飞行员操作飞行手册Pilot Operational Flying Manual

帅哥

you look at it, one to the front and one

to the back door. The other two please go

to the left hand side, you to the front and

you to the back door.

Don't mention "the back" by itself

or they will take it literally.

When you get in, please do not step on

the floats, but use the foot rests on the

skids which will be pointed out to you.

Once you are in, we will do up the seat

belts and close the doors. After you land,

we'll get you out, so just sit tight and

wait for us.

Some very important safety points—

please don't touch the door handles in

flight, don't throw anything out of the

windows, and keep away from the tail

rotor—always move towards the front

where the pilot can see you."

Again, this sort of stuff should be on

the standard Passenger Briefing

Leaflet—you could hand out a few

to keep people in the queue

occupied, as they won't listen to you

properly, anyway. Have one enlarged

and pinned to a large board so it can

be read from a distance. The cashier

will need a small pile of change, but

you could keep the price at a round

figure so you don't need it in the first

place (try multiples of 5). If in doubt

as to what constitutes an infant—

charge. When it's closing time and

obvious that not everyone will get a

trip, stop selling in good time.

Keep an eye out for your Inspector! He will

be the one lurking behind a tree with

a notebook.

212 Operational Flying

The Technical Bits (UK)

The Operational Area,

which is under positive

control of the Company,

encompasses the

Landing Site, the

taxiways, HAAs and

IAAs (see below for

definitions) and takeoff,

climb and approach

slopes. It has side

surfaces rising upwards

and outwards to 100 feet

at a gradient of 1:1 from

its edges, unpenetrated

by obstacles and will be

fenced, roped off or

otherwise protected from

intrusion by

unauthorised persons—

therefore it should not

include a public right-of

way. Rope and stakes

used for demarcation and

public control are not

obstacles for this, though

they may be for

performance planning.

Final Approach and

Takeoff Area (FATO)

This is inside the Safety

Area (see below), where

the final phase of the

approach to hover or

landing is completed, and

from which takeoff is

commenced. It may be

square or circular and the

minimum size is 1½ x

the rotor diameter

(popular helicopters are

listed later).

Safety Area (SA)

帅哥

Surrounds the FATO,

for reducing damage to

Special Use Of Aircraft 213

helicopters accidentally diverging

from it. It is also square or circular,

according to the FATO, and the

minimum size is 3m or ¼ of the

rotor diameter, whichever is the

greater. It must be free from

obstacles.

The combined size of the FATO

and SA should be at least twice the

overall length, including rotors, of

the helicopter and, where it contains

the TLOF (see below), the surface

should be firm and not blow away

with downwash.

Touchdown and Liftoff Area (TLOF)

A load bearing area for touch down

and lift off; it should be free from

slopes, to ease passenger

embarkation and disembarkation,

and not have them walking uphill

into tail rotors. The TLOF has a

diameter of at least twice the length

of the helicopter, including rotors,

and is normally contained within the

FATO (it's the same minimum size),

but may be separate.

Taxiways

Used where the TLOF is remote

from the FATO, with a minimum

clearance of 1 rotor diameter from

obstructions either side of the rotor

disc (that is, a minimum overall

width of 3 rotor diameters, or 33.9m

for the Bell 47).

Helicopter Acceleration Area (HAA)

Should have a minimum width of

30m or twice the overall length of

the helicopter, whichever is the

greater, obstacle-free and long

enough to accommodate one third

of the "Takeoff Distance to 100

feet" (168m—Bell 47) given in the

Flight Manual (therefore 56m). The

surface should be substantially level

so a helicopter can land safely if an

engine fails, without risk of injury to

the occupants or third parties.

Takeoff Area (TA)

At the upwind end of the HAA, with

the same width and at least twice the

length, and free from significant

obstacles. The minimum Takeoff

Distance Available (Helicopters)

(TODAH) should be greater than

the Takeoff Distance Required to

achieve a height of 100 feet, e.g.

more than the HAA and TA

combined. The total length of the

TODAH is therefore about 168m.

Note: Performance figures here are

for the Bell 206B for +20o C and

1000 feet PA at max AUW (hot

Bank Holidays).

The Takeoff Area and downwind

two-thirds of the IAA may contain

insignificant or frangible obstacles

only. The remainder should be

obstacle-free (rope and stakes used

for demarcation and public control

are not considered to be obstacles).

