friendly jet with its engines idling).Operational Procedures 99Priorities are control surface hinges,engine intakes or static ports. Somemanufacturers, however, don'trecommend using fluids at allbecause of the possible effect on thebonding of composite materials.Some people recommend usingwarm water, but I'm not so sureabout that – I know that if you wantto freeze water quickly, you put it inthe freezer hot.De-icing FluidsThe main types are what used to beknown as AEA (Association ofEuropean Airlines) Type I(unthickened) with a high glycolcontent and low viscosity, and TypeII (thickened) with a minimumglycol content of about 80% which,with a thickening agent (one or twoteaspoons ofcornflour), remainson surfaces forlonger, butremember it has toblow off before youactuallyget airborne. Theidea is to decreasethe freezing point ofwater but, as the ice melts, the fluidmixes with the water, both diluting itand making it more runny.What's left after repeatedapplications to combat this is of anunknown concentration, and mayrefreeze quickly. Type III liessomewhere between the two.Type I fluids have good de-icingproperties, but may refreeze - theyare for de-icing, not anti-icing. UnionCarbide Ultra fluid (potentially TypeIV, and green in colour) appears toincrease the times given by the tablesbelow by 1.5 over Type II and waymore for Type I – they give generalguidance on the use of I and II, andthe likely protection you might get onthe ground (most fluids are gone byrotation speed):Type I holdover timesApproximate holdover times under various weatherconditions (hours:minutes)OAT(Co)Frost FrzgFogSnow FrzgRainRaincoldsoakedwingsAbove 0 0:18 –0:450:12 –0:300:06 –0:150:02 –0:050:06 –0:150 to –7 0:18 –0:450:06 –0:150:06 –0:150:01 –0:03N/Abelow –7 0:12 –0:300:06 –0:150:06 –0:15N/A N/ASource: (ISO) 11076:1993(E) Table 3Type II holdover timesApprox anticipated under various conditions (hours:minutes)Source: ISO 11076:1993(E) Table 4. Under extreme conditions,heat neat fluid (60°C max) for sprayability. No significant increaseis achieved with a stronger mix of type 1 (AEA) fluids. Stationsusing Kilfrost will normally mix 50/50 or 60/40. Freezing Raincolumns have sometimes been replaced with Light Freezing Rainand Freezing Drizzle.General PrecautionsDeposits must be swept fromhinge areas and system intakes,and the sprays themselvesshould not be directed to them,since the fluid may be furtherdiluted by the melting ice it isdesigned to remove, and mayrefreeze. It may also causesmearing on cockpit windowsand loss of vision.OAT (°C) undilfluid/waterFrost Frzg Fog Snow Frzg Rain Rain coldsoakedwingsabove 0 100/0 12:00 1:15–3:00 0:25–1:00 0:08–0:20 0:24–1:0075/25 6:00 0:50–2:00 0:20–0:45 0:04–0:10 0:18–0:4550/50 4:00 0:35–1:30 0:15–0:30 0:02–0:05 0:12–0:300 100/0 8:00 0:35–1:30 0:20–0:45 0:08–0:20 N/A
0 to –7 75/25 5:00 0:25–1:00 0:15–0:30 0:04–0:10 N/A50/50 3:00 0:20–0:45 0:05–0:15 0:01–0:03 N/A–7 to –14 100/0 8:00 0:35–1:30 0:20–0:45 N/A N/A75/25 5:00 0:25–1:00 0:15–0:30 N/A N/A–14 to –25 100/0 8:00 0:35–1:30 0:20–0:45 N/A N/A100 Operational FlyingAfterwards, confirm that flyingand control surfaces are clearand move over their full range,and intake and drain holes arefree of obstructions. Jet enginecompressors should be rotatedby hand to ensure they are notfrozen in position. Propellerspinners should be checked fortrapped snow or moisture,which could subsequentlyrefreeze and cause an imbalance.Don't forget the undercarriage.Further PrecautionsHoldover time can be affectedby high winds or jet blastsdamaging the fluid film, and skintemperatures can be significantlylower than the OAT, whichmakes them a morerepresentative entry point intothe tables above.Technical LogAn appropriate entry must bemade and signed in the tech log,including the start andcompletion times.Flight ProceduresFlight Plan Annotation of VFR/IFRYou should normally use the mostconvenient airways under IFR,regardless of weather, although youcan go VFR if there aren’t any.Certain flights, such as aerialphotography, need VFR bydefinition, but IFR can still be useden route. The (operational) flightplan should indicate clearly what youuse. Changes should be annotatedon the flight plan, as well as wherethey take place. Revised clearancesshould be requested immediatelyfrom ATC. Obviously, maintainVMC until IFR clearance is received.Minimum Radar ServiceWhen outside airways or advisoryroutes, a minimum of RadarInformation Service should always beavailable. In UK, you have:·
