Original subtitles

Ladies and gentlemen,

we're beginning our descent towards

Amsterdam Schiphol Airport.

Thank you.

Turkish Airlines Flight 1951

is preparing to land in Amsterdam.

Amsterdam, Turkish 1951.

Descending to 7,000, speed two, five, zero.

The crew is flying

a state-of-the-art Boeing 737.

Flaps, 15.

Localizer alive, localizer capture.

In the final moments of the flight,

the landing turns into a catastrophe.

The plane falls like a rock.

The crash of Turkish Airlines Flight 1951

involves the most popular plane on Earth.

With nearly one and a half million passengers

boarding 737s every day, investigators need to figure out

if the problem was with the plane

or with the pilots flying it.

Mayday, Mayday.

On the morning of February the 25th, 2009,

Turkish Airlines Flight 1951 becomes the first plane

to crash at Amsterdam's Schiphol Airport

in more than 10 years.

It smashed into the ground really hard.

It made a tremendous noise.

The plane hits the ground in a muddy field

just north of runway 18 Right.

Since the crash was so close to the airport

rescue workers arrive quickly.

Most of the passengers have survived

but many are badly injured.

Survivors are taken straight to local hospitals.

Images of the Amsterdam accident

quickly spread around the world.

This is the third crash of a passenger jet

in the past six weeks.

The sudden nature of this accident adds to the mystery.

It doesn't take long for the Dutch Safety Board

to arrive at the scene.

They will be investigating this accident

but they won't be alone.

The crash involved an American made plane

so the U.S. National Transportation Safety Board

sends Joe Sedor.

One of its most experienced investigators to Amsterdam.

When it's a non U.S. registered aircraft

that crashes overseas, such as this Turkish Airlines,

we are the state of manufacturing

and design of the airframe.

And also in this case the engines.

Fuselage in three large pieces.

Engines forward of the main wreck site.

Flight 1951 was one

of the most advanced aircraft in the skies.

The Boeing seven 37 800 series.

It's designed to travel longer routes at higher altitudes.

The new generation 737 is still

the best airplane Boeing ever built.

We developed an airplane that had an improved wing,

improved avionics, simpler systems

that required less maintenance.

Investigators know this isn't just any plane.

The 737 is the world's best selling commercial jet.

Finding out why this one crashed is imperative.

There are more than 5,000 of them in the skies.

They carry about one and a half million passengers a day.

Investigators must quickly determine if there's a flaw

with the plane that could cause another accident.

What they know so far is that Flight 1951

had been traveling from Istanbul, Turkey to Amsterdam.

There were 128 passengers on board the early morning flight

including four engineers from Boeing.

Ladies and gentlemen,

we're beginning our descent towards

Amsterdam Schiphol Airport.

Please raise your seat backs to the upright position

and stow away your tray tables.

There was no mention on board

of any kind of trouble in the cockpit.

The crash has killed nine people, including three members

of the Boeing team and the pilots in the cockpit.

See if you can get me some aerials of the crash site.

There are eerie similarities

to another recent accident involving a Boeing aircraft.

British Airways Flight 38.

Approximately a year before this,

there had been a 777 short landing at Heathrow,

which had a dual engine flame up.

In that accident, a Boeing 777 fell

to the ground short of the runway.

The British Airways pilots reported

that both their engines stopped delivering power

just before landing.

At the time of the Turkish Airways crash

the cause of that accident hasn't been found.

Like in that case, investigators have plenty

of clues to work with.

The plane and its engines are largely intact.

The flight data recorder and cockpit voice recorder

are found in good condition.

There are also plenty of survivors

to describe what happened.

According to the passengers, the landing had been routine,

but then suddenly the plane simply dropped out

of the sky and hit the ground.

But perhaps the biggest clue

comes from the crash site itself.

The wreckage is not spread out.

It tells investigators that the plane

could not have been traveling forward at high speed

when it hit the ground.

The way the aircraft had crashed, it did appear

to be some sort of a landing accident

in which there was moderate control of some sort.

The pattern of debris

and the passenger reports point investigators

to an immediate suspect.

The engines.

The engines issue was a very big issue

in my thought process at the time, initially.

There's no evidence of fire on the fuselage.

In many crashes fuel in the planes tanks ignites on impact.

The lack of fire raises an obvious question.

Did the engine stop running because Flight 1951

had simply run out of gas?

