Original subtitles

Fierce winter weather...

Whew, really cold here.

Whew, really cold here.

...wreaks havoc with three different flights...

Almost instantly, it was clear that that aircraft

Almost instantly, it was clear that that aircraft

was not flying normally.

B-1.

...after a captain misses a step at takeoff.

...after a captain misses a step at takeoff.

Larry, we're going down, Larry!

I know it!

Unbelievable.

Unbelievable.

When pilots neglect icy wings...

We're in a dive.

We're in a dive.

You never give up.

You do what you got to do to try to make it.

You do what you got to do to try to make it.

And when crews misread warning signs...

Mayday! Mayday!

Mayday! Mayday!

Mayday!

Sol Flight 5428!

...investigators are faced with a conundrum.

...investigators are faced with a conundrum.

How could three modern aircraft end up with frozen wings?

How could three modern aircraft end up with frozen wings?

Ladies and gentlemen, we are starting our approach.

We lost both engines.

Emergency. Lift up

Mayday!

Mayday!

Mayday!

Brace for impact!

It's going to crash!

A heavy snowstorm blankets the US Capitol.

A heavy snowstorm blankets the US Capitol.

Planes at Washington's National Airport are grounded.

The 74 passengers and five crew on board Air Florida Flight 90

The 74 passengers and five crew on board Air Florida Flight 90

hoped to be in the air by now, but they're still at the gate.

We should have rebooked when we saw the weather.

We should have rebooked when we saw the weather.

We might still make it.

Joe Stiley is a businessman and private pilot.

Joe Stiley is a businessman and private pilot.

He's traveling with his assistant Nikki Felch.

He's traveling with his assistant Nikki Felch.

Everybody realized that it was one of those days.

It was a snowy day.

The chances of getting out were 50/50 maybe.

The chances of getting out were 50/50 maybe.

Captain Larry Wheaton is in command of Flight 90.

Captain Larry Wheaton is in command of Flight 90.

60 degrees in Tampa and we're stuck in a snowstorm.

His first officer is former Air Force

pilot 31-year-old Roger Pettit.

pilot 31-year-old Roger Pettit.

Florida is home to both men.

Florida is home to both men.

Airport crews work furiously to clear the runway.

And after an hour and a quarter...

Tower.

Tower.

Reopening now.

Copy that.

OK, showtime!

OK, showtime!

Air Florida Flight 90 soon gets the green light

Air Florida Flight 90 soon gets the green light

from controllers.

Palm 90, taxi into position, and be

ready for an immediate takeoff.

ready for an immediate takeoff.

Palm 90.

Today, First Officer Pettit

Today, First Officer Pettit

will fly the Boeing 737, while Captain

Wheaton monitors instruments.

Whoa.

Whew.

Whew.

Really cold here.

Real cold.

To get airborne, the plane must reach 139 knots.

To get airborne, the plane must reach 139 knots.

Wow, look at that thing.

Wow, look at that thing.

The first officer checks the power levels.

That don't seem right, does it?

That don't seem right, does it?

Yes it is.

There's 80.

OK.

Maybe it is right.

Maybe it is right.

120.

120.

120.

B-1.

When we got airborne, almost instantly,

it was clear that that aircraft was not flying normally.

it was clear that that aircraft was not flying normally.

Airspeed low!

Easy!

Easy!

Forward.

Forward.

Come on.

Forward.

Forward.

Forward.

Barely climbing.

Stay down.

Keep your head down.

It won't come up.

It won't come up.

Terrain.

Terrain.

Larry, we're going down, Larry!

Larry, we're going down, Larry!

I know it!

Air Florida Flight 90 has plunged into Washington,

Air Florida Flight 90 has plunged into Washington,

DC's Potomac River.

Of the 79 people on board, only six escaped the wreckage

Of the 79 people on board, only six escaped the wreckage

and make it to the surface.

On the bridge, four people are dead and four more injured.

On the bridge, four people are dead and four more injured.

News cameraman Chester Panzer arrives on the scene in time

to cover rescue efforts.

to cover rescue efforts.

I started rolling, and the first thing I saw

was someone being loaded into an ambulance.

was someone being loaded into an ambulance.

The rest of the survivors

are still trapped in the icy water.

are still trapped in the icy water.

A fellow who was strapped into his seat right in front of us,

who couldn't get out because a bunch of cables and things

who couldn't get out because a bunch of cables and things

like that had gotten around him, and he

was just wired in place there.

was just wired in place there.

And then I turned to Nikki and I said, I'm all broken up

and I know I can't swim.

and I know I can't swim.

My legs aren't working.

The survivors won't last

long in the freezing water.

Flight attendant Kelly Duncan manages to reach the line.

Flight attendant Kelly Duncan manages to reach the line.

