for 700 may not be 1843-558 (1285),but the actual figure of 1294, whichis enough of a difference to cause aninsurance company to have qualmsabout paying up in an accident.Basic Weight is that on the Weight andCentre of Gravity Schedule (in the FlightManual), which must be establishedby actual weighing before themachine is used for commercial airtransport, and reweighing every 4years, unless fleet masses are used, inwhich case try every 9 years. Thefigures are used to calculate a DOM(Dry Operating Mass) and CG for eachmachine or fleet, as appropriate.Note: Newer documentation usesthe word Mass instead of Weight.The Maximum Taxi (Ramp) Weight(Mass) is the max permitted weight atwhich the aircraft may be moved,under its own power or otherwise.The Maximum Takeoff Weight (Mass) isthat in the Flight Manual, which isnot necessarily the Maximum PermittedTakeoff Weight, or Maximum StructuralTakeoff Mass, the max weight at thestart of the take-off run that variesdue to performance factors such aslength and slope of runway,temperature, humidity, obstacles andaltitude. Any maximum take-offweight less than the full maximumdue to performance factors is knownas the Restricted (or Regulated) TakeoffWeight (RTOW) and is the startingpoint for calculating maximumpayload available. Sometimes,RTOW is the same as MTOW, butthis will only tend to happen atlarger airfields or landing sites withplenty of room. Maximum Taxi78 Operational FlyingWeight can therefore be higher thanMaximum Takeoff Weight, and youshould be able to burn off thedifference before getting airborne.It’s well known that all aircraft willfly overweight to a certain extent, ifonly because there’s a tolerancerange in the performance figures–ferry flights frequently do so, withthe extra weight being fuel, buthaving the physical ability doesn’tmean that you should. You will atsome stage be under some pressureto take an extra bit of baggage or topup with that bit of fuel that will saveyou making a stop en route, butconsider the implications. Firstly, anyinsurance cover will be invalid if youdon’t fly the aircraft within the limitsof the flight manual, and, secondly,you will be leaving yourself nothingin hand for turbulence and the like,which will increase your weightartificially. The designer will haveallowed for 60-degree turns all theway up to MAUW, but not heavierthan that.Maximum Structural Landing Mass(Max Landing Weight) speaks foritself, and is there to help preventthe impact with the runway beingtransmitted through theundercarriage to the rest of theaircraft, which can only happen ifthe weight is kept within certainlimits (it also assists you to reducethe downward velocity at the pointof landing, such as withautorotations in a helicopter). This
weight may very well be restrictedperformance-wise in a similar way toTake-off Weight, and could equallybe a factor in further reducing yourpayload at the start of a flight.As fuel is carried in the wings ofmost aeroplanes, excessive payload(in the cabin) relative to fuel weightwill increase the design bendingmoment, being most critical with afull load and zero fuel. A MaximumZero Fuel Weight (Mass) will limit theweight in the cabin, being a weightbeyond which any increase in loadmust consist entirely of fuel, or, inother words, the maximumOperational Procedures 79permissible mass with no useablefuel. This is to ensure that the wingsare forced downwards during flight,and is why using inboard tanks firstis often recommended.As well as the above technicalweights, there are operationalweights, the most important beingthe Aircraft Prepared for Service Weight(APS), which is the basic weight plusor minus changes to seat layouts,fixed equipment, unuseable fuel andcrew equipment, such as flightguides. It's the basis of the loadsheet,and is sometimes the same as theDry Operating Mass (DOM), an APSweight that also includes the crew,their baggage, catering equipment,etc. Wet Operating Weight, on theother hand, includes useable take-offfuel plus engine additives.The Traffic Load is the weight ofcargo, passengers and baggage, andwill include loading equipment(pallets, nets, etc.). The AllowedTraffic Load (not necessarily the samething) is just the payload, which iscalculated by subtracting theOperating Weight from the RTOW.With under 12 seats, withoutdispensation, you must use actualweights for passengers, whereasotherwise a statistically derivedstandard