you look at it, one to the front and oneto the back door. The other two please goto the left hand side, you to the front andyou to the back door.Don't mention "the back" by itselfor they will take it literally.When you get in, please do not step onthe floats, but use the foot rests on theskids which will be pointed out to you.Once you are in, we will do up the seatbelts and close the doors. After you land,we'll get you out, so just sit tight andwait for us.Some very important safety points—please don't touch the door handles inflight, don't throw anything out of thewindows, and keep away from the tailrotor—always move towards the frontwhere the pilot can see you."Again, this sort of stuff should be onthe standard Passenger BriefingLeaflet—you could hand out a fewto keep people in the queueoccupied, as they won't listen to youproperly, anyway. Have one enlargedand pinned to a large board so it canbe read from a distance. The cashierwill need a small pile of change, butyou could keep the price at a roundfigure so you don't need it in the firstplace (try multiples of 5). If in doubtas to what constitutes an infant—charge. When it's closing time andobvious that not everyone will get atrip, stop selling in good time.Keep an eye out for your Inspector! He willbe the one lurking behind a tree witha notebook.212 Operational FlyingThe Technical Bits (UK)The Operational Area,which is under positivecontrol of the Company,encompasses theLanding Site, thetaxiways, HAAs andIAAs (see below fordefinitions) and takeoff,climb and approachslopes. It has sidesurfaces rising upwardsand outwards to 100 feetat a gradient of 1:1 fromits edges, unpenetratedby obstacles and will befenced, roped off orotherwise protected fromintrusion byunauthorised persons—therefore it should notinclude a public right-ofway. Rope and stakesused for demarcation andpublic control are notobstacles for this, thoughthey may be forperformance planning.Final Approach andTakeoff Area (FATO)This is inside the SafetyArea (see below), wherethe final phase of theapproach to hover orlanding is completed, andfrom which takeoff iscommenced. It may besquare or circular and theminimum size is 1½ xthe rotor diameter(popular helicopters arelisted later).Safety Area (SA)
Surrounds the FATO,for reducing damage toSpecial Use Of Aircraft 213helicopters accidentally divergingfrom it. It is also square or circular,according to the FATO, and theminimum size is 3m or ¼ of therotor diameter, whichever is thegreater. It must be free fromobstacles.The combined size of the FATOand SA should be at least twice theoverall length, including rotors, ofthe helicopter and, where it containsthe TLOF (see below), the surfaceshould be firm and not blow awaywith downwash.Touchdown and Liftoff Area (TLOF)A load bearing area for touch downand lift off; it should be free fromslopes, to ease passengerembarkation and disembarkation,and not have them walking uphillinto tail rotors. The TLOF has adiameter of at least twice the lengthof the helicopter, including rotors,and is normally contained within theFATO (it's the same minimum size),but may be separate.TaxiwaysUsed where the TLOF is remotefrom the FATO, with a minimumclearance of 1 rotor diameter fromobstructions either side of the rotordisc (that is, a minimum overallwidth of 3 rotor diameters, or 33.9mfor the Bell 47).Helicopter Acceleration Area (HAA)Should have a minimum width of30m or twice the overall length ofthe helicopter, whichever is thegreater, obstacle-free and longenough to accommodate one thirdof the "Takeoff Distance to 100feet" (168m—Bell 47) given in theFlight Manual (therefore 56m). Thesurface should be substantially levelso a helicopter can land safely if anengine fails, without risk of injury tothe occupants or third parties.Takeoff Area (TA)At the upwind end of the HAA, withthe same width and at least twice thelength, and free from significantobstacles. The minimum TakeoffDistance Available (Helicopters)(TODAH) should be greater thanthe Takeoff Distance Required toachieve a height of 100 feet, e.g.more than the HAA and TAcombined. The total length of theTODAH is therefore about 168m.Note: Performance figures here arefor the Bell 206B for +20o C and1000 feet PA at max AUW (hotBank Holidays).The Takeoff Area and downwindtwo-thirds of the IAA may containinsignificant or frangible obstaclesonly. The remainder should beobstacle-free (rope and stakes usedfor demarcation and public controlare not considered to be obstacles).Inner Approach Area (IAA)For each direction of landing, hasthe same width as the HAA andaccommodates the Landing DistanceRequired from 100 feet as detailed inthe Flight Manual (but see JARs).The upwind third of the IAA shouldbe completely free from obstacles.The minimum Landing Distance