She was holding on, and the helicopter

was just flying her in.

was just flying her in.

Joe Stiley does all he can

to help Nikki and fellow passenger Priscilla Tirado.

I had Priscilla in a kind of an arm lock on this side,

and I had Nikki on this side.

and I had Nikki on this side.

But this arm wasn't working very well.

And then the helicopter began to pull us away into the water.

And then the helicopter began to pull us away into the water.

I lost Nikki almost instantly because this whole arm just

was dysfunctional.

was dysfunctional.

And I had Priscilla under that arm for about halfway

And I had Priscilla under that arm for about halfway

across the river, and we started running into the broken ice.

At some point during that, I lost my grip on Priscilla

At some point during that, I lost my grip on Priscilla

and left her laying there on top of a block of ice.

Joe is pulled to safety.

Joe is pulled to safety.

The helicopter drops Priscilla a life ring,

The helicopter drops Priscilla a life ring,

but she can't hang on.

That's when it hit me that this woman was

That's when it hit me that this woman was

going to drown in front of me.

She was in the open water.

She's being pushed under the water by the helicopter wash.

She's being pushed under the water by the helicopter wash.

A bystander takes action.

He didn't think about how cold the water was.

He didn't think about how cold the water was.

Didn't think what it would do to him.

Lenny Skutnik saves Priscilla's life.

Nikki is the last survivor pulled from the water.

78 people have lost their lives in the tragic accident.

78 people have lost their lives in the tragic accident.

Within hours, investigators from the National Transportation

Within hours, investigators from the National Transportation

Safety Board are on the job.

Other aircraft did depart.

Other aircraft did depart.

Which means that things were successful in other jetways.

What was wrong with this particular aircraft

What was wrong with this particular aircraft

that caused the crash?

Early in the investigation,

Air Florida's flight recorders are found.

Air Florida's flight recorders are found.

The data gives the team its first clues.

It told us the altitude and the time.

It told us the altitude and the time.

And so you knew how long it rolled down the runway

before it lifted off.

Takeoff was very slow.

Takeoff was very slow.

Flight 90 took 15 seconds longer

than usual to get airborne.

than usual to get airborne.

It's got to be something about their engine power.

B-1.

B-1.

It didn't climb in a normal way.

So obviously there was something wrong with the amount

So obviously there was something wrong with the amount

of the power.

In 1982, aircraft data recorders

aren't sophisticated enough to pinpoint what

aren't sophisticated enough to pinpoint what

was wrong with the engines.

Oh, this is bad.

Oh, this is bad.

It's probably the worst storm I've seen.

Investigators now turn to the cockpit voice

recordings.

recordings.

Can you see your wingtip?

I got a little bit on mine.

I got a little bit on mine.

A little.

This wing's got about a quarter to a half an inch on it.

All the way.

All the way.

Wheaton and Pettit are heard

discussing the removal of ice from the aircraft's wings.

discussing the removal of ice from the aircraft's wings.

They pulled up in back of another aircraft, a DC-9,

thinking that they might be able to warm

thinking that they might be able to warm

up and blow off their aircraft.

The captain maneuvers his plane

into the exhaust stream of the plane ahead.

into the exhaust stream of the plane ahead.

It's an unconventional strategy to deice without losing

It's an unconventional strategy to deice without losing

the plane's place in the queue.

But so far, Macidull has heard nothing that would explain

But so far, Macidull has heard nothing that would explain

the loss of engine power.

You're throttles.

You're throttles.

OK.

Then he hears something disturbing.

Oh.

Yeah, look at that thing.

The first officer thinks there's a problem

The first officer thinks there's a problem

with the plane's acceleration.

That don't seem right.

Does it?

Does it?

Yes, it is.

There's 80.

But the captain sees no cause for alarm.

Uh, maybe it is right.

Uh, maybe it is right.

Despite the first officer's hesitation,

the captain thinks the engine power

the captain thinks the engine power

is sufficient for takeoff.

The team must now determine Flight 90's exact power levels.

The team must now determine Flight 90's exact power levels.

Come on.

I've got an idea.

The sound of the engines is recorded in the background

The sound of the engines is recorded in the background

on the cockpit voice recorder.

The sound of Flight 90's engines

should tell Macidull how much power they were generating.

should tell Macidull how much power they were generating.

Are you ready to go?

Yeah.

Yeah.

OK.

Forward.

Forward.

They eliminate the pilots' voices

and isolate the engine sounds.

and isolate the engine sounds.

Jet engines contain turbines, which

make different sounds depending on how

make different sounds depending on how

quickly they're spinning.

When the engine needs more power,

the turbine spins faster and the pitch of the sound changes.

the turbine spins faster and the pitch of the sound changes.

Can you turn that up a bit?

Can you turn that up a bit?

The results are dramatic.