weight (which will includebaggage) may be used (see overleaf).The Maximum Compartment Weight isthe most you can have in anyspecific compartment, subject torestrictions on floor loadings, andLoose Equipment Weight is additionalequipment which may or may not beincluded in APS.You can use standard or actualmasses for the crew and baggage inthe DOM and actual figures foreverything else, not forgetting theengine oil. Actual figures must alsobe used for freight or ballast. Thefuel load must be calculated actual orstandard density values of 0.71 forgasoline, 0.79 for JP1 and 0.76 forJP4. On-board fuel must always becompared with that remainingbefore refuelling plus the amountuplifted, as a gross error check.Standard Mass ValuesAeroplanePassengers, 20 seats or morePassenger Seats 20 + 30 and moreMale Female All AdultNon-charters 88 kg 70 kg 84 kgHoliday charters 83 kg 69 kg 76 kgChildren (2-12 ) 35 kg 35 kg 35 kgHoliday charter is part of holiday package.Passengers, 19 seats or lessPassenger Seats 1–5 6–9 10–19Male 104 kg 96 kg 92 kgFemale 86 kg 78 kg 74 kgChildren 2-12 years 35 kg 35 kg 35 kgWith no hand baggage, or if separate, deduct 6 kg from male andfemale (except overcoats, umbrellas, handbags, etc).Checked baggage 20+ seatsType of Flight Baggage standard MassDomestic 11 kgWithin Europe 13 kgIntercontinental 15 kgAll Other 13 kgWith 19 passenger seats or less, use actual mass. Domestic flightmeans one with origin and destination(s) within the borders of onestate, within Europe means flights, other than Domestic ones,whose origin and destination are within the EEC, andIntercontinental flight, other than within Europe, means with originand destination in different continents.Mass Values for CrewCrew Position Std Mass inc Hand BgeFlight Crew 85 kgCabin Crew 75 kgHelicoptersUse actual values, but see below (youmight have an Arrangement). Engineoil will be in the APS or DOM, soignore it for balance purposes. Whenpossible, specific gravity should be80 Operational Flyingused for the fuel load, but standardvalues are 7.2 lbs/Imp Gal (0.72kg/litre) for Avgas and 7.9 lbs/ImpGal (0.79 kg/litre) for JP4. Fornotional weights, tables 1, 2 and 3include infants below 2 carried by anadult on one passenger seat. Infantsin separate seats are children.Table 1Passenger Seats 20 +* 30 +*
Male Female All AdultsAll flights 82 kg 64 kg 78 kgChildren (2-12 ) 35 kg 35 kg 35 kgHand Bge 6 kgSurvival Suit 3 kgTable 2Passenger Seats 10 to 19Male Female Child (2-12)All flights 86 kg 68 kg 35 kgTable 3PaxSeats1 to 5 6 to 9M F Child Male Fem ChildAll flts kg 98 80 35 90 72 35Table 4Passenger Seats 20 or more*Checked BaggageAll flights 13 kgWith 20 or more seats, the values apply to eachpiece of checked baggage. With 19 or less, useactual mass.Table 5Mass Values for CrewCrew Position Standard Mass Inc Hand BgeFlight Crew 85 kgCabin Crew 75 kgCanadaSummer Winter182 lbs Males (>12) 188 lbs135 lbs Females (>12) 141 lbs75 lbs Children (2-11) 75 lbs30 lbs Infants (0-<2) 30 lbsDistributionRight, now we come to weightdistribution. Incorrect loadingnaturally affects aircraftperformance, and will possiblyprevent the thing from even gettingairborne. A Centre of Gravity too farforward will make it more difficult toraise the nose on take-off (orlanding), possibly overstress thenosewheel as a result, and make theflight less economical by excessiveuse of trim tabs, which causes moredrag. There are certain advantages tohaving the C of G towards the rear(by making the tailplane contributeto total lift, or at least not detractfrom it, which also reduces thepower required and hence fuel used),but too much will make the aircraftless stable, more fatiguing to fly andcause similar drag and nosewheelproblems (but in reverse) asexcessive forward C of G. Also, ifyou don’t have the elevatormovement to get yourself out of astall, you could end up in a flat spinyou can’t get out of.In a helicopter, if the C of G is toofar aft or forward of its idealposition, there is a danger of runningout of cyclic control in the oppositedirection – one too far forward, forexample, will mean you will not beable to pull the cyclic back farenough to cope with certain stagesof flight (as fuel is consumed, forexample, when the C of G generallymoves forward), as a lot of its rangewill be taken up with the unusualattitude, although a forward positionis needed to counteract flapback.Not being able to flare in anautorotation could well ruin your day(in fact, if your engine fails and youdon't have enough cyclic movementto counteract the nose downOperational Procedures 81