Inner Approach Area (IAA)

For each direction of landing, has

the same width as the HAA and

accommodates the Landing Distance

Required from 100 feet as detailed in

the Flight Manual (but see JARs).

The upwind third of the IAA should

be completely free from obstacles.

The minimum Landing Distance

帅哥

Available (Helicopters) (LDAH) should

exceed the Landing Distance Required

from 100 feet.

Note: The TODAH and the IAA

are essentially the same patch of

ground, except the TODA is slightly

longer. As both the HAA and the

214 Operational Flying

upwind third of the IAA must be

obstacle-free and are at opposite

ends of this area, the whole TODA

should be obstacle-free.

Side Surfaces and Slopes

The Operational Area will have side

surfaces rising upwards and

outwards to 100 feet at a gradient of

1:1 from the edges of the HAA,

Takeoff Area or IAA which will not

be penetrated by any obstacle, fixed

or transient. It will also be fenced,

roped off or otherwise protected

from intrusion by unauthorised

persons, and therefore should not

include an unguarded right of way.

Takeoff, climb and approach slopes

(which may be curved) must not be

over large areas of water unless you

can land safely on it in emergency.

They should be obstruction-free

with a gradient of not less than 1:8

and be 1000m long, possessing areas

suitable for emergency landing.

Special Events (for UK)

Vast amounts of people being

moved into a major sporting event

(such as The British Grand Prix at

Silverstone) make the feeder sites

used for their lifting and dropping

off liable for special treatment.

These events are good for

business—one good day at

Silverstone keeps some companies in

profit for the year. As for Pleasure

Flying sites, the authorities need to

be notified (in this case at least 28

days before), but other

considerations arise as well.

First of all, if you sell single seats to

the public, rather than the whole

capacity of the aircraft on a "sole

use" charter basis, you will either

need a full Air Transport Licence, or

an exemption (pleasure flying is a

special case). It also needs to be

done in your own right; you can't do

it on the back of someone else, as

you can with an AOC sometimes.

Again, there is a special form to fill

in which will cut out most of the

lack of communication over this

subject, and you should find a copy

in Ops.

Secondly, you will need to arrange

arrival and departure slots, which are

usually at a premium. Because of the

numbers of aircraft involved (usually

over 126 H1 types alone at the

Grand Prix), there will be a briefing

for all concerned well before the

event, at which all companies are

expected to send a representative. At

the very least a Notam will be issued.

H1 helicopters, by the way, are less

than 15m long, and H2s between 15-

24m; they therefore require different

treatment at their feeder sites.

A feeder site is one where more than

five movements take place in any

one day in connection with an event,

as a result of which they require

special facilities (a movement is a

takeoff or a landing). If using H1s

帅哥

you can get away with normal

equipment as used for pleasure

flying, but H2s need something a bit

more macho. Actually, it's basically

the same, but the vehicle must have

four-wheel drive and there must be a

minimum of 60 gallons of water and

5 gallons of foam concentrate, with

equipment able to deliver it at 40

gallons per minute. A minimum of

100 lbs of CO2 or 50 lbs of dry

powder or BCF is also required.

The rescue and medical equipment

requirements are also more

comprehensive, needing transfusion

Special Use Of Aircraft 215

and resuscitator gear to be readily

available 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 6

spare 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 with

spare cylinder

· Chisel and retaining spring

· quick release knife with a sheath

· enough pairs of flame resistant

gloves

· 24" bolt cropper

· 3' 6" crowbar

Line Patrol

It's pretty hard to get lost doing this!

You will be carrying observers from

the Electricity Boards, under their

normal procedures, which are pretty

exhaustive. All their staff are fully

and professionally trained to

exacting standards. They need to be,

as following and inspecting tower

lines calls for a high degree of

proficiency and concentration from

everyone. The very nature of the

exercise (flying close to the lines

inspected) means that for most of

the time you will be very near the

avoid area of the Height/Velocity

envelope. In fact, you will be flying

at such a speed (around 50 kts) that,

if the engine fails, you will be going

nowhere but down, which is quite

interesting when the line runs

through trees and you have to decide

whether you're better off in them or

dodging the cables.

For normal wooden poles, being one

and a half rotor spans laterally and

flying at about 50 kts is the ideal,

although 11 Kv ring circuits in a

clover leaf pattern could make this

difficult. At the very least, you need

a positive airspeed, that is, one

showing on the ASI.

