Original subtitles

NARRATOR: High above the cornfields of Iowa,

- United Airlines Flight 232... - (METALLIC RATTLING)

Is in serious trouble.

- I have it. - What was that?

NARRATOR: One of the DC-10's three engines has exploded.

- The plane is out of control. - Close the throttles.

NARRATOR: The crew's best hope at landing happens to be in the cabin.

(DRAMATIC MUSIC)

Denny Fitch knows more about flying a DC-10 than almost anyone on Earth.

That's how I transitioned from a passenger to a crew member.

You wanna go forward, Al.

Let it come back. It'll lead it away.

NARRATOR: But nothing in his vast experience

has prepared him for what he finds.

DUDLEY: Lost all three hydraulic systems.

DENNY: I took it all in.

The immediate fast conclusion is,

"Denny...

today is the day you're gonna die."

Mayday, Mayday!

NARRATOR: United Airlines Flight 232 is halfway through its journey

from Denver, Colorado, to Chicago.

The DC-10 is cruising at 37,000 feet.

The clear weather makes this a relatively easy flight

for the captain and his first officer, both former fighter pilots.

Oh, looks like we're gonna make Chicago on time.

BILL: The airplane was trimmed up.

We'd enjoyed a cup of coffee, and weather was good.

There was absolutely no reason

why we shouldn't have a pretty normal flight that day.

NARRATOR: Today is Children's Day at United Airlines.

A child's ticket costs only a penny.

- (INDISTINCT CHATTER) - (BABY CRYING)

Of the 285 passengers on the flight, 52 are children.

Thanks for the cookies, Jan. Now how about some more coffee?

NARRATOR: Denny Fitch is a United Airlines pilot

and a flight instructor for the DC-10.

The flight was normal in all respects.

We had climbed to altitude. The lunch had been served.

The tray was being removed,

and I asked the flight attendant if I may have a cup of coffee.

- Heading home for a few days? - Yeah.

It'll be good to get back.

Excuse me.

I'll take a refill when you have a second. Thank you.

NARRATOR: Jerry Schemmel is a basketball executive on his way through Chicago

for a draft of college players.

It was a very smooth flight.

In fact, we were told when we got on the plane

that there wasn't any expected turbulence at all.

Should be a real smooth ride for two hours to Chicago.

(ALARMS CHIMING, ENGINES WINDING DOWN)

BILL: Now, all of a sudden, with a bang

it's just like being thrown into a great, big tornado of activity.

NARRATOR: First officer Bill Records immediately shuts off the autopilot

and takes manual control.

- I have it. - What was that?

There was no alarms at all, no bells, no whistles,

no lights flashing, just this big explosion and that was it.

- (PASSENGERS YELPING) - (BABY CRYING)

JERRY: The first thing I thought when I heard it,

and then I could feel it kind of rip through the cabin,

was a bomb has gone off.

And I thought, "That's it for everybody."

And the conscious thought hit me

that people don't survive bombs going off in planes.

NARRATOR: Denny Fitch pays close attention to the DC-10's every move.

DENNY: The coffee cup no longer had coffee in it.

It was all over the table linens.

My fanny was no longer in the middle of the seat.

It was now up against the left arm rest.

That was followed by ten seconds

of quite pronounced, violent airframe shuddering.

I got control. Check the gauges.

NARRATOR: The pilots can barely control the plane.

Captain Al Haynes tries to figure out why.

The airplane was shaking so bad, you couldn't read the instruments

and you had to lean way up near the panel to read it.

We've lost the number two engine.

(METALLIC RATTLING)

NARRATOR: The DC-10 has three engines.

The number two engine is mounted on the tail.

It's the one that suffered a catastrophic failure.

The people in my area were calm, but you could tell they were very nervous.

They were anticipating like I was what might happen,

and we knew that what might happen wasn't going to be very positive.

NARRATOR: Records is not able to level the plane.

We're losing hydraulics.

I'll shut number two down.

The reason you shut down an engine when it fails

is that you don't know what the damage is to the engine.

