Original subtitles

American 329. Traffic 7 mile final. 737 runway. 27 position hold.

PILOT: Position hold 27 American 329.

NARRATOR: What makes a dangerous airport?

You're really looking at an airport that brings together

a number of factors in one place.

MAN: The first thing is the runway.

Is it long enough?

If it's a very short runway, you've got a problem.

Having been in the front end of a 747,

I'm not sure that I would go stand out there.

I think they're nuts, but that's just my personal opinion.

It was like being at the top of a roller-coaster and going down.

You will have extreme winds

that are caused by turbulence off the top of mountains

that will cause colossal wind shears associated with the approaches.

And when these conditions aren't navigated properly,

they can be catastrophic.

ANNOUNCER: These are the world's 10 most extreme airports.

Three million people around the world

commute on commercial aircraft every day.

Passengers are unaware that some of the airports

they are departing from or arriving at are considered to be extreme.

The perils are many.

Short runways, high altitude, unpredictable weather,

difficult terrain, take-off and approach procedures

and in the worst cases, a combination of all these dangers.

Coming in at number 10...

At the tip of Southern California

lies San Diego's Lindbergh Field Airport.

San Diego perfectly illustrates the principle of air traffic congestion.

The skies directly above the city are typically filled with planes.

At peak traffic, there are 55 flights coming and going every hour.

This airport is extreme.

Not just based on the volume of traffic,

but also on its proximity to the city's population centre.

The situation is made even more treacherous

because San Diego is the one-runway wonder.

MAN: It is the busiest single-runway commercial airport in this country,

which I find extraordinary,

because it's not a true international airport.

It really is a regional airport.

We handle a total of 550 flights a day,

so that's a combination of arrival and departure.

So about 225 arrivals, 225 departures.

Because Lindbergh's airspace is always stretched to maximum capacity,

it creates constant motion in the air and on the ground.

You've got aircraft wanting to go in multiple directions

but they have to share the same piece of pavement.

And so the air traffic controllers have to be on their toes

with monitoring what they can see

and anticipating where the arrivals are going

and anticipating when the departures are coming up.

Air traffic controllers weave an intricate choreography.

But it hasn't been without tragedy.

ALDRICH: In September, 1978,

PSA Flight 182, which originated in Sacramento,

was making its approach into Lindbergh Field.

The commuter flight had 128 passengers

and 7 crew members onboard.

The aeroplane had a midair collision over North Park

with a Cessna that was being flown by a student at the time.

I was standing out on my apartment balcony with a friend,

just having coffee, and the window suddenly shook like an earthquake.

And up in the sky, what I saw was PSA.

It was trailing flames and smoke out of the wing.

And then there was just dead silence.

A student pilot in a small Cessna suddenly cut across the jet's path,

causing both planes to collide.

Then all of a sudden this shockwave came up

and the smoke and flames began to roll up into the air.

The scene was utter devastation.

It was a sight that can't even be imagined.

Every tree had fragments of bodies hanging from it.

I got on the two-way radio and I looked around me

and I tried to describe it, but I couldn't do this all in one gulp.

What I said was, "There are signs of fatalities around here."

It was an understatement. It was the best I could do at that time.

Tragically, everyone on the aircraft plus the two people in the Cessna

and another seven people on the ground

were killed in the ensuing crash.

In all, 144 people lost their lives that September morning.

But the city of San Diego had a deep personal connection to the disaster.

Pacific Southwest Airlines was based at Lindbergh.

MAN: We'd never had an accident before

so it was very traumatic to us.

It was very traumatic to the community.

They'd never had that kind of an incident happen here in San Diego.

It remains the worst aviation accident in California history

and at the time, it was the worst aviation accident in the US.

The crash of PSA 182 brought attention and scrutiny

to the congested airspace above San Diego.

ALDRICH: It is a fairly dramatic approach

but it was procedures that created the collision.

There was a small aircraft operating in an area

where today, you wouldn't operate a small aircraft.

ENARSON: What occurred with 182 created what we call the 'TCA' -

the Terminal Control Area.

The fact that a small aeroplane crossed through the approach

into Lindbergh Field

doesn't occur anymore

and now that's at all airports.

So because of that incident, that really created that major change.

But the safety measures were too late to save the crew and passengers

of Flight 182.

It took a long time for us to get over that incident.

Matter of fact, one could say we never really have.

BLOOM: This happened in San Diego.

We took this personally. This was our airline, PSA.

Pacific Southwest Airlines was never able to fully recover

and was bought by US Air in 1988.

Since then, the city has grown up, literally, around the airport.

This has created a series of structures

that pilots must navigate as they pass over the city.

MAN: The challenge in San Diego is not so much the mountainous terrain.

The challenge is more the surrounding community.

It's not just the terrain, the fog, the approach,

all the traffic that's going in there...

You're a little close to the buildings.

Maybe closer than you would be at other airports.

But it meets all of the standards for clearances

and distances from buildings and obstructions.

The runway in San Diego is relatively short

for the size of the airport that it has.

And because of the terrain,

we come in higher than we normally would on the approach

before we can descend to land.

