All language subtitles for M.2003-S23E03-Mixed.Signals.Independent.Air.Flight.1851.WEBDL-1080pEAC3.5.1h264-PiTBULL_track4_[eng]

NARRATOR: It’s the worst aviation
disaster in Portuguese history.

144 people are killed.

The scope of the
devastation was remarkable.

NARRATOR:
The wreckage provides little evidence.

MALE:
They’re way too damaged to test.

NARRATOR:
Air Traffic Control offers no insight.

- Were they advised to use the ILS?
- Yes.

(plane engine roars)

NARRATOR: Only the final seconds
of Independent Air Flight 1851...

- (beeps)
- Pull Up.

They had seven seconds until impact.

NARRATOR:
Reveal the whole story.

They don’t say anything?

I've never encountered
anything like this before and

I never encountered
anything like this afterwards.

To say it was unique
would be an understatement.

(thunderstorm)

MAN:
Mayday! Mayday!

Pull up.

- (muffled dialogue over radio)
- (theme music plays)

NARRATOR: Independent Air Flight 1851
cruises above the Atlantic Ocean.

(plane engine roars)

There are 137 tourists onboard
the American charter flight.

(uptempo theme music playing)

Santa Maria, Independent Air 1851,
requesting MET report.

NARRATOR:
Less than 30 minutes before landing,

the crew prepares for descent.

MALE ATC (over radio):
1851, wind two-six-zero, 14 knots.

NARRATOR: 34-year-old
Flight Engineer Jorge Gonzalez

checks the weather ahead.

He’s a US Air Force veteran
with a sterling reputation.

41-year-old Captain
Leon James Daugherty is also

from the military and has been flying
jetliners for almost a decade.

Let's request descent.

Santa Maria Control, Independent Air 1851
would like to descend.

NARRATOR:
36-year-old First Officer Sammy Adcock

just started with
Independent Air two weeks ago.

MALE ATC (over radio):
Independent Air 1851 clear to

- descend to flight level four-zero.
- Cleared to flight level four-zero,

Independent Air 1851.

The crew was a balanced crew.
They had flown together for

about a week or ten days and
they were doing fine.

(engine roars)

NARRATOR:
They’re flying a four-engine Boeing 707.

The long-range, narrow-bodied jetliner has

dominated passenger travel
for more than three decades.

It wasn't a modern jet at the time.
It was 21 years old.

But it was well maintained
within all the safety regulations.

NARRATOR:
Today’s flight from Bergamo, Italy,

will refuel at Santa Maria,
an island in the remote Azores,

before continuing to
its final destination,

Punta Cana in the Dominican Republic.

Santa Maria was a popular destination for,

for refueling, uh, because of
its location in the Atlantic.

It's a small island with a
large mountain in the center.

That mountain is called Pico Alto.

NARRATOR: At almost 2,000 feet,
Pico Alto or High Peak,

is the highest point of a mountain range
stretching across Santa Maria.

(gentle theme music plays)

(door opens)

Hey, close the door.
It’s a jungle out there. (soft chuckle)

- Are you finished with those?
- Yeah. Thanks.

Thank you.

MALE ATC (over radio): What’s your
passing level, Independent Air 1851?

Passing flight level two-two-zero.

NARRATOR:
60 miles from the airport,

the first officer tunes in to the
frequency for Santa Maria Airport.

(suspenseful music plays)

ADCOCK (over radio):
Good afternoon, Santa Maria tower.

NARRATOR: Today, a trainee
in the tower is guiding in

the flight with the help of a supervisor.

ADCOCK (over radio):
Independent Air 1851 passing

flight level two-zero-zero
to flight level four-zero.

Independent 1851, roger.

In 1989, I would describe the
Santa Maria air traffic control facility

as being very unsophisticated, very small.

NARRATOR: The airport is
also not equipped with radar.

There were only three
scheduled airline flights per day.

It doesn't justify the cost
of air traffic control radar,

which is very challenging
for air traffic control.

(phone ringing)

You’re cleared 3,000 feet
on QNH one-zero-two-seven.

Runway will be one-niner.

(suspenseful music)

Expect ILS approach runway
one-niner. Report reaching 3,000.