If it kept turning, it could tear itself apart.

(SIGHS) Okay, that's got it.

NARRATOR: But Denny Fitch suspects there may be more to worry about

than the loss of an engine.

DENNY: I was looking at the window for clues, and one of the clues

that first appeared to me and it was an abnormality

was the fact that the right wing of this aircraft was dropping.

It doesn't make sense. The number two engine can't cause these wing behaviors.

In other words, its loss doesn't have anything to do with what I'm seeing.

AL: Bill said, "Al, I can't control the airplane."

And that's a real attention-getter.

And so I look forward to see what the flight controls were doing.

NARRATOR: The damaged engine has been shut down.

The plane is not responding to the first officer's commands.

It's banking further and further to the right.

BILL: It's a very sickening feeling to have the controls all the way over

and have them all the way back as far as you can go

and the airplane was in fact going the opposite direction.

I've got it, Bill.

NARRATOR: If the pilots can't find a way to level the plane,

it will soon be upside-down.

AL: He had the control wheel as far as it can go to the left

and as far back in your lap as it would go.

You can't do that in flight,

so there's something drastically wrong there.

But the airplane was starting to roll over on its back,

and we had to stop that.

This isn't working.

NARRATOR: The plane has become impossible to steer.

It's a dire situation, and it can't be explained by the loss of one engine.

Dudley, check the gauges. What's going on back there?

We have no hydraulic fluid left. All systems are down to zero.

All three? That's impossible.

NARRATOR: A complex hydraulic system carries the commands

from the pilot's control column to the aircraft's control surfaces

such as the elevators, rudder, and ailerons.

Without fluid in the system,

there is no way to move these crucial flight controls.

JOHN: Hydraulics are the lifeblood of the airplane.

They provide the muscle to move the flight controls,

to retract and lower the landing gear, to move the flaps.

A lot of the things that move on the airplane are done hydraulically.

If you do not have hydraulics, you have absolutely no control.

You might as well just take the control column out

and throw it out the window.

NARRATOR: Even though the control columns have no effect

on the movement of the plane,

both pilots instinctively use them as though they did.

BILL: It's like driving a car.

If you're sliding on ice, nobody lets go of the steering wheel

even though the steering wheel is not effective.

And this is the same way.

You're holding onto the controls hoping, I guess,

that maybe there's some hydraulic fluid in there someplace.

What's it say in the book?

NARRATOR: The DC-10 has three separate hydraulic systems.

If one fails, the other two act as backup.

But all three systems are now empty of fluid.

There's nothing in here for anything like this.

AL: A billion to one were the odds that this would happen.

You're never trained for that, you never drill for it,

you never train for it, because technically, it can never happen.

NARRATOR: No hydraulics means no flight controls.

The plane could spiral to the ground at any moment.

- Let's use the engines. - Yeah, why not?

BILL: Well, we kind of made it up as we went along.

Everybody realized that this was something that we didn't have a procedure for,

so you just kind of grabbed for whatever's working.

NARRATOR: The left and right engines are still running.

The pilots decide to use them to their advantage.

I'm gonna pull back number one about 10%.

You go up on number three 10%, nice and slow.

NARRATOR: By adjusting the power to the two remaining engines,

they may be able to level the aircraft and make it fly straight.

Easy does it.

NARRATOR: The engines are at cruising speed.

The slightest miscalculation could be catastrophic.

The plane begins to level off.

Okay, that's got it.

NARRATOR: The improvised method of control seems to be working,

but with no hydraulics,

the crew and all their passengers are still in grave danger.

- How far to O'Hare? - About 400 miles.

NARRATOR: Flying to Chicago with only two engines may be possible,

but without flight controls,

the pilots have no idea if they'll be able to make a landing.

How are we gonna land this thing?

NARRATOR: None of the parts used to control the plane can be moved.

No pilot has ever safely landed a DC-10 without hydraulics.

296 people will soon die

unless the pilots can find a way to do it now.