Available (Helicopters) (LDAH) shouldexceed the Landing Distance Requiredfrom 100 feet.Note: The TODAH and the IAAare essentially the same patch ofground, except the TODA is slightlylonger. As both the HAA and the214 Operational Flyingupwind third of the IAA must beobstacle-free and are at oppositeends of this area, the whole TODAshould be obstacle-free.Side Surfaces and SlopesThe Operational Area will have sidesurfaces rising upwards andoutwards to 100 feet at a gradient of1:1 from the edges of the HAA,Takeoff Area or IAA which will notbe penetrated by any obstacle, fixedor transient. It will also be fenced,roped off or otherwise protectedfrom intrusion by unauthorisedpersons, and therefore should notinclude an unguarded right of way.Takeoff, climb and approach slopes(which may be curved) must not beover large areas of water unless youcan land safely on it in emergency.They should be obstruction-freewith a gradient of not less than 1:8and be 1000m long, possessing areassuitable for emergency landing.Special Events (for UK)Vast amounts of people beingmoved into a major sporting event(such as The British Grand Prix atSilverstone) make the feeder sitesused for their lifting and droppingoff liable for special treatment.These events are good forbusiness—one good day atSilverstone keeps some companies inprofit for the year. As for PleasureFlying sites, the authorities need tobe notified (in this case at least 28days before), but otherconsiderations arise as well.First of all, if you sell single seats tothe public, rather than the wholecapacity of the aircraft on a "soleuse" charter basis, you will eitherneed a full Air Transport Licence, oran exemption (pleasure flying is aspecial case). It also needs to bedone in your own right; you can't doit on the back of someone else, asyou can with an AOC sometimes.Again, there is a special form to fillin which will cut out most of thelack of communication over thissubject, and you should find a copyin Ops.Secondly, you will need to arrangearrival and departure slots, which areusually at a premium. Because of thenumbers of aircraft involved (usuallyover 126 H1 types alone at theGrand Prix), there will be a briefingfor all concerned well before theevent, at which all companies areexpected to send a representative. Atthe very least a Notam will be issued.H1 helicopters, by the way, are lessthan 15m long, and H2s between 15-24m; they therefore require differenttreatment at their feeder sites.A feeder site is one where more thanfive movements take place in anyone day in connection with an event,as a result of which they requirespecial facilities (a movement is atakeoff or a landing). If using H1s
you can get away with normalequipment as used for pleasureflying, but H2s need something a bitmore macho. Actually, it's basicallythe same, but the vehicle must havefour-wheel drive and there must be aminimum of 60 gallons of water and5 gallons of foam concentrate, withequipment able to deliver it at 40gallons per minute. A minimum of100 lbs of CO2 or 50 lbs of drypowder or BCF is also required.The rescue and medical equipmentrequirements are also morecomprehensive, needing transfusionSpecial Use Of Aircraft 215and resuscitator gear to be readilyavailable in addition to:·
large non-wedging axe·
small non-wedging axe·
grab or salving hook·
1" cold chisel·
4lb hammer·
fire resisting blanket·
heavy duty hacksaw with 6spare blades·
suitably large ladder·
feet of 2" line·
1 pair 7" side cutting pliers·
24" saw·
large slotted screwdriver·
large Philips screwdriver·
1 pair tin snippers·
pneumatic rescue chisel withspare cylinder·
Chisel and retaining spring·
quick release knife with a sheath·
enough pairs of flame resistantgloves·
24" bolt cropper·
3' 6" crowbarLine PatrolIt's pretty hard to get lost doing this!You will be carrying observers fromthe Electricity Boards, under theirnormal procedures, which are prettyexhaustive. All their staff are fullyand professionally trained toexacting standards. They need to be,as following and inspecting towerlines calls for a high degree ofproficiency and concentration fromeveryone. The very nature of theexercise (flying close to the linesinspected) means that for most ofthe time you will be very near theavoid area of the Height/Velocityenvelope. In fact, you will be flyingat such a speed (around 50 kts) that,if the engine fails, you will be goingnowhere but down, which is quiteinteresting when the line runsthrough trees and you have to decidewhether you're better off in them ordodging the cables.For normal wooden poles, being oneand a half rotor spans laterally andflying at about 50 kts is the ideal,although 11 Kv ring circuits in aclover leaf pattern could make thisdifficult. At the very least, you needa positive airspeed, that is, oneshowing on the ASI.The authorities assume the flightwon't take place in the avoid area, solow flying exemptions, etc. aregeared towards looking after thirdparties on the ground not directlyconnected with your activities.However, the