(muffled radio chatter)

The controller is relying solely
on position reports from the pilot.

So they have to be meticulous
about protecting the airspace

and documenting the altitude
that the aircraft is at.

Is that what they said?

- Ten-27 on the millibars?
- Yep.

NARRATOR:
Just over 13 minutes from the airport,

the crew readies the plane for landing.

(beeps)

(muffled chatter from passengers)

(soft theme music plays)

Seatbelts and shoulder harness.

- Secured. We’re having fun now.
- Hey, hey!

On that day, the weather in Santa Maria
was fine. There was just some

cloud cover in the vicinity of Pico Alto.
That is very common.

Switching off autopilot.

NARRATOR:
The captain takes control of the aircraft.

The captain would likely
be hand-flying the airplane

to get comfortable controlling it.

(rattling)

- It ain't looking too hot out there.
- Yeah, we'll get down below.

It depends on what level those are.

NARRATOR:
There’s cloud cover ahead.

If conditions get worse,
the crew will have to make

the approach using only their
instruments for reference.

Okay, I'm gonna to go ahead and

- put the ILS in on my side.
- DAUGHERTY: Okay.

NARRATOR:
ILS, or Instrument Landing System,

is a navigation system
that provides vertical and

horizontal guidance to the runway.

That means that he can fly in clouds until

he gets onto final approach.
It's always better to have help.

NARRATOR:
35 miles from the airport,

the coastline of
Santa Maria comes into view.

FRANCISCO:
When approaching from the east,

you will see some big cliffs,
some green... A lot of green.

(music intensifies)

- Where’s the airport?
- It’s on the other side of the island.

(beeps)

NARRATOR:
As they approach the island,

an alert in the cockpit
tells the pilots that they are

500 feet above their selected altitude.

400 to go. Don't know if we're
gonna get visual or not here.

- (ominous music plays)
- (plane engine roars)

Starting to pass through the layers.

NARRATOR: As they cross the coast of
Santa Maria, weather conditions worsen.

- (gusting winds)
- (music intensifies)

The winds can be pretty severe around
the Pico Alto and this can present

a challenge for the pilots to
maintain control over their aircraft.

- (plane rattles)
- BOTH: (grunt)

(music intensifies)

(grunts)
I can't keep this damn thing level.

- (music continues)
- (cabin rattles)

- Help you?
- No.

NARRATOR:
Just two minutes from the airport,

Flight 1851 is seen
flying very low overhead.

AUTOMATED WARNING: Pull up. (beeps) Pull up.

(alarm beeping)
Terrain. Terrain. Pull up.

The equipment is telling the crew they
are in a potentially dangerous situation.

(engine roars loudly)

(explosion)

NARRATOR:
Just four and a half miles from

the Santa Maria Airport in the Azores,

Portuguese firefighters and civilians
discover a horrific scene of devastation.

Independent Air
Flight 1851 has crashed into

the island’s highest mountain.

(melancholy music plays)

The jet hit Pico Alto very near
the top of the mountain.

The accident site was a
bit of a chaotic scene.

The wreckage was strewn
all over the mountain.

There were some small fires.
It was a very steep terrain.

Just very difficult for
rescuers to work there.

NARRATOR:
It soon becomes clear that

all 144 passengers and crew
have been killed.

It was a big challenge for the locals,
mostly, to deal with that.

Santa Maria has only 5,000 people living
there and, in a flash,

they became the scenario of the worst
air disaster to occur in Portugal.

NARRATOR:
Rescuers work through the night.

By daybreak, the Portuguese
Civil Aviation Authority,

known as the DGAC,
arrives at the crash site.

They're soon joined by American
representatives from the NTSB,

the National Transportation Safety Board.

The terrain that we traversed was,
was very challenging.

It was a lot of personal effects.
People were dressed vacation,

there were children who...
Whose dolls I could see in the trees.

The scope of the devastation,
it was remarkable.

NARRATOR:
Investigators need to get

a better perspective if they are
to understand why Flight 1851

crashed into a mountain so
close to Santa Maria’s airport.

