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发表于 2009-3-20 23:51:10
109 109 109 109 85 67 48109 109 109 96 75 57 --109 109 108 84 66 48 --109 109 95 74 57 -- --109 108 84 66 48 -- --109 109 94 72 49 -- --09 103 81 59 -- -- --109 91 70 48 -- -- --109 80 59 -- -- -- --109 70 48 -- -- -- --20406080100020406080100MAXIMUM VNE DOORS OFF - 102 MPH IASVNE - MPH IASGROSSWEIGHTMORETHAN1,700LBS1,700LBSORLESSNEVER EXCEED SPEEDPressure Alt. 1,000 Feet0 2 4 6 8 10 12 141101009080706050KIASVNE-20°C0° C+20° C+40° CMAX ALT.Figure 6-6. Various VNE placards.ers should describe the systems in a manner that isunderstandable to most pilots. For larger, more complex rotorcraft, the manufacturer may assume a higherdegree of knowledge. (For more information on rotorcraft systems, refer to Chapter 5—Helicopter Systemsand Chapter 18—Gyroplane Systems.)HANDLING, SERVICING, ANDMAINTENANCEThe Handling, Servicing, and Maintenance sectiondescribes the maintenance and inspections recommended by the manufacturer, as well as those requiredby the regulations, and Airworthiness Directive (AD)compliance procedures. There are also suggestions onhow the pilot/operator can ensure that the work is doneproperly.
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发表于 2009-3-20 23:51:23
This section also describes preventative maintenancethat may be accomplished by certificated pilots, aswell as the manufacturer’s recommended ground handling procedures, including considerations forhangaring, tie down, and general storage proceduresfor the rotorcraft.SUPPLEMENTSThe Supplements Section describes pertinent information necessary to operate optional equipment installed onthe rotorcraft that would not be installed on a standardaircraft. Some of this information may be supplied by theaircraft manufacturer, or by the maker of the optionalequipment. The information is then inserted into theflight manual at the time the equipment is installed.SAFETY AND OPERATIONAL TIPSThe Safety and Operational Tips is an optional sectionthat contains a review of information that couldenhance the safety of the operation. Some examples ofthe information that might be covered include: physiological factors, general weather information, fuel conservation procedures, external load warnings, low rotorr.p.m. considerations, and recommendations that if notadhered to could lead to an emergency.Airworthiness Directive (AD)—Aregulatory notice that is sent outby the FAA to the registered owners of aircraft informing them ofthe discovery of a condition thatkeeps their aircraft from continuing to meet its conditions for airworthiness. AirworthinessDirectives must be complied withwithin the required time limit, andthe fact of compliance, the date ofcompliance, and the method ofcompliance must be recorded inthe aircraft maintenance records.6-4These charts, graphs, and tables vary in style but allcontain the same basic information. Some examplesof the performance information that can be found inmost flight manuals include a calibrated versus indicated airspeed conversion graph, hovering ceilingversus gross weight charts, and a height-velocity diagram. For information on how to use thecharts, graphs, and tables, refer to Chapter 8—Performance.WEIGHT AND BALANCEThe Weight and Balance section should contain all theinformation required by the FAA that is necessary tocalculate weight and balance. To help you correctlycompute the proper data, most manufacturers includesample problems. (Weight and balance is further discussed in Chapter 7—Weight and Balance.)AIRCRAFT AND SYSTEMSDESCRIPTIONThe Aircraft and Systems Description section is anexcellent place to study and familiarize yourself withall the systems found on your aircraft. The manufactur-1,500 1,40002,000
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发表于 2009-3-20 23:51:42
4,0006,0008,00010,00012,0001,600 1,700 1,800PRESSURE ALTITUDE ~ FEETGROSS WEIGHT ~ LBS8,000 FT.DENSITY ALTITUDEMIXTUREFULL RICHOAT120°FOAT100°FOAT80°FOAT60°FOAT40°FOAT20°FOAT0°FFigure 6-7. One of the performance charts in the PerformanceSection is the “In Ground Effect Hover Ceiling versus GrossWeight” chart. This chart allows you to determine how muchweight you can carry and still operate at a specific pressurealtitude, or if you are carrying a specific weight, what is youraltitude limitation.7-1It is vital to comply with weight and balance limitsestablished for helicopters. Operating above the maximum weight limitation compromises the structuralintegrity of the helicopter and adversely affects performance. Balance is also critical because on somefully loaded helicopters, center of gravity deviations assmall as three inches can dramatically change a helicopter’s handling characteristics. Taking off in a helicopter that is not within the weight and