flights are stillCommercial Air Transport, andentering the avoid curve is thereforeprohibited. If prolonged incursionsare likely, consider using a twin.Even where a single-enginedmachine could be used, it's usuallyover areas that aren't suitable forforced landings or are unable toafford safety for the passengers(hostile environments). There shouldbe a full restraint harness for eachoccupant together with a protectivehelmet and flameproof overalls, orclothing with sensible shoes.216 Operational FlyingNo flights should be made at night,over fuel installations or congestedareas of any city, town or settlement.Dispensations will be required to flynear nuclear installations andprisons, just in case they think you'repart of an escape plan.Flights should also be confined towithin 300 feet of the linesconcerned (but no closer than 1½rotor diameters to the lines whenlevel, or 1 diameter plus 30 feetwhen above). Flying above and tothe right is most preferable. Inaddition, lines should be crossedvertically at least 100 feet abovethem (common sense dictates thatyou should do this over a pylonrather than the lines themselves).You will not be allowed closer than100 feet to any people or vehiclesdirectly concerned with lineoperations and 200 feet to any otherstructures than those to do with the
lines themselves. You shouldn't, butif you have to go under a wire, getyour skids on the ground as near to apylon as possible.As well as the proper permissions,other problems include insurance.Ensure that whatever you get alsocovers you for frightened animalsbolting and causing havoc—thisusually happens with sharplychanging noise levels caused by rapidmanoeuvres. If you can't help flyingover animals, at least try not to chasethem through the fence!Line patrol should not normallyhappen if the visibility is less thanabout 1 mile, and 2 if raining (1 mileis approximately 6 towers or polesahead). These limits are higher thanusual because moisture will stick tothe windscreen at slower speeds, andthings are further complicated if youhave no windscreen wipers, asprecipitation won't blow away either.Under those conditions, speeding upto get rid of water is not what youwant to be doing, especially whenthose grey towers merge into theweather! Give serious considerationto aborting if there is a lot of rain,although really heavy stuff will tendto run off better than the lightvariety. Also, line patrol should notnormally be attempted if the wind isabove 25 knots, and the cloudbasebelow 400 feet.Lines are patrolled at whatever speedis comfortable, generally between 20or 50 knots, a little above pole heightand to one side, depending on whatis being looked for. This could bejust trees encroaching on the wires,but also could be lightning damage.Observers will normally be on theopposite side to you so the lines willbe closest to them. They makecommentaries on tape which arelater transcribed into usefulinformation.Always try to follow the line as nearinto wind as possible, or, if not, intrim at least, which will help if youlose tail rotor authority. If it's around10 knots or so, being downwindgenerally will only ensure the transittime along the wire is too fast, withthe consequent danger of you tryingto slow down and having noairspeed—if more it may be rough aswell, especially in the mountains.Monitor the instruments and beparticularly aware of overtorquing orovertemping. Don't forget tail rotorand wire strikes, and other lines(especially tower lines) crossing—theobservers will be too busy to assistyour lookout. If a closer inspectionis called for, DO NOT try to comeSpecial Use Of Aircraft 217to the hover and backtrack, but gainheight and speed, positively identifythe area and make a conventionalcircuit and approach to come to thehover alongside the line into wind.A constant lookout must bemaintained at all times, especially forfast, low flying military aircraft, soHigh Intensity Strobe Lights (HISLs),nav lights, landing lights and anticollision beacons must be on at alltimes. HISLs should be at least 2000candela in power (so don’t drop oneor you’ll have to pick them all up). Ifthey become unserviceable, patrolabove 500 feet. Don't plan on doingmore than two to three hours perday due to the high workload.Power Line Cleaning & MaintenanceDone when the Electricity peoplecan’t get to them by road. As youcan imagine, a lot of training isrequired for this, especially when thelines are kept live. Your hoveringneeds to be precise for long periods.There is a platform on yourhelicopter, on which the linemansits, who connects the machine tothe line to equalise the potential.This means that the helicopter is liveas well, so special maintenance iscarried out beforehand to ensure theship's normal electrics aren't fried.For cleaning or deicing, a waterpressure system powered by a smallgasoline engine is used, and you getto hover a bit further away.Civil Aviation Notification Procedure(CANP)In UK, powerline survey, sportingactivities, aerial photography, cropspraying, underslung loads andanything else low level (i.e. below1000 feet) that will affect militaryoperations should be notified on0800 515544. The relevant (RAF andATC) authorities will informed bythe duty airman of the details.Naturally, try to give them as muchnotice as possible.Pipeline SurveyThis is similar to Line Patrol, somost of what is said there will applyhere. Gas pipelines (or whatever) arenot very far below the surface of the
