from rotor downwash.6. Flying in the cross-hatched or shaded area of theheight-velocity diagram.7. Flying in a crosswind that could lead to loss oftail rotor effectiveness.SURFACE TAXIA "surface taxi," for those helicopters with wheels, isused whenever you wish to minimize the effects ofrotor downwash. TECHNIQUEThe helicopter should be in a stationary position on thesurface with the collective full down and the r.p.m. thesame as that used for a hover. This r.p.m. should bemaintained throughout the maneuver. Then, move thecyclic slightly forward and apply gradual upward pressure on the collective to move the helicopter forwardHover Taxi(25 Feet or Less)Poor Surface Conditions or Skid Type HelicoptersFigure 9-5. Hover taxi.Air Taxi(100 Feet or Less)Faster TravelFigure 9-6. Air taxi.Surface TaxiLess Rotor DownwashFigure 9-7. Surface taxi.9-10along the surface. Use the antitorque pedals to maintainheading and the cyclic to maintain ground track. Thecollective controls starting, stopping, and speed whiletaxiing. The higher the collective pitch, the faster thetaxi speed; however, you should not taxi faster than abrisk walk. If your helicopter is equipped with brakes,use them to help you slow down. Do not use the cyclicto control groundspeed.During a crosswind taxi, hold the cyclic into the wind asufficient amount to eliminate any drifting movement.COMMON ERRORS
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发表于 2009-3-20 23:57:17
1. Improper use of cyclic.2. Failure to use antitorque pedals for headingcontrol.3. Improper use of the controls during crosswindoperations.4. Failure to maintain proper r.p.m.NORMAL TAKEOFF FROM A HOVERA normal takeoff from a hover is an orderly transitionto forward flight and is executed to increase altitudesafely and expeditiously. During the takeoff, fly a profile that avoids the cross-hatched or shaded areas of theheight-velocity diagram.TECHNIQUERefer to figure 9-8 (position 1). Bring the helicopter toa hover and make a performance check, whichincludes power, balance, and flight controls. The powercheck should include an evaluation of the amount ofexcess power available; that is, the difference betweenthe power being used to hover and the power availableat the existing altitude and temperature conditions. Thebalance condition of the helicopter is indicated by theposition of the cyclic when maintaining a stationaryhover. Wind will necessitate some cyclic deflection,but there should not be an extreme deviation fromneutral. Flight controls must move freely, and the helicopter should respond normally. Then visually clearthe area all around.Start the helicopter moving by smoothly and slowly easing the cyclic forward (position 2). As the helicopterstarts to move forward, increase the collective, as necessary, to prevent the helicopter from sinking and adjustthe throttle to maintain r.p.m. The increase in powerrequires an increase in the proper antitorque pedal tomaintain heading. Maintain a straight takeoff paththroughout the takeoff. As you accelerate through effective translational lift (position 3), the helicopter beginsto climb and the nose tends to rise due to increased lift.At this point adjust the collective to obtain normal climbpower and apply enough forward cyclic to overcomethe tendency of the nose to rise. At position 4, hold anattitude that allows a smooth acceleration toward climbing airspeed and a commensurate gain in altitude so thatthe takeoff profile does not take you through any of thecross-hatched or shaded areas of the height-velocitydiagram. As airspeed increases (position 5), the streamlining of the fuselage reduces engine torque effect,requiring a gradual reduction of antitorque pedalpressure. As the helicopter continues to climb and accelerate to best rate of climb, apply aft cyclic pressure toraise the nose smoothly to the normal climb attitude.COMMON ERRORS1. Failing to use sufficient collective pitch to prevent loss of altitude prior to attaining translational lift.2. Adding power too rapidly at the beginning of thetransition from hovering to forward flight withoutforward cyclic compensation, causing the helicopterto gain excessive altitude before acquiring airspeed.Figure 9-8. The helicopter takes several positions during a normal takeoff from a hover. The numbered positions in the text referto the numbers in this illustration.9-113. Assuming an extreme nose-down attitude nearthe surface in the transition from hovering toforward flight.4. Failing to maintain a straight flight path over thesurface (ground track).5. Failing to maintain proper airspeed during theclimb.6. Failing to adjust the throttle to maintain properr.p.m.NORMAL TAKEOFF FROM THESURFACENormal takeoff from the surface is used to move thehelicopter from a position on the surface into effectivetranslational lift and a normal climb using a minimumamount of power. If the surface is dusty or covered withloose snow, this technique provides the most favorablevisibility conditions and reduces the possibility ofdebris being ingested by the engine.TECHNIQUEPlace the helicopter in a stationary position on the surface. Lower the collective to the full down position,and reduce the r.p.m. below operating r.p.m. Visuallyclear the area and select terrain features, or otherobjects, to aid in maintaining the desired track duringtakeoff and climb out. Increase the throttle to theproper r.p.m. and raise the collective slowly until thehelicopter is light on the skids. Hesitate momentarilyand adjust the cyclic and antitorque pedals, as necessary, to prevent any surface movement. Continue toapply upward collective and, as the helicopter breaksground, use the cyclic, as necessary, to begin forwardmovement as altitude is gained. Continue to accelerate, and as effective translational lift is attained, thehelicopter begins to climb. Adjust attitude and power,if necessary, to climb in the same manner as a takeofffrom a hover.COMMOM ERRORS1. Departing the surface in an attitude that is toonose-low. This situation requires the use of excessive power to initiate a climb.2. Using excessive power combined with a levelattitude, which causes a vertical climb.3. Too abrupt application of the collective whendeparting the surface, causing r.p.m. and headingcontrol errors.CROSSWIND CONSIDERATIONSDURING TAKEOFFSIf the takeoff is made during crosswind conditions, the