Radar Advisory Service (RAS),which gives information andadvisory avoiding action fromconflicting traffic. It can berequested at any time, but isusually used in IMC. This canbe time wasting, especially if it'sa clear day and you'recontinually given vectorsdownwind that take ages tocatch up on; although you arenot obliged to accept the advice,you must inform the controllers,as you must if you changeheading or altitude for anyreason. This can also beexpensive, as you immediatelybecome subject to Eurocharges,100% in UK (but only 25% inFrance).·
Radar Information Service merelyprovides information aboutconflicting traffic. How youavoid it is up to you.·
Radar Control Service in controlled
airspace, where you do whatyou’re told.Flight Information Service is justsomeone to talk to. There's no radarand very limited information aboutother traffic as not everybody callsup. They can, however give youweather and Notams, as they'reusually not as busy as radarcontrollers.Operational Procedures 101Procedural Service gives separationbetween participating traffic butwithout the luxury of radar. It'smainly used on approach andadvisory routes. The controller willstate the type of service provided (soit goes on tape and can be used atthe subsequent Board of Inquiry), soeven though you may have beenidentified, don't assume you have theservice requested until told so. InVMC, it's still your responsibility forcollision avoidance, so you will needto maintain a good lookout.Flying VFR where weather or othercircumstances demand that youshould be IFR (i.e. in order to avoidEurocharges) should be avoided. Inthe same vein, Special VFR shouldnot be used to get around Rule 5,that is, you can't use a clearance of"not above 1000'" as an excuse to flylow over Birmingham where youshould be over 2000. If you are socleared, it's only from an Air Trafficpoint of view—they're assuming youknow what you're doing.Special Helicopter ZonesThe London Specified Area is whereyou can't fly so low in a helicopterthat you cannot land clear if anengine fails, so no single-enginedhelicopter can operate in it unlessalong the River Thames. As you'reover water, flotation equipment isrequired, together with approved lifejackets for all occupants.Specific routes for helicopters flyingin the London Control Zone andthrough the Specified Area areshown in the Air Pilot and includedin other guides. They're alsooverprinted on a special OS map, acopy of which you must have withyou. Information on other zoneswith special helicopter procedures,such as Glasgow, will also be foundin the Air Pilot.Recording Of Flight TimesFlight times in personal flyinglogbooks are from first movementunder power until rotor rundown forhelicopters, and first chocks away(with the intention of taking off)until final chocks on for fixed wing.Those in Technical Logs, bycontrast, are from take-off to landingonly, sometimes entered in decimalhours. It's common practice, whereseveral flights are made per hourwithout closing down (pleasureflying), to record the first take-offand last landing times and to notethe actual airborne time in between.There are many ways of doing this,the most accurate being with astopwatch, but there is an unofficialand widely used practice (byarrangement with your local CAAsurveyor), when pleasure flying, ofusing two thirds of the total time
between first take-off and lastlanding. Accountants love it, butengineers don't, as they regard thewear and tear as still taking place.Too much of this sort of paperworkwill really play havoc with servicingschedules (and profit and lossfigures) as parts will wear out quickerthan anticipated, despite the 'fudgefactor' allowed by the CAA whensetting up maintenancerequirements.Timings should be local, unlessconsistently in another time zone.Navigation ProceduresThe definition of navigation is takingan aircraft from place to placewithout reference to the ground.102 Operational FlyingSome points to note about doing itin the Arctic are that it’s darker forlonger and there are fewer navaids.Mercator doesn't work, and youneed to switch to PolarStereographic, so