ground, and potential hazardsinclude building works, ditchconstruction, drainage, flooding,leakage and falling trees.1/250,000 scale maps will beprovided, on which the pipelineroute should be marked, though itwill be obvious when it’s just beenlaid. Observers will be using largerscale maps supplied by theircompanies. The normal patrol heightis 300 feet (in UK, anyway), with anassociated speed of 50-80 kts, takinginto account the efficiency ofinspection, terrain, wind directionand practical helicopter operation(avoid curves, etc.). However,between 500-700 is recommended toavoid low flying military aircraft.You should not approach closerthan 300 feet to any person, vessel,or structure, and only closer than500 feet within a horizontal distanceof 300 feet from the pipelines.The cloudbase must be at least 200feet above inspection height, with aminimum visibility of 1500 feet.UK Police OperationsA police force will either own itsown aircraft or charter fromoperators as and when required, in218 Operational Flyingwhich case the only things you canget away with are low flying (closerthan 500 feet, etc) and going in badweather. Even then, you can’t getcloser than 50 feet, or 1.5 rotordiameters, whichever is greater. Infact, to take full advantage of anyrestrictions, your passenger needs tobe either a police officer, anemployee of the police authority, amedical attendant, a pilot undertraining, an Inspector, a Fire Officer,a Customs Officer on a jointoperation, or any other agreed inwriting by the authorities. However,there will always be a policeobserver, and the job involves a lotof cross-controlling when onobservation, not to mention shortnotice tasking.As they may need to recover theircosts from time to time, they mayalso need a Police AOC and OpsManual (PAOM), though thisdepends on the country.PrisonersA prisoner is a passenger andqualifies for the normal safetyconsiderations, although theirmovement is definitely not routine.Handcuffing should always be doneto the front, so seat belts can bereleased in emergencies.Potentially violent prisoners shouldbe carried one at a time and haveenough escorts to restrain them. Inany case, at least two should be used,ensuring that neither the pilot, thecontrols or the exits can be reached.If a prisoner does become violent,land as soon as practicable and havethem continue the journey bysurface means.Persons under the influenceThese should be avoided, butsometimes it can’t be helped. First ofall, you will need to decide whetherthey are fit for a normal seat or needa stretcher. You will need at leasttwo escorts for both restraint andemergency evacuation, and a suitablereceptacle for vomit.As with prisoners, land as soon aspracticable if there are any signs ofviolence. Further movement shouldbe undertaken by surface means.Bodies and remainsTheir carriage is affected by howinaccessible they are, that is,precluding other methods oftransport. The main considerationsare the health and hygiene of theaircraft occupants, which means theymight have to be carried outside ifthey are a bit ripe, so you need to becurrent on winching or slung loads.Whatever you choose, bodies andremains should be in body bags orcoffins. Naturally, any spillage ofbody fluids needs a thorough washdown as soon as possible.Police DogsShould be embarked or disembarkedwith the aircraft shut down, but ifthis is not possible, the observershould meet the handler and dogclear of the aircraft for the briefing.The dog should be on a short lead,so it doesn’t interfere with anything.Fly smoothly, but be prepared toland if the dog becomes unwell,although you will find that theymostly like travelling and prefer tolook out of the window rather thanbeing made to lie down.Special Use Of Aircraft 219If the dog breaks free and goes forthe tail rotor or propeller(s), thehandler must not attempt to follow,but give you a signal to close down.Weapons and MunitionsThe overriding consideration is the
elimination of danger to the aircraft,its occupants and persons andproperty on the ground. Munitionsinclude gas/smoke canisters, stungrenades, shotgun cartridges andammunition for rifles and sidearms.These weapons should not becarried in a loaded state:·
double-barrelled shotgun·
single-barrelled shotgun (unlessautomatic or pump action)·
baton gun·
CS discharger·