It's a non-precision approach.

So you obviously can't go straight down like a helicopter,

so you come down at an angle.

For a pilot, the airport does present a little bit of a challenge.

The most difficult part of the approach

isn't the proximity to skyscrapers.

It's the four-storey car park

that lies just 180m from the end of the runway.

The parking garage on the approach into San Diego

is one of those obstructions

that most people would not normally associate with an airport.

If you were gonna build a building, the last place around an airport

you would think of doing it is in front of the runway.

That's exactly where this structure was built.

It presents a little bit of a challenge

but it's no more different

than going over the same terrain coming down,

it's just stepping down like another mountain.

CONDON: It's part of the reason we have a displace threshold

down at that end of the runway.

So the first 1,810ft of that end of the runway, you can't land.

But it still leaves us with plenty of landing distance on the runway.

Lindbergh is part of the fabric of the city.

In 2006, San Diegans voted against a proposal to build a new airport,

keeping Lindbergh's busy runway

and constant flight pattern a visible part of the city.

Next, modern technology and engineering

can't beat the dangers of Mother Nature.

MAN: Birds, if ingested into a jet engine, can cause serious damage.

An airport so dangerous, it had to be shut down.

MAN 2: If you were landing from the seaside,

you are landing towards the mountains.

If you were landing from the mountainside,

you couldn't come over the top and drop in.

The world's most extreme airports aren't confined to urban settings

or high mountain passes.

Some exist in more idyllic locations.

ANNOUNCER: Number 9 on our list...

The Portugese island of Madeira.

Funchal Airport is extreme due to its location.

Cut out of the side of the mountain,

it has a runway that extends into the ocean.

MAN: Once, many years ago as a co-pilot,

I was watching a captain get very, very nervous going into Madeira.

And this gentleman that I was flying with - he was sitting there,

literally with his hands shaking on the throttles on the aircraft,

which was not the most reassuring.

And we did, in fact, end up having to make a missed approach.

With mountains located next to its shoreline,

wind patterns here can be devastating.

Madeira has canyon winds that blow from both ends of the runway,

but in different directions.

So that you can have a very, very dramatic wind shift

just at a time you're trying to touch down.

Madeira was limited both by terrain and what they could build around it.

You have a seaside airport butting up against a mountain.

So you deal with onshore, offshore winds,

winds coming down the mountainside, turbulence and, of course, seabirds.

Birdstrikes certainly aren't limited to Madeira.

But they are a problem

that technology and engineering can't completely rectify.

Birds, if ingested into a jet engine, can cause serious damage

and they even caused that engine to be shut down.

The most sensationalised birdstrike is US Air in the Hudson River.

Since the miracle on the Hudson,

a lot of people have questions about birdstrikes.

Airports use a lot of techniques including noise generators,

hiring falconers,

and even going out with shotguns

to fire really loud blanks to scare them away.

Birds, weather and location all must be accounted for here.

But the final challenge to face at Madeira is the runway.

Measuring just 5,000ft,

an Air Portugal 727 carrying 164 passengers and crew

overshot this landing strip in 1977.

131 of those aboard died that day.

The runway was extended to 9,000ft, but to accommodate the length,

it had to be built out into the ocean,

meaning it is perched on concrete supports.

It's on stilts at either end,

so although the runway's perfectly good,

you know that if you go over the end, it's not gonna be nice

because you've got a 60ft drop there.

Flying in mountain areas

may be the most difficult challenge any pilot faces.

Updrafts, loss of horsepower

and especially weather conditions

often come together with deadly consequences.

At 1,400ft in elevation,

the Rocky Mountains combine many of these challenges.

ANNOUNCER: Coming in at number 8...

The most extreme of the the Rockies' airports

services the resort town of Vail -

Eagle County Airport.

Mountain flying is the overall awareness

of the terrain threat area.

It takes somebody that's got a respect

for the weather and the terrain.

It changes all the time - weather, snow, visibility.

This tends to keep us on our toes

and gives us a certain level of alertness.

Vail is one of the more challenging airports

in the United States, if not the Northern Hemisphere.

You get turbulence from the wind,

you get high altitude,

which decreases the performance of the aircraft.

The higher you get in the atmosphere, the thinner the air.

It's less dense.

And those air molecules are what an aircraft uses

to create lift over a wing

and then the engines also use that to create thrust,

or energy, to move the aircraft around.

To make up for this lack of horsepower,

velocity must be increased.

If you're going faster over the ground,

that means you cover more runway when you land.

And on a departure, the aeroplane requires more runway for take-off

and requires actually more groundspeed.

So that's one of the challenges that you face.

The approach itself is also treacherous.

KELLY: One of the things about flying through Vail

is that it's in a valley

that initially limits the lateral movement you have

that you get at the airport.

But these are rocky mountains. They're 10, 11, 12,000ft.

So you have to go in over the top of the mountain

then descend down into the airport,

keeping in mind that there's probably weather

a good chunk of the year in there

and you're gonna have fog and things like this.

So you're limited in which way you can descend down.