That was one of the first thoughts that I had

was did this airplane have fuel aboard

because otherwise how does a 737 literally fall out

of the sky on approach to an airport?

But the location and condition

of the plane's engines suggest

that perhaps they didn't quit in flight.

Sure looks like it was running.

When we first looked at where the engines ended up,

at the initial impression was that they probably

were producing thrust that had impact,

given that they were so far forward of the main wreckage.

That was just a very general conclusion.

Only the flight data recorder

can tell investigators how much power the engines

were generating in the seconds before the crash.

Lots of fuel.

Rules that out.

It doesn't take long to discover

that there was plenty of fuel in the planes tanks.

Flight 1951 definitely did not run out of gas.

Passengers report that in the final seconds

before the crash, the plane hit what felt like turbulence.

It points investigators to a well-known culprit.

A microburst.

A microburst is a powerful column of air

that shoots out of storm clouds.

It can literally slam a low flying plane to the ground.

If an airplane flies into that at approach speed,

you're not gonna be flying anymore,

you're gonna come out of the sky.

Certainly it was one of the things

that all of us took a look at at the beginning,

was there a microburst.

In 1985, a Delta Airlines flight

was caught in a microburst while landing

at Dallas Fort Worth Airport.

The plane hit the ground short of the runway.

137 people were killed.

Investigators learned that there were heavy clouds

above the airport at the time of the accident.

A powerful gust of wind may well have accompanied them.

The flight data recorder would have recorded wind speeds

outside the plane.

Investigators will need to analyze the flight data

to prove the microburst theory.

In the meantime, the rescue has led to an unusual discovery.

There was three pilots in the cockpit.

Which is unusual, this is a two crew cockpit.

So why was that third pilot there?

Since none of the three pilots

survived the accident, it's all the more urgent

for investigators to retrieve the data

from the cockpit voice recorder.

It records conversations in the cockpit.

They're in luck

Because of the way that the aircraft crashed the access

to the recorders and the condition

of the recorders was excellent.

The reason for the third pilot

is soon uncovered.

Flying standard arrival route.

Visibility 3,500 meters.

Expected to decrease to 2,500 meters.

For First Officer Murat Sezer,

this had been a training flight of sorts.

He was new to the airline and was being shown

the intricacies of landing at Amsterdam's Airport.

In the Jeppesen charts which is what all pilots use

to navigate to and from Schiphol,

there's 102 pages of information on Schiphol alone.

So there's dozens of approaches.

Runway 18 Right has three high-speed exits to the left.

The Captain, Hasan Arisan

was doing double duty.

He was training his first officer...

Make small corrections as we get close to the runway.

And was in command of Flight 1951.

It's because Captain Arisan was teaching

that there was the third pilot in the cockpit.

Olgay Ozgur was a Safety Pilot.

He was there to keep an eye on the flights progress

during this training mission.

The purpose of that second set of eyes

is to make sure that the Captain and the First Officer

if they're in a situation where it's a little bit

of a training portion of the flight,

that they don't miss something.

We got a clean recording.

The voice recorder reveals

that the three crew members began preparations

for landing when still above 8,500 feet.

Amsterdam, Turkish 1951.

Descending to 7,000.

Speed, two, five, zero.

But the voice recorder

has picked up an unusual sound.

A warning that makes no sense at this stage of the flight.

One of the investigators from Boeing

was an engineering pilot that came

and helped with the CVR.

And he's listening to see are there any unusual sounds

that can be heard that would not be normal.

Feet okay for ILS, 18 Right.

Descent to 4,000.

ILS 18 Right.

The alarm keeps sounding.

It's the landing gear configuration warning horn.

Captain Arisan continually dismisses it.

Turkish 1951, descent 4,000 ILS 18 Right.

Landing gear.

Is that the landing gear warning?

They're 8,300 feet here.

The warning is a solid clue.

But investigators can't yet see

how it could possibly have caused a crash.

The crew of Turkish Airlines Flight 1951

got warnings to extend their landing gear

while still thousands of feet in the air.

On the initial listen, we heard a gear warning horn

occur as the aircraft was approaching when it was still up

and it was coming in about 10,000 feet below.

Investigators now turn

to the flight data recorder to help solve some

of the mystery surrounding this flight.

The analysis of wind speeds

outside the aircraft is completed.

It's clear none are drastic enough

to have brought down the plane.

No evidence of a microburst.

But the flight data recorder does provide

some valuable insight into the cause

of the landing gear warning.