dartgunLoading, unloading or firing ofweapons on aircraft is not permitted.Where all passengers are securelyseated throughout the flight, loadedweapons must be in a safe condition,weapons and munitions should becarried in holds, compartments, orother areas that are inaccessible inflight, and secured normally.Weapons or munitions must not bedistributed among passengers untilthe aircraft has landed.Weapon Safe ConditionSelf-loading pistol.self-loading rifle,carbine, automaticshotgun or pumpaction shotgun,bolt action rifle,automatic rifle.Working parts forwardand trigger released,safety catch appliedwhere possible,magazine charged withammunition and fitted tothe weapon. NO ROUNDIN THE BREACH.Revolver Cylinder loaded withammunition; weapon in asecure holster, toprevent accidentaldischarge.When passengers on a specialoperation need their weapons handy,hand weapons and spareammunition for them may be carriedin readily accessible boxes orholsters, with the ammunition inpockets. Rifles and shotguns may bestowed securely within the cabin,with spare ammunition in body beltsor readily accessible boxes.Gas/smoke canisters must be inboxes but these may be readilyaccessible. Boxes must be stronglyconstructed, fire resistant and havean “explosives” label.Hover Emplaning and DeplaningDefined as allowing trained personsto enter or leave the helicopterwithout its full weight on theground, and done where you can’tland properly:There should be no danger to thirdparties and minimal risk to theaircraft, crew, seated passengers andthose carrying out the activity. Themajor consideration is engine failure.You should be able to hover at leastat 4 ft, in day VFR, although theactual height should be a lot lessthan that, with one skid or wheel in220 Operational Flyingcontact with the ground to get rid ofstatic. One passenger should be
seated before the next gets on board.To give you a decent power margin,the maximum weight should notgreater than 95% of the maximum,and you should have at least a 15%power reserve in the low hoveranyway. The time in the hovershould not be more than the timelimit for take-off power. Cargoshould not shift.Your safety briefings should includethe effects of C of G changes.Deplaning ProcedureSeat belts must be unbuckled asinstructed, then rebuckled. Only oneperson or item of cargo should leavethe helicopter at a time, from the leftside, with the weights gentlytransferred to the ground. Oneperson should ensure that all doors(passenger and cargo) are closedafter everything has been unloaded.Persons and cargo should remaingrouped ahead of the passenger dooruntil the helicopter has departed.Emplaning ProcedureSeat positions should be determinedbeforehand, with persons and cargogrouped in one location beside theintended arrival area.People must only approach whensignalled (either thumbs up, or anexaggerated head nod), from the leftside, with only one person or itementering the helicopter at a time.Weights should be gently transferredfrom the ground to the helicopter.Seat belts should be immediatelyfastened once persons are seated,and doors closed.Formation FlyingUsed when chasing another aircraft,but not at night, in cloud, or whenthe cloud base is below 500 ft orvisibility below 3 km. As the pilot ofthe other machine may not be awareof your intentions, and might noteven wish to be identified, youshouldn’t do this too closely. Inother words, spend the shortestpossible time at the minimumpermitted distance from the othermachine, and shadow from themaximum range consistent withgetting photographs, or otherevidence, and maintaining visualcontact. Remember one officialdefinition, which is "flight by solereference to another aircraft"Do not endanger the other machineor attempt to force it to alter heightor heading, or to land, because youmay need to take safe avoidingaction if the other machine attemptsto endanger you.If you cannot establish RT contact,approach while the target is instraight flight, which may be level, orclimbing, or descending. Establish astand-off position behind, between 4and 8 o'clock, not closer than 200m.Reduce the range slowly andprogressively to at least 100m,moving back out once the requiredevidence of registration, type andother features have been noted.Landing Helicopters on RoadsThe area must first be secured (butsee below), with radio or verbalcommunication having taken placeto confirm that you have authority toland there. Unaffected carriageways