ABEND: It can be challenging from the standpoint of the weather

when it's reported at the beginning of the approach

can be absolutely marvellous.

When we are halfway into the approach,

a snowstorm or squall can move in

and bring our visibility down to a point

that it's below what we call our 'minimums'

and we have to go around and try it again.

The valley can be extremely difficult for new pilots,

sometimes, with tragic consequences.

LEDERHAUSE: People don't respect the altitude.

And if somebody comes from the prairies

and tries to fly up a canyon or up a valley,

a lot of times, they won't make it out.

I've lost several friends that way - that didn't make it

and they all went down.

You just have to be careful and you have to respect the weather.

It can change quick.

The runway was recently lengthened from 8,000ft to 9,000ft.

But taking off is still a challenge.

Eagle has a lot of precision to it.

It requires that the captain have currency into that airport

every 18 months

and it requires a special checkout from a check airman

both in landing and departure.

BOWLES: The departure follows a very precise path through an area

they call Cottonwood Pass

that allows for terrain clearance

for the larger commercial aeroplanes.

It's a very precise manoeuvre from the time you take off

till you reach terrain clearance altitude

and are headed towards your cruise altitude.

FARRIS: The terrain, obviously, is the biggest problem with the airport

and just requires a little more of a pilot to be on his A-game.

PILOT: Take-off brief.

OK, it's going to be a standard brief.

We'll be, uh, straight ahead to 400 feet, left turn at 215.

The departure from Eagle is challenging primarily to the west

because you're dealing with the quick turn out

to follow Cottonwood Pass.

Rotating.

At 400ft, you start a left-hand turn,

which allows us to fly through a valley

avoiding some of the highest terrain in the area.

What that allows you to do is, worst-case scenario,

if you were to lose an engine on the departure roll,

you would still maintain obstacle clearance through a valley,

allowing you to miss all the terrain, deal with the emergency

and hopefully, return here or go somewhere else.

MAN: Juliet, approaching VOR to VOA to 25. Airport is in sight.

Here, with the terrain and the steep gradients that we have to land in,

and the possible poor weather, makes us a little more alert,

a little more aware of what's going on,

aware of the aeroplane coming into a place like this

versus just being complacent with some of the easier airports.

Next, an airport which combines every dangerous element

to challenge even the most experienced pilots.

MAN: It has a four-lane highway that goes right through the middle.

An airport so dangerous, it had to be shut down.

LEARMONT: If you were landing from the seaside,

you were landing towards the mountains.

If you were landing from the mountainside,

you couldn't come over the top and drop in.

ANNOUNCER: The seventh most extreme airport..

This next airport is extreme in its design.

High in the French Alps is Courchevel Airport.

It makes its mark due to its short roller-coaster runway.

ADAM: The runway at Courchevel is a ski jump at one end

and it's like a roller-coaster at Magic Mountain going along it.

ABEND: It's at 6,500 feet on the altitude.

1,700 feet is it for runway length.

And then the slope is just unbelievable.

It's 18.5 degrees going one direction.

The extreme slope is out of necessity.

The airstrip, constructed in 1961,

was originally built for vacationers

coming to this isolated mountain town.

With no flat area for miles around,

designers literally carved the runway out of the mountainside,

creating an extreme ride for the privileged few.

From one direction

it is a very, very steep uphill that you're landing on,

and one of the issues there obviously,

assuming that you've mastered the approach and got in there,

is with the very steep slope,

and if you end up not judging your landing flare correctly,

you could end up driving the nose wheel of the aeroplane

into the slope that's coming up to meet you.

ANNOUNCER: Number six on our most extreme airport list...

Nobody can deny that Hong Kong's Kai Tak Airport

will go down in history as an extreme airport.

One of a kind,

pilots still talk about

the difficulties in navigating this strip.

There was no approach anywhere in the world

that had all the things going for it that Kai Tak did.

Kai Tak was a visual landing,

meaning pilots had to identify a spot on the ground to mark their approach.

LEARMONT: If you were landing from the seaside,

you were landing towards the mountains.

If you were landing from the mountainside,

you couldn't come over the top and drop in.

You had to come down paralleling the mountains

and then make a turn before you went in.

Now, they thought, "How are we going to help the pilots to do that,

"especially when the visibility is a little bit marginal?"

And they said,

"Right, we're going to build a big aiming point

"where you have to begin your turn."

So up on the mountainside, they built a huge flat space,

actually aiming down the approach the pilots would have to fly,

and it was painted in red and white checks.

If you could see the checkerboard,

that generally meant that you had the visibility

to then make that right turn to land.

If you didn't, you'd go around and come around and try again.

You fly towards a mountain, you follow lead-in lights.

At about 400ft, you turn. The runway comes into view.

Kai Tak's other challenges include a lack of bail-out area.

Most airlines say at 500ft,

that is your last chance to throw the approach away

and go around again.

But at Kai Tak, you can't even level your wings

until you've got only 300ft to go,

and as a result of that,

Hong Kong has seen a load of spectacular landings.