The overhead view revealed to us just how
concentrated the wreckage

was on the side of the mountain
where the airplane struck it.

That was something I had not seen before.

So this is the flight path. The plane
impacts the east side of Pico Alto.

Correct.

NARRATOR: Investigators examine
the wreckage pattern for clues

as to how Flight 1851
was flying before impact.

PEDRO:
All concentrated right here,

sending debris over the mountain ridge.

NARRATOR: Scars on the ridge
give investigators their first clues.

It looks like low angle, high velocity.
They must have been flying level.

- C-FIT?
- It looks like it.

NARRATOR:
They quickly recognize this incident

to be a Controlled Flight
Into Terrain or C-FIT.

If one looks at C-FIT accidents,
there are really two types.

One where an airplane
descends prematurely.

The other where it hits
the side of a mountain.

- They must have known about the mountains.
- What was the altitude where they hit?

BARRY: 1,795 feet.

And Pico Alto? What does the
Jeppesen chart show?

BARRY: It’s listed as 1,936 feet.

NARRATOR: Pico Alto is clearly identified
on the Santa Maria approach chart.

So they struck the mountain 140 feet
below what was listed on their chart.

What were they doing so low?

The possibilities were;
One, they were, the crew was off course.

Two, there was an altitude error.

It was our job to find out which of those
would explain the accident.

- What’s the minimum sector altitude?
- 3,000 feet.

(dramatic music plays)

NARRATOR:
The minimum sector altitude

is at least 1,000 feet above all terrain
within 25 miles of the airport.

There’s plenty of room.

According to the company’s operations
manual, there should be at least

two Jeppesen charts onboard
the plane at all times.

- They had to have known.
- Yeah.

This was the question.
I mean, why did these guys

descend so low when they
knew by the charts that the

minimum altitude was 3,000 feet
and there was a mountain there?

(uptempo music plays)

- So this was the last flight of the day?
- Yes, it was.

What was the minimum
sector altitude you gave them?

NARRATOR: The team turns to
the air traffic controller for

insight into why the aircraft
was flying below 3,000 feet.

- (sighs) Uh, 3,000 feet.
- You’re sure?

Yeah, I even made a
note of it on my flight strip.

He was perfectly calm.
He had a normal behavior.

He thought he had done a good job.

Were you the only
controller on duty at the time?

- My supervisor was also there.
- It was such a slow airport.

It was certainly not unusual

for a supervisor to provide on-the-job
training for an air traffic trainee.

What was the weather like?

(music continues)

Fairly good at the airport. No rain or
strong winds. Visibility was unlimited.

However, the top of
Pico Alto was in cloud,

and winds can be unpredictable up there.

The weather was okay.
The focus for the, for the investigators

was on how the, uh, the cloud layer
affected the pilot's ability to see

and avoid the top of the mountain.

- Were they advised to use the ILS?
- Yes.

Expect ILS approach, runway one-niner.
Report reaching 3,000.

NARRATOR:
The investigator learns that

the pilots did encounter
cloud cover near Pico Alto,

but they shouldn’t have had a
problem using their instruments

to get them to the runway.

(heavy sigh) Did the crew
report any mechanical issues?

No. Not to me anyways.

Thank you for your time.

I couldn't find anything that
explains what happened from his part.

So if the controller gave them the
proper clearance, why are they so low?

What if there was an issue with the
plane that they didn't report?

NARRATOR: The team must now
consider if a mechanical issue

that wasn't reported to the
controller prevented the crew

from maintaining a safe
altitude above the mountain.

It was possible. We couldn't rule this
out until we looked more closely at

the evidence that something
very quickly happened, uh,

something catastrophic just before impact.

(plane engine roars)

(gentle theme music plays)

- Is this everything?
- So far.

NARRATOR:
Investigators are looking for clues

in the wreckage of Flight 1851
to explain why it descended

below minimum altitude and crashed
into a mountain on Santa Maria island.

Let's start here.

NARRATOR:
Could a malfunctioning engine

have forced the aircraft
below the minimum safe altitude?

It says here the jet had less than
45,000 hours in the air

with seven service bulletins
over the last six years.

- Any issues?
- Well, in 1983,

engine two had suffered turbine failure.
It looks like it was repaired.