The results are dramatic.

The sound analysis indicated that the engines

were running at a speed that would produce about 70% power.

were running at a speed that would produce about 70% power.

Investigators now know that the Boeing

Investigators now know that the Boeing

737's engines weren't running at full power during takeoff.

737's engines weren't running at full power during takeoff.

Why didn't the pilots notice?

The efforts to recover Air Florida Flight 90 pay off.

The efforts to recover Air Florida Flight 90 pay off.

Investigators look to a key piece of wreckage for answers.

Investigators look to a key piece of wreckage for answers.

They hope the engine pressure ratio gauge, or EPR,

They hope the engine pressure ratio gauge, or EPR,

will help explain why the plane didn't

lift off with full power.

lift off with full power.

The EPR is connected to a sensor at the front of the engine.

It calculates thrust by measuring the increasing air

It calculates thrust by measuring the increasing air

pressure passing through it.

Your throttles.

OK.

OK.

The gauge tells pilots when they

have enough power to climb.

If it was malfunctioning, it might have given

If it was malfunctioning, it might have given

the crew a faulty reading.

The first officer had doubts about the EPR.

The first officer had doubts about the EPR.

God, look at that thing.

That don't seem right, does it?

That don't seem right, does it?

But the captain made the mistake of only focusing

on the aircraft's speed...

Yes, it is.

Yes, it is.

There's 80.

...and ignoring the irregular

reading on the EPR gauge.

Uh, maybe it is right.

Uh, maybe it is right.

Close examination of the gauge

Close examination of the gauge

reveals something strange.

It can't be right.

The needle is displaying

The needle is displaying

an impossible reading.

They indicated the engines were

producing more power than the engines

producing more power than the engines

were capable of producing.

That was a huge red flag.

It seems likely that the gauge

It seems likely that the gauge

was giving a false reading throughout the short flight.

The pilots were seeing more power than they were getting.

The pilots were seeing more power than they were getting.

So what would have caused that?

Did snow and the bitter cold affect the reading?

Did snow and the bitter cold affect the reading?

They focus on the EPR's tiny sensor

at the front of the engine.

at the front of the engine.

If it was coated with ice, it could have sent

incorrect data to the cockpit.

incorrect data to the cockpit.

I got a hold of another 737 because I

already suspected the engine pressure ratio gauges.

already suspected the engine pressure ratio gauges.

To test his theory, Macidull

uses tape to simulate ice covering the engine sensor.

uses tape to simulate ice covering the engine sensor.

He then recreates the pilots' actions

on the day of the flight...

on the day of the flight...

OK, start her up.

...and records the sound of the engines...

Keep throttling up.

...until the engine gauges matched the target

...until the engine gauges matched the target

set by Flight 90's crew.

Got it.

Macidull compares the sound of his test flight

Macidull compares the sound of his test flight

to engine noise captured during Flight 90's takeoff.

That's a perfect match.

That's a perfect match.

I concluded that both engines were blocked with something...

probably ice.

Investigators realize the iced-over sensors

caused pilots to believe they had enough power to climb.

caused pilots to believe they had enough power to climb.

As the 737 speeds along the runway...

As the 737 speeds along the runway...

You got throttles?

...Pettit begins pushing

the thrust levers forward, aiming

the thrust levers forward, aiming

for the target of 2.04 EPR.

Because the EPR sensors are blocked with ice,

Because the EPR sensors are blocked with ice,

the gauge shoots up quickly and gives the crew a false reading.

Whoa.

Whoa.

Whew.

The Air Florida pilots attribute

the unusual engine behavior...

the unusual engine behavior...

Really cold here.

Real cold.

...to the bitterly cold weather.

Seconds after liftoff, the stick shaker

activates, warning the pilots that they

activates, warning the pilots that they

are beginning to stall.

Air speed low.

Air speed low.

Forward.

Forward.

And with ice on the wings,

it's impossible to recover.

They did apply full power.

But that was only about five seconds before impact,

But that was only about five seconds before impact,

and it was too late.

But an important question lingers.

But an important question lingers.

Why didn't the plane's anti-icing system

keep the sensors clear?

keep the sensors clear?

The answer may be found when the team

turns its attention to the pilot's

pre-departure preparations.

pre-departure preparations.

EPR all the way to 204.

Set.

Set.

Anti-ice.

Off.

Investigators are surprised.

Ladies and gentlemen,

Ladies and gentlemen,

we've just been cleared on the runway for takeoff.

Unbelievable.

Flight attendants, please...

One of the worst snowstorms, and they

have their anti-ice turned off.

have their anti-ice turned off.

The Florida-based pilots seem to be

following their usual warm weather routine.

following their usual warm weather routine.

They weren't in the cold weather scenario

mindset at that moment.