The challenges resulted in 14 incidents

during Kai Tak's time in service.

One of the most memorable occurred in 1993,

when an incoming flight skidded across the runway,

landing in the shallow water of Hong Kong's harbour.

There were no deaths

but it served as another reminder of this dangerous airport.

The one-runway airport

was the third busiest in the world for air traffic,

and had been pushed beyond its limits.

So in 1998, the city opened a new airport, Chek Lap Chok.

The combination of all the technology and improvements

that the new Hong Kong airport have,

make it a worldwide model for many airports to aspire to.

And even with all the safety improvements

and wind shear detection devices

that really aren't on many airports in the world,

I still miss flying into Kai Tak.

Next, an airport which combines every dangerous element

to challenge even the most experienced pilots.

MAN: It has a four-lane highway that goes right through the middle.

And our next airport's biggest danger occurs

just outside the airport's gates

as thrillseekers gamble with their lives

in the jet blast of departing aircraft.

I've watched people being carried into the air 50ft or more.

The world's most extreme airports

have all made our list for different reasons -

congestion in close proximity to population centres,

design flaws,

and difficult approaches requiring visual cues for landing.

But there's only one airport that combines

all of the extreme condition combinations together.

ANNOUNCER: Coming in at number five...

Gibraltar Airport.

Located on the southern tip of Spain,

the Rock of Gibraltar guards the entrance to the Mediterranean Sea,

and it's the location of Gibraltar that makes this airport so dangerous.

Gibraltar Airport is unique

because of the peculiar conditions surrounding it.

You have sea on either side.

Yachts are a problem.

The adverse weather conditions.

Wind is a major issue.

You have high-rise buildings in the area.

There's also a sports complex,

which is immediately to the south of the runway.

Gibraltar is unique because it's a huge rock

sitting on a small promontory at the end of Spain,

but it's not owned by Spain - it's owned by Britain.

It's owned by Britain

because British marines and Dutch marines captured it in 1704.

It is a source of enormous irritation to Spain,

but it is, of course, hugely important to Britain.

Control of Gibraltar

has been disputed by both countries for centuries.

As a result,

the Spanish have only recently allowed flights

to pass into their airspace.

The use of the airfield at Gibraltar

brought with it an airspace control problem,

and rulers of Spain have used airspace as a weapon

to try and get rid of the Brits.

What they've said is,

"That bit of airspace off the end of the runway belongs to us."

But what this actually creates is a problem for pilots.

The problem is that Spanish airspace

is right next to where you're landing.

If it weren't for that Spanish airspace,

you'd have a straight-in approach above the sea on one side,

so no obstructions,

and the other side, a straight-in approach over the sea.

MAN: So you have a sharp 90-degree turn to avoid Spanish airspace.

This does not require particularly difficult skills,

but it is a more demanding approach than you would expect

at a normal international airport.

WOMAN: (OVER RADIO) Oscar Kilo Charlie,

turn right base, runway zero niner.

Roger. Turn right base, runway zero niner.

Oscar Kilo Charlie.

But the biggest problems for pilots here

are the high pressure weather systems that form over the Iberian Peninsula.

Gibraltar Airfield suffers uniquely from wind.

There is a famous wind called the levanter,

which is a moist easterly wind

that flows from the Mediterranean out through to the Atlantic.

When it hits the Rock of Gibraltar,

it creates a large teardrop-shaped cloud,

almost seems as if it's smoke emanating from the top of the rock,

and this hangs over the town of Gibraltar.

That in itself, though, is not a problem for aviation.

It's the south-westerly wind that really causes the problem,

where the turbulence over the rock

creates a severe downdraft at about 300ft on the approach to land.

If you've got a crosswind on the runway it's got to go over the rock.

And as a result of it, it comes over the top of the rock

and it tumbles

and that tumbling causes really nasty turbulence,

but also it sneaks around the side and the base

so you've got a tailwind when you're landing,

and it robs you of airspeed - you lose lift.

And so you start to drop, you've got to slam the throttles open

and you've really got to be watching the approach at every moment,

and then just as you're putting the aeroplane down

and you think you've got everything under control,

then the stuff tumbling over the top,

it just grabs you and it tries to throw you over.

So everything you're having to do is changing at all times.

You can't simulate that, it's just not possible.

You can prepare people mentally for it,

but I'm afraid you have to go there to find out what it's like.

The most peculiar feature of Gibraltar Airport

simply defies logic.

Perhaps the most unique feature

is the fact it has a four-lane highway

that goes right through the middle.

MAN: Every time an aircraft comes in they put the barriers down.

So they stop traffic

and the traffic backs up very quickly into the town area.

So you do get a lot of congestion,

especially when the military are in Gibraltar, doing exercises.

The barrier could be down for, I've experienced, over half an hour.

Having a busy road that intersects a runway creates nightmares for locals.

This is the airport barrier, which has been pulled down

in order for the planes to either land or to take off.

It takes about 10 minutes and then traffic goes back to normal again.

We're going to go through the barrier now,

which has just been opened.

As you can see, we've got traffic lights, we've got the barriers

which is controlled by the control tower just opposite there,

and this is the runway.