It's full of wood and dirt.

NARRATOR: A quick
examination provides an answer.

There’s nothing wrong with these engines.

Engines that are generating power
at impact, if they hit a field of trees,

will ingest part of the
vegetation into the engines and

that will bring the
engine fan blades to a stop.

And that's what happened here.

Engines that are not turning,
that are not working, won't do that.

What about the altimeter?

(dramatic music plays)

NARRATOR:
If the altimeters were malfunctioning,

the crew might have believed they were
flying higher than they actually were.

AUTOMATED WARNING:
Pull up.

Hi. Thank you. Look, way too damaged
to test. What do the service records say?

They were last calibrated
four months ago. No problems.

NARRATOR:
It’s another dead end.

- Maybe the Altitude Alert survived?
- Let's take a look.

NARRATOR:
The Altitude Alert warns the crew

with an audio alert when they’re
approaching a pre-set altitude.

(beeps)

- Hang on. Is this it?
- Yeah. That’s it.

It doesn't look too bad.

Yeah, check this out, the
altimeter alert is set to 2,000.

NARRATOR: Investigators discover
the Altitude Alert was set for

2,000 feet, not the
required altitude of 3,000 feet.

I remember this shocked all of us.
We, we just couldn't believe it,

how that could happen.

Why would the
altimeter alert be set to 2,000

when the controller gave
them a clearance of 3,000?

Maybe the controller remembered wrong.

Let's check the tapes.

PEDRO: ATC recordings gives
you what's exchanged during

the different phases of the flight.

So you can confirm absolutely
what was said either contacting

the plane or inside the ATC.

ADCOCK (over tape):
Good afternoon, Santa Maria Tower.

NARRATOR: Will the air traffic
control audio recording confirm

what the trainee told investigators?

MALE ATC (over tape):
Independent 1851, roger.

You’re cleared to 3,000 feet on
QNH one-zero-two-seven...

Runway one-niner. Expect ILS approach.

Runway one-niner. Report reaching 3,000.

- Stop there.
- He said it. Twice.

NARRATOR:
The control tower recording confirms that

the controller gave
a 3,000-foot clearance.

Listening to the clearance did not explain

the 1,000-foot error in the altimeter
alert. We needed to listen to the CVR.

Take it from the point where they
first contact the controller.

NARRATOR:
Investigators now listen to the cockpit

conversation to determine
why the crew descended below

the 3,000-foot minimum sector altitude
given by the controller.

ADCOCK (over tape):
Good afternoon, Santa Maria Tower.

Independent Air 1851 passing

flight level two-zero-zero
to flight level four-zero.

That’s the first officer.

ATC (over tape):
Independent 1851, roger.

You're cleared to 3,000 feet on
QNH one-zero-two-seven.

ADCOCK (over tape):
Cleared to 2,000.

- Did the First Officer just say 2,000?
- Go back. Play it again.

(stopping and rewinding tape)

ADCOCK (over tape):
Cleared to 2,000.

NARRATOR: Investigators wonder
why the first officer misheard

the altitude clearance as 2,000 feet
instead of 3,000 feet.

Maybe he heard, "To 3,000,"
and mistook it for, "2,000."

It's possible.

It looked to us that perhaps
the word three never, uh,

was listened by the First Officer.
So the First Officer only listened,

“You are cleared 2,000.”
Not to 3,000 but 2,000.

So he never heard the word three.

NARRATOR:
The CVR recorded the First Officer

reading back an incorrect clearance.

It was very puzzling to us, when we heard
the CVR, why the crew did not act.

It was clear that that
wasn't given much credence.

The controller should have
corrected him too. But doesn’t. Why?

BARRY: And that's an important
part of this accident investigation.

We couldn't figure out why
the air traffic controller

did not correct the first officer.

Hang on a second.

(suspenseful music plays)

The first officer's read back of 2,000
feet isn't in the controller's transcript.

So he never heard it?
How is that possible?

We couldn't figure out
how they could miss each other.

It was, it was inexplicable.

(music crescendos then fades)

All right, so the First Officer
mishears the altitude,

he reads it back to the
controller as 2,000 at 13:56:59.