One of the instruments that measures altitude

had the plane already on the ground.

When we looked and saw the radio altimeter data,

on the recorder it said about 8,000 feet

and then immediately it went down to about minus eight.

Minus eight feet is an indication that the aircraft's

on the ground, but of course it's still at 2,000 feet.

The Boeing 737 is equipped

with two separate altimeters.

One measures air pressure to determine

the planes height above sea level.

That reading is displayed prominently in the cockpit

on both pilots flight display.

Sensor.

The plane is also equipped

with a radio altimeter.

It's made up of four antennas.

Two transmit signals to the ground

and two others read the signal that bounces back

to determine the plane's height.

It's precise.

It's very, very precise.

Pressure altimeters can sometime be not as accurate.

And radar altimeters are a 100% accurate.

If they're working properly.

One antenna feeds the reading

to the First Officer's display.

The other feeds the Captains instruments.

In the case of Flight 1951, the Captain side was wrong

most of the flight.

Investigators go back over the CVR

and make a puzzling discovery.

Amsterdam, Turkish 1951.

Descending to 7,000.

Speed, two, five, zero.

Radio altimeter.

Captain Arisan seems to have known

that the landing gear warning was being caused

by a faulty radio altimeter.

The airplane thought that it was low to the ground

and the gear was not down.

And the Captain recognized that the problem

was really in the radio altimeter.

Showing him that they should be on the ground

and he goes, "It's just the radio altimeter."

Throughout much of the approach,

the Captain's radio altimeter had been displaying a reading

of minus eight feet.

Triggering the warning to lower the gear.

They treated it like it was a nuisance.

Turkish 1951, descent to 2,000.

2,000, 1951.

Investigators dig for any other abnormalities.

They learn that with Flight 1951 still about 17 kilometers

from the airport controllers directed the pilots

to begin their final turn to line up with the runway.

Turkish 1951.

Left heading , two, one, zero.

Clear approach, one eight right.

Left, two, one, zero.

Clear ILS, Turkish 1951.

Two, one, zero, set, sir.

This turn puts flight 1951

in line with runway 18 Right.

It's equipped with an instrument landing system,

which sends out a signal outlining the ideal descent path

to the foot of the runway.

The autopilot follows that glide path until the plane

is a few hundred feet from the ground.

Then the pilot takes over.

It makes landing almost effortless.

The ILS is pretty easy to follow.

It's a video game.

My daughter has a flown in a simulator

and can land a 737 using the ILS.

The crew begins configuring their plane

for landing unfazed by the warning horn

that's repeatedly triggered

by the malfunctioning radio altimeter.

Flaps 15.

10 kilometers out, Flight 1951 picks up

the ILS signal that will guide the plane to the runway.

Localizer alive.

Localizer capture.

The Safety Pilot, Olgay Ozgur,

now reminds Captain Arisan about the failed altimeter.

We have radio altimeter failure, sir.

Okay.

Turkish 1951.

Runway one, eight, right.

Cleared to land.

Cleared the land.

Thank you.

Investigators are stumped.

The crew knew about the malfunction

and continued their approach.

How had it then caused them to crash?

Clearly, there was more to this accident

than a faulty altimeter.

The whole premise of airline safety

and the way we build the airplanes,

the way we fly them is based on the idea

that we can have any number of failures

and we should still be able to arrive safely.

The radio altimeter is just one instrument.

There's no way in the world that that one instrument

if it fails should be a major cause of worry

that we're gonna have a crash.

Investigators wonder if the crew

had been given proper guidance for their approach.

They turned to exchanges between the pilots

and the controller who guided them in.

They carefully review every instruction.

Turkish 1951, descend to 4,000.

Speed okay for ILS, one, eight, right.

Turkish 1951, descend to 2,000.

Turkish 1951, left heading, two, one, zero.

Cleared approach, one, eight, right.

By following the controller's instructions

the crew made their final turn much too close to the runway.

For the intercept properly, they should be here.

International guidelines, call

for approaching planes to intercept the signal

that guides them to the runway from below.

It's so pilots don't have to make any drastic

last minute course corrections to get to it.

To intercept here, they had to descend.

But Flight 1951 was given instructions

that brought it to the threshold of the glide slope

while still way above it.

It's a common practice at Schiphol

because it gets planes to the runway faster.

Because they were so close, they had

to capture the glide slope from above.