We've got a road going through the...sideways through the runway.

This runway is 2,000 yards long.

Obviously for tourists, they find it very strange

when they have to cross a runway.

We had a problem with pedestrians crossing the runway

who would stop in the middle of the runway

for their family photograph,

photograph of the rock, aeroplanes, and so on.

They think that the runway is a big car park.

Because they...sometimes they don't realise that

you've got a control tower and the air terminal just back there.

So you've got this voice coming from the air control tower

telling them to please move on,

that they can't stop in the middle of the runway.

Weather, a challenging flight path,

and constant traffic crossing its runway

makes Gibraltar an extreme airport.

Our next airport's biggest danger occurs

just outside the airport's gates

as thrillseekers gamble with their lives

in the jet blast of departing aircraft...

MAN: I've watched people being carried into the air 50ft or more.

..and the runway so short...

..there's no room for planes to stop.

MAN: Whoa! (WOMAN SQUEALS)

Some of the world's most extreme airports

are tucked in between mountains,

others are in the middle of major cities,

and some have design flaws that surprise.

But all of the world's most extreme airports share one universal trait -

dangerous terrain.

And this airport is no exception.

ANNOUNCER: The fourth most extreme airport...

St Maarten's Princess Juliana Airport.

South-east of Miami lies the island of St Maarten.

St Maarten -

it is the world's smallest inhabited island divided by two nations.

France and Holland share this 37-mile vacation spot,

creating unusually high air traffic for this gateway to the Caribbean.

The airport is extremely busy.

The island gets 1.7 million passengers annually.

The main reason why St Maarten is so busy

is because St Maarten is a hub.

It is the only way for a lot of people coming down into the islands

to connect to the surrounding islands.

The congestion is only the first factor

in making this airport dangerous.

Location is St Maarten's most extreme condition.

On one side of the runway, it's the quick ascent at take-off,

trying to avoid steep, mountainous terrain.

The aircraft have to take off at a sharp incline

because the mountains are about 800m high.

The aircraft have to avoid these mountains as quickly as possible.

You have to remember that these aircrafts are loaded with passengers

and with luggage and sometimes even with cargo.

For the pilot, it is a tremendous challenge for him

to get that bird into the air safely.

And on the other side of the runway,

the approach takes planes directly over the beach.

BOWLES: St Maarten is an airport busy

like all of the other islands in the Caribbean,

slightly more than a lot of the island destinations.

The thing that makes it different

is the approach path is in very close proximity

to hotels, people walking around on the beach,

and cars driving by at the end of the runway.

The beach is one of the island's busiest

and aircraft wheels pass

just a few feet over the heads of patrons at the local beach bar.

Because of the close proximity of the aircraft

to the road and the beach,

it's probably the greatest aeroplane viewing spot in the world.

The big attraction, of course, of the St Maarten Airport

is the end of the runway

which is famously known as the Sunset Bar area.

ABEND: Most of us enjoy the sun, most of us enjoy the water,

and just the entire beach atmosphere.

The Sunset Bar collects all of that.

And one of the unique things that the Sunset Bar does

is on a surfboard, they put the arrivals.

I also understand that there's a pastime called 'riding the fence'.

The biggest danger of Princess Juliana

occurs just outside the airport's gates,

with this local ritual.

Thrillseekers literally climb on a chain-link fence, get a tight grip,

wait for the jet blast from departing aircraft

then hang on for the ride of their life.

American 667 clear for take-off, Runway 10 in 1500.

MAN: Roger, American 667, Runway 10 clear for take-off.

Roger.

REY: I think it's the only airport in the world

where you can actually get that close to the runway

and experience a jet blast from an aircraft such as a 747,

which is a very powerful aircraft.

They can very literally blow cars off their wheels.

I think they're nuts, but that's just my personal opinion.

I've watched people being blown off the fence into the water,

and carried into the air 50ft or more.

I guess I'll be riding that guy right there,

and he's a big boy but I think I can handle him.

It'd be interesting to feel the force of a 747 jet engine

against my body at such a close distance.

So, we'll see what happens.

KELLY: Having been in the front end of a 747,

I'm not sure that I would go stand out there.

You're moving 770,000 pounds or more

from zero to 180 in a few thousand feet.

These people are in for a ride of their lives.

They do have warning signs at the end of the runway

warning people to stay out of that area

especially during take-offs of aircrafts,

but people just don't take those warnings seriously.

People have to take into consideration

that it's very dangerous.

That was kind of fun. It hurt at first, but then it goes away.

Just like a really strong hurricane.

All of a sudden you feel a pelt of sand and dirt, dust and small rocks

in your face and your body

and that isn't too enjoyable.

Juliana isn't the only dangerous airport in the Caribbean.

The next airport has a runway so short

there's no room for planes to stop.

MAN: That guy's gotta stop.

Whoa! (WOMAN SQUEALS)

MAN: Just look at the terrain around things here.

It's an accident looking for a place to happen.

And an airport where the terrain is so bad,

pilots have to learn to control their fear.