NARRATOR: Investigators compare
the conversations between the

controller and the
first officer of Flight 1851

to better understand why there was
miscommunication between them.

- What does the controller say next?
- Well, he repeats the clearance by saying,

"Expect ILS approach runway one-niner
report reaching 3,000."

- That's it.
- Hmm.

(suspenseful music droans)

Hang on.

(music intensifies)

- They were talking at the same time.
- Yeah. They cancelled each other out.

NARRATOR:
It’s a troubling realization,

an overlap of communication
between the tower and the pilot.

Passing flight level two-zero-zero
for flight level four-zero.

You’re cleared to 3,000 feet on
QNH one-zero-two-seven.

Runway one niner.

- We’re cleared to 2,000 feet...
- Expect ILS approach...

- And uh...
- Runway one-niner.

- One-zero-two-seven.
- Report reaching 3,000.

It was stunning. We were stunned

to finally understand
how the two transmissions

overlapped perfectly
to cancel each other out.

I was an investigator for
over 30 years in the NTSB.

I’ve never encountered
anything like this before and

I never encountered
anything like this afterwards.

If they're both talking at the same time,

- they're both pushing their PTTs.
- That's right.

NARRATOR:
Pilots and controllers use

a Push-to-Talk, or PTT, button.

When it’s pressed, the radio
transmits but cannot receive.

To think that so many people died because

of a simple error that was just...
That's sad.

That's hard to deal
with as an investigator.

So the controller doesn't hear it.

But he should still insist the
first officer read it back or repeat it.

There are some readbacks
in air traffic control that you

simply have to get back every single time,
and altitude is one of them.

The trainee controller did not
request an altitude readback and

the supervisor didn't notice and,
and that was unfortunate.

- What about the supervisor?
- Good question.

According to
the controller, she was there.

- Maybe she was busy with other things?
- Possible.

NARRATOR:
Investigators wonder if the supervisor

monitoring the trainee during the
approach clearance was somehow distracted.

Check this out. According to the phone
records, she took a call during her shift.

(phone ringing)

(music intensifies)

You don't wanna take a
phone call during something

important like a descent
clearance because they have to

give them a course to follow
and an altitude to maintain.

Really important stuff
that you cannot possibly miss.

Something doesn't line up.

(slow piano music plays)

The plane’s altimeter alert was
incorrectly set to 2,000 feet.

Even at that altitude, they would have
cleared the ridge by some 200 feet.

Yeah.

We still had to explain why the
airplane struck the mountain 200

or so feet even further below the altitude
that they were trying to maintain.

Something had to explain that.

- What else affects altitude?
- QNH.

NARRATOR: QNH is a pressure
setting pilots input so their

altimeter measures the
proper height above sea level.

It can change with weather conditions.

If the altimeter is set
to a higher QNH than is actual,

the aircraft will actually
be lower than what

the altimeter is telling the pilots.

It says here they were
given a QNH of 10-19 at 1:44 pm.

Then they were given a
reading of 10-27 at 1:56 pm.

Okay. So it changed...

...eight millibars in 12 minutes?

- Could that be right?
- I'll check the weather reports.

For an eight millibar
change to occur in 12 minutes

would be something that may occur
during a hurricane or something like that.

(suspenseful music plays)

I don't see anything
that would make that possible.

So how much would they drop
with an eight millibar increase?

NARRATOR:
Investigators calculate the

change in altitude
between the two QNH values.

That QNH brought them
at least 200 feet below 2,000.

Right into the mountain.

NARRATOR:
The team concludes that an

incorrect altimeter setting put the flight
on a collision course with Pico Alto.

When you're close to the ground in
restricted visibility conditions,

an accurate altimeter
setting is everything.

That will protect the
airplane from a C-FIT accident.

- Thanks for talking with me again.
- Yeah, of course.

Uh, just one a follow-up question here.

What was the pressure
setting you gave them?

NARRATOR:
Investigators conduct a second interview

with the controller to understand
why he gave two very different

QNH settings to the pilots.

One-zero-one-nine was on the MET report.