rhumb lines aretherefore not the shortest course,and you must use great circlesinstead. Naturally, compasses beginto get unreliable, and there isincreased deviation due to theaircraft's own magnetic field.Otherwise, equipment not directlyrequired for navigation should betuned to ground stations to checkaccuracy or ground speed, so errorscan be detected and the equipmentavailable in an emergency. It alsokeeps the circuits warm, but this isreally a hangover from old steamdriven equipment that would gounserviceable if bumped around toomuch when cold.Don't rely on a beacon until it hasbeen identified and confirmed byboth pilots. For computerisedequipment, one pilot should readaloud the co-ordinates, tracks ordistances, while the other operatesthe keyboard and reads them back asa cross-check. Otherwise, for singlepilot operations, conscientious selfmonitoring should be adopted.Nav logs should be comprehensivelycompleted en route, except in busyterminal areas at lower altitudes, andETAs should be kept up to date as amatter of course, as well asdiversions, including a briefdescription of the circumstances, thetime the alteration was made, andany fuel replanning calculationswhich were necessary. In general,enough information should berecorded to assist a post-flightinvestigation, so that problems canbe avoided on future flights over thesame route.For Minimum Navigation PerformanceSpecification (MNPS) and POLARairspace, and that designated forArea Navigation (RNAV), you needapproval from the CAA, a minimumlevel of navigational equipment, andspecific briefing and/or training.Altimeter ChecksAltimeters must be checked beforeflight as follows, ensuring thatrotation of the knob through ± 10mb produces a correspondingdifference in height of about ± 300ft in the appropriate direction.·
Both should be set to theaerodrome QFE and should
indicate within ±50 feet of zero,within 50 feet of each other.·
With No.1 on QFE and No.2on aerodrome QNH, thedifference should equal theaerodrome altitude AMSL, towithin 50 feet.·
With both on aerodrome QNH,indications should be within±50 feet of the aerodromeelevation, and 50 feet of eachother, although some areas willbe different from published.Note: No.1 is the handlingpilot’s primary instrument andNo.2 the secondary.Setting ProceduresTo avoid confusion if your altimeterdoes not have a decimal point on themb sub-scale, round down pressuresettings to the nearest wholemillibar; a QFE of 1002.9 mbs willbe set as 1002 mbs. Altimeters mustOperational Procedures 103be set, and cross-checked with newsettings, as follows:Stage No.1 No.2 RemarksBefore T/o QNH QNH Aerodrome settingClimb &CruiseQNH QNH Below Transition AltitudeClimb 1013.2 QNH When cleared to FLEn route 1013.2 1013.2Descent 1013.2 1013.2 Cleared to intermediateFlight LevelsDescent QNH QNH When cleared to analtitude and no furtherflight Level reports arerequired by ATCInit App Airfield QNH Aerodrome QNHFinals Airfield QNH Aerodrome QNHMissedApproachAirfield QNH Aerodrome QNHWhen en route, Regional QNH should be set, unless below aTMA when the Zone QNH, or suitable Aerodrome QNH can beused. Alternatively, aerodrome QFE may be used on finals, inwhich case it should be on the No.1 altimeter when single-pilot,and on both otherwise. When single crew, No.2 altimeter mayremain on the relevant QNH. A third altimeter must be set torelevant QNH when at or below MOCA or MORA.Temperature ErrorPressure altimeters indicate truealtitude under ISA, so you will geterrors if it’s too cold. When thesurface temperature is well belowISA, correct altitudes by:Surface Temp (ISA) Correction–16°C to –30°C + 10%–31°C to –50°C + 20%–51°C or below + 25%Altitude Alerting SystemsThese include devices that giveaudio/visual warnings, and thosethat merely act as a reminder, using adigital indicator, of the requiredaltitude or flight level. Either shouldbe reset every time a change is made,and cross-checked by the other pilot.Exercise care with the AutomaticFlight Control System (AFCS), toprevent unplanned departures fromthe flight path.Audio Voice Alerting DeviceHelicopters over water more than 10minutes from land at normal cruisemust carry a radio altimeter with anaudio voice warning below a pre-setheight, and a visual warning thatoperates at a selectable height.