Investigators wonder about the crew's cold weather

Investigators wonder about the crew's cold weather

experience.

They study Captain Wheaton's records...

They study Captain Wheaton's records...

Unsatisfactory adherence to regulations.

Checklists usage pre-flight, unsatisfactory.

Checklists usage pre-flight, unsatisfactory.

Flight procedures, unsatisfactory.

...and learn he has a history of errors, especially

...and learn he has a history of errors, especially

during takeoffs and landings.

The captain's history of poor decision-making

The captain's history of poor decision-making

helps to explain his unconventional

deicing maneuver...

Going to go to your wing now.

Going to go to your wing now.

...using the exhaust of a plane in front.

What they really did was get some warm air

What they really did was get some warm air

on a part of the leading edge of the wing,

and any snow that was clinging to it

and any snow that was clinging to it

ran back as water and refroze.

ran back as water and refroze.

Did they get yours?

Can you see your wingtip?

I got a little bit on mine.

Consequently, they did a lot more harm to their aircraft,

Consequently, they did a lot more harm to their aircraft,

Investigators believe the pilots underestimated

Investigators believe the pilots underestimated

the dangers they were facing.

Neither pilot was really used to flying in snow

Neither pilot was really used to flying in snow

or wintertime conditions.

The captain had, I think it was,

eight takeoffs in that kind of weather.

eight takeoffs in that kind of weather.

The first officer, who was going to make

the takeoff as the pilot flying, had two experiences.

the takeoff as the pilot flying, had two experiences.

They were literally unqualified.

They were literally unqualified.

Investigators have now identified

the factors that led to the tragic accident in the Potomac

River.

River.

The captain's poor judgment, combined

with both pilots' inexperience flying in winter weather,

with both pilots' inexperience flying in winter weather,

proved deadly.

God, look at that thing.

That don't seem right, does it?

That don't seem right, does it?

The captain should probably have said, hey, a minute.

Let's abort this takeoff and let's figure out what's

Let's abort this takeoff and let's figure out what's

wrong with these engines.

We're going down, Larry!

I know it!

The accident occurred because of accumulation

of numerous decisions that were made

by this particular flight crew.

by this particular flight crew.

The Air Florida disaster was a wake-up call

to the aviation industry.

to the aviation industry.

Northern airports now have plain deicing

facilities near the runway for use just prior to takeoff.

facilities near the runway for use just prior to takeoff.

Pilots and regulators now better understand the risk

of flying in icy conditions.

of flying in icy conditions.

Even the most rule-abiding pilots

are powerless to battle frozen wings if they've

are powerless to battle frozen wings if they've

received misleading training.

On a frosty winter afternoon, 26 passengers

are taking Comair Flight 3272?

are taking Comair Flight 3272?

From Cincinnati, Ohio, to Detroit, Michigan.

From Cincinnati, Ohio, to Detroit, Michigan.

It's a short, one-hour trip on board an Embraer-120,

a Brazilian-made turboprop.

a Brazilian-made turboprop.

First Officer Kenneth Reese and Captain Dan Carlson

are on the third leg of the day.

are on the third leg of the day.

The first officer is at the controls.

Out at Detroit, we're looking at 239 radio.

Out at Detroit, we're looking at 239 radio.

Heading 030 to join the arrival, Comair 3272.

Heading 030 to join the arrival, Comair 3272.

For now, the crew has the plane on autopilot.

As they descend from 19,000 feet toward their destination...

As they descend from 19,000 feet toward their destination...

Just some bumps.

...they hit some unexpected turbulence

...they hit some unexpected turbulence

15 minutes before their scheduled arrival.

Let's run the descent check.

Ice protection.

Windshield, props, standard 7.

Windshield, props, standard 7.

Pressurization.

Comair 3272, now turn left, heading 090.

Comair 3272, now turn left, heading 090.

Heading 0-niner-0, Comair 3272.

Heading 0-niner-0, Comair 3272.

The pilots make their final turn,

and the plane banks left.

It looks like your low-speed indicator.

Yeah, I see it.

Yeah, I see it.

Power.

Thanks.

For some reason, the aircraft doesn't gain speed.

For some reason, the aircraft doesn't gain speed.

The autopilot disconnects.

The autopilot disconnects.

Then the plane rolls steeply to the left.

Then the plane rolls steeply to the left.

We're in a dive.

We're in a dive.

We're in a dive.

Huh!

Oh, God!

No!

No!

You never give up.

You do what you got to do to try to make it.

Oh, God!

No!

Comair Flight 3272 has crashed into a field

Comair Flight 3272 has crashed into a field

22 miles from the Detroit Airport.

All 26 passengers and three crew members are dead.

All 26 passengers and three crew members are dead.