Immediately after we touched down, he started braking very hard

and we felt like it wasn't braking anymore.

The world's most extreme airports have uniquely dangerous conditions.

And for this airport, it has an unbelievably short runway.

ANNOUNCER: Number three on our list.

The French island of St Barth's

is a short hop from the Caribbean hub of St Maarten,

but this 12-minute flight can be hair-raising.

The approach to the airport runway

is one of the most thrilling experiences.

I personally am always thrilled to experience the landing

and people have literally got out of aircraft,

and got down on their knees and kissed the ground

after landing in St Barth's.

What a lot of people don't realise

is the number of training flights

pilots have to do to land in St Barth's.

It all starts with flyovers, of course,

and we have had some experience

with people assuming that they can easily land in St Barth's

without any prior experience or training for that matter.

And there have been a couple of mishaps.

This landing, captured in 2009,

underscores just how challenging this short 2,000-foot runway can be.

MAN: As safe as it's going to be anyway.

Dude, that guy's got to stop.

Whoa. (WOMAN GASPS)

Crap.

That kind of blows.

Fortunately, these mishaps in St Barth's have not been fatal.

You cannot underestimate the St Barth's runway.

You have to have a lot of hours, you have to have a lot of training.

You have to be checked out to land in St Barth's.

Runway 2-8. Tango Whiskey. We're all set to go.

The problem at St Barth's

is further complicated by its difficult approach pattern.

MAN: St Barth's airport is unique,

because you need a special licence to land here.

It's a short runway surrounded on all three sides by hills.

It's got a clear approach from the water,

but then there's no go-around procedure

because you cannot outclimb the hills.

It's got wind issues, it's got a short runway issue,

and also it's downhill.

Traffic directly below the approach path can be extremely hazardous.

Whenever you have somebody that puts themselves in the path

or on the approach path of the runway,

we have to make approaches around them.

That makes it pretty dangerous.

Some people can't do it, some people just can't get it,

because you have to have...

You have to be what we call a pretty good stick.

You have to have very good eye/hand coordination,

and you have to have very good stick and rudder skills.

It's very important when you train for this airport

that you do it under different wind conditions.

That's why we don't advocate training in one day,

because in one day it's very rare

that you're going to encounter all wind conditions.

The wind is coming from the south now.

MAN: OK. The wind changed by the way.

Cool.

They're really trying to get it so that the access is hard.

It's difficult to use the airport.

It's an airport that requires a special set of skills to land here.

It's not an airport that was ever designed,

nor will ever be designed, for large aircraft.

100 knots, 500m.

Exactly where I want it. Roger. Ground speed, 100.

So now what we're doing

is we're going to put our left wing close to the ground here.

We don't call these pilots 'pilots'. They are aviators.

Any pilot that gets his wings here in the Caribbean

and has the right training

can go on to any other destination in the world

and fly any type of aircraft.

MAN: Just look at the terrain around Tegucigalpa.

It's an accident looking for a place to happen.

Next, an airport where the terrain is so bad,

pilots have to learn to control their fear.

Immediately after we touched down, he started braking very...very hard,

and we felt like he wasn't braking anymore.

The world's most extreme airports all present challenges for pilots.

ANNOUNCER: The second-most extreme airport.

Toncontin International Airport, Central America.

The capital of Honduras, Tegucigalpa,

lies amid the awe-inspiring Sierra Madre Mountains.

It is here you'll find Toncontin International Airport,

call letters 'TNT',

and these three letters are fitting for this extreme airport.

MAN: The first time I came into Tegucigalpa, it was a shocker.

It really was.

MAN 2: Just look at the terrain around Tegucigalpa.

It's an accident looking for a place to happen.

Tegucigalpa in Honduras is the most extreme airport that's out there.

Everyone gets scared.

What you have to learn to do is control fear.

It holds the distinction of being the international airport

that has the shortest runway

that has commercial traffic coming into it.

It's an airport that you have to have utmost respect,

even in a beautiful day, with a brand-new aeroplane,

with the optimum conditions.

If you're not careful it's going to blow up in your face.

Toncontin's difficulties are numerous,

but it's the approach and runway

that combine to make this airport so dangerous.

Aircraft are forced to descend rapidly on approach,

not only because of the nearby terrain,

but also because of the extremely short landing strip,

which has a 65-foot cliff

looming ominously at the opposite end of the runway.

We train every one of our pilots that come here.

The airport is surrounded by mountains.

We have a series of landmarks,

and that may seem foreign for people,

thinking that pilots fly on instruments all the time.

We actually go from one hill,

to a freeway,

to cross over a house that has a pool.

It's like a treasure hunt.

You look for the next point

to take you all the way around to get to the airport.

There's a mark on the runway,

and about 400 to 500 feet beyond that is another mark.

And if you don't touch down in between those two marks,

we're going to do a manoeuvre where...

..we call it a go-around -

where you're going to take off and come back and try it again.

Tegucigalpa's mountain location also plays a role in making it dangerous.

Quick-moving fronts can roll over the mountains and affect vision,

altering typical flight patterns.