12 minutes later when you
gave them 3,000-foot clearance,

you said QNH one-zero-two-seven.

(soft music plays)

I asked the controller directly about the
QNH he had given to the plane and,

uh, and he couldn't explain
why he had given that QNH at all.

In my view, it's just he didn't notice
he was giving the wrong information.

Sorry. I don’t know where
I got that second number.

For that QNH to change so rapidly,
it should have been noticed by

both the air traffic trainee and their
supervisor and the pilots as well.

I'm surprised that the pilots
didn't reach out and say,

"Hey, can you repeat that QNH again?"

After the first officer gets the
minimum descent altitude wrong,

he questions the QNH.

Is that what they said?

- 10-27 on the millibars?
- Yep.

- He was right to question it.
- But the captain just dismisses it.

- Thank you.
- And the first officer just accepts it.

Because of the
different experience levels,

because of the prominence
and assertiveness with which

the captain said it,
it shut off any discussion

when, in fact, there should have been.

It makes me wonder
what else these guys missed.

(uptempo theme music plays)

Yeah, let’s play the tape.

NARRATOR: Investigators return
to the cockpit voice recording

to learn how the crew of
Independent Air Flight 1851

allowed so many errors to accumulate
on approach to Santa Maria.

- ADCOCK: Altimeters?
- DAUGHERTY: Set and cross-checked.

- Set and cross-checked.
- Seatbelts and shoulder harness.

(sighs) Secured.

- ADCOCK: We’re having fun now.
- DAUGHERTY: Hey, hey!

That’s it? Stop the tape.

NARRATOR:
They discover the pilots missed

important steps on the checklist.

They don't even mention
the minimum decent altitude.

PEDRO: Or Pico Alto here.

NARRATOR: They hear a briefing
that doesn't include reference

to the navigation charts that
were available to the pilots.

Had they done the
approach briefing and reviewed

the information and articulated
the information as required,

it’s highly unlikely in my opinion that
they would have struck the mountain.

(sighs) Another unfortunate error.

There were a couple of things
in the performance of the captain

that were questionable.

He didn't try to understand what
was the real QNH that was given.

Then he didn't insist
in a complete checklist.

Let's hear what comes next.

(music intensifies)

DAUGHERTY:
It ain't looking too hot out there.

Yeah, we'll get down below.
It depends on what level those are.

Okay I'm gonna go ahead
and put the ILS in on my side.

Okay.

Uh, after 2,000...

...yeah, we'll get below these clouds.

Stop. Right there. 2,000 again.

The captain says nothing and
descends to 2,000. Why?

The captain is ultimately responsible as
the pilot in command

but each crew member,
uh, failed in that respect.

Play the tape.

- ADCOCK: Uh, 1,000 to go.
- DAUGHERTY: One to go.

WOMAN FLIGHT ATTENDANT:
Wow. Look.

There’s the island.

Stop it. Who was that?

NARRATOR: Investigators hear
an unknown female speaking in

the cockpit on approach into Santa Maria.

She appears twice over 16 minutes starting
when they begin their descent.

The Flight Attendant maybe?
But what is she doing there?

I don't know. That's not what
I call a sterile cockpit.

And the captain lets it happen.

NARRATOR:
The Captain violated the

sterile cockpit rule, which bans
non-essential conversation

in the cockpit below 10,000 feet.

I believe that violating
the sterile cockpit rule

was consistent with the
way they flew the approach.

They weren't sitting on
the edge of their seats.

They were far too relaxed.

DAUGHERTY:
There is no place like Santa Maria.

- Is it nice?
- Yeah. To have a beer. (chuckles)

See you on the ground.

(dramatic music plays)

Ignoring standard procedures,
distractions. The list keeps growing.

ADCOCK:
Startin' to pass through the layers.

(grunts)

Can't keep this damn thing level.

- Help you?
- No.

(beeps)
AUTOMATED WARNING: Pull Up.

(warning continues)

AUTOMATED WARNING:
Pull Up.

(tape stops)

They don't say anything?

When the GPWS went off there was
no response from the crew.

There was not even a,
"What's that? What's going on?"

There was nothing.

They don't say anything.
But did they do anything?