Ground Proximity Warning SystemsThis should be energised and usedthroughout the flight, unless it isunserviceable and the MEL allows it.GPWS is supposed to provide awarning just before you go intoTerrain Impact Mode, based onexcessive rate of descent or closurerate, negative climb rate or approachtoo close to the ground with the gearup. It is not infallible, but animmediate and positive responsemust be made to all its alerts andwarnings, even if you've previouslyhad spurious ones, leavinginvestigation till later. An Alert is acaution, whilst a Warning is a command,which may be genuine, a nuisance(where you are actually in a safeprocedure), or false. When you get awarning, pull up smoothly and applythrust until it ceases.Basic GPWSThis gives warnings, rather thanalerts, in all modes except 5, DescentBelow Glideslope, where activation willcause the audio warning ‘Glideslope’to be repeated; you take immediateaction to regain the glideslope asquickly as possible, until the alertceases. Whenever a warning isreceived, the immediate responsemust normally be to level the wingsand initiate a maximum gradientclimb to MSA for the sector beingflown, but see below.104 Operational FlyingAdvanced GPWSThis not only indicates the mode ofoperation, but provides alerts as wellas warnings. Do not recover theoriginal flight path until the cause ofthe alert has been positivelyestablished and eliminated.Whenever a warning is received, theimmediate response must be to levelthe wings and initiate a max gradientclimb to MSA for the sector beingflown, except as below.Warnings – Discretionary Action byCommanderResponses to warnings may bereduced to those for alerts onlyduring the day, when you are 1 nmhorizontally and 1000 feet verticallyfrom cloud, with at least 5 nm vis,and it’s obvious there is no danger.LimitationsThere is no forward looking facility,so you will get little or no warning ofanything in front of you. Alerts andwarnings in Modes 1 and 2 are onlygiven when you are less than 2,500 ftabove the local terrain. If nocorrective action is taken, amaximum of some 20 seconds willelapse between the initial alert orwarning and contact with theground, which will be lessened if therate of descent is excessive, or thereis rising ground beneath you.Unwanted WarningsUnwanted (that is, false or nuisance)warnings may be received when, forexample, you are being vectored byATC and descending into hills. AMode 5 (glideslope) alert may betriggered when you are outside thevalidity area of the glideslope signal,as you would when circling. You willalso get an alert/warning if the flapsare set wrongly.