- (ENGINES SPINNING UP) - (PASSENGER YELPS)

- The nose is going down. - What's going on here?

(CABIN RATTLING)

NARRATOR: United Airlines Flight 232 has begun to accelerate downwards.

Normally, pulling back on the control column

would raise the elevators and lift the nose of the plane.

We have no elevators.

NARRATOR: But with no hydraulics, that control is gone.

AL: Normally, you'd just pull back and add a little power

and pull the nose up, but we didn't have the controls.

Okay, let's ease 'em up. See what happens.

NARRATOR: The only things working on the plane are the two forward engines.

Let's try 10%. Watch the gauges.

Easy.

NARRATOR: By increasing power to the engines,

the pilots hope they can create enough lift under the wings to raise the nose.

This is what you have to do

because the power creates the lift and that's what you need.

NARRATOR: The maneuver works. The plane pulls out of the dive.

Okay. That's got it.

Easy, easy.

We just dropped 1,000 feet.

Okay, we gotta land this thing.

Find out where the hell we are and get us to the nearest airport.

NARRATOR: Since the engine failure, the plane has been drifting to the right.

There is no way Flight 232 can make it to Chicago without flight controls.

The pilots need to find a safe place to land as soon as possible.

This is United 232.

We are declaring an emergency

and requesting a vector to the nearest airport.

- What's going on? - We've lost hydraulics.

We have to make an emergency landing.

AIR TRAFFIC CONTROLLER (OVER RADIO): United 232,

you're heading towards Sioux City.

Would you like to go there?

- We'll take Sioux City. - Affirmative.

Start getting the cabin ready.

Okay, now we're climbing.

NARRATOR: The plane suddenly begins to climb.

As it does, airspeed drops. The wings begin to lose lift.

If the climb continues, the plane will stall

and fall from the sky.

The hell's going on here?

- Watch the right side. - I got it.

NARRATOR: To lower the nose,

Captain Haynes must reduce engine power while struggling to maintain level flight.

Okay, that's got it.

JERRY: I felt the plane start to drop and I'm just trying to think,

"All right, what the heck is going on with this aircraft?"

We're dropping again.

Ease it up.

Gently, gently.

Okay.

Two-seven-five.

(SIGHS) Jesus.

NARRATOR: The plane has dropped another 1,500 feet.

AL: How far is Sioux City?

About 55 miles.

NARRATOR: In 30 minutes, the plane will hit the ground.

Jan, don't worry about this.

This airplane will fly fine on two engines.

When I told her that, she replied to me, "Oh, no, Denny.

"I just came from the cockpit.

Both the pilots are trying to fly the aircraft."

The captain has told us we've lost all our hydraulics.

Bingo.

That means no landing gear, no slats, no flaps, no flight controls.

Okay, tell the captain we've got a DC-10 training check airman back here.

If there's anything I can do to help, I'm happy to do so.

(DRAMATIC MUSIC)

(BREATHES DEEPLY)

United 232, understand you're requesting an emergency landing?

AL (OVER RADIO): That's affirmative.

We've lost all hydraulic control. Requesting a vector to the airport.

United 232, radar contact. Turn left heading two-five-five.

I don't think turning left is something we want to try.

I wouldn't want to risk it.

Agreed.

NARRATOR: The heading to Sioux City requires a left turn,

but for some reason, the damaged plane only wants to turn right.

Forcing it to turn left could be disastrous.

Okay, we're gonna right turn right now.

That's about the only way we can go.

Tower gave us a heading to fly. We try to fly it.

And if we would drift off to the right

because we would lose it somewhere in the manipulation of the throttles,

rather than try and turn left, we would just do a 360.

United 232, heavy. Roger.

Right turn heading two-five-five.

NARRATOR: The pilots must execute a precise right turn

without the use of the plane's ailerons.

They carefully alternate power between the two engines

to turn the crippled plane around.

As they begin to turn, the nose suddenly falls again.

The plane accelerates downward.