Although it is an unusual situation,

it is one that can be handled by a flight crew

if it is managed properly.

Approaching a glide slope from above

is more difficult mostly because the crew has

to suddenly slow the plane and descend rapidly

to intercept the signal.

We also call this a slam dunk approach.

And some pilots like it, some pilots don't.

It's a little bit harder and things happen quicker

when you're above the glide path, trying

to intercept from above.

And it's just a challenge for a lot of pilots.

The approach from above

increased the crew's workload but it's standard practice

at Schiphol Airport.

I've flown into Schiphol dozens of times and I expect it.

If the controller's instructions

had somehow overtaxed this crew,

their conversations would indicate it.

They're just five kilometers from the runway.

- Thousand. - Check.

Flaps 40.

Speed brake.

Speed brake armed.

Green light.

One thing at a time.

Landing gear.

Gear down.

Three green.

- Flaps? - Flaps, 40.

Greenlight.

- 500. - All lights on.

Please warn the cabin crew.

Okay.

Cabin crew.

Take your seats.

Then real trouble.

A stall warning.

- Speed, sir. - I have control.

100 knots of speed.

Arisan forced to save his plane.

But just 400 feet above the ground,

and only one and a half kilometers from the runway,

the Boeing 737 suddenly fell straight down.

It only took a few seconds for it to hit the ground.

Turkish 1951.

The recording sheds light

on the final minutes of the flight.

The crew was configuring their plane for landing

well after it should have been done.

- Flaps? - Flaps 40, green light.

Most airlines have regulations

that call for a flight to be stabilized

to have all checklists completed

by the time the plane hits 1,000 feet.

In instrument conditions, you required at a 1,000 feet

to have basically everything done.

The airplane is configured.

You have slowed.

You have runned your before landing check

and you have received your landing clearance

and from a 1,000 feet on in,

you just monitor the instruments

and we're looking for the runway.

Please warn the cabin crew.

Yeah.

Cabin crew.

In fact, this crew was still running

their checklist up to the moment the crisis hit,

460 feet above the ground.

This approach was not stabilized.

Because of the aircraft was unstable

the flight crew was in a very high workload environment

in the last 1,000 feet of flight.

The radio altimeter was malfunctioning.

The aircraft was giving off warnings.

The crew was assigned a challenging approach

and they were executing a checklist late.

But none of this explains why Flight 1951 crashed.

In these types of accidents, you can never get inside

the head of the pilots.

And that's a very frustrating type of accident.

But the flight data recorder

does provide another intriguing clue.

Moments before Flight 1951 hit the ground

the planes engines were at idle,

hardly providing any power.

Perhaps this accident is a repeat of the Heathrow incident.

The engines, it was interesting to note

were at idle approximately the last two minutes

of the flight until the very end

when the thrust was increased again.

That was a big red flag right there.

The question is, is why was that the case?

But then they spot something

that's very different from the accident at Heathrow.

Retard Flare Mode.

For some reason,

while still more than a 1,000 feet above the ground

the planes computer began preparing to touch down.

In Retard Flare Mode, engine power is reduced

to idle by the flight computer.

And the planes nose automatically pitches up

to the flare position.

Planes should only be in this configuration

just before they touch the ground.

The autopilot raises the nose to break the descent.

The auto throttles brings the power back to flight idle.

And you touched down with the power

either all the way in idle or just about to be an idol.

But Flight 1951 went

into a slow nose up position well before touchdown.

Causing the plane to fly slower

and slower throughout its descent.

So why was Flight 1951 in landing mode?

And why hadn't any of the three crew members

noticed how slowly they were flying?

So what else was going on when the engines went to idle?

The troubles seems to start

with a malfunctioning altimeter.

We have to look at the system as a whole

and to see how that minus eight

affected the other systems on the aircraft.

And that was a very big portion of this investigation.

We had to say, how did the autopilot use that data?

More importantly, how did the auto throttle use that data?

The computer that flies the plane consists

of two main systems, the auto pilot and the auto throttle.

The auto throttle determines how much power

to ask the engines for while the autopilot controls

the planes altitude and direction.

The two systems work independently of each other.

And only one of the radio altimeters

provides information to the auto throttle.

In this case, I had to learn everything there

was about radio altimeters and auto throttle systems,

which I didn't know before.

The pieces of the puzzle begin coming together

when they find the connection

between the faulty radio altimeter

and engine power.