tendency, the airflow will meet thedisc edge-on and not go up throughit, so you will not enter autorotation,and the RPM will decrease evenmore – ouch!). As well, lateral C of Gmay be affected with some loads,such as when hoisting.Passenger seats occupy the wholefloor space evenly; this loadspreading principle needs to beborne in mind with freight (cargo isbest distributed like passengerswould be), which makes it easier toprovide decent restraint on eachpack, because access areas to exitsabove and around the cargo areneeded for when the load has movedafter an emergency stop. You mayfind it helpful to line the floor withsomething waterproof if you're notsure what you're carrying—peoplesending packages don't generallyknow about Dangerous Goods andmay send items that leak something'orrible all over the place. Loadsmust be restrained with nets orstraps (or a combination of both)and must distribute the load overavailable fixtures, such as seatattachments. The range of C of G formost helicopters is a short distancefore and aft of the main rotor mast.The reference datum is an imaginarypoint from which all calculationsstart and where some C of G rangesare expressed (for example, 106" aftof datum). Mostly, it is at, or slightlyforward of, the nose, but can be atthe rotor mast of a helicopter. Onlarge aircraft, C of G limits may alsobe expressed in terms of % MAC, orThe Mean Aerodynamic Chord, which isthe average distance from the leadingto the trailing edges of the wing, orthe chord of an imaginaryrectangular wing with the samecentre of pressure, that is easier touse than a swept back one:LEMAC is the distance from thedatum to the leading edge of theMAC, at the front, and TEMAC isthe distance to the trailing edge, atthe back. LEMAC is therefore 0%MAC and may also expressed as adistance aft of the datum. So, the Cof G will lie somewhere betweenLEMAC and TEMAC, dependingon the weight and configuration.This formula calculates the %MAC(use the same units):%MAC = CG-LEMAC x 100MACFind the conventional C of G first,then divide its distance aft ofLEMAC into the MAC (TEMACminus LEMAC). The reason youneed to know the %MAC settings isbecause some jets have theirhorizontal stabiliser trim settingsmarked in this value (the figures area product of the C of G and flapsetting). Others, such as the 737have them marked in units of noseup trim, and you will need to look inthe trim tables to get the settings for agiven C of G. To convert %MACfigures back to an arm (for C of Gchange – see below), first convertthe C of G as %MAC to C of G inins aft of LEMAC:CG (aft LEMAC) = CG%MAC/100 x MAC82 Operational FlyingThen just add the figure obtained
above to the distance from Datumto LEMAC.The arm is the distance from thereference datum to the area inquestion, such as a passenger seat orthe fuel tank. It may be measured inImperial or Metric units, and youmust use the same ones. Theexpression station may also be used.To get the C of G of an aircraft, youmultiply the weight of each item in itby the arm to get the moment, or theamount of leverage that itemcontributes.The aircraft itself will have an armand a moment from when it was lastweighed, and this is where you start.You can find it in the weight andbalance schedule (usually in the flightmanual), and it may be varied if youadd or take off various items ofequipment, such as the hook or hoistin a helicopter.Because you might end up using verylong numbers, sometimes you use amoment index, the result of dividingthe moment by 1,000 to make thefigures more manageable. Here is asimplified typical calculation for aBell 206 helicopter (the principlesare the same for larger machines):Item Wt Arm MomentAircraft 1881 116.5 219137Front pax 185 65 13000Rear Pax 185 104 19240Baggage 50 147.50 7375Fuel 310 110.7 34273Total 2611 112.22 293025The total C of G for takeoff is112.22, obtained by dividing the totalmoment figure (293025) by the totalweight (2611). This particularmachine's fuel has a variable CGrange, meaning that it has one all onits own (that is, the arm will changewith fuel weight), so the figure of110.7 will change with the amount,for which check the flight manual.Also look for a graph like this:The procedure is to multiply theweights by the arms to get themoments, and