balancelimitations is unsafe.WEIGHTWhen determining if your helicopter is within theweight limits, you must consider the weight of the basichelicopter, crew, passengers, cargo, and fuel. Althoughthe effective weight (load factor) varies during maneuvering flight, this chapter primarily considers theweight of the loaded helicopter while at rest.The following terms are used when computing a helicopter’s weight.BASIC EMPTY WEIGHT—The starting point forweight computations is the basic empty weight, whichis the weight of the standard helicopter, optionalequipment, unusable fuel, and full operating fluidsincluding full engine oil. Some helicopters might usethe term “licensed empty weight,” which is nearly thesame as basic empty weight, except that it does notinclude full engine oil, just undrainable oil. If you fly ahelicopter that lists a licensed empty weight, be sure toadd the weight of the oil to your computations.USEFUL LOAD—The difference between the grossweight and the basic empty weight is referred to asuseful load. It includes the flight crew, usable fuel,drainable oil, if applicable, and payload.PAYLOAD—The weight of the passengers, cargo, andbaggage.GROSS WEIGHT—The sum of the basic empty weight
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发表于 2009-3-20 23:51:55
and useful load.MAXIMUM GROSS WEIGHT— The maximumweight of the helicopter. Most helicopters have an internal maximum gross weight, which refers to the weightwithin the helicopter structure and an external maximumgross weight, which refers to the weight of the helicopterwith an external load.WEIGHT LIMITATIONSWeight limitations are necessary to guarantee the structural integrity of the helicopter, as well as enabling youto predict helicopter performance accurately. Althoughaircraft manufacturers build in safety factors, youshould never intentionally exceed the load limits forwhich a helicopter is certificated. Operating above amaximum weight could result in structural deformationor failure during flight if you encounter excessive loadfactors, strong wind gusts, or turbulence. Operatingbelow a minimum weight could adversely affect thehandling characteristics of the helicopter. During single-pilot operations in some helicopters, you may haveto use a large amount of forward cyclic in order tomaintain a hover. By adding ballast to the helicopter,the cyclic will be closer to the center, which gives youa greater range of control motion in every direction.Additional weight also improves autorotational characteristics since the autorotational descent can be established sooner. In addition, operating below minimumweight could prevent you from achieving the desirablerotor r.p.m. during autorotations.Although a helicopter is certificated for a specifiedmaximum gross weight, it is not safe to take off withthis load under all conditions. Anything that adverselyaffects takeoff, climb, hovering, and landing performance may require off-loading of fuel, passengers, orbaggage to some weight less than the published maximum. Factors which can affect performance includehigh altitude, high temperature, and high humidity conditions, which result in a high density altitude.DETERMINING EMPTY WEIGHTA helicopter’s weight and balance records containessential data, including a complete list of all installedoptional equipment. Use these records to determine theweight and balance condition of the empty helicopter.When a helicopter is delivered from the factory, the basicempty weight, empty weight center of gravity (CG), anduseful load are recorded on a weight and balance datasheet included in the FAA-Approved Rotocraft FlightManual. The basic empty weight can vary even in thesame model of helicopter because of differences ininstalled equipment. If the owner or operator of a helicopter has equipment removed, replaced, or additionalequipment installed, these changes must be reflected inthe weight and balance records. In addition, major7-2repairs or alterations must be recorded by a certified
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发表于 2009-3-20 23:52:06
mechanic. When the revised weight and moment arerecorded on a new form, the old record is marked withthe word “superseded” and dated with the effectivedate of the new record. This makes it easy to determinewhich weight and balance form is the latest version.You must use the latest weight and balance data forcomputing all loading problems.BALANCEHelicopter performance is not only affected by grossweight, but also by the position of that weight. It isessential to load the aircraft within the allowable centerof-gravity range specified in the rotorcraft flight manual’s weight and balance limitations.CENTER OF GRAVITY (CG)The center of gravity is defined as the theoretical pointwhere all of the aircraft’s weight is