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发表于 2009-3-20 23:57:30
helicopter is flown in a slip during the early stages ofthe maneuver. The cyclic is held into thewind a sufficient amount to maintain the desiredground track for the takeoff. The heading is maintainedwith the use of the antitorque pedals. In other words,the rotor is tilted into the wind so that the sidewardmovement of the helicopter is just enough to counteract the crosswind effect. To prevent the nose fromturning in the direction of the rotor tilt, it is necessaryto increase the antitorque pedal pressure on the sideopposite the rotor tilt.After approximately 50 feet of altitude is gained, makea coordinated turn into the wind to maintain the desiredground track. This is called crabbing into the wind. Thestronger the crosswind, the more you have to turn thehelicopter into the wind to maintain the desired groundtrack. WindMovementHelicopterSide MovementFigure 9-9. During a slip, the rotor disc is tilted into the wind.WindMovementHelicopter GroundTrackHelicopterHeadingFigure 9-10. To compensate for wind drift at altitude, crab thehelicopter into the wind.9-12STRAIGHT-AND-LEVEL FLIGHTStraight-and-level flight is flight in which a constantaltitude and heading are maintained. The attitude of thehelicopter determines the airspeed and is controlled bythe cyclic. Altitude is primarily controlled by use of thecollective.TECHNIQUETo maintain forward flight, the rotor tip-path plane mustbe tilted forward to obtain the necessary horizontalthrust component from the main rotor. This generallyresults in a nose-low attitude. The lower the nose, thegreater the power required to maintain altitude, and thehigher the resulting airspeed. Conversely, the greaterthe power used, the lower the nose must be to maintainaltitude. When in straight-and-level flight, any increase in thecollective, while holding airspeed constant, causes thehelicopter to climb. A decrease in the collective, whileholding airspeed constant, causes the helicopter todescend. A change in the collective requires a coordinated change of the throttle to maintain a constantr.p.m. Additionally, the antitorque pedals need to beadjusted to maintain heading and to keep the helicopterin longitudinal trim.To increase airspeed in straight-and-level flight, applyforward pressure on the cyclic and raise the collectiveas necessary to maintain altitude. To decrease airspeed,apply rearward pressure on the cyclic and lower thecollective, as necessary, to maintain altitude.Although the cyclic is sensitive, there is a slight delayin control reaction, and it will be necessary to anticipate actual movement of the helicopter. When makingcyclic inputs to control the altitude or airspeed of a helicopter, take care not to overcontrol. If the nose of thehelicopter rises above the level-flight attitude, applyforward pressure to the cyclic to bring the nose down.If this correction is held too long, the nose drops toolow. Since the helicopter continues to change attitudemomentarily after the controls reach neutral, return thecyclic to neutral slightly before the desired attitude isreached. This principal holds true for any cyclic input.Since helicopters are inherently unstable, if a gust orturbulence causes the nose to drop, the nose tends tocontinue to drop instead of returning to a straight-andlevel attitude as would a fixed-wing aircraft.Therefore, you must remain alert and FLY the helicopter at all times.COMMON ERRORS1. Failure to properly trim the helicopter, tending tohold antitorque pedal pressure and oppositecyclic. This is commonly called cross-controlling.2. Failure to maintain desired airspeed.3. Failure to hold proper control position to maintain desired ground track.TURNSA turn is a maneuver used to change the heading of thehelicopter. The aerodynamics of a turn were previouslydiscussed in Chapter 3—Aerodynamics of Flight.TECHNIQUEBefore beginning any turn, the area in the direction ofthe turn must be cleared not only at the helicopter’s altitude, but also above and below. To enter a turn fromstraight-and-level flight, apply sideward pressure onthe cyclic in the direction the turn is to be made. This isthe only control movement needed to start the turn. Donot use the pedals to assist the turn. Use the pedals onlyto compensate for torque to keep the helicopter in longitudinal trim. How fast the helicopter banks depends on how muchlateral cyclic pressure you apply. How far the helicopter banks (the steepness of the bank) depends on howlong you displace the cyclic. After establishing theproper bank angle, return the cyclic toward the neutralposition. Increase the collective and throttle to main-Tip-Path PlaneFigure 9-11. You can maintain a straight-and-level attitude bykeeping the tip-path plane parallel to and a constant distanceabove or below the natural horizon. For any given airspeed,this distance remains the same as long as you sit in the sameposition in the same type of aircraft.HCLInertiaFigure 9-12. During a level, coordinated turn, the rate of turnis commensurate with the angle of bank used, and inertia andhorizontal component of lift (HCL) are equal.