The radio altimeter provides information

to the auto throttle from the Captains side.

The only altimeter feeding information

to the auto throttle was the captains and it was wrong.

It showed minus eight feet throughout most

of Flight 1951s approach.

It's beginning to look like the faulty radio altimeter

triggered the events that led to the crash.

Investigators need to know what went wrong with it.

On a 737, the transmitting and receiving antennas

for both radio altimeters are lined up

underneath the cockpit.

Three of the antennas were all but destroyed in the crash.

They can't be tested.

But one antenna from the captain side is undamaged.

Investigators consider two possibilities.

A failure of one of the components

or some sort of interference

that caused the faulty reading.

The only component that survived the crash checks out.

The computers that control the system also work.

But investigators do make a curious discovery about them.

They aren't the same ones that were installed on the plane

when it was delivered to Turkish Airlines seven years ago.

This find changes the focus of the investigation.

The maintenance aspect of this accident aircraft

was one that we looked at as deeply as we could.

When the plane's maintenance log is studied,

investigators find that the radio altimeter on this plane

had a problematic history.

We got additional data from Turkish Airlines

and that data showed that on this one aircraft

of the past, I believe over a 1,000 flights

there was about 150 flights

that had faulty radio altimeter systems.

The documents show that a little more

than a year before the crash, both computers were replaced

because of complaints, they were causing faulty readings.

One of the incidents involved a radio altimeter reading

of minus eight feet.

So that was telling us that there was an issue

that had been there.

The issue did not just occur on this flight.

The faulty readings persisted.

Mechanics repeatedly swapped the computers

and replaced the antennas to try to solve the problem.

It's determined that Turkish Airlines tried several ways

to fix the altimeter.

But they couldn't find a repair that worked.

At the time of the accident, Turkish Airlines had a fleet

of 52 Boeing 737 800 series airplanes.

It's on page 93.

When we reviewed the maintenance data,

we found that radio altimeter problems

had been written up several times

on both the accident airplane and the fleet.

Investigators discover

that in the year before the crash

Turkish Airlines dealt with 235 system faults

with the radio altimeters on their 737s.

Fixes ranged from replacing and exchanging antennas,

cleaning of the systems, exchanging

and replacing the computers

and installing gaskets to shield the system

from possible water damage.

It's not like they weren't doing anything about it.

The Turkish Airlines maintenance personnel knew

that the radio altimeter problem was one

of their highest issues with regard to maintenance.

16 of those altimeter repairs were made

to the plane that crashed in February, 2009.

If the problem was so widespread, investigators wonder

why it hadn't caused serious problems before this accident.

They don't have to dig too far back

to find out that in fact it had,

on this very same plane.

On two recent flights, they had the exact same problem.

Twice in the 48 hours leading up

to the accident, the radio altimeter

showed a negative reading,

putting the plane into Retard Flare Mode.

Both times the crew noticed the problem.

Disengage the also throttles

and brought the plane in for a safe landing.

You just disconnect them and fly the airplane.

In the months after the crash,

other operators come forward with similar stories.

In Australia, in the Netherlands, in Canada

in Austria pilots report their 737s

going into Retard Flare Mode when the left radio altimeter

showed a faulty reading.

Each of those crews reacted the same way.

They disengage the auto throttle

and push the power back up manually.

They all landed safely.

Things are gonna break on an airplane

and usually you're able to identify that

and make it so that it's not a threat for the landing.

In 2008, Boeing received a whopping 2,569

reports of faulty radio altimeters on their latest 737s.

But very few of those cases involved

the plane going into Retard Flare Mode.

Hardly any reports at all.

Boeing also tried, but couldn't find

the cause of the failures.

They concluded that the radio altimeter problem

was not a threat to safety because

the 737 gives off enough warnings

so that crews can intervene and land safely.

In fact, in every instance

where the radio altimeter failed

crews were able to recover.

Turkish Airlines Flight 1951 seems

to be the one exception.

Investigators still don't know why.

It really got us wondering of what happened.

And that's when we started to look really closely

at the actions of the flight crews

while it was on that final approach

in less than a 1,000 feet.

Finally, as investigators again revisit

the last minutes of Flight 1951,

the circumstances of the tragedy become clear.

They see a remarkable sequence of events

that transpire to bring down this plane.

So what was happening when

the plane went into Retard Flare Mode?

They discover that the plane

went into landing mode and pulled back power

at the worst possible moment.