AL: We're trying to keep the airplane straight and level,

but as the airplane wanted to turn to the right,

there were times that we would turn to the right,

the nose would go down and the tendency is to go over on your back.

We had to avoid that.

NARRATOR: They manage to complete the turn,

but they've dropped another thousand feet.

Sioux City is still 64 kilometers away.

AL: I don't think we're gonna make the airport, fellas.

(KNOCK ON DOOR)

There's a DC-10 instructor on board who's offering assistance.

Having a trainer, an instructor, on board the airplane was a relief to us

because we thought he could give us inputs that we didn't have.

Maybe he could help.

And he volunteered to come up,

and we were very happy to have him come up.

Okay, let him come up.

JAN: Could you come with me?

And so that's how I transitioned from a passenger

to a crew member.

(KNOCK ON DOOR, DOOR OPENS)

And I remember their forearms and their tendons being tense.

I remember their knuckles being white.

They both were on the flight control wheels,

their respective wheels, trying to fly the airplane together.

Now, that's an anomaly 'cause the airplane will fly quite nicely

with one person and two fingertips.

That's just the nature of the beast when it's normal.

This is clearly not normal.

You want to go forward, Al.

Now go forward. Let it come back and lead it away.

DUDLEY: Lost all three hydraulic systems.

DENNY: When I took it all in,

the immediate, fast conclusion is...

"Denny,

today is the day you're gonna die."

Tell me what you want, and I'll help you.

Take the throttles.

'Cause he can stand between Bill and myself now

and he can operate the alternating thrust a lot easier than we can.

Okay.

AL: Pull back, pull back.

Start it down.

NARRATOR: Fitch must ease back on the throttles

to stop the plane from climbing.

And it didn't take long

before I started to sense the airplane's behavior.

No, no, no, no, no. Not yet.

Wait a minute till it levels off.

NARRATOR: The flight attendants are discreetly preparing

for an emergency landing.

JERRY: Doesn't look good.

I watched the flight attendants, I think, like a lot of people did,

very closely just to kind of get a feel for what they might be thinking

and what they might know, what they might be feeling.

And for several minutes, they just spent time clearing the cabin.

NARRATOR: Denny Fitch keeps his eyes on the control column

to figure out what the pilots want him to do.

Is this Sioux City down to the right?

That's Sioux City.

NARRATOR: Finally, their destination is in sight.

Normally, the pilots would begin reducing their speed on approach to the airport,

but with no flight controls, that's something they can't do.

Because of the loss of hydraulics,

they were not able to configure the wings for the normal landing,

so they had to come in much, much faster to maintain the necessary lift.

We had absolutely no way to control the speed.

That was the biggest concern of us all was how fast we were going

and to try and slow down.

And there just was nothing we could do about it.

NARRATOR: If they can line up with the runway at all,

they'll be hitting it at a very high speed.

There's no telling what the impact will do to the plane.

What was going to happen when we touched down was a great concern

because we couldn't bring the nose up for a landing attitude.

And when we hit the ground, what's gonna happen is...

was a question in my mind.

And were we gonna actually make the runway?

Little more right.

NARRATOR: Fitch continues to keep the plane level and on course

by alternating power to the two engines.

Intuitively, I started to sense the airplane,

and I felt that it was becoming one with me, if that makes sense.

I felt that the airplane was sending me signals

that it was gonna do something before it did.

- I'm Al Haynes. - Hi, Al. Denny Fitch.

Bill Records here.

I tell you what.

We'll have a beer when this is all done.

Well, I don't drink, but I'll sure as hell have one.

(ALL CHUCKLE)

We were facing death.

All of us were. And our passengers.

NARRATOR: United 232 is less than ten minutes

from a nearly impossible landing.

No one is expected to survive.

(SIRENS WAILING)

Emergency workers prepare for the worst.

As the pilots approach the airport, Captain Haynes decides

it's time to tell the passengers precisely what they are facing.

Ladies and gentlemen, this is Captain Al Haynes speaking.

As you must be aware by now,

we're having some control difficulties with the plane.