This was never more evident than on a rainy morning in 1989.

The result remains the country's worst aviation disaster.

BOWLES: From what I can gather

from the flight path depiction that is shown in the report,

the crew failed to follow the established step-down procedures

for the approach due to the terrain,

and, um... literally flew it into the ground.

127 of the 146 people onboard died.

Who knows why that happened?

The flight path clearly shows

that they missed about every minimum step-down altitude procedure point

on the entire approach.

It's a very well-defined and well-structured approach,

and has to be flown precisely.

Unfortunately, there have been other incidents...

..including one in 1997

where a US Air Force cargo plane overshot the runway,

killing three Americans.

These tragedies are a sobering reminder

of the difficulties at Tegucigalpa.

We have a TACA Airbus that is arriving.

He already has his gear down - the wheels -

because you're nice and slow at this point.

He already has flaps up which also allows him to fly slower.

He's continuing just to make this gentle turn all the way around.

Fairly shortly he'll start a much more aggressive turn to the left,

and that will be putting him in line with the main road

that is running just in front of the hills there.

At this point, he's about 600 feet above the airport,

about 200 feet above the terrain.

So from here, the heart rate's starting to pick up

because the pilot is looking at the airport,

he's looking for his landing area -

the white stripe on the end of the runway here -

and he's judging it so that his approach will get him right to that.

And if you look at the terrain below him there,

that's probably about 150 feet above that terrain.

Very shortly he will be banking left again and lining up on the runway.

Now he's lined up and he's aiming intently on the landing zone.

Where he should be touching down is right on those white lines.

This looks like it's going to be good.

Right there. Perfect.

The aeroplane down.

Here it's a matter of bringing in 188 people

that are in the back, that are counting on you

to deliver the aeroplane in a safe manner

to an airport that's challenging.

But not all landings are that precise.

The most recent incident occurred in May 2008.

MAN: It was a cloudy day,

and the pilot made the first attempt to landing,

and eventually couldn't.

And so he announced, "We tried landing. We couldn't.

"We're going to make a next attempt.

"Don't worry - we'll keep you informed."

It puts a lot of pressure,

the first approach you're making to Tegucigalpa.

I would rather suggest go to the alternate airport.

You try again, your vision narrows,

your brain decisions narrow, and definitely you are scared.

MAN: The wind was predominantly coming from the south, actually,

and moving northwards, which pushed the plane to a higher groundspeed.

The touchdown was perfect.

We practically couldn't even feel when the plane touched down.

What we did feel is that immediately after we touched down

he started braking very...very hard,

and then there was a fraction of a second

where we felt like he wasn't braking anymore,

and then it was like

being at the top of a roller-coaster and going down.

He landed with a tailwind,

touched down basically three quarters down the runway...

..and he went off the runway.

There was smoke in the cabin.

There were...

..things were starting falling out of the overhead containers.

There were a few seconds of dead silence.

I think everybody was sort of, uh...

..trying to determine, "Am I alive? What happened?"

The 65-foot drop resulted in only five fatalities -

three onboard, and two on the ground.

Despite the advances of modern aviation,

overshot runways are still a common occurrence.

Since 1984,

there has been an average of three to four overruns every month.

But measures are being made to improve safety.

Approximately 20 United States airports

now have a restraint device called an EMAS system.

EMAS is an acronym for Engineered Material Arrestor System.

It's actually blocks made of what's called cellular concrete,

designed to collapse under the weight of an aircraft,

slow the aircraft down, and stop the aircraft safely.

There's been a number of aircraft stopped safely,

in every instance no injuries,

so they work as advertised.

Tegucigalpa has taken its own measures to prevent another tragedy.

The airport was closed for six weeks

and the airstrip was extended 900 feet

by literally cutting down a hill at the end of the runway

to reduce the steep incline of the approach.

The improvements are cosmetics.

The cancer is still there.

The mountains are still there, the runway's the same,

and I surprise myself that in spite of all the flights in all the years,

very few accidents have happened.

And next, in the middle of the world's highest mountain range,

an airport so extreme, pilots refuse to land.

If you don't check the aircraft at the last touchdown point,

your nose will hit.

There's a dead end.

The airports we have seen so far

have all been uniquely challenging for pilots.

ANNOUNCER: Coming in at number one...

None of the airports are more dangerous

than the most extreme airport,

Nepal's Lukla Airport.

KELLY: Lukla Airport, Nepal,

brings together all these variables we've been talking about

and it's really what makes an airport extreme.

You have the altitude, mountains, windshear, turbulence,

a short runway, constantly changing weather.

It is the most extreme airport.

Officially called Tenzing-Hillary Airport,

it is named for the first men to reach the summit of Mount Everest -

Sir Edmund Hillary and Sherpa Tenzing Norgay.

Long known as Lukla,

it is located high in the north-eastern corner of Nepal

in the heart of the Himalayas.

There are 30 daily flights between Kathmandu and Lukla.

While only 85 miles apart,

they can feature drastically different weather.

Positioned at an elevation of 9,382ft,

it is one of the world's highest airports, and the gateway to Everest.