By morning, a team from the National Transportation Safety

Board, or NTSB, begins recovering pieces

Board, or NTSB, begins recovering pieces

of wreckage for analysis.

What a mess.

Richard Rodriguez leads the investigation.

The team gets a lucky break when the flight recorders are

recovered in good condition.

recovered in good condition.

Let's get those both packed up.

They hope the devices will help

They hope the devices will help

them unravel the mystery of how a routine flight ended

in disaster.

OK, we all ready?

A first glance at the flight data

A first glance at the flight data

is enough to give Rodriguez a solid lead.

4,000 feet, and it falls from the sky.

4,000 feet, and it falls from the sky.

The aircraft's sudden plunge

could be the result of icing.

could be the result of icing.

This occurs when a buildup of ice on the plane's wings

leads to an aerodynamic stall.

leads to an aerodynamic stall.

Ice reshapes the wing surface.

So these aerodynamic surfaces aren't doing

So these aerodynamic surfaces aren't doing

what they're supposed to do.

If frozen wings caused the plane to stall,

If frozen wings caused the plane to stall,

the team wonders why no other aircraft

was affected by the weather.

was affected by the weather.

None of the other airplanes that

were on approach to Detroit experienced any problems.

So we needed to look hard about what

So we needed to look hard about what

was unique about this airplane.

Come on!

Get out of here, for God's sake!

We're in a dive.

We're in a dive.

Oh!

Oh!

Ah!

What was so different about Flight 3272

that weather made it fall out of the sky?

that weather made it fall out of the sky?

Investigators need to learn all they can

about the weather conditions faced by the pilots of Comair

Flight 3272.

Flight 3272.

OK, let's pull up the weather data.

The weather data began to paint a picture of an airplane that

was on approach, flying in what were considered

was on approach, flying in what were considered

light icing conditions.

According to Detroit air traffic controllers,

According to Detroit air traffic controllers,

other aircraft reported icing conditions.

Strangely, the Comair pilots didn't.

Strangely, the Comair pilots didn't.

Comair 3272, just a little turbulence, but that's all.

Comair 3272, just a little turbulence, but that's all.

It definitely flew through icing conditions.

It definitely flew through icing conditions.

The Embraer-180 has both anti-icing and deicing

systems for winter-weather flying.

systems for winter-weather flying.

Let's play it.

Something doesn't add up.

Let's run the descent check.

They turn to the cockpit

voice recorder for answers.

Ice protection.

Ice protection.

The pilots are required to go through an approach checklist.

One of the items is the various anti-icing facilities

One of the items is the various anti-icing facilities

that they have on the aircraft.

The anti-icing protection

The anti-icing protection

uses electricity to heat the windshield and propellers.

But the wings have a different system.

But the wings have a different system.

They rely on mechanical devices, called deicing boots.

They rely on mechanical devices, called deicing boots.

Made of rubber, the boots are part of the leading

edge of the wings.

When activated, they inflate, expand,

When activated, they inflate, expand,

and crack off accumulated ice.

The ice is just hard enough that it cracks,

The ice is just hard enough that it cracks,

and the air stream blows it away.

Pressurization.

Pressurization.

It's reset for our landing in Detroit.

Rodriguez listens, waiting for the pilots

to activate the deicing boots.

to activate the deicing boots.

Landing lights.

Landing lights on.

Cross-read.

Cross-read.

Cross-read is off.

That completes that.

That completes that.

He makes a stunning discovery.

There was no discussion to indicate

that they were concerned about icing on the aircraft.

that they were concerned about icing on the aircraft.

Investigators check dispatch

records to determine if the crew was briefed

records to determine if the crew was briefed

on the weather conditions.

The flight had received their papers

for dispatch, which included warnings about icing

for dispatch, which included warnings about icing

in the Detroit area.

There could be some ice in our path.

There could be some ice in our path.

They knew they were going to hit ice,

but they never popped the boots.

but they never popped the boots.

NTSB investigators wonder

why pilots with plenty of winter flying experience

why pilots with plenty of winter flying experience

never activated the deicing boots.

The captain was known as a by-the-book type of pilot.

The captain was known as a by-the-book type of pilot.

They contact other Comair pilots for information.

They contact other Comair pilots for information.

So if ice is just beginning to form on your wing,

what would you do?

You'd wait.

You'd wait?

OK.

OK.

We were getting feedback that they'd

wait until 1/4 to 1/2 inch of ice

wait until 1/4 to 1/2 inch of ice

had accumulated before they'd activate the deice boots.

And why would you wait?

Bridging.

Bridging.

When deice boots were first invented,

they inflated at a very slow pressure,

and stayed inflated for a while.

and stayed inflated for a while.

And pilots became concerned that ice

might form over the inflated shape of the boot...

might form over the inflated shape of the boot...

a phenomenon known as bridging.