considered to beconcentrated. If a helicopter was suspended by a cableattached to the center-of-gravity point, it would balancelike a teeter-totter. For helicopters with a single mainrotor, the CG is usually close to the main rotor mast.Improper balance of a helicopter’s load can result inserious control problems. The allowable range in whichthe CG may fall is called the “CG range.” The exactCG location and range are specified in the rotorcraftflight manual for each helicopter. In addition to makinga helicopter difficult to control, an out-of-balance loading condition also decreases maneuverability sincecyclic control is less effective in the direction oppositeto the CG location.Ideally, you should try to perfectly balance a helicopterso that the fuselage remains horizontal in hoveringflight, with no cyclic pitch control needed except forwind correction. Since the fuselage acts as a pendulumsuspended from the rotor, changing the center of gravity changes the angle at which the aircraft hangs fromthe rotor. When the center of gravity is directly underthe rotor mast, the helicopter hangs horizontal; if theCG is too far forward of the mast, the helicopter hangswith its nose tilted down; if the CG is too far aft of themast, the nose tilts up. CG FORWARD OF FORWARD LIMITA forward CG may occur when a heavy pilot and passenger take off without baggage or proper ballastlocated aft of the rotor mast. This situation becomesworse if the fuel tanks are located aft of the rotor mastbecause as fuel burns the weight located aft of the rotormast becomes less.You can recognize this condition when coming to ahover following a vertical takeoff. The helicopter willhave a nose-low attitude, and you will need excessiverearward displacement of the cyclic control to maintaina hover in a no-wind condition. You should not continueflight in this condition, since you could rapidly run outof rearward cyclic control as you consume fuel. You alsomay find it impossible to decelerate sufficiently to bring
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发表于 2009-3-20 23:52:18
the helicopter to a stop. In the event of engine failure andthe resulting autorotation, you may not have enoughcyclic control to flare properly for the landing.A forward CG will not be as obvious when hovering intoa strong wind, since less rearward cyclic displacement isrequired than when hovering with no wind. When determining whether a critical balance condition exists, it isessential to consider the wind velocity and its relation tothe rearward displacement of the cyclic control.CG AFT OF AFT LIMITWithout proper ballast in the cockpit, exceeding the aftCG may occur when:• A lightweight pilot takes off solo with a full loadof fuel located aft of the rotor mast.• A lightweight pilot takes off with maximum baggage allowed in a baggage compartment locatedaft of the rotor mast.• A lightweight pilot takes off with a combinationof baggage and substantial fuel where both are aftof the rotor mast.You can recognize the aft CG condition when comingto a hover following a vertical takeoff. The helicopterwill have a tail-low attitude, and you will need exces-Forward CGCG Directly Under The Rotor Mast Aft CGFigure 7-1. The location of the center of gravity strongly influences how the helicopter handles.7-3sive forward displacement of cyclic control to maintain a hover in a no-wind condition. If there is a wind,you need even greater forward cyclic.If flight is continued in this condition, you may find itimpossible to fly in the upper allowable airspeed rangedue to inadequate forward cyclic authority to maintain anose-low attitude. In addition, with an extreme aft CG,gusty or rough air could accelerate the helicopter to aspeed faster than that produced with full forward cycliccontrol. In this case, dissymmetry of lift and blade flapping could cause the rotor disc to tilt aft. With full forward cyclic control already applied, you might not beable to lower the rotor disc, resulting in possible loss ofcontrol, or the rotor blades striking the tailboom.LATERAL BALANCEFor most helicopters, it is usually not necessary todetermine the lateral CG for normal flight instructionand passenger flights. This is because helicopter cabins are relatively narrow and most optional equipment is located near the center line. However, somehelicopter manuals specify the seat from which youmust conduct solo flight. In addition, if there is anunusual situation, such as a heavy pilot and a fullload of fuel on one side of the helicopter, which couldaffect the lateral CG, its position should be checkedagainst the CG envelope. If carrying external loads ina position that requires large lateral cyclic controldisplacement to maintain level flight, fore and aftcyclic effectiveness could be dramatically limited.