The short 1,600ft runway features a 2,000ft drop into the valley below.

MAN: Lots of people find it very crazy to be landing here

and they're really surprised seeing this runway

and they're just shocked.

MAN 2: The tourists who come to Nepal have Everest in mind,

so they do have some kind of feeling that it'll be a difficult airport.

And when they see the runway, it's a lot scarier for them.

MAN 3: It was the most terrifying experience of my entire life.

When I saw that bit of tarmac, I honestly thought I was gonna die.

WOMAN: My first experience was seeing the mountains

and after I've seen the mountains, trying to work out

where the hell we were going to land.

Because all you see are mountains and ridges and valleys.

You don't see any flat land.

Then when I realized we weren't even landing on a ridge,

my heart stopped.

The other end of the runway seems to slope uphill

towards the peaks behind it.

The gradient of 12 degrees is the equivalent of a 10-storey building.

You can't prepare for it. You really can't.

You can't read about it, but you can never appreciate how scary it is

until you actually fly in.

The fact that this runway moves uphill

actually helps the aircraft stop.

When you come to Lukla, there's a dead end.

If you don't check the aircraft at the last touchdown point,

your nose will hit.

You cannot overshoot. There's no go around.

That's crazy!

MAN: OK. Ignition on.

Because of these intricacies,

the airport is always treated with extreme precision and caution.

All set for departure.

You have to start from scratch here.

Any other pilots flying any other airfields in the world

cannot just come and fly here.

They have to come get used to it.

Just like the trekkers and hikers when they come here,

they have to get acclimatised.

We don't clear pilots to land here without instructors.

During the high season in October,

nearly 500 passengers travel daily to this remote spot

near the top of the world.

The approach into Lukla is treacherous

because of the decreased horsepower of planes at this altitude.

As a result, once a landing attempt has begun, there is no going back.

It requires a coordinated effort on the ground.

Everyone needs to be ready.

Once the departure happens from Kathmandu,

we sound the siren to let the airlines as well as passengers know

that the aircraft has actually departed from Kathmandu.

The runway is used as a short cut into town

so the sound of a siren warns the locals to get off the runway.

(INDISTINCT RADIO COMMUNICATION)

OK, guys. We're landing.

LAMA: When you initiate an approach from 9,300 onward,

that's a point of no return.

You cannot overshoot. You cannot fly out of it.

You have to come, land, final go.

Lukla has been the site of numerous crashes.

Coming up, we'll examine one of the most deadly.

MAN: The aircraft came to final and we could see it descend,

but just suddenly the fog lifted off

and we just expected it to come out of it, but it didn't.

Nepal's Lukla Airport

is named for Sir Edmund Hillary and Sherpa Tenzing Norgay,

not just because of their epic feat,

but because Hillary was instrumental in building the airport.

11 years after their climb, Hillary made plans to build the airport.

While he saw it as a way

to get mountaineers to Everest base camp more quickly,

he also did it to help the locals.

LAMA: It was Sir Edmund Hillary with his vision

who felt it was something that he wanted to give back to the society

that he loved so much.

The construction was completed in 1964

and has been serving the area ever since.

70% of the area is still not accessible by land

so there's no way out

unless there's an aircraft or helicopter landing into that area.

See, most of the people don't even know what a car looks like,

but ask them about aircraft, they'll tell you,

because that's what they have grown up with.

While Lukla has seen some modernisation,

like the paving of the runway in 2001,

it remains treacherous.

Due to the altitude, the weather is always a challenge to overcome.

The weather is totally unpredictable.

Usually in the morning, the weather seems to be clear

and that's when most of the planes take off and land.

So most of the flights are done during the morning hours.

LAMA: When the weather's clear, it's turbulent.

When the weather's not clear, it's cloudy.

It's difficult to come in an approach here,

but you have to know exactly what you are doing.

In spite of all the warnings,

there have still been several incidents over the years,

including four in the past six years,

the most recent occurring on an autumn morning in October 2008.

It's not a controlled airport.

We don't clear the aircraft to land or depart.

We just inform them of the weather condition and the runway condition.

On that morning, we had informed the pilot

there's fog below the approach level initially, and he continued.

And I think he also was caught by surprise

the way the fog just lifted up and maybe he was blinded.

The aircraft came to final and we could see it descend,

but just suddenly the fog lifted off

and we just expected it to come out of it, but it didn't.

It just went too low.

We could just see flames.

MAN: There were 19 people on board. 18 of them died.

There was only one survivor, the pilot...

..and he was yelling with pain.

The actual cause of the crash is still undetermined,

but its consequence, 18 fatalities,

remains a constant reminder of the perils of Lukla.

It's an extreme airport because there's so many factors -

weather, clouds, rain,

icing conditions, snow.

Wind factor plays a big role.

Other reasons are the terrain.

It's a rugged area, as you can see for yourself.

We fly through the mountains. The other one is the upslope.

You have to be accurate.

We combine all these together, put them in a cup,

drink that as a potion, and come and land here with all that in our mind!