The authorities assume the flight

won't take place in the avoid area, so

low flying exemptions, etc. are

geared towards looking after third

parties on the ground not directly

connected with your activities.

However, the flights are still

Commercial Air Transport, and

entering the avoid curve is therefore

prohibited. If prolonged incursions

are likely, consider using a twin.

Even where a single-engined

machine could be used, it's usually

over areas that aren't suitable for

forced landings or are unable to

afford safety for the passengers

(hostile environments). There should

be a full restraint harness for each

occupant together with a protective

helmet and flameproof overalls, or

clothing with sensible shoes.

216 Operational Flying

No flights should be made at night,

over fuel installations or congested

areas of any city, town or settlement.

Dispensations will be required to fly

near nuclear installations and

prisons, just in case they think you're

part of an escape plan.

Flights should also be confined to

within 300 feet of the lines

concerned (but no closer than 1½

rotor diameters to the lines when

level, or 1 diameter plus 30 feet

when above). Flying above and to

the right is most preferable. In

addition, lines should be crossed

vertically at least 100 feet above

them (common sense dictates that

you should do this over a pylon

rather than the lines themselves).

You will not be allowed closer than

100 feet to any people or vehicles

directly concerned with line

operations and 200 feet to any other

structures than those to do with the

帅哥

lines themselves. You shouldn't, but

if you have to go under a wire, get

your skids on the ground as near to a

pylon as possible.

As well as the proper permissions,

other problems include insurance.

Ensure that whatever you get also

covers you for frightened animals

bolting and causing havoc—this

usually happens with sharply

changing noise levels caused by rapid

manoeuvres. If you can't help flying

over animals, at least try not to chase

them through the fence!

Line patrol should not normally

happen if the visibility is less than

about 1 mile, and 2 if raining (1 mile

is approximately 6 towers or poles

ahead). These limits are higher than

usual because moisture will stick to

the windscreen at slower speeds, and

things are further complicated if you

have no windscreen wipers, as

precipitation won't blow away either.

Under those conditions, speeding up

to get rid of water is not what you

want to be doing, especially when

those grey towers merge into the

weather! Give serious consideration

to aborting if there is a lot of rain,

although really heavy stuff will tend

to run off better than the light

variety. Also, line patrol should not

normally be attempted if the wind is

above 25 knots, and the cloudbase

below 400 feet.

Lines are patrolled at whatever speed

is comfortable, generally between 20

or 50 knots, a little above pole height

and to one side, depending on what

is being looked for. This could be

just trees encroaching on the wires,

but also could be lightning damage.

Observers will normally be on the

opposite side to you so the lines will

be closest to them. They make

commentaries on tape which are

later transcribed into useful

information.

Always try to follow the line as near

into wind as possible, or, if not, in

trim at least, which will help if you

lose tail rotor authority. If it's around

10 knots or so, being downwind

generally will only ensure the transit

time along the wire is too fast, with

the consequent danger of you trying

to slow down and having no

airspeed—if more it may be rough as

well, especially in the mountains.

Monitor the instruments and be

particularly aware of overtorquing or

overtemping. Don't forget tail rotor

and wire strikes, and other lines

(especially tower lines) crossing—the

observers will be too busy to assist

your lookout. If a closer inspection

is called for, DO NOT try to come

Special Use Of Aircraft 217

to the hover and backtrack, but gain

height and speed, positively identify

the area and make a conventional

circuit and approach to come to the

hover alongside the line into wind.

A constant lookout must be

maintained at all times, especially for

fast, low flying military aircraft, so

High Intensity Strobe Lights (HISLs),

nav lights, landing lights and anticollision beacons must be on at all

times. HISLs should be at least 2000

candela in power (so don’t drop one

or you’ll have to pick them all up). If

they become unserviceable, patrol

above 500 feet. Don't plan on doing

more than two to three hours per

day due to the high workload.

Power Line Cleaning & Maintenance

Done when the Electricity people

can’t get to them by road. As you

can imagine, a lot of training is

required for this, especially when the

lines are kept live. Your hovering

needs to be precise for long periods.

There is a platform on your

helicopter, on which the lineman

sits, who connects the machine to

the line to equalise the potential.

This means that the helicopter is live

as well, so special maintenance is

carried out beforehand to ensure the

ship's normal electrics aren't fried.