should be closed at all times.Normally, you can only land at anunsecured site (i.e. where the policeSpecial Use Of Aircraft 221are not in attendance) in remoterural areas outside congested areas,but you may do so on dualcarriageways (divided highways) ormotorways (turnpikes) in daylight,where no traffic is moving—nolandings should be made by night.In any case, there must be no threatto persons or vehicles on the groundfrom the helicopter, or vice versa.Always be aware of the effects ofyour downwash, which may blowaway crucial evidence, not tomention dislodging broken glass andother loose debris, particularly fromdamaged buildings, at bomb scenes.Try not to land in school or otherplay grounds, or areas wherechildren might be confined orsuddenly emerge. Don’t use theaircraft presence or public addresssystem to clear children from a site.Parachute DroppingIn UK, no parachute droppingshould be undertaken unless (as apilot) you've been approved by theBritish Parachute Association andthe parachutists themselves are inpossession of an Operations Manualauthorised by them. It’s probablysimilar elsewhere. You get yourcertificate by passing a check ridewith a TRE, who in turn has beenapproved by the BPA. The normalregulations for the dropping ofarticles from aircraft also apply. Inaddition, the Flight Manual shouldinclude a Supplement to cover thesituation. For some strange reason,parachutists do not seem to beclassed as passengers or freight, soit's a good question as to whether aparachute trip is actually CommercialAir Transport or not. Check yourinsurance cover, even though on theway down they are not in theaircraft, and on the way up they arenormal passengers.Parachutists should be strapped in atall times except immediately prior todropping, and before takeoff theyshould be shown how to secureseatbelts so they don't flap around inflight, as part of a proper briefing.There should be no loose articles inthe cabin, and seats must beremoved, as must be dual controls ifone intends to drop from the frontseat (of a helicopter). There shouldbe no other passengers.Don't use static lines and remove thedoors (check the Flight Manual forlimitations on flight without them).A typical freefall drop needs onepass over the drop site into wind atapproximately 2000 feet, where thejumpmaster will drop weightedpaper markers. You then commenceclimbing to the drop height, turningdownwind and keeping the markersin view all the time. When at dropheight, come over the site again atabout 60 knots into wind, where thejumpmaster will guide you to wherehe wants to be.When dropping, use both sides ofthe aircraft if possible (difficult in aBell 47), so the lateral centre of
gravity limits are not exceeded – thisis one of those times when youmight want to calculate it for takeoffand landing. The helicopter shouldbe level, above 2000' agl with anairspeed between 20-70 kts IAS.Mountain FlyingIn the mountains, general principlescommon to other areas will be vastlydifferent. You must be prepared toadapt your flying techniques as the222 Operational Flyingneed arises, for the peculiarities ofthe region and the type of aircraft. Inother words, have not only Plan A,but Plan B, C, etc. up your sleeve,because, very often, once you’velooked at a site and gone round forfinals, you will find a cloud has gotthere before you! You cannot affordto assume that a particular situationis the same as, or similar to, anyother you might have encounteredpreviously. You can also expect fog,especially in the early morning,which will often stick to the sides ofvalleys for quite some time.Sometimes, you can create your ownclouds, by pulling down warm airfrom an inversion above.In UK, mountainous areas includeScotland and Wales, the Lake andPeak Districts, and generally any hillycountry above 1500 feet amsl,although a geologist would probablyexpect to see 2000. In many otherparts of the world, these would beconsidered as just foothills, as onedescription of mountain flyingincludes a reference to 5000 feetDensity Altitude. Actually, it reads:"experience in maneuvring ahelicopter at density altitudes of over5000 feet to include numeroustakeoffs and landings in situationsindicative to difficult mountainousterrain. This terrain consists ofabrupt, rapidly rising terrain resultingin a high land mass projecting aboveits surroundings, wherein complexstructures in which folding, faulting,and igneous activity have taken part.These mountainous areas producevertical mountain winds, turbulenceassociated with mountain waves,producing abrupt changes in winddirection often resulting in upflowing or down flowing aircurrents. In the contiguous UnitedStates, the boundaries of thesemountainous areas are defined in theaeronautical information manual."In Canada, look out for DesignatedMountain Areas, which naturallyinclude the Rockies, extending intothe USA (don't blame me for theEnglish above - it was written by theUS Forestry people).However, air behaves the same wayround pointy bits of groundwhatever its height above sea level,and this includes flying aroundbuildings (we will look at laminarflow shortly). The big differencehere is that you have less power toplay with, hence the mention ofdensity altitude.Performance changes drasticallywhen both temperature and heightincrease—just the opposite to flyingin cold weather, but you knew thatanyway. As far as altitude is