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发表于 2009-3-20 23:57:41
9-13tain altitude and r.p.m. As the torque increases, increasethe proper antitorque pedal pressure to maintain longitudinal trim. Depending on the degree of bank, additional forward cyclic pressure may be required tomaintain airspeed.Rolling out of the turn to straight-and-level flight is thesame as the entry into the turn except that pressure onthe cyclic is applied in the opposite direction. Since thehelicopter continues to turn as long as there is any bank,start the rollout before reaching the desired heading.The discussion on level turns is equally applicable tomaking turns while climbing or descending. The onlydifference being that the helicopter is in a climbing ordescending attitude rather than that of level flight. If asimultaneous entry is desired, merely combine thetechniques of both maneuvers—climb or descententry and turn entry. When recovering from a climbingor descending turn, the desired heading and altitude arerarely reached at the same time. If the heading isreached first, stop the turn and maintain the climb ordescent until reaching the desired altitude. On theother hand, if the altitude is reached first, establish thelevel flight attitude and continue the turn to thedesired heading.SLIPSA slip occurs when the helicopter slides sidewaystoward the center of the turn. It is causedby an insufficient amount of antitorque pedal in thedirection of the turn, or too much in the direction opposite the turn, in relation to the amount of power used. Inother words, if you hold improper antitorque pedal pressure, which keeps the nose from following the turn, thehelicopter slips sideways toward the center of the turn.SKIDSA skid occurs when the helicopter slides sidewaysaway from the center of the turn. It iscaused by too much antitorque pedal pressure in thedirection of the turn, or by too little in the directionopposite the turn in relation to the amount of powerused. If the helicopter is forced to turn faster withincreased pedal pressure instead of by increasing thedegree of the bank, it skids sideways away from thecenter of the turn instead of flying in its normal curvedpattern.In summary, a skid occurs when the rate of turn is toofast for the amount of bank being used, and a slip occurswhen the rate of turn is too slow for the amount of bankbeing used.COMMON ERRORS1. Using antitorque pedal pressures for turns. This isusually not necessary for small helicopters.2. Slipping or skidding in the turn.NORMAL CLIMBThe entry into a climb from a hover has already beendiscussed under “Normal Takeoff from a Hover;” therefore, this discussion is limited to a climb entry fromcruising flight.TECHNIQUETo enter a climb from cruising flight, apply aft cyclic toobtain the approximate climb attitude. Simultaneouslyincrease the collective and throttle to obtain climbpower and maintain r.p.m. In a counterclockwise rotorsystem, increase the left antitorque pedal pressure tocompensate for the increased torque. As the airspeedapproaches normal climb airspeed, adjust the cyclic tohold this airspeed. Throughout the maneuver, maintainclimb attitude, heading, and airspeed with the cyclic;climb power and r.p.m. with the collective and throttle;and longitudinal trim with the antitorque pedals.To level off from a climb, start adjusting the attitude to thelevel flight attitude a few feet prior to reaching the desiredaltitude. The amount of lead depends on the rate of climbat the time of level-off (the higher the rate of climb, theSlipInertia HCLFigure 9-13. During a slip, the rate of turn is too slow for theangle of bank used, and the horizontal component of lift(HCL) exceeds inertia.SkidHCL InertiaFigure 9-14. During a skid, the rate of turn is too fast for theangle of bank used, and inertia exceeds the horizontal component of lift (HCL).9-14more the lead). Generally, the lead is 10 percent of theclimb rate. For example, if your climb rate is 500 feet perminute, you should lead the level-off by 50 feet.To begin the level-off, apply forward cyclic to adjustand maintain a level flight attitude, which is slightlynose low. You should maintain climb power until theairspeed approaches the desired cruising airspeed, thenlower the collective to obtain cruising power and adjustthe throttle to obtain and maintain cruising r.p.m.Throughout the level-off, maintain longitudinal trimand heading with the antitorque pedals.COMMON ERRORS1. Failure to maintain proper power and airspeed.2. Holding too much or too little antitorque pedal.3. In the level-off, decreasing power before lowering the nose to cruising attitude.NORMAL DESCENTA normal descent is a maneuver in which the helicopter loses altitude at a controlled rate in a controlledattitude.TECHNIQUETo establish a normal descent from straight-and-levelflight at cruising airspeed, lower the collective to obtainproper power, adjust the throttle to maintain r.p.m., andincrease right antitorque pedal pressure to maintainheading in a counterclockwise rotor system, or left