(music crescendos then fades)

Thank you. So this is the plane’s
descent approaching Santa Maria.

NARRATOR: Investigators examine
the flight data to determine

how the pilots responded to
the Ground Proximity Warning.

So they’re descending
at about 2500 feet per minute.

They level off here.
And the GPWS goes off here.

And they crash about seven seconds later.

No reaction. No change in altitude.

NARRATOR:
The data shows there were no inputs

from the pilots to recover the aircraft.

It’s like they ignored the alarm.

When the GPWS goes on,
you apply maximum power,

climb at the maximum rate
and get the heck outta there.

Seven seconds. They had seven seconds
from the first warning until impact.

They could have climbed
over the mountain in that time

had they done what they should have done.

And they didn't do that, and
we couldn't figure that out.

(beeps)
AUTOMATED WARNING: Pull Up.

NARRATOR: Why didn't the
crew respond to the warning?

Surely the crew was trained to respond
to the ground proximity warning.

NARRATOR:
Investigators closely examine

the training manuals for Independent Air.

You are not gonna believe this.

The simulators were programmed
with different approach speeds

and flap settings than
the accident aircraft.

What does that mean?

It means that the GPWS would go off
during normal approaches.

(dramatic music swells)

NARRATOR:
Independent Air rented time

on another company’s 707 simulator.

It was configured differently
from the accident aircraft.

- ADCOCK: Flaps 40.
- (beeps)

- AUTOMATED WARNING: Pull Up.
- ADCOCK: Sir?

(beeps)
AUTOMATED WARNING: Pull Up.

By training the crew to ignore
the GPWS in the simulators,

they gave the crew the message to ignore
the GPWS in the airplane.

(sighs) I can't believe
how many things went wrong.

NARRATOR: Investigators conclude that by
avoiding any one of the minor errors,

Flight 1851 would have cleared Pico Alto,

preventing the deaths of 144 people.

It all starts with the first officer
mishearing the minimum sector altitude.

MALE ATC:
Independent 1851, roger.

- You're cleared to 3,000 feet.
- Cleared to 2,000.

Make it three.

NARRATOR: If the First Officer
had referred to his charts...

Roger. Good catch.

NARRATOR: The altitude alert would
have been set at the proper elevation,

and the aircraft would have cleared
the mountain by more than 1,000 feet.

The same result if the air traffic
controller had asked for a readback.

Independent Air 1851.
Uh, you’re cleared to 3,000.

I say again, report reaching 3,000.
Over.

Or if the captain kept a sterile cockpit.

Uh, after 2,000, yeah,
we'll get below these clouds.

- Wow. Look.
- There’s the island.

It should be 3,000, not 2,000.
It's time to return to the cabin.

You cannot be inattentive, especially in
the last period of the flight.

Even with all those mistakes,
if the trainee controller had

given them the proper altimeter setting...

You're cleared to 3,000 on
QNH one-zero-two-seven.

Uh, correction.
One-zero-one-nine.

Flight 1851 would have
cleared Pico Alto by 200 feet.

- (rattling)
- Whoa!

- It would have been close.
- Finally, the GPWS.

(beeps)
AUTOMATED WARNING: Pull Up.

NARRATOR: If the crew had
the proper GPWS training...

Go around!

NARRATOR: They would have had one last
chance to avoid hitting the mountain.

(music crescendos then fades)

They might have made it.

I have never seen an
accident with these many factors

happened where any one of which,
had they not been there,

we wouldn't have had an accident.

NARRATOR:
In the wake of the crash,

the NTSB recommends a careful review
of airline training programs

with a focus on international
operations and safety,

especially those
related to the GPWS response.

The major lesson was
that airlines need to train

their crews better to
improve aviation safety.

NARRATOR:
Independent Air later settled with

the victims’ families
for 34 million U.S. dollars

before a compensation
case ever went to trial.

Independent Air went
out of business in 1990.

JIM:
In the aviation business,

there is no room at all for complacency.

The longer we do a job, the
more complacent we tend to get.

After a while, some of the things we do,

even if they're unsafe,
start to appear to be safe.

And, unfortunately, we
can have an accident like

the one that we witnessed here.