divide the totalmoments by the total weights to getthe C of G. Then refer to the flightmanual to see if the figure fits intothe authorised range on the graph.Simply take the all-up weight youend up with, and the final C of G,and line them up horizontally andvertically. If they are inside theenvelope, you are OK, but don'tforget you have to land again! YourC of G may well be fine for takeoff,but check again after the fuel hasbeen used! %MAC charts, by theway, show the limits before fuel hasbeen loaded.Although charts in the exams lookmore complex, it’s quite easy to readthe arm against the position it is in –just don’t mix metric and Imperial.For a helicopter with an externalload, bear in mind that the maximumall-up weight with something on thehook is often higher than it wouldbe for passengers only (an extra 150Operational Procedures 83lbs for a 206, but check the maxweight for the hook itself), and ifyou take a door off, it will affect thelateral C of G as well, which works
the same way as longitudinal C of Gdoes, except the figures are smallerand easier to work with. In fact, theymay even be zeroed if the items arein the centre, as the hook would be.You would normally only be worriedabout it when taking a door off, asabove, or hoisting, but fuelconsumption has an influence aswell. Items left of the centreline havea negative sign, and those on theright are positive, so lateral momentsfor the front doors on a 206 wouldbe –12 for the left and +12 for theright. Here’s an example lateral C ofG calculation for the 206:Item Wt Arm MomentAircraft 1881 .41 773Pilot 185 14 2590Front pax 185 -11 -2035Left Rear Pax 185 -16 -2960Centre Rear Pax 185 0 0Right Rear Pax 185 16 2960Baggage 50 147.50 7375Fuel 310 0 0Total 3166 2.75 8703Again, there will be a chart in theFlight Manual to show you whereyour plot lies.Flight Manuals often have helpfulcharts with precalculated momentfigures for fuel and baggage (the armfigures will be excluded). They arequite simple to use, except that theexam will require you to interpolatehere and there. However, you shouldwatch for special conditions, as withany chart, especially for maximumweights in particular locations. Theremay also be a plan view of theaircraft with the arms displayed nextto the locations they refer to.The figures on the outside of thefuselage are the longitudinalmoments – those inside the seats arethe lateral ones.If you’re overweight in one sectionand want to redistribute the load,here’s how to figure out what tomove and where:X = W x Ddwhere:X Weight to be movedW Total weight of aircraftD Distance the C of G is outd Distance between old and newlocations of load movedSo, if your gross weight is 3000 lbs,your load is 1½ inches outside theenvelope (aft), to be moved from thebaggage compartment to the rearseats, all of 34 inches, you need tomove 133 lbs to get back in limits:133 = 3000 x 1.534Remember that the C of G willfollow the weight, that is, if themovement is forward, the C of Gwill go that way, too.84 Operational FlyingTo find a change in C of G:D = X x dWA company mass and balancedocument should be raised induplicate for each commercial airtransport flight. One copy must beon the aircraft, with anotheravailable on the ground for at least 3
days. It must contain details of allloaded items, including fuel, andindicate whether standard or actualvalues have been used. Whoever'ssupervising the loading mustconfirm by signature that the loadand its distribution are as stated onthe mass and balance document,which must also have the name ofthe person who prepared it. Thedocument must be acceptable to,and countersigned by, thecommander, to whom latealterations must be passed, andentered in the ‘last minute changes’spaces. Of course, this won’t be sonecessary if you make several tripswith loads that don’t change verymuch, in which case a Load Plansystem is more practical (see below).There are many ways of expressingC of G position, ranging from asimple statement of fact (like 75inches from a specified point),through using a graph in the FlightManual (which will give an envelopein which it may be plotted), to usingindex numbers on larger aircraftwhich are more manageable than thetelephone numbers you would get ifcalculations were doneconventionally. However, fine detailis outside the scope of this book,and we are dealing with smalleraircraft anyway. There are ways ofmaking life easier with