We're attempting an emergency landing in Sioux City.

We'll be landing in approximately eight minutes.

We've got about as much control over the plane as we can get,

but I need you to understand this is going to be a crash landing.

- (PASSENGERS EXCLAIMING) - Please review your emergency procedures.

This is gonna be worse than anything you've ever been through before

and you need to be ready.

We will do everything in our power to get everyone to the ground,

but we need your cooperation.

I think Captain Haynes wanted to be as honest as he could with us.

He didn't want to sugar-coat anything.

He wanted to let us know that we are in a very dire circumstance.

I was convinced I wasn't going to make it.

I thought, "This is my day to go."

There was serious uncertainty as to what the outcome was going to be.

I think there was a realization

that the airplane was going to be very badly damaged

and that there was a high likelihood of injury or worse.

Okay, let's start this sucker down.

NARRATOR: Flight 232 is 9,000 feet from the ground

and less than ten minutes from the airport,

but it's still traveling far too fast to land safely.

Instead of being at the normal 120-140 knot range,

they were well over 200 knots to be able to control the airplane.

This means that it is going to arrive with a whole lot more force.

It's gonna need a much, much greater distance to land

and equally, their margin for error now becomes extremely small.

Anybody got any ideas about putting the gear down?

I would.

NARRATOR: Lowering the landing gear will help slow the plane down.

Without hydraulics, the pilots have to release the gear manually

and hope that gravity locks it into place.

I hope that does it.

(METALLIC CREAKING)

NARRATOR: If the gear doesn't lock, the plane is doomed.

(LANDING GEAR THUMPS)

All green.

NARRATOR: The gear creates enough drag to slightly reduce the airspeed,

but the plane is still traveling almost 70 knots faster than it should be.

Okay, let's start it down now.

NARRATOR: The passengers try to prepare themselves

for what may be their final moments.

JERRY: The last three things I said to my wife were...

or last three words were I love you.

I thought things were in place for me not to survive this incident.

And then the last couple minutes, I started thinking to myself,

"You know what, just in case you're wrong,

you better get ready and form a game plan here."

So the last four or five minutes, I thought to myself,

"All right, if you hit the ground and you're dead or you're hurt seriously,

"you might not be able to help.

"But if you aren't, don't flee the plane.

"Don't panic, stay around,

stay under control and try to help other people as best I could."

NARRATOR: The plane is only 27 kilometers away from the airport.

Do you want this seat?

Yeah. Do you mind?

Okay.

NARRATOR: All the pilots will need to be securely strapped in

for the attempted landing.

Only a few kilometers away from the airport,

the crew must make another circle to the right to adjust their course.

Airport's down there. Got it.

I don't see it yet.

As soon as it starts down, back we go.

The concern then was how fast are we gonna hit the ground

and what's going to happen when we hit the ground.

When we hit the ground hard, let's hope it's not hard enough

to tear the airplane apart.

- Forward, forward, forward. - (ENGINES SPINNING UP)

NARRATOR: Without flaps, airspeed is the only thing keeping the plane in the air.

The pilots have no choice but to keep the engines at close to full power.

- Won't this be a fun landing? - (ALL CHUCKLE)

Hold the heading if you can.

That's fine.

NARRATOR: From an altitude of 37,000 feet,

the pilots have corkscrewed their way down to within sight of a runway.

Now, they have to get the plane on the ground.

The plane is descending to the runway at 1,600 feet per minute,

faster than the space shuttle comes in to land.

That's fine.

I got the runway. It's off to the right over there.

Over there.

NARRATOR: But the pilots can't slow their plane.

In fact, Fitch must increase engine speed to keep the nose up.

BILL: Bring it on down.

Oh, baby, ease her on down.

Tell 'em we're two minutes away from landing.

Two minutes away from landing, two minutes.

Your attitude is, "You will get this done, I will do this,

"I will do it, I will not accept failure,

"I will not accept anything less than the best

"and so even if I die, that's the way I die.

That's the way I'm gonna die."