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发表于 2009-3-20 23:52:29
WEIGHT AND BALANCECALCULATIONSWhen determining whether your helicopter is properlyloaded, you must answer two questions:1. Is the gross weight less than or equal to the maximum allowable gross weight?2. Is the center of gravity within the allowable CGrange, and will it stay within the allowable rangeas fuel is burned off?To answer the first question, just add the weight of theitems comprising the useful load (pilot, passengers,fuel, oil, if applicable, cargo, and baggage) to the basicempty weight of the helicopter. Check that the total weightdoes not exceed the maximum allowable gross weight.To answer the second question, you need to use CG ormoment information from loading charts, tables, or graphsin the rotorcraft flight manual. Then using one of themethods described below, calculate the loaded momentand/or loaded CG and verify that it falls within the allowable CG range shown in the rotorcraft flight manual.It is important to note that any weight and balance computation is only as accurate as the information provided.Therefore, you should ask passengers what they weighand add a few pounds to cover the additional weight ofclothing, especially during the winter months. The baggage weight should be determined by the use of a scale, ifpractical. If a scale is not available, be conservative andoverestimate the weight. Figure 7-2 indicates the standard weights for specific operating fluids.The following terms are used when computing a helicopter’s balance.REFERENCE DATUM—Balance is determined by thelocation of the CG, which is usually described as agiven number of inches from the reference datum. Thehorizontal reference datum is an imaginary verticalplane or point, arbitrarily fixed somewhere along thelongitudinal axis of the helicopter, from which all horizontal distances are measured for weight and balancepurposes. There is no fixed rule for its location. It maybe located at the rotor mast, the nose of the helicopter,or even at a point in space ahead of the helicopter.Aviation Gasoline (AVGAS) . . . . . . . . . . . . . . . . . . .6 lbs. / gal.Jet Fuel (JP-4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 lbs. / gal.Jet Fuel (JP-5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 lbs. / gal.Reciprocating Engine Oil . . . . . . . . . . . . . . . . . . 7.5 lbs. / gal.*Turbine Engine Oil . . Varies between 7.5 and 8.5 lbs. / gal.*Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.35 lbs. / gal.* Oil weight is given in pounds per gallon while oil capacityis usually given in quarts; therefore, you must convert theamount of oil to gallons before calculating its weight.Figure 7-2. When making weight and balance computations,always use actual weights if they are available, especially ifthe helicopter is loaded near the weight and balance limits.Datum+ –Figure 7-3. While the horizontal reference datum can be anywhere the manufacturer chooses, most small training helicopters have the horizontal reference datum 100 inchesforward of the main rotor shaft centerline. This is to keep allthe computed values positive.
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发表于 2009-3-20 23:52:41
7-4The lateral reference datum, is usually located at thecenter of the helicopter. The location of the referencedatums is established by the manufacturer and isdefined in the rotorcraft flight manual. ARM—The horizontal distance from the datum to anycomponent of the helicopter or to any object locatedwithin the helicopter is called the arm. Another termthat can be used interchangeably with arm is station.If the component or object is located to the rear of thedatum, it is measured as a positive number and usually is referred to as inches aft of the datum.Conversely, if the component or object is located forward of the datum, it is indicated as a negative number and is usually referred to as inches forward of thedatum.MOMENT—If the weight of an object is multiplied byits arm, the result is known as its moment. You maythink of moment as a force that results from an object’sweight acting at a distance. Moment is also referred toas the tendency of an object to rotate or pivot about apoint. The farther an object is from a pivotal point, thegreater its force.CENTER OF GRAVITY COMPUTATION—By totaling theweights and moments of all components and objects carried, you can determine the point where a loaded helicopter would balance. This point is known as the centerof gravity.WEIGHT AND BALANCE METHODSSince weight and balance is so critical to the safe operation of a helicopter, it is important to know how tocheck this condition for each loading arrangement.Most helicopter manufacturers use one of two methods, or a combination of the methods, to check