Exactly as the crew was descending to meet the glide slope.

It masked what was actually happening.

As the crew configured their plane

to drop down to meet the glide slope,

they expected the plane to slow down

as part of that maneuver.

But the plane was actually slowing down

because the computer was in landing mode.

That's why none of the three pilots said anything

about the throttles moving to idle.

It was insidious.

Were it first captured in the Retard Mode,

it didn't hurt them at all because they were actually high

and they were a little bit fast.

And the pilots actually wanted the power back anyway,

in fact the throttles may have already

been in the flight idle mode as they were trying

to get down and slow down.

Right the trouble starts here at 8,300 feet,

13 miles out from the airport, minutes before the crash.

Amsterdam, Turkish 1951 descending 7,000.

Speed, two, five, zero.

Turkish 1951.

Descend to 4,000.

Speed okay

for ILS, one, eight, right.

Radio altimeter.

But would the crew have known

that because of that radio altimeter

they would've gone to a Retard Flare Mode

in their throttles?

No.

It's a common problem at the airline

that the crew couldn't see the risk it posed this flight.

We have an airplane that was malfunctioning

in a very minor way, but in a way

that if not caught could and did metastasize

into something much more virulent.

Turkish 1951.

Descend to 2,000.

2,000.

1951.

Turkish 1951.

Left heading two, one, zero.

Clear approach, one, eight, right.

Left two, one, zero.

Clear ILS.

Turkish 1951.

Left at 210 degrees,

maintaining 2,000 feet.

Brings the flight in right here.

Five point five miles out.

We now have to intercept the the glide slope from above.

At 2,000 feet with the glide slope below them

the pilots have to reduce their speed

while descending steeply.

Speed, one, four, zero.

They believe the throttles are moving back

for the descent to the glide slope.

In fact, the auto throttle is slowing the plane down

because it's gone into landing mode.

It will continue to slow the plane until it stalls.

What we found is that when the flight crew

was doing their before landing checklist, each one of them

was doing something while they should've been

monitoring their airspeed.

For the next 100 seconds,

no one notices what's happening.

Until it's too late.

Established altitude set, 1,000.

Check.

- Flaps, 40. - Speed, set.

The experienced pilot recognize

that the First Officer's probably a little bit behind

on the approach so he calls for flaps 40

and moves the lever, informing the First Officer

that he has done so.

He's trying to help the First Officer catch up

to the position of the aircraft.

- Speed brake. - Speed brake, armed.

Green light. - One thing at the time.

Landing gear.

The plane is now 700 feet from the ground.

- Gear down, three green. - Flaps.

Flaps, 40, green light.

In their haste to complete their checklist,

none of the three crew members notice the warnings

that their speed is dropping dangerously.

First, a red bar appeared on their flight display.

Then when the air speed continued to drop

a flashing box appeared around their actual air speed

to draw the pilot's attention to it.

At this point, no one sees either.

Cabin report confirmed.

The aircraft is now 600 feet from landing.

When things start changing colors,

it's a warning to you, it's a caution to you

that you're approaching the limits of the aircraft.

Missed approach.

Altitude set 500.

So all of these indications the crew has in front

of them saying that the aircraft is slowing down.

During that time they were still completing their checklist.

Of course the aircraft

is getting closer to the ground.

In fact, it's less than 500 feet

from touch down.

And right before the stick shaker started

the captain told the Safety Pilot...

Please warn the cabin crew.

Cabin crew, take your seats.

Speed, sir. - I have control.

By the time they advanced their throttles

to full power, it was unrecoverable.

They were too low for the engines to catch up.

And that's it.

It's now too late to save this plane.

They all knew about the altimeter problem

but knowing didn't help.

Boeing also didn't foresee

the potentially deadly effect of a faulty altimeter.

But on February the 25th, 2009,

it triggered an unusual sequence of events

that brought down a jetliner and killed nine people.

The official report into the accident

blames it on a convergence of circumstances.

There is never ever just one cause to an airline accident.

It simply doesn't exist.

Maybe someday God will swap one out of the sky

but until then, there's never one cause.

The Dutch report also points out

that Boeing could have realized the problem

with the radio altimeter system

could have had an impact on safety.

Given that no one foresaw how

that failure might cause a crash.

The Turkish Airlines accident raises a big question.

Are airplanes becoming too complex?

Investigators have determined

that Turkish Airlines Flight 1951 crashed mainly

because the pilots didn't recognize the consequences

of the warnings they were getting.

