do too much, and maintain theminimum RPM to let it circulate.264 Operational FlyingSynthetic oils have come fromturbine oil development, but theyhave one drawback, in that thesludge in tends to centrifuge outinside the dome of a constant speedpropeller and make cycling a bitdifficult. They also holdcontaminants longer.Many Flight Manuals recommendnot changing brands of oil (e.g. theJetRanger), but if you check with theengine manufacturer’s manual (inthis case Allison), you may find thatit is permitted on a top-up basis, thatis, if you already have one brand inthere, just start using the new stuffuntil eventually the contents changecompletely. Do not drain yourpresent oil, and replace it in one go,because oils have different cleaningcharacteristics—your new brand maybe more efficient and you get bits ofcoke and carbon floating around thatcould cause a seizure. However, thisis something you should discuss withyour maintenance people.Carburettor IcingThis is actually one aspect of inductionsystem icing. The other two are fuelicing, arising from water suspended infuel, and impact ice, which builds upon the airframe around the variousintakes that serve the engine. Evenon a warm day, if it's humid,carburettor icing is a danger,especially with small throttleopenings where there's less area forthe ice to block off in the first place(as when descending, etc.). Also, thetemperature drop (between the OATand that in the venturi) can beanywhere between 20-30°C, so icing(in an R22, anyway) can happen evenwhen the OAT is as high as 21°C(70°F), or more. Tests haveproduced icing at descent power attemperatures above 30°C, with arelative humidity below 30%, in clearair. Because it is more volatile, andlikely to contain more water, you canexpect more fuel and carb icing withMOGAS than AVGAS.It usually arises from the action ofthe venturi in the throat, just beforethe butterfly valve, which regulatesthe amount of fuel into the engine.You will remember the venturi'spurpose is to accelerate airflow byrestricting the size of thepassageway, which has the effect ofreducing the pressure and pulling thefuel in. Unfortunately, this processalso reduces the temperature, as doesthe fuel vapourisation, hence theproblem (the lower temperaturemeans greater relative humidity, andcloseness to the dewpoint, and thevapourisation takes its latent heatfrom the surroundings, making thesituation worse). In fact, thevapourisation (and cooling) can carryon most of the way to the cylinders,causing the problem to persist,especially with the butterfly semiclosed, which produces anotherrestriction and more of the same.Any water vapour under thoseconditions will sublimate, or turndirectly to ice. Note also that warmair will produce more ice because it
can hold more moisture.With smaller engines, use fullsettings—that is, either on or off, withno in-betweens - the greatest risk isat reduced power. Out of GroundEffect hover performance charts forhelicopters usually assume the carbair is cold (the R22 requires heatbelow 18" MP). In fact, when heat isapplied, an engine will typically losearound 9% of its rated power.Techie Stuff 265Rough running may increase asmelted ice goes through the engine.Also, be careful you don't get anoverboost or too much RPM whenyou reselect cold. Of course,aeroplanes have some advantage ifthe engine stops from carb icing, asthe propeller keeps the engineturning, giving you a chance to dosomething about it.In a helicopter, due to the freewheelthat allows autorotation, the practiceof only selecting hot air when youactually get carb ice may not be sucha good idea – usually, a gauge is usedwith a yellow arc on it, showing thedanger range.Use carb heat as necessary to keepout if it. The other peculiarity withregard to helicopters is that theytend to use power as required ontakeoff, whereas aeroplanes use fullthrottle. This makes them morevulnerable, as the butterfly openingis smaller, and is particularlyapparent on the first takeoff of theday, when the engine and inductionsystem are still cold. If it is filtered,your carb heat may be used topreheat the induction system duringthe engine warm-up.Oil CansWhatever you use to open them,don't bang it down on the lid, butgently prise it open, so you don't getslivers of metal in the oil which maydisagree with your engine.Schermuly FlaresFlares should be stored for amaximum of 4 yrs between 0-25º C,and only be installed for 1 year or1000 flying hours. Check that thecentre contact in the mountingmoves freely and is clean, and thelocking and securing ring threads fordamage. When not carrying flares,the plastic cover plate should befitted and the securing ring lockedwith the locking