weightand balance conditions.COMPUTATIONAL METHODWith the computational method, you use simple mathematics to solve weight and balance problems. The firststep is to look up the basic empty weight and totalmoment for the particular helicopter you fly. If the center of gravity is given, it should also be noted. Theempty weight CG can be considered the arm of theempty helicopter. This should be the first item recordedon the weight and balance form. Next, the weights of the oil, if required, pilot, passengers, baggage, and fuel are recorded. Use care inrecording the weight of each passenger and baggage.Recording each weight in its proper location isextremely important to the accurate calculation of aCG. Once you have recorded all of the weights, addthem together to determine the total weight of theloaded helicopter.Now, check to see that the total weight does not exceedthe maximum allowable weight under existing conditions. In this case, the total weight of the helicopter isunder the maximum gross weight of 3,200 pounds.Figure 7-4. The lateral reference datum is located longitudinally through the center of the helicopter; therefore, there are
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发表于 2009-3-20 23:52:55
positive and negative values.Weight Arm Moment(pounds) (inches) (lb/inches)Basic Empty WeightOilPilotForward PassengerPassengers AftBaggageFuelTotalCG1,70012190170510405533,175116.5179.065.065.0104148120109.9198,0502,14812,35011,05053,0405,92066,360348,918Max Gross Weight = 3,200 lbs. CG Range 106.0 – 114.2 in.Figure 7-5. In this example, the helicopter’s weight of 1,700pounds is recorded in the first column, its CG or arm of 116.5inches in the second, and its moment of 198,050 poundinches in the last. Notice that the weight of the helicopter,multiplied by its CG, equals its moment.LateralDatum+ –+ –Front ViewTop View7-5Once you are satisfied that the total weight is withinprescribed limits, multiply each individual weight byits associated arm to determine its moment. Then, addthe moments together to arrive at the total moment forthe helicopter. Your final computation is to find thecenter of gravity of the loaded helicopter by dividingthe total moment by the total weight.After determining the helicopter’s weight and centerof gravity location, you need to determine if the CGis within acceptable limits. In this example, theallowable range is between 106.0 inches and 114.2inches. Therefore, the CG location is within theacceptable range. If the CG falls outside the acceptable limits, you will have to adjust the loading of thehelicopter.LOADING CHART METHOD
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发表于 2009-3-20 23:53:07
You can determine if a helicopter is within weight andCG limits using a loading chart similar to the one infigure 7-6. To use this chart, first subtotal the emptyweight, pilot, and passengers. This is the weight atwhich you enter the chart on the left. The next step is tofollow the upsloping lines for baggage and then for fuelto arrive at your final weight and CG. Any value on orinside the envelope is within the range.SAMPLE PROBLEM 1Determine if the gross weight and center of gravity arewithin allowable limits under the following loadingconditions for a helicopter based on the loading chartin figure 7-6.To use the loading chart for the helicopter in this example, you must add up the items in a certain order. Themaximum allowable gross weight is 1,600 pounds.ITEM POUNDSBasic empty weight 1,040Pilot 135Passenger 200Subtotal 1,375 (point A)Baggage compartment load 25Subtotal 1,400 (point B)Fuel load (30 gallons) 180Total weight 1,580 (point C)1. Follow the green arrows in figure 7-6. Enter thegraph on the left side at 1,375 lb., the subtotal ofthe empty weight and the passenger weight.Move right to the yellow line. (point A)2. Move up and to the right, parallel to the baggagecompartment loading lines to 1,400 lb. (Point B)3. Continue up and to the right, this time parallel tothe fuel loading lines, to the total weight of 1,580lb. (Point C).Point C is within allowable weight and CG limits.SAMPLE PROBLEM 2Assume that the pilot in sample problem 1 dischargesthe passenger after using only 20 pounds of fuel.ITEM POUNDSBasic empty weight 1,040Pilot 135Subtotal 1,175 (point D)Baggage compartment load 25Subtotal 1,200 (point E)Fuel load 160Total weight 1,360 (point F)Follow the blue arrows in figure 7-6, starting at 1,175lb. on the left side of the graph, then to point D, E, andF. Although the total weight of the helicopter is wellbelow the maximum allowable gross weight, point Ffalls outside the aft allowable CG limit.As you can see, it is important to reevaluate the balancein a helicopter whenever you change the loading. Unlike
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