But bridging on deicing boots

hasn't posed a risk to modern airlines for many years.

hasn't posed a risk to modern airlines for many years.

The deice boots on this airplane

inflate rapidly, in less than a second,

inflate rapidly, in less than a second,

would break off any amount of ice that was accumulated,

and deflate again right away with vacuum suction.

and deflate again right away with vacuum suction.

So deice boot bridging was not going

to happen on this airplane.

to happen on this airplane.

All right.

Let's take a look at the manuals these guys are following.

Investigators need to find out what guidance the crew

Investigators need to find out what guidance the crew

received to deal with icing.

They compare Comair's manual to that

They compare Comair's manual to that

of the manufacturer, Embraer.

That leads to a surprising discovery.

That leads to a surprising discovery.

The Comair manual tells him to wait.

The Comair manual advises pilots to wait

The Comair manual advises pilots to wait

until half an inch of ice forms before deicing,

while the Embraer manual says something different.

while the Embraer manual says something different.

Activate boots at the first sign of icing.

The team must find out why the pilots were

The team must find out why the pilots were

given conflicting instructions.

They soon uncover a revision to the Embraer flight manual.

They soon uncover a revision to the Embraer flight manual.

It clearly explained the need to deice quickly.

So why didn't the Comair pilots follow that procedure?

So why didn't the Comair pilots follow that procedure?

There could be some ice in our path.

Oh, what a shock.

Ice in January.

Ice in January.

Investigators learned that the FAA

Investigators learned that the FAA

approved the Embraer revision.

But it overlooked the critical next step...

instructing the airlines to adopt the change.

instructing the airlines to adopt the change.

Why not make it mandatory?

It's a no-brainer.

It's a no-brainer.

While the FAA had a great deal of information,

they never did officially sanction a standard

they never did officially sanction a standard

that should be adhered to.

Investigators now know what led to Comair

flight 3272's fatal crash.

flight 3272's fatal crash.

Just before landing, the pilots entered icing conditions.

Just before landing, the pilots entered icing conditions.

Ice protection.

But the captain waited to activate the deicing boots.

But the captain waited to activate the deicing boots.

Props, standard 7.

Per the instructions in the flight manual,

Per the instructions in the flight manual,

they were waiting until a significant amount of ice

had accumulated.

Comair 3272, reduce speed 150.

Comair 3272, reduce speed 150.

The controller then instructed them to reduce speed

The controller then instructed them to reduce speed

as they approached the airport.

Speed 150, Comair 3272.

As the plane slowed, the drag from the ice

As the plane slowed, the drag from the ice

on the wings increased.

To make matters worse, the plane was on autopilot.

To make matters worse, the plane was on autopilot.

When the autopilot is on, the pilot

can't feel what's happening until he

can't feel what's happening until he

starts to see something on the instrument gauges.

starts to see something on the instrument gauges.

Looks like your Low Speed Indicator.

Yeah, I see it.

Power.

Power.

Thanks.

But that action comes too late.

The left wing had already lost lift.

The left wing had already lost lift.

The aircraft rolled rapidly to the left.

They went from about 45 degrees angle of bank to the left

They went from about 45 degrees angle of bank to the left

to 140 degrees.

to 140 degrees.

Which is basically inverted.

We're in a dive!

We're in a dive!

We're in a dive!

When that nose pitched straight into the ground,

their fate was sealed.

their fate was sealed.

No!

No!

No!

The NTSB faults the Federal Aviation Administration

The NTSB faults the Federal Aviation Administration

for failing to establish adequate standards for flights

in icing conditions.

in icing conditions.

Ultimately, we didn't believe that the FAA put forth

Ultimately, we didn't believe that the FAA put forth

the right leadership to help dispel the myth of deice boot

bridging.

bridging.

They recommend that all pilots be instructed

to activate the boots the moment they

encounter icing conditions.

encounter icing conditions.

Our mission is to find the cause of an accident,

make recommendations that will prevent

make recommendations that will prevent

it from ever happening again.

And when several mistakes in the cockpit

add up to frozen wings, a flight spirals out

add up to frozen wings, a flight spirals out

of control above the remote steppes of Patagonia.

On a cold night in Argentina...

Positive rate.

Positive rate.

...Sol Flight 5428 is headed

from Neuquen to the port city of Comodoro

Rivadavia on the coast.

Rivadavia on the coast.

Tonight, Captain Juan Raffo is piloting

Tonight, Captain Juan Raffo is piloting

a Swedish-made Saab-340 turboprop.

Adriano Bolatti is his first officer.

Engage autopilot.

Engage autopilot.

The aircraft begins to climb to a cruising altitude

of 19,000 feet.

of 19,000 feet.

Buenos Aires, Sol Flight 5428, reporting waypoint in Copa.