regard tothese, the most common of which isa Load Plan.The Load PlanUsed to save the constant workingout of C of G on loads that are fairlystandard. Weight ranges need to beworked out, as the aircraft willfrequently be loaded by nontechnical staff (like oil rig workers orslashers), who will want as littledetail and as much flexibility aspossible (these weight ranges shouldnot be confused with standardweights, mentioned above). C of Glimits in Load Plans will therefore bemore stringent. Your Inspector willwant to see pre-worked examples forworst case situations (including fulland empty tank positions). Flightsoutside the Load Plan will need theC of G and a Loadsheet to beworked out in full.Sample Load PlanThe following example Plans may beused for the Bell 206 helicopter withthe fuel and payloads as shown (justadapt the method to suit otheraircraft). The Load Plan numbershould be included in the Tech Logbefore flight. The figures assume anAPS wt of up to 2,100 lbs and amaximum weight of 3,200 lbs. Pilotand passenger weights may be up to200 lbs including baggage(remember, not a standard weight).With less than 4 passengers, baggagemay be loaded on the rear seats or inthe hold, but maximum weight in thebaggage hold is 250 lbs. Fuel loadsabove 75 gallons assume a rangeextender, so watch the minimumpilot weight.Operational Procedures 85Load Plan Pax Fuel(gals)B3 3 50B2 2 83B1 1 93
Passengers will be loaded front torear as follows:FIRST Forward passenger seatSECOND Starboard rear passenger seatTHIRD Port rear passenger seatFOURTH Centre rear passenger seatAs you can see, everything needs tobe spelt out so anybody can get itright with all possibilities catered for.If you need to reduce weight,manipulate the payload, not the fuel,although commercially you mightfind you can make a tech stop.LoadsheetsThese are not required for aircraftbelow 2,730 kg, or for training,positioning or private flights, butyou will still need to know your C ofG as a matter of airmanship.Loadsheets should be drawn upoutside the conditions imposed by aLoad Plan and should account for allitems of the laden weight. Generally,they could be used in thecircumstances below, although youcould probably think of more. Theposition of the laden C of G must bespecified, together with the loaddistribution, but noting its positionwithin a range will be enough, unlessit's required for other purposes, suchas airworthiness or performance. Acopy should be left behind with aresponsible person or organisation,or placed in a fireproof containerwith the Tech Log on a helicopter.You need loadsheets:·
outside load plan provisions,such as with more thananticipated baggage·
with any combination of doorsremoved·
with camera mount andcameraman on board·
with an underslung load·
With freight only·
When parachute droppingPaperworkAlterations should be done so theoriginal entry can still be seen, with anote as to why the alteration wasmade, when and by whom.ATS Flight PlanThere are many reasons for filingflight plans – first of all, they helpget you slotted into the system, evenif it isn’t quite the route you askedfor. Next, they help with radiofailures, as, once you’re in the pipe,so to speak, everyone knows whereyou’re supposed to be going and canact accordingly. Then there areforced landings, where an educatedguess may be made as to yourposition, followed by statistics, and,finally, because the law says so.A flight plan must be filed for allcommercial flights, except thoseunder VFR taking off and landing atthe same aerodrome. Just to clarify,this includes positioning, private andline training. You can, of course, fileone at any time at your discretion,but don't forget to close it properlyif required (e.g. in Canada),otherwise you will be overrun byC130s. Booking out is enough forother flights, such as local area86 Operational Flyingtraining flights, or air tests. The