Turkish 1951, descend to 4,000.

This is not the first plane

to crash because the crew didn't understand

what their plane was telling them.

Our problem is not the automation,

our problem is the depth of the training

and the ability of the human beings

to recover from mistakes made in interfacing

with the automation.

Mica Endsley studies the relationship

between pilots and technology.

We haven't really designed the automation

to take best advantage of what people do well

and take away the parts that people don't do well.

In 1996, the crew of an Aeroperu 757 crashed

when the pilots couldn't decipher contradictory warnings

about their altitude and airspeed.

The plane flew into the Pacific Ocean.

61 passengers and nine crew members were killed.

In 1995, the flight management system on a Boeing 757

could and should have stared the plane to a safe landing

in Cali, Colombia.

But a last minute change to the flight plan meant

the crew had to reprogram their computer.

They mistaken the entered a course

that took them headlong into a 9,000 foot mountain.

159 people died in the crash.

The cautionary tale here is

that we can get this equipment.

We can get these silicon-based units,

if you will, so sophisticated

that we can't talk to them effectively.

And when they go berserk or they have a problem

or we misprogram them, we end up putting ourselves

and our passengers in danger while we're trying

to figure it out.

NASA is working on something

called the Integrated Intelligent Flight Deck.

It's a project aimed at helping humans better use

the technology that surrounds them in the cockpit.

They're looking at automated flight manual systems,

voice recognition systems.

They've developed new kinds of microphones

that are bone conducting chips.

They're developing new displays for understanding

the ground environment for being able to detect

where other aircraft are in the environment.

What some researchers are finding

is that the best technology shouldn't replace pilots

but work with them.

Really integrating people with technology more effectively

has to do with designing the displays so

that you can really understand what it's doing

and you can make it simpler to understand how

to make it do what it is you want it to do.

You shouldn't have to push 16 buttons through eight levels

of menus to figure out what's going on with the system.

It should be integrated and presented effectively.

It should be as easy to communicate

with as the person next to you.

Boeing and Airbus,

the two largest manufacturers of passenger planes

take very different approaches to the relationship

between humans and technology.

Airbus gives the flight computer much

of the decision-making power in the cockpit.

In their view, this is a way to prevent a lot

of human errors by my making sure the airplane

doesn't do something that's gonna cause a crash,

even if the humans want them to.

But Boeing has a different view.

Its philosophy is to provide information

to pilots and have them make decisions.

Having more information is better for the pilot,

having the pilot in the loop, in the equation,

so to speak, I kind of liked that.

Airbus will argue vociferously and in continuous fashion

that that view is archaic and incorrect.

I think the jury is still out.

The final report

into the Turkish Airlines tragedy blames the crash

of Flight 1951, partly on a failure of technology.

The erroneous radio altimeter data caused

the auto throttle to go to a improper mode

that is of course not a good situation.

The cause of the radio altimeter failure

was never uncovered.

The Dutch investigation asks Boeing

to improve the reliability of the system.

We learned a lot about the radio altimeter system

and how it affects the auto throttle system.

Boeing is currently working on system improvements

to prevent this type of auto throttle event

from occurring again.

But the report also faults the crew

for not noticing that their speed

was dropping dangerously low.

In spite of the fact that there were three pilots on board.

Forget that you got an auto throttle,

you look at the airspeed and you look at the altitude.

You look out the damn window if you want to.

But air speed is crucial component

of staying alive in an airplane.

And you always need to know what your speed is.

But to Mica Endsley, the crew's failure

to monitor instruments is entirely understandable

and maybe more the fault of the instruments than the crew.

It's actually very difficult for people

to be monitors of automation.

One of the things that people don't do a good job

of actually is monitoring.

We're very good on-the-spot decision makers.

We're very good at coming up with creative solutions

to problems, but repetitive monitoring

is a kind of thing that actually people

aren't very good at at all.

So what we have to do is design automation

to work with people in a way that keeps them more actively,

cognitively involved and in the loop

and not just monitoring a piece of automation

to say is it doing what it's supposed to be doing?

Who's the ultimate computer?

The pilot.

The individual who should be able to say,

I don't know what this thing is doing to me

but I'm punching it off and flying the airplane.

Fly the jet.

Probably the smartest thing we ever learned

to say in our training in the airlines,

fly the jet do that first or nothing else counts.

That's what they forgot to do.