Buenos Aires, Sol Flight 5428, reporting waypoint in Copa.

We are climbing through flight level 50 for 190.

ATC Buenos Aires, received.

ATC Buenos Aires, received.

It looks like we're picking up some ice.

Nothing to worry about.

We were expecting some light icing.

It should be better when we get to 19,000.

It should be better when we get to 19,000.

At that higher altitude,

water droplets freeze solid before they

can cling to the aircraft.

can cling to the aircraft.

But as they climb, the icing conditions worsen.

But as they climb, the icing conditions worsen.

Captain Raffo decides to change the plan.

OK, let's get it down to where it's warmer to melt it off.

Roger.

Sol Flight 5428, requesting descent to flight level 140.

Sol Flight 5428, requesting descent to flight level 140.

Sol 5428, you are cleared to 140.

Sol 5428, you are cleared to 140.

As Sol 5428 descends to a lower altitude...

As Sol 5428 descends to a lower altitude...

All finished?

...the flight continues without incident.

...the flight continues without incident.

Feel that?

Feel that?

The propeller is vibrating.

But then everything changes.

But then everything changes.

Put them on max.

Roger.

Oh, hell!

What's wrong?

I don't know.

Pull back!

Pull back!

Pull back!

I'm trying!

I'm trying!

Come on!

Come on!

Come on!

Mayday! Mayday!

Mayday! Mayday!

Mayday!

Sol Flight 5428! Mayday!

Mayday!

Mayday!

It won't come up.

It won't come up.

The turboprop crashes in a remote region

of Patagonia.

There are no survivors.

22 fatalities.

22 fatalities.

My God.

Augusto De Santis is coordinating the various teams

Augusto De Santis is coordinating the various teams

from Argentina's Civil Aviation Accident Investigation Board.

Catalog every piece, no matter how small.

Catalog every piece, no matter how small.

While some members of the team remain on the site,

While some members of the team remain on the site,

De Santis studies the weather conditions

on the night of the crash.

This is the flight path from Neuquen to Comodoro.

This is the flight path from Neuquen to Comodoro.

Look what's waiting for them here.

Look what's waiting for them here.

They flew right into this cold front.

The information showed that there was severe icing.

The information showed that there was severe icing.

Was ice a factor in the accident?

Was ice a factor in the accident?

Investigators focus on the plane's deicing systems.

All that survived are the valves.

All that survived are the valves.

The valves are a key component of the deicing boots.

Their main function is to control the flow

of pressurized air that inflates the boots on the plane's wings.

of pressurized air that inflates the boots on the plane's wings.

We isolated the anti-ice valve, and we

analyzed what was left of it.

analyzed what was left of it.

The tests reveal that pressurized air

was passing to the valves.

was passing to the valves.

Take a look.

No failures.

The team must look elsewhere for new leads.

The team must look elsewhere for new leads.

So there was no doubt that the systems were being operated

So there was no doubt that the systems were being operated

and that they were working.

They turn to the flight data recording.

They turn to the flight data recording.

OK, look here.

Their airspeed dropped to 129 knots, then 126 knots.

Their airspeed dropped to 129 knots, then 126 knots.

They were in ice.

They should be speeding up, not slowing down.

They should be speeding up, not slowing down.

When climbing in icing conditions,

the minimum speed is 160 knots.

the minimum speed is 160 knots.

They were 30 knots below that.

They lost so much speed, they stalled.

They lost so much speed, they stalled.

The speed was progressively decreasing, which harmed

the aircraft aerodynamically...

Oh, hell!

...and took it to a final stall and loss of control.

...and took it to a final stall and loss of control.

You pick up ice, you should increase your speed.

You pick up ice, you should increase your speed.

Pretty basic.

Why didn't these guys do that?

Why didn't these guys do that?

The team wonders why pilots would

make such a fundamental error.

They hope the flight data will provide more clues.

They hope the flight data will provide more clues.

Let's check their autopilot settings.

Did the pilots use the correct setting for the weather

Did the pilots use the correct setting for the weather

conditions they faced?

It was set to vertical speed after they leveled off.

It was set to vertical speed after they leveled off.

Vertical speed is an autopilot setting that

controls the rate of climb.

controls the rate of climb.

But to get through ice faster, the pilot

should have selected the setting that maintains speed.

should have selected the setting that maintains speed.

That's their mistake.

Vertical climb not only slows the plane,

Vertical climb not only slows the plane,

it also pitches the nose upward.

It's going to expose the whole underside of the wing,

It's going to expose the whole underside of the wing,

and you're just going to pack on ice even faster.

What's worse, the Saab turboprop

isn't equipped with anti-ice protection on its underside.

isn't equipped with anti-ice protection on its underside.

This ice buildup adds weight on different parts

This ice buildup adds weight on different parts

of the aircraft, which makes it less controllable.