For cleaning or deicing, a water

pressure system powered by a small

gasoline engine is used, and you get

to hover a bit further away.

Civil Aviation Notification Procedure

(CANP)

In UK, powerline survey, sporting

activities, aerial photography, crop

spraying, underslung loads and

anything else low level (i.e. below

1000 feet) that will affect military

operations should be notified on

0800 515544. The relevant (RAF and

ATC) authorities will informed by

the duty airman of the details.

Naturally, try to give them as much

notice as possible.

Pipeline Survey

This is similar to Line Patrol, so

most of what is said there will apply

here. Gas pipelines (or whatever) are

not very far below the surface of the

帅哥

ground, and potential hazards

include building works, ditch

construction, drainage, flooding,

leakage and falling trees.

1/250,000 scale maps will be

provided, on which the pipeline

route should be marked, though it

will be obvious when it’s just been

laid. Observers will be using larger

scale maps supplied by their

companies. The normal patrol height

is 300 feet (in UK, anyway), with an

associated speed of 50-80 kts, taking

into account the efficiency of

inspection, terrain, wind direction

and practical helicopter operation

(avoid curves, etc.). However,

between 500-700 is recommended to

avoid low flying military aircraft.

You should not approach closer

than 300 feet to any person, vessel,

or structure, and only closer than

500 feet within a horizontal distance

of 300 feet from the pipelines.

The cloudbase must be at least 200

feet above inspection height, with a

minimum visibility of 1500 feet.

UK Police Operations

A police force will either own its

own aircraft or charter from

operators as and when required, in

218 Operational Flying

which case the only things you can

get away with are low flying (closer

than 500 feet, etc) and going in bad

weather. Even then, you can’t get

closer than 50 feet, or 1.5 rotor

diameters, whichever is greater. In

fact, to take full advantage of any

restrictions, your passenger needs to

be either a police officer, an

employee of the police authority, a

medical attendant, a pilot under

training, an Inspector, a Fire Officer,

a Customs Officer on a joint

operation, or any other agreed in

writing by the authorities. However,

there will always be a police

observer, and the job involves a lot

of cross-controlling when on

observation, not to mention shortnotice tasking.

As they may need to recover their

costs from time to time, they may

also need a Police AOC and Ops

Manual (PAOM), though this

depends on the country.

Prisoners

A prisoner is a passenger and

qualifies for the normal safety

considerations, although their

movement is definitely not routine.

Handcuffing should always be done

to the front, so seat belts can be

released in emergencies.

Potentially violent prisoners should

be carried one at a time and have

enough escorts to restrain them. In

any case, at least two should be used,

ensuring that neither the pilot, the

controls or the exits can be reached.

If a prisoner does become violent,

land as soon as practicable and have

them continue the journey by

surface means.

Persons under the influence

These should be avoided, but

sometimes it can’t be helped. First of

all, you will need to decide whether

they are fit for a normal seat or need

a stretcher. You will need at least

two escorts for both restraint and

emergency evacuation, and a suitable

receptacle for vomit.

As with prisoners, land as soon as

practicable if there are any signs of

violence. Further movement should

be undertaken by surface means.

Bodies and remains

Their carriage is affected by how

inaccessible they are, that is,

precluding other methods of

transport. The main considerations

are the health and hygiene of the

aircraft occupants, which means they

might have to be carried outside if

they are a bit ripe, so you need to be

current on winching or slung loads.

Whatever you choose, bodies and

remains should be in body bags or

coffins. Naturally, any spillage of

body fluids needs a thorough wash

down as soon as possible.

Police Dogs

Should be embarked or disembarked

with the aircraft shut down, but if

this is not possible, the observer

should meet the handler and dog

clear 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 to

land if the dog becomes unwell,

although you will find that they

mostly like travelling and prefer to

look out of the window rather than

being made to lie down.

Special Use Of Aircraft 219

If the dog breaks free and goes for

the tail rotor or propeller(s), the

handler must not attempt to follow,

but give you a signal to close down.

Weapons and Munitions

The overriding consideration is the

帅哥

elimination of danger to the aircraft,

its occupants and persons and

property on the ground. Munitions

include gas/smoke canisters, stun

grenades, shotgun cartridges and

ammunition for rifles and sidearms.

These weapons should not be

carried in a loaded state:

· double-barrelled shotgun

· single-barrelled shotgun (unless

automatic or pump action)

· baton gun

· CS discharger

· dartgun

Loading, unloading or firing of

weapons on aircraft is not permitted.