Company must have someone onthe ground responsible formonitoring flight progress, and foralerting the emergency services ifyou do not arrive within 1 hour ofETA. You are responsible forensuring that a plan has been filed,and being fully aware of the details.Because Canada is such a large place,you must file at least a VFR FlightPlan or Flight Itinerary wherever yougo, unless you are within 25nm ofthe aerodrome. The latter can be leftOperational Procedures 87with a Responsible Person, whoundertakes to notify the relevantauthorities if something happens.International flights always require aflight plan, but flights from Canadato the USA are not considered assuch for this purpose, so there is adifferent form.Operational Flight PlanA Navigation Log and Fuel Flight Plan(sometimes known as a Progress Log,or PLOG) is used for all IFR flights.There are many variations on thistheme, but there is a suggestedsample overleaf for you to adapt asnecessary. There are occasions whena reusable one is appropriate, like oncertain schedules and trips under 100nm, but it's easier just to use a newone all the time. In a helicopter youmay not need one anyway. Thecompany will normally issue aprepared plan for each flight, but toproduce your own, you need at leastthe following information:·
aircraft registration, type andvariant·
date and identification of flight·
names of flight crew members,and their duty assignments·
places and times of departureand arrival (off-block time, takeoff time)·
type of operation (ETOPS,VFR, Ferry, training, etc.)·
route with waypoints, distances,time and tracks·
planned cruising speed andflying times between checkpoints/waypoints. Estimatedand actual times overhead·
safe altitudes and minimumlevels·
planned altitudes and FLs; theactual height should be enteredon each leg—check it's notbelow the MSA! If it is, 'V' (forVFR) should follow the levelentered, which you would be ifyou've any sense.·
fuel calculations (i.e. records ofin-flight fuel checks). For morethan 1 hour, fuel should berecorded roughly every hour,but use discretion where anatural sector break occurswithin 5 or 10 minutes.·
fuel on board when starting andshutting down engines·
alternates(s) for destination,take-off and en-route, shownimmediately after thedestination workings, leavingone line blank. It's normallyenough to enter the straighttrack between the destinationand alternate, the MSA, track
and calculated flight time, a fiveminute let down allowance andthe leg fuel. However, althoughstraight line diversions are oftenadequate, they should berealistic and include SIDs,STARs, etc. where theycomplicate the issue, because ifyou need an alternate, you willneed it badly, and it doesn’t payto skimp on the planning.·
initial ATS clearance andsubsequent re-clearance(s).·
in-flight re-planning calculations·
relevant met information. Thereis a requirement to record pre88 Operational Flyingand inflight weather for thedestination and alternates.Minima must be calculated andentered prior to departure if lessthan twice the minima isforecast (weather obtained forflight planning purposes shouldbe carried on the flight andincluded in the voyage report).If you've got room, leave a blank linebetween each sector to help dealwith reroutings and direct clearances.When given changes in heading,altitude, squawk or radio frequency,write them down and cross the oldone out. It's too easy to forget whenthings are busy.Technical LogA system for recording defects andmaintenance between scheduledservicing, as well as informationrelevant to flight safety andmaintenance. In other words, it’s theformal means of communicationbetween flight crews andengineering. In Canada, theequivalent is the Journey Log – theTech Log is not allowed toaccompany the aircraft.The types of Tech Log (as they'reknown) are many and varied, fromthose with many sectors per page, toa page per sector—it all depends onthe amount of information required,which in turn depends on thecomplexity of the aircraft—a TechLog can contain other documents,such as a propeller or airframe log.Actually, many Tech Logs arehopeless, being badly designed andobviously concocted to satisfy legalrequirements with no thought forpeople who use them. If you everdesign one, please resist thetemptation to include a loadsheetwith it—keep it separate if you can.The main reason for Tech Logsbeing bad is that people cram toomuch information on them; if youraircraft are below a certain weight,loadsheets are not required anyway.ExamplesAn official example is in the sampleOps Manual from the CAA, but theone included in the next couple ofpages is a practical multi-sector onetypically used by small operators. Adifferent page is used for each day,but successive flights by differentpilots may be entered on the sameone (because provision has beenmade to identify the pilot in eachcase). It's your responsibility toensure that the Check A (DailyCheck) slot is signed, preferably by