TCAS/ACASAirborne Collision and Avoidance Systems(ACAS) provide you with anindependent back up to the Mark 1Eyeball and ATC by alerting you tocollision hazards. TCAS II (TrafficAlert and Collision Avoidance SystemType II) is the current equipment,which provides advice in the verticalplane, as a Traffic Advisory (TA),telling you where nearby (Mode A)transponding aircraft are, orResolution Advisory (RA) detectingaircraft transponding Mode C, andwhat to do about it. TCAS III canissue horizontal suggestions. Notrequired in UK, but may be used ifyou have it. It uses four antennae, acomputer and Mode S transponderto continually survey the airspacearound you and predict the flightpaths of likely intruders. Mode Suses a 24-bit interrogation address,which reduces mistakes and allowsthe system more capacity andefficiency. It can also provide twoway data link communications on1030 and 1090 MHz, used in thiscase for manoeuvre messages, butalso as a back up for VHF voice.The size of the Caution Area varieswith your speed.A TA alerts you that an RA,requiring a change in flight path, mayfollow—it is displayed 35-48seconds from the time the intruderaircraft is predicted to enter thecollision area, displaying range,bearing and altitude, but rememberthat this system relies ontransponder-equipped aircraftreceiving information from others—RAs will only be generated if bothOperational Procedures 105use Mode C – if only Mode A isavailable, you will only get TrafficAdvisory information. Theequipment cannot resolve withcomplete accuracy the bearing,heading or vertical rates of intrudingaircraft, so you should not rely solelyon TAs. Look where the conflictingtraffic is supposed to be, and getATC to help. Otherwise, manoeuvreaway from the collision risk. Onceclear, advise ATC.The Warning Area extends 20-30seconds from when an intruderwould enter the collision area, whichis when RAs are issued. They aremeant to advise you of verticalmanoeuvres required for adequateseparation from a threat. A correctiveadvisory calls for a change in verticalspeed and a preventive advisoryrestricts it. A response should beinitiated immediately, not in theopposite direction, and crew membersnot involved should check for othertraffic. Once adequate separation hasbeen achieved, or there is no longera conflict, you should return to yourintended flight path, and informATC. An RA may be disregardedonly when you visually identify theconflicting traffic and decide that nodeviation is necessary. If an RA andATC conflict, follow the RA.Nuisance or false advisories shouldbe treated as genuine unless theintruder has been positivelyidentified and shown visually to beno longer a threat. Departures from
ATC clearances in compliance withan RA should be reported to theCompany and/or authorities.In-Flight Fuel ManagementYou must carry out fuel checks, thatis, record the remaining fuel, atregular intervals, such as hourly, orat convenient times when the flightis less than an hour and the cockpitworkload is low. The idea is tocompare actual consumption withthat planned, and ensure you haveenough to complete the flight withthe expected fuel remaining.For an isolated destinationaerodrome, if the expected fuelremaining at the point of lastpossible diversion is less than thesum for diversion, contingency andfinal reserve fuel, you must eitherdivert, or continue to thedestination, provided it has twoseparate runways and the expectedweather conditions are as planned.You must declare an emergencywhen the useable fuel on board isless than final reserve fuel.Adverse & Hazardous AtmosphericConditionsThunderstormsThe airflow is greatly disturbedanywhere near a thunderstorm,usually noticeable by strong up anddown draughts, together with heavyrain and lightning. Avoid them evenat the cost of diversion or anintermediate landing, but should thisbe impossible, there are certainthings you can do to help. It can beat least as dangerous up high aslow—you can expect anything fromlightning and turbulence to icing andhail, each with hazards of theirown—lightning, for instance, couldexplode a fuel tank, and strikes canoccur up to 20 nm from a storm cell.Not only that, even over baby onesnear to larger storms, you will needat least 5000 feet clearance. Similarly,try not to fly underneath, either, ormake steep turns.106 Operational FlyingApproaching thunderstorm areaSeat belts should be tightened,and loose articles stowed. Onepilot should control the aircraftand the other monitor the flightinstruments. Select an altitudefor penetration that will keepyou clear of obstacles, and usethe weather radar to select thesafest track. Set the power forthe recommended turbulencespeed, adjust the trim and noteits position, so any excessivechanges from autopilot or machtrim can be quickly assessed.Height, mach, rate of climb ordescent and airspeed locksshould be disengaged but yawdamper(s) should be on.Switch on the pitot heaters,deicing, and continuous ignitionsystem, where fitted. Disregardany beacons subject tointerference, such as ADF andOMEGA (although tuning theformer to its lowest frequencywill give you a primitivelightning detector). Turn thecockpit lighting fully on andlower crew seats and visors to