232, you are cleared to land on any runway.

Oh, you want to make it particular and make it a runway, huh?

(ALL CHUCKLE)

I know that we're close enough now, coming in fast enough now

that we're gonna make the airport.

That was the main thing.

Whether we actually made the runway or not, uh, I don't know.

NARRATOR: The aircraft is still traveling much faster than normal,

but the crew cannot delay any longer.

This is their only shot at a landing.

- Get on the brakes with me. - Yeah.

NARRATOR: They will have only minimal braking power and reverse thrust

to stop the plane on the ground.

They won't be able to steer.

No pilot at the controls of a commercial jetliner

has ever landed a DC-10 safely at this speed,

with or without flight controls.

AL: Pull the power back.

That's right. Pull the left one back.

You could hear people crying and every once in a while,

you could hear people kind of scream a little bit.

And I remember at the end thinking,

"All right, there's nothing else I can do to get ready here.

Now, I just gotta see what happens, see what unfolds."

NARRATOR: The plane is 30 seconds from landing.

AL: Brace, brace, brace.

BILL: Had no idea what was gonna happen when we touched down.

We were going way too fast, we had no flaps, we had no brakes,

and we had no way to steer the airplane once we did arrive at the runway.

DENNY: At very bottom, I was hoping to do the pitch-up

by putting more power in, pulling the nose up,

causing the whole belly to become drag into the wind and slow us down

so that we would touch down on the landing gear

and then roll down the runway.

NARRATOR: Controllers can't bear to watch what's about to unfold.

(INDISTINCT RADIO CHATTER)

Only 100 feet from the ground, the nose dips again,

increasing its already dangerous speed.

The nose lowered and the airspeed began to build up again

and the right wing started to go down again,

and we couldn't have that. We had to try and get it level.

Close the throttles.

Close 'em off. Pull 'em all off.

I can't pull 'em off or we'll lose it.

That's what turning you.

And we both said, "Okay.

He's in charge of the throttles. Do whatever you have to do."

There had to be complete trust.

Okay, okay.

- (SIRENS WAILING) - (PLANE ENGINES WHIRRING)

Left! Roll it left, left, left, left!

We're turning, we're turning, we're turning.

(SIGHS)

(INHALES DEEPLY)

Didn't get it quite right, and, uh...

We hit very hard.

My head smashed on into the radio rack in front of me.

It's just like somebody had a giant hand on the back of my head

and just forced me face down into this rack.

We had hit just incredibly hard.

I don't think for all the thoughts about what it might be like

that I was ready for that impact.

I could feel the plane go upside down

and we slid upside down and backwards for what seemed like forever.

I remember looking out the window and saw it got blue for a split second.

Darkened again to brown and green.

And then more violence than I can put in words.

I had to take a couple of seconds to figure out

whether I was alive or not.

I figured if I'm feeling pain, I must be alive.

And then I realized what had happened. I realized we had flipped over.

I was hanging upside down in my chair.

I had no choice but to go back

because smoke was chasing us all to the back of the plane.

And I finally found an opening where we had broken off the tail section

and got out that way.

And I stepped out of the plane, realized I was in a corn field.

And I'd been in plenty of ‘em. That gave me some comfort.

I knew that at this point, I was probably in pretty good shape

and that I wasn't going to perish in that crash.

(BABY CRYING)

I took a couple of steps out of the plane

and I heard a baby crying back inside the wreckage.

And I didn't stand there and weigh the risks,

I didn't think it through, I just reacted to the sound.

The next think I remember, I'm back inside the wreckage.

- (BABY CRYING) - It's okay.

(SOFT MUSIC PLAYING)

(SHUDDERS) It's okay.

NARRATOR: Jerry Schemmel manages to find the child

and helps reunite her with her parents.

It's okay.

NARRATOR: But others are not so lucky.

The plane lies in pieces on the runway and in a cornfield.

There is no sign of the cockpit or the pilots.

On the initial viewing of the aircraft hitting the ground

and tumbling down the ground in a huge fireball and so on and so forth,

we didn't expect to find survivors.