ring.Test the firing circuit with a suitable50W 24V bulb and holder in a cutdown fired flare case. Beforeinstallation of any flares a "no volts"check of the firing circuit (using amillivoltmeter) should be made.The securing ring must make a goodelectrical contact with the flare case,achieved by rotating the flare withthe securing ring partially tightened.When tightening the ring, rotatingthe flare will help give the requiredtightness. The locking ring must betightened (if in doubt, theflare/circuit resistance should be lessthan 5 ohms). If a circuit resistancecheck is performed, a safetyohmmeter must be used and themeasured resistance should be in therange .8-1.2 ohms.Height/Velocity CurveOtherwise known as the Dead Man's
Curve, this is a chart for helicoptersthat compares speeds against heightsto give you an idea of where not tobe if you don't want to kill yourself ifan engine fails, that is, you don't wantto be at high altitudes with lowspeeds, or low ones with high266 Operational Flyingspeeds, so the best place to be is inthe gap between the shaded areas:In other words, the graph showscombinations of speed and heightthat the average pilot would find itimpossible to make a safe emergencylanding from. For more of a chance,a one-second delay is factored in forminimum skill levels.A couple of points to note first ofall: one is that you should check tosee if the chart is in the Limitations orPerformance section of the FlightManual (the BK 117's moves to thelimitations section once you go intohigh density seating). If it's in thelatter, its requirements arerecommended, not mandatory. Anotheris that it is not necessarily valid forapproaches, being calculated forlevel flight conditions (see below).Some helicopters, like the TwinStar,sometimes don't have one at all. It'simportance, therefore is for takeoff,although in some circumstances, it ismore dangerous to try to avoid thecurve, especially if you might only bein it for a few seconds (as whengetting out of a confined area, forexample).Anyhow, the vertical shaded area inthe diagram above is called the lowspeed section, which is actually split intwo parts at the knee of the curve,although it's never shown (the kneeis the furthest point at which thecurve extends). The lower portion isfor takeoff power (no intervention),and the upper portion is for levelflight (cruise power, hand notnecessarily near the collective, so onesecond allowed for interventiontime), and the whole area willexpand with Density Altitude. Onapproach, you have your hands onthe controls and are using less thancruise power, so the same figuresdon't work.The other shaded area is called thehigh speed section, and the clear areabetween them is the takeoff corridor.Takeoffs and performancecalculations should definitely takeaccount of the curve, which isconstructed at maximum weight,with no wind at a density altitude ofat least 7,000 feet. Those of lesserquality must be verified (that is,actually flown) by the relevantAuthority.Aircraft HusbandryA company can tell how well itspilots look after their aircraft by theamount it spends on servicing—thelower the costs, the better they are.Aircraft should not be parked onsoft or sloping ground, and suitablechocks should be placed under themain gear wheels of aeroplanes.They should be parked into windwhenever possible, with thenosewheel in line with the fore andaft axis. Control locks and coversshould be used whenever convenient
(especially when wind speeds areexpected to be high, in which caseconsider picketing as well), and alldoors, hatches and windows shouldTechie Stuff 267be closed when the aircraft is leftunattended.Anti-collision lights should beswitched on immediately beforestarting engines, but it is suggested(like the military) that this be doneimmediately the aircraft is occupied,always having due regard for thecapabilities of your battery. Speakingof which, always leave the anti-collight switches on when leaving theaircraft, because that lets you knowyou've left the Master switch on.Don't forget the usual taxyingprocedures, such as not using thebrakes too much, or using aircraftmomentum when turning corners tosave using the engine. Engine runups(like on power checks) should bedone into wind for better enginecooling and least strain on the prop,and away from loose items on theground, both to protect peoplebehind and the prop itself, as it theairflow around the tips will tend topull bits of gravel etc towards it, andcause damage.Lastly, let me mention oil cans,which come sealed so you need aspecial implement to open them.Actually, you can use a screwdriver,but whatever you use, don't bang itdown on the lid to get your way in,but gently