minimise the blinding effect oflightning flashes.Within the Storm AreaAs the speed of vertical aircurrents may well exceed thecapabilities of the aircraft, fly byattitude at the recommendedturbulence speed and maintainyour original heading—do notcorrect for altitude, except forobstacles; avoid harsh orexcessive control movements,particularly with power, exceptto restore margins from stallwarnings or high speed buffets.Do not be misled by conflictingindications on otherinstruments, and don’t roll toomuch. If auto-trim variations arelarge, disengage the autopilot.Movement of the mach trim,where it occurs, though, isnecessary and desirable. Checkthe yaw-damper remainsengaged. You might gettemporary warnings (e.g. low oilpressure) from negative G,which should be ignored.Air Traffic Control ConsiderationsObtain clearance from, ornotify, ATC so they can separateyou from others. If you can't,keep manoeuvres to a minimum,and inform them ASAP.Take-off and LandingDo not take off if athunderstorm is overhead orapproaching within 5 nm. Atdestination, hold clear or divert.Use of Weather RadarThis detects rainfall to avoid (notpenetrate) severe weather, aslarge raindrops in a small areaare a dead giveaway forthunderstorms or, rather, theiractivity is - turbulence isproportional to the rate at whichrainfall increases or decreasesover a given distance. Yourdecisions are therefore based ona deduction from certain facts.A clear area on the radar screendoesn’t mean there isn’t anycloud, as minute cloud droplets,ice, dry snow and dry hail havelow reflective levels, if at all. It ismore likely to indicate largewater droplets, as they willabsorb energy as they approachthe size of the radar wave.Operational Procedures 107Operation is quite simple, butfull use on the ground should beavoided (not below 500 feet, infact). Naturally, you've got tocheck the equipment beforedeparture, but most sets have aninternal procedure for this.When you do switch it on, itshould be set to Standby for atleast 3 minutes first, to allowthings to warm up. You willhave several scan ranges tochoose from, possibly from 250miles down to 5, but 80 isadequate, which is about whatyou would get with a 10 inchantenna, the usual fit in smallaircraft. The smaller it is, thewider the beam and the dispersalof energy, which means that alot of it will pass by whatever
storm is around, giving you anindication very much less thanthe true hazard. You would besafe in assuming that whateveryou see is one or two levelsmore severe.Once airborne, there is a tiltcapability which will point theantenna upwards or downwardsso you can get more detail aboutany storm cells you may beapproaching, but don’t expect tosee the tops of a storm, becausethe crystals there won’t reflectthe energy in the first place, andyour beam focussing will be toonarrow to include it. In the sameway, you will also get groundechoes, which are good fordetecting the enemy coast ahead,but only because the water willabsorb all the echoes and youwill see a big black hole in itsplace. Buildings and the likewon’t reflect properly at all –you might just see a mass ofconfusing colours.If you haven't got the luxury ofcolour and computer controlledecho highlighting (and have torely on steam), there are certaindistinctive storm patterns tolook out for, such as the hook,finger and U-shape, which all looksimilar to a figure 6. These, plusscalloped edges round a cloudoutline, are all characteristic ofhail. They can change quickly, sothey need careful monitoring(hail shows up better when thegain is reduced). The heaviestprecipitation, and the heaviestturbulence, will show up asblack holes, or red when usingcolour, which will be bestdetected in Contour mode.Remember that radar signalsweaken, and might show the endof the weather falsely.Iso-Echo produces a hole in astrong echo when the returnedsignal is above a pre-set value.The edge of the hole thatactually appears on the screenhas the same rainfall rate, and islike a contour line, hence thename. When it is narrow, thereis a strong intensity gradient, soavoid hooked echoes, especiallyrapidly changing ones.Avoid the brightest returns (i.e.those that are changing rapidly)by at least 20 nm. Above thefreezing level, make it 5 nm and10 nm when below. If you seeanything at all between 50-70nm, keep well away from it.108 Operational FlyingIcing ConditionsIce adversely affects performance,not only by adding weight, but alsoaltering the shape of lift producingsurfaces, which changes your stallingspeed – autorotation in a helicoptercould therefore be a lot moreinteresting than normal. The USArmy found that half an inch on theleading edge reduces your liftingcapacity by up to 50%, and increasesdrag by the same amount. On top ofthat, fuel could freeze in wing tanks,as could control surfaces, and slush