Where all passengers are securely

seated throughout the flight, loaded

weapons must be in a safe condition,

weapons and munitions should be

carried in holds, compartments, or

other areas that are inaccessible in

flight, and secured normally.

Weapons or munitions must not be

distributed among passengers until

the aircraft has landed.

Weapon Safe Condition

Self-loading pistol.

self-loading rifle,

carbine, automatic

shotgun or pump

action shotgun,

bolt action rifle,

automatic rifle.

Working parts forward

and trigger released,

safety catch applied

where possible,

magazine charged with

ammunition and fitted to

the weapon. NO ROUND

IN THE BREACH.

Revolver Cylinder loaded with

ammunition; weapon in a

secure holster, to

prevent accidental

discharge.

When passengers on a special

operation need their weapons handy,

hand weapons and spare

ammunition for them may be carried

in readily accessible boxes or

holsters, with the ammunition in

pockets. Rifles and shotguns may be

stowed securely within the cabin,

with spare ammunition in body belts

or readily accessible boxes.

Gas/smoke canisters must be in

boxes but these may be readily

accessible. Boxes must be strongly

constructed, fire resistant and have

an “explosives” label.

Hover Emplaning and Deplaning

Defined as allowing trained persons

to enter or leave the helicopter

without its full weight on the

ground, and done where you can’t

land properly:

There should be no danger to third

parties and minimal risk to the

aircraft, crew, seated passengers and

those carrying out the activity. The

major consideration is engine failure.

You should be able to hover at least

at 4 ft, in day VFR, although the

actual height should be a lot less

than that, with one skid or wheel in

220 Operational Flying

contact with the ground to get rid of

static. One passenger should be

帅哥

seated before the next gets on board.

To give you a decent power margin,

the maximum weight should not

greater than 95% of the maximum,

and you should have at least a 15%

power reserve in the low hover

anyway. The time in the hover

should not be more than the time

limit for take-off power. Cargo

should not shift.

Your safety briefings should include

the effects of C of G changes.

Deplaning Procedure

Seat belts must be unbuckled as

instructed, then rebuckled. Only one

person or item of cargo should leave

the helicopter at a time, from the left

side, with the weights gently

transferred to the ground. One

person should ensure that all doors

(passenger and cargo) are closed

after everything has been unloaded.

Persons and cargo should remain

grouped ahead of the passenger door

until the helicopter has departed.

Emplaning Procedure

Seat positions should be determined

beforehand, with persons and cargo

grouped in one location beside the

intended arrival area.

People must only approach when

signalled (either thumbs up, or an

exaggerated head nod), from the left

side, with only one person or item

entering the helicopter at a time.

Weights should be gently transferred

from the ground to the helicopter.

Seat belts should be immediately

fastened once persons are seated,

and doors closed.

Formation Flying

Used when chasing another aircraft,

but not at night, in cloud, or when

the cloud base is below 500 ft or

visibility below 3 km. As the pilot of

the other machine may not be aware

of your intentions, and might not

even wish to be identified, you

shouldn’t do this too closely. In

other words, spend the shortest

possible time at the minimum

permitted distance from the other

machine, and shadow from the

maximum range consistent with

getting photographs, or other

evidence, and maintaining visual

contact. Remember one official

definition, which is "flight by sole

reference to another aircraft"

Do not endanger the other machine

or attempt to force it to alter height

or heading, or to land, because you

may need to take safe avoiding

action if the other machine attempts

to endanger you.

If you cannot establish RT contact,

approach while the target is in

straight flight, which may be level, or

climbing, or descending. Establish a

stand-off position behind, between 4

and 8 o'clock, not closer than 200m.

Reduce the range slowly and

progressively to at least 100m,

moving back out once the required

evidence of registration, type and

other features have been noted.

Landing Helicopters on Roads

The area must first be secured (but

see below), with radio or verbal

communication having taken place

to confirm that you have authority to

land there. Unaffected carriageways

帅哥

should be closed at all times.

Normally, you can only land at an

unsecured site (i.e. where the police

Special Use Of Aircraft 221

are not in attendance) in remote

rural areas outside congested areas,

but you may do so on dual

carriageways (divided highways) or

motorways (turnpikes) in daylight,

where no traffic is moving—no

landings should be made by night.