It becomes a major effort for the crew, or the autopilot,

It becomes a major effort for the crew, or the autopilot,

to control the aircraft.

The question is, why did the pilots let this happen?

The question is, why did the pilots let this happen?

Airspeed 140 knots.

Airspeed 140 knots.

Check.

Investigators hope the cockpit voice recorder of Sol

Investigators hope the cockpit voice recorder of Sol

Flight 5428 will help explain how the pilots responded

Flight 5428 will help explain how the pilots responded

to the buildup of ice.

Flaps up.

Flaps up.

Engage autopilot.

It looks like we're picking up some ice.

It looks like we're picking up some ice.

There it is.

Nothing to worry about.

We were expecting some light icing.

We were expecting some light icing.

I don't know, Juan.

It might be more than we thought.

They were aware that there was ice buildup

and that it was progressing.

and that it was progressing.

It should be better when we get to 19,000.

They're just focused on getting above the bad weather.

They're just focused on getting above the bad weather.

The pilot's strategy was to climb

above icing conditions.

above icing conditions.

They can't.

They're carrying too much ice to climb any higher.

Once it became apparent that they were picking up ice

Once it became apparent that they were picking up ice

quickly and they were unable to climb,

they make a decision to descend and find

they make a decision to descend and find

an altitude where the temperature is

such that that ice would melt.

I don't think that helped very much.

I don't think that helped very much.

Ice is hitting everywhere.

It's OK.

We're going to stay at this altitude for now.

We're going to stay at this altitude for now.

We'll keep deicing until we get there.

The pilots can't rely entirely on deicing.

They also need to push the throttles

They also need to push the throttles

forward to increase power.

While they were aware of the ice buildup

While they were aware of the ice buildup

and how things were progressing, they

and how things were progressing, they

were not taking strong measures to change the situation.

You feel that?

You feel that?

The propeller is vibrating.

The first sign of stalling.

Oh, it's because there's too much ice on the propellers.

Put them on max.

Roger.

Propellers?

Propellers?

They're misreading the signals from the plane.

What was actually happening was a structural vibration

of the entire aircraft.

of the entire aircraft.

The aircraft was virtually dying.

It was at a speed threshold where

It was at a speed threshold where

the next thing was the loss of control

due to the loss of lift.

As the plane begins to stall,

Captain Raffo makes a dangerous call.

Captain Raffo makes a dangerous call.

Pull back!

Pull back!

Pull back!

They're trying to level the plane.

Unbelievable.

They're making the stall even worse.

It's a shocking revelation.

It's a shocking revelation.

The pilots are doing the opposite of what needs to be

done to prevent a catastrophe.

Mayday! Mayday!

Mayday!

Sol Flight 5428! Mayday!

Mayday! Mayday!

Investigators now know why Sol 5428 crashed.

Investigators now know why Sol 5428 crashed.

A wrong autopilot setting here, a misread of the plane's

A wrong autopilot setting here, a misread of the plane's

vibrations here, and when they finally stall,

they try to pull the nose up to level off instead

they try to pull the nose up to level off instead

of trying to gain speed.

What kind of training did these guys get?

What kind of training did these guys get?

When investigators examine

the pilots' training records, they

make a surprising discovery.

make a surprising discovery.

No training is done on what to do once the ice buildup has

advanced and how to get out of that situation by increasing

advanced and how to get out of that situation by increasing

speed.

It's the last piece of the puzzle

It's the last piece of the puzzle

explaining the fatal crash.

It should be better when we get to 19,000.

It should be better when we get to 19,000.

Investigators conclude that the airline's lack

of proper training resulted in the pilots

not only selecting the wrong autopilot settings...

not only selecting the wrong autopilot settings...

I can put it on vertical.

OK.

The sooner, the better.

The sooner, the better.

Roger.

...but also failing to increase

speed in icing conditions.

speed in icing conditions.

Oh, hell!

What's wrong?

I don't know!

What began as ice on the wings

What began as ice on the wings

resulted in a mismanaged...

Pull back!

Pull back!

...and ultimately unrecoverable stall.

...and ultimately unrecoverable stall.

The problem was that the actions they took

were not effective enough in order

were not effective enough in order

to mitigate the situation.

Pull up! Pull up!

Pull up!

No!

No!

No!

In their final report, investigators recommend

sweeping changes to commercial pilot

sweeping changes to commercial pilot

training for icy conditions.

Icing has been with us since Lindbergh, who iced up

as he went across the Atlantic.

as he went across the Atlantic.

And it will continue to be with us even in the future.

Three different cases of frozen wings

all leading to tragic outcomes.

But the insight gained from these accidents led

But the insight gained from these accidents led

to improved flight safety in winter

conditions across the globe.

conditions across the globe.