NARRATOR: 45 minutes after the crash,

the cockpit is discovered 180 meters from the rest of the wreckage.

All four pilots have survived.

I was unconscious, fortunately.

I was knocked out on impact.

I have absolutely no recollection of the crash at all.

And then the next thing I heard is somebody say,

"Are there really four of you in there?" and I heard more than once voice say yes.

I knew at the time that I saw this fireman coming across the field that

I have been in a crash and I'm alive.

Had no idea what kind of shape I was in,

whether my legs were attached.

I had no... I couldn't move my fingers. I was just literally pinned to the ground.

I was compressed in the wreckage,

a white hot pain in my back and my side.

Broken ribs punctured the lung.

I never lost consciousness. I have complete recall of it all.

My time in the hospital, first night, almost died.

Subsequently, nine surgeries and 18 months of recovery.

NARRATOR: 111 passengers and crew are dead, including 11 children.

But 185 people have survived the fiery crash landing.

JOHN: The first feelings were

there are not likely to be any survivors out of this.

And yet, there were. There were a large number of survivors.

NARRATOR: The damage to the tail section confirms what the pilots reported.

The number two engine exploded in mid-flight.

Investigators need to know why

and how it led to the catastrophic loss of all hydraulics.

We already pretty well knew what we were looking for.

We knew we'd had an engine failure of horrific proportions.

We knew we'd had a hydraulic issue

that had depleted all three hydraulic systems.

NARRATOR: The NTSB's Bob Maclntosh is in charge of the team

dispatched to Sioux City.

The investigation focused fairly quickly on the shrapnel,

the trajectories of the various parts,

and how they could have disabled the airplane in the way that it did.

NARRATOR: It doesn't take investigators long to discover

that a vital piece of the engine is missing.

The fan disk is such an obvious part of the front of the engine

that when it's missing, you know it.

NARRATOR: The fan disk is one of the largest pieces of the engine.

It is responsible for bringing air into the core.

It's around almost 400 pounds. It's about 32 inches in diameter.

That was missing.

And we knew that it was going to be our job to find that

because that was the destructive force that had brought this airplane down.

NARRATOR: Since the accident involved the failure of such a key component,

metallurgists joined the NTSB to help find the cause.

The rotating parts in the engines of jet airplanes

have to withstand a lot of stress,

so you want to use material that optimizes the strength

while minimizing the weight.

So at the front of the engine, the fan disk, for example,

they use titanium alloys.

NARRATOR: Jet engines are extremely reliable.

To have a fan disk break off is almost unheard of.

The failure of a major rotating part of any kind,

whether it be at the front end or anywhere in the engine,

is a major event.

NARRATOR: Before they can understand this rare failure,

investigators must find the missing fan blade assembly.

The clue to solving the mystery behind the crash

is likely lying in a farmer's field somewhere in Iowa.

A massive search gets underway.

BOB: It was extremely frustrating to us

because we knew we didn't have it

and we knew it was gonna be a pretty tough job to find it.

We were motivated to find it, but we knew it was going to be tough.

Al, I can't control the airplane.

NARRATOR: Meanwhile, investigators turn their attention to the plane's hydraulics,

wondering how a system with triple redundancy could have failed.

BOB: In theory,

if you lose an engine, you lose one of the systems.

Our challenge recognizing that the number two engine

was the origin of the problem

was to try and figure out why all three hydraulic systems had failed.

NARRATOR: Each of the three hydraulic systems

is powered by one of the three engines.

Since only one engine failed,

two hydraulic systems should have kept working.

Investigators examine the wreckage around the number two engine.

They begin to see what might have happened.

BOB: There was a place where all three hydraulic systems

were getting together and that was in the horizontal stabilizer

to actuate the elevators for up and down control.

NARRATOR: All three of the plane's hydraulic lines

concentrate at the back of the plane below the rear engine.

The number two system was destroyed when the fan disk blew apart.

Exploding shrapnel damaged the two remaining systems.