In any case, there must be no threat

to persons or vehicles on the ground

from the helicopter, or vice versa.

Always be aware of the effects of

your downwash, which may blow

away crucial evidence, not to

mention dislodging broken glass and

other loose debris, particularly from

damaged buildings, at bomb scenes.

Try not to land in school or other

play grounds, or areas where

children might be confined or

suddenly emerge. Don’t use the

aircraft presence or public address

system to clear children from a site.

Parachute Dropping

In UK, no parachute dropping

should be undertaken unless (as a

pilot) you've been approved by the

British Parachute Association and

the parachutists themselves are in

possession of an Operations Manual

authorised by them. It’s probably

similar elsewhere. You get your

certificate by passing a check ride

with a TRE, who in turn has been

approved by the BPA. The normal

regulations for the dropping of

articles from aircraft also apply. In

addition, the Flight Manual should

include a Supplement to cover the

situation. For some strange reason,

parachutists do not seem to be

classed as passengers or freight, so

it's a good question as to whether a

parachute trip is actually Commercial

Air Transport or not. Check your

insurance cover, even though on the

way down they are not in the

aircraft, and on the way up they are

normal passengers.

Parachutists should be strapped in at

all times except immediately prior to

dropping, and before takeoff they

should be shown how to secure

seatbelts so they don't flap around in

flight, as part of a proper briefing.

There should be no loose articles in

the cabin, and seats must be

removed, as must be dual controls if

one intends to drop from the front

seat (of a helicopter). There should

be no other passengers.

Don't use static lines and remove the

doors (check the Flight Manual for

limitations on flight without them).

A typical freefall drop needs one

pass over the drop site into wind at

approximately 2000 feet, where the

jumpmaster will drop weighted

paper markers. You then commence

climbing to the drop height, turning

downwind and keeping the markers

in view all the time. When at drop

height, come over the site again at

about 60 knots into wind, where the

jumpmaster will guide you to where

he wants to be.

When dropping, use both sides of

the aircraft if possible (difficult in a

Bell 47), so the lateral centre of

帅哥

gravity limits are not exceeded – this

is one of those times when you

might want to calculate it for takeoff

and landing. The helicopter should

be level, above 2000' agl with an

airspeed between 20-70 kts IAS.

Mountain Flying

In the mountains, general principles

common to other areas will be vastly

different. You must be prepared to

adapt your flying techniques as the

222 Operational Flying

need arises, for the peculiarities of

the region and the type of aircraft. In

other words, have not only Plan A,

but Plan B, C, etc. up your sleeve,

because, very often, once you’ve

looked at a site and gone round for

finals, you will find a cloud has got

there before you! You cannot afford

to assume that a particular situation

is the same as, or similar to, any

other you might have encountered

previously. You can also expect fog,

especially in the early morning,

which will often stick to the sides of

valleys for quite some time.

Sometimes, you can create your own

clouds, by pulling down warm air

from an inversion above.

In UK, mountainous areas include

Scotland and Wales, the Lake and

Peak Districts, and generally any hilly

country above 1500 feet amsl,

although a geologist would probably

expect to see 2000. In many other

parts of the world, these would be

considered as just foothills, as one

description of mountain flying

includes a reference to 5000 feet

Density Altitude. Actually, it reads:

"experience in maneuvring a

helicopter at density altitudes of over

5000 feet to include numerous

takeoffs and landings in situations

indicative to difficult mountainous

terrain. This terrain consists of

abrupt, rapidly rising terrain resulting

in a high land mass projecting above

its surroundings, wherein complex

structures in which folding, faulting,

and igneous activity have taken part.

These mountainous areas produce

vertical mountain winds, turbulence

associated with mountain waves,

producing abrupt changes in wind

direction often resulting in up

flowing or down flowing air

currents. In the contiguous United

States, the boundaries of these

mountainous areas are defined in the

aeronautical information manual."

In Canada, look out for Designated

Mountain Areas, which naturally

include the Rockies, extending into

the USA (don't blame me for the

English above - it was written by the

US Forestry people).

However, air behaves the same way

round pointy bits of ground

whatever its height above sea level,

and this includes flying around

buildings (we will look at laminar

flow shortly). The big difference

here is that you have less power to

play with, hence the mention of

density altitude.

Performance changes drastically

when both temperature and height

increase—just the opposite to flying

in cold weather, but you knew that

anyway. As far as altitude is