prise it open. This stopsyou getting slivers of metal in the oilwhich may disagree with yourengine.MaintenanceThere are two types of maintenance,Scheduled and Unscheduled, whichbasically speak for themselves. Bothare supposed to ensure that anaircraft is kept at an acceptablestandard of airworthiness.Depending on the performancecategory and its maximumauthorised weight, there will bedifferent schemes covering this, butthe nature of General Aviationmeans that aircraft are very often notseen by an engineer from onescheduled check to the next. Aircraftbelow 2730 kg come under thegeneral umbrella of the Light AircraftMaintenance Schedule (LAMS). Thoseexceeding this weight must complywith an approved maintenanceschedule.The Maintenance Schedule (which isonly valid for a given period, and isnot usually transferrable) containsthe name and address of the owneror operator and notes the type ofaircraft and equipment fitted. It laysdown the periods when every part ofthe machine will be inspected(including the Check A) togetherwith the type and degree of theinspection, including the periods ofcleaning, lubricating and adjustment.Maintenance Schedules are writtenspecially for each aircraft (althoughthey can share the same one) so itcan be awkward to changeMaintenance Contractors as theequivalent of an Annual Check mayhave be carried out before an aircraft
is accepted by the new one.Types of check include 50-hour,100-hour and Annual, the last beingwhere the C of A is renewed as well(unless the MAUW is below 2730kg). There are variations, but regularchecks (such as 50- and 100-hourchecks) can be extended by 5 or10%, respectively, for scheduling,but this should not be used as partof normal operations (lack ofplanning on your part doesn't justifyan emergency on an engineer's part).268 Operational FlyingChecks are also valid for a period oftime, 62 days for public transport, sothe servicing will still have to becarried out, even if no flying hastaken place (this can also beextended for a short time at theengineers' discretion). Somemaintenance companies submitschedules for checks at 75 or 150hours, and vary other aspects oftheir operation. In between, therewill also be times when componentsneed to be changed, either on aplanned or emergency basis.A Certificate of Maintenance Review isissued after every Annual Check anda Certificate of Release to Service after aregular service (or 62 dayinspection). Both documents shouldbe current at all times. A Certificateof Release to Service is not valid byitself—it must be backed up by aCertificate of Maintenance Review.When a company applies for an AirOperator's Certificate (see Setting UpA Company), Flight Ops 7 of theCAA will want to ensure that thisaspect of your operations issatisfactory. It's not so much aproblem if the maintenance is donein-house, but if your Company hassub-contracted this out, a writtenagreement needs to be in forcebetween the two parties detailingexactly who does what and thegeneral divisions of responsibility.You would be forgiven for thinkingthere are certain things anengineering outfit gets up to that canbe taken for granted, but such is notthe case. For example, you wouldexpect them to supply tools, sparesand suitably trained personnel as amatter of course, but your contractneeds to spell this out in detail.Engineering companies haveEngineering Manuals andexpositions, which are equivalent toOps Manuals, and their standardprocedures will also be laid out inthese, so between the two of you,you should be able to crossreference everything quitesatisfactorily. Just in case this isdifficult, here's a small sample ofwhat you may need to include:Operator's name and AOC number,and equivalent details of theengineering support organisation.Title and reference number of theExposition or Engineering Manualconcerned.Any sub-contracts arranged foreither party for anything specialised,such as Avionics.·
Specific responsibilities forcompliance with statutoryrequirements, Service Bulletins,mandatory modifications,
provision of spares, tools,personnel and the compilationof and amendment to anytechnical publications that maybe about, including thecompletion of log books.·
Control of deferred andrepetitive defects; somebodyneeds to keep an eye on theTech Logs as they are returnedfrom each flight to make surethe same faults don't keeprecurring.The agreement should also includetermination or expiry arrangements(not financial) and any action thatmay be taken without the Company'sapproval, or which need agreement.Techie Stuff 269Type CertificationThis happens at the end of anaircraft’s certification process, whenthe aircraft is proven to have metminimum design requirements. AType Certificate Data Sheet (TCDS) willdetail the equipment needed for theaircraft to continue meeting the,which is where the MEL and CDLare derived, since pilots will notnormally have access to it. The C ofA will require that the aircraft beoperated under the TCDS.If equipment used is not cargo, isused during flight and interacts withcontrols or systems, or affectsperformance, aerodynamics orhandling, you need a SupplementalType Certificate (STC) for it, whichmay also be included in the FlightManual if pilot attention is required.BusbarsThe lighter an aircraft is, the better,so it's impractical (if only for weightsaving) to run a wire from thebattery to every component used onit. A better solution is to run a single(big) wire to a collection of electricalappliances and serve all of themfrom the end of that line, which iswhat a busbar is all about. Physically,an electrical busbar (bus for short) isa metal bar with provisions to makeelectrical contact with a number ofdevices that use electricity. There'snothing to stop you having mainbuses supplying secondary ones.Essential things to know about busesare what they power, how to reroutepower to them and how to isolatethem, like fuel tanks. All aircraftmust have standby electrical powersystems, in case the normal one goesdown. For small aircraft, this isusually the main battery, which isoversized for this reason. Theproblem is, it's time-limited and,although there is a theoreticalminimum, it's not always safe to relyon more than about 10 minutes.It's helpful to know whichequipment (on which buses) uses theleast power, which will be listed inthe Flight Manual. It's perfectlypossible to navigate successfully byonly turning the VOR (or whatever)on every 5 minutes and off after aminute having fixed your position.The same principles apply toeverything else, and will go a longway towards conserving battery life.Fire
Fire has three elements—fuel,oxygen and the heat. Take one awayand it stops. With dangerous goods,you can get fire from the chemicalreaction of flammable materials withan oxidising agent – you don’tnecessarily need a source of ignition.A Class A fire is an ordinary one,that is, of normal combustiblematerial on which water is mosteffective. A Class B fire is in aflammable liquid, such as oil orgrease, where you would probablyuse a blanket. A Class C fire iselectrical, for which you need a nonconducting extinguishing agent. Forthe latter two, you could use eitherCarbon Dioxide or Dry Powder(which ruins the avionics), but thefumes may be toxic, so you will needplenty of ventilation afterwards. AClass D covers other materials, suchas metals, that may burn.To help you identify the source,smoke associated with electrical firesis usually grey or tan and very270 Operational Flyingirritating to the nose or eyes (itdoesn't smell too good, either).Anything else (say from the heater)tends to be white, but you may getsome black from upholstery.If you think you have an electricalfire, it's no good just using theextinguisher, because you may justbe treating the symptom and not thecause, although there is a school ofthought that advocates not using anextinguisher at all if you can possiblyhelp it, due to the fumes and stuffyou have to breath in till you land.Whatever you do, transmit a Maydaybefore it’s too late—you can alwaysdowngrade it afterwards. Bear inmind also that your first strike withyour extinguisher is the best, becausethe contents and pressure decreasefrom then on.Next, put an oxygen or smoke maskon, if you have one, then bring onessential electrics one at a time untilthe smoke appears again.On the ground, engine fire drills mayvary considerably between differenttypes, and these will have to bememorised, but there are somegeneral points that can be made.One is, before evacuating theaircraft, make sure the parking brakeis off, so it can be movedsomewhere safer if things get out ofhand, always being aware that itcould run off by itself, as well! If thefire has been caused by spilt fuel, hasspread to the ground under the wingand the other engine has beenstarted, taxi clear of the area (ormore specifically, the fuel on theground) before evacuation, keepingthe fire on the downwind side. If theother engine has not been started,evacuate first, carrying out whatdrills you can.If you can, use the radio to summonhelp, and don't forget to take theextinguisher. Remember that humanbeings en masse need very differenthandling than when single.In the air, initial shut down actionsare similar everywhere—afterperforming vital actions frommemory (e.g. identifying the sourceand all that), refer to the checklist tosee if you haven't forgotten anything.If the engine has been securedpromptly, the fire should go outquickly after the fuel supply has beencut off. You will find, however, thatstructural failure of the wing will beimminent after about two minutes ifthe fire is uncontrolled, which is asobering enough thought to makeyou commence emergency descentIMMEDIATELY, no matter howgood it looks.If you've got extinguishers in theengine bays, delay actuating themuntil the engine has been securedand you've no reason to suspect afalse alarm; that is, unless you canactually see signs of a fire. In thecabin, whether in the air or on theground, the priority is to get out, andas soon as possible, because if theflames don't get you, the fumes will.The only difference between the twosituations is how quickly this can bedone, and what you can do about it.Legal StuffThe first point to bear in mind isthat this chapter applies mainly tothe UK, though there are enoughhints for people elsewhere tobenefit, especially in Canada, wherethe legal systems are similar, and alot of it is international anyway. Thesecond is quite simple—I am not alawyer. I have had some training in itas part of wider Transportexaminations, but I cannot lay claimto any great theoretical knowledge.However, in much the same way thatyou don't have to be a doctor todiagnose a headache, a layman can
have views on what is usuallyregarded as the province of experts(after all, the Wright Brothers werebicycle mechanics). And that is whatthis Chapter contains; my views, thatmay very well have suffered from theattempt to translate laws into plainEnglish, so if you need it, get properlegal advice. In other words, stickingto the medical theme, a headachemay be a symptom of somethingworse.Digression: The “proper” legaladvice can often be wrong, which ishelpful when your legal insuranceinsists you do what their lawyer says.Law in GeneralYou probably feel by now thatyou’ve had enough law to last you alifetime! The trouble is that aviationis affected by a lot more aboutnormal commercial life that needs tobe known to protect your interests,which, when you think we all startedoff with Ten Commandments,makes you wonder. The backgroundto some is international, but mostcome about in the way that UK lawis usually created, the mostdistinguishing feature being that notall of it is written down. Luckily,most of what concerns you is.Common LawVery briefly, but accurately enoughfor our purposes, UK lawcommences with the Common Law,which derives its power from havingbeen around from "timeimmemorial", a phrase whichtechnically means from before 1189,and from not having been put intoabeyance by Act of Parliament.272 Operational FlyingCommon Law is not written down,but its principles are regarded ascommon knowledge among thepopulation, based on the idea thatpeople have certain rights as a resultof being created by God (who issupreme). During medieval times,when people went off on Crusades,etc., they would return to find theKing had declared their lands vacantand taken them for himself, whichwould include towns, animals, serfs,and the rest, so, on June 15, 1215,various Lords forced King John tosign the Magna Carta at Runnymede,which guaranteed the common manhis rights, hence Common Law.One of these was the right to enterinto contracts, and be bound bythem, which becomes relevant withPublic Transport, mentioned later,but what’s more important right nowis the Common Law Right ofSilence, which means you're notobliged to say anything to anyone onthe very reasonable premise of notbeing expected to incriminateyourself. New legal developments donot propose to take this away, butallow juries to take your silence, andreasons for it, into account, whichmay be commercial, or otherwise(but see also Statements, below).Common Law cannot be altered byParliament or any other authority. Itcan, however, be put into abeyance,but comes back into effect whenthat provision is repealed orreplaced. The common law applies
unless it is expressly or necessarilyimplied that it has been properly putinto abeyance by plain words in anAct of Parliament.In the US, Common Law wasreplaced with Merchant Law in 1938,at least at the federal level, becausethere were two systems running atonce (i.e. Civil and Common), and itneeded to be sorted out. In fact, insome states, such as Ohio, CommonLaw activities are no longer legal,including marriage.Administrative LawParliament often makes laws aboutsubjects it knows nothing about, orcannot keep up with, or which arestrictly for a local area (i.e. bye-laws),so it may grant a suitably qualifiedauthority the power to make laws onits behalf, which saves a lot of time.This is known as subordinatelegislation (or more commonly, andwrongly, as delegated legislation). TheCanadians call it Administrative Law,which is a better name. It is broughtto the notice of the public mostly bystatutory instruments (in this context, an"instrument" is another name for adocument), which is where we comein, because that is how the AirNavigation Order, and most otherlaws that affect your professionallife, have been made (the ANO isboth a Statutory Instrument and anOrder in Council). In contrast, CAACharges Schemes are subordinatelegislation but not statutoryinstruments, in the same position asthe appointment documents of anAuthorised Person, discussed later.The major point concerning thistype of law is that it can be invalidunder certain circumstances, whereasan Act of Parliament cannot. Whenthis happens, it is known as beingultra vires when it purports to dealwith subjects outwith its terms ofreference (ultra vires is Latin for"outside the powers"). This could bewhere some conditions concerningits existence are not fulfilled, such asthe print size in the SI documentLegal Stuff 273being not the same as specified. Youmay think this is a technicality, butthis method of law-making musthave strict controls, for obviousreasons, and every effort is made togive the citizen the benefit of thedoubt, as it's not on to depriveanyone of their rights becausesomebody got the procedureswrong. For example, there was agentleman who escaped a parkingticket because the yellow lines hewas parked on were 2 inches thinnerthan the size specified. In this way,Parliament is supposed to keep atight control on any authority thatmay be created by Act of Parliament,because the end result could be thatCivil Servants make unauthorisedlaws, and they aren't elected.In Canada, the Aeronautics Actconfers upon the Governor-inCouncil (i.e. the Cabinet) theauthority to make regulations whichare then part of the Act, i.e. CARs.The Governor-in-Council in turnmakes regulations authorising theMinister of Transport. Enforcement
provisions thus become part of theAct. As long as the Act andRegulations are not foundunconstitutional, as an Act ofParliament they are valid andenforceable. Ordinary rules of legalprocedure apply and a personaggrieved by a charge has the right toseek legal representation to overturnthe charge (having said that, be waryof the enforcement division’stendency to impose sanctionswithout benefit of a hearing).Anyway, in UK, to be enforceable,subordinate legislation must also begiven judicial notice, so it can beadmissible evidence in a Court ofLaw. It's worth noting that the CivilAviation Act 1982 does not appearto grant this to its subordinatelegislation, which has the effect ofshifting the burden of proof of beingintra vires (or within its terms ofreference) to the maker of the law,rather than to you to prove theopposite, that is, that it may be ultravires. In the absence of provisionsrequiring judicial notice to be takenof it, subordinate legislation must bepleaded (and proved by) the partyseeking to rely on it, but this virtuallynever happens.Although subordinate legislationneed not necessarily be brought toParliament’s notice (because there'sso much of it), the Act behind itusually requires submission toAffirmative or Negative Resolutionprocedure. The difference is simple;where affirmative procedure is used,SIs do not become law unlessactually approved by Parliament—inother words, a vote of approval isspecifically given. Negativeprocedure means they are law unlessrejected by Parliament within 40days. In the case of the CivilAviation Act 1982, as to whether aparticular procedure is used or notdepends on Schedule 13, whichexpressly provides that negativeresolution procedure is to be used,except for noise certification, whichuses the affirmative.The process is overseen by aCommittee, which unfortunatelyonly has jurisdiction while theInstrument lays before Parliament. Itmeets every 14 days, so it is possible,with judicious timing, forInstruments to get the minimumtime for scrutiny, as there is no prepublicity – it just arrives on the table,so to speak, at the same time as in274 Operational Flyingthe shops and both Houses. As thereare not many members on thecommittee, and they may need tolook at over 100 at a sitting, for allpractical purposes Instruments arenot read.There is no general rule as to whenan Instrument may be unenforceablebecause the wrong procedure wasused, because each case turns on itsown circumstances. A penal statute(that is, one which involves penaltiesfor its contravention), however,must be strictly observed, a classiccase being that of Ronald Biggs, whocould not be extradited fromTrinidad because the extraditiontreaty between Trinidad and the UK