All the hydraulic lines were either punctured or severed.

The plane essentially bled to death.

So we were able to understand how an engine failure in number two

would result in number one and number three

being rendered inoperative.

Left! Roll it left, left, left, left, left,

left, left, left, left, left, left, left, left!

NARRATOR: Now that investigators know how much damage

the broken fan disk caused,

it's all the more urgent to figure out why it failed.

They must find the broken piece.

A $50,000 reward is offered to anyone who can find it.

NARRATOR: Three months after United Flight 232 crash-landed

in Sioux City, Iowa, a farmer finds the crucial piece of the puzzle

lying in her field about 100 kilometers from the airport.

This is the hole I came upon in the combine.

And the combine... there was resistance.

I backed up and I thought, "Oh! My gosh, this is it!"

The lady who found the fan disk was our hero of the day.

This was an extremely important piece of evidence.

NARRATOR: The massive disk is broken into two pieces.

How could it break like that?

It was extremely unusual and we really wanted to

try and figure out why this thing had, what we call, burst.

NARRATOR: The titanium alloy used

to make this vital part is extremely strong and resilient.

It shouldn't just snap in two.

Take a look at this.

When you first see the disk broken,

it's almost unimaginable to see how something so large

could break into two big pieces.

It didn't happen overnight.

NARRATOR: A close examination of the broken part

reveals surprising evidence of why it fractured.

It's definitely fatigue.

It was pretty easy to visually... to look at this

to see that there was a fatigue crack there.

The investigation then continued to see

where did the fatigue crack initiate?

Can you cut me a small section? From here.

NARRATOR: Investigators need to know what had weakened this powerful alloy.

They trace the fracture back to where it began

and remove the section for testing.

Well, well, well.

NARRATOR: They find elements that should not be in the metal,

nitrogen and oxygen mixed in with the titanium.

Nitrogen and other elements such as oxygen,

if they are present in the titanium alloy, cause an increase in brittleness

so that when you load this area, it'll crack very, very easily.

- A bad batch of titanium? - I'd say so.

NARRATOR: Investigators conclude that a microscopic imperfection

in the titanium used to make the fan blade caused a crack

that developed slowly over 17 years.

BOB: It kept progressively getting bigger and bigger

each time the engine started and stopped.

NARRATOR: It was only a matter of time before the disk finally broke.

- I have it. - What was that?

NARRATOR: And disaster occurred.

This part was supposed to be inspected on a regular basis

and indeed it was, but where the crack was located

simply was extremely difficult to detect.

NARRATOR: The NTSB immediately recommends

more thorough inspections of all engine fan disks.

Titanium is now melted three times in a vacuum to remove impurities.

Any kind of oxygen and nitrogen that might be in the material

is sucked out into the vacuum and drawn out.

NARRATOR: The DC-10's hydraulic system also gets an upgrade.

Designers add a series of valves

so that a line can be sealed in case of a rupture.

Every accident is a learning experience.

And Sioux City, although it was several decades ago,

continues to be a learning experience.

NARRATOR: Despite the loss of life, the pilots' actions during the disaster

are hailed as a magnificent feat of flying.

I think it surprised some, the survivors, that they had made it,

but it was a testament to the skill of the crew

and the ruggedness of the airplane.

We have no hydraulic fluid left. All systems are down to zero.

That's impossible.

Once they lost the third hydraulic system,

they were in an uncharted area

with no checklist and having to improvise it.

Let's use the engines.

It was a catastrophic event

that they made to turn out reasonably well.

Tell me what you want and I'll help you.

Take the throttles.

NARRATOR: Captain Haynes' decision to accept an offer of help

in the moment of crisis is what many believe

saved the lives of 185 people.

Okay.

For Al Haynes to give a perfect stranger

the only thing controlling his airplane,

and I think he knew clearly at this point that was all that was there,

I think is a phenomenal feat.

And I can't give enough kudos to him for that.

NARRATOR: All four pilots received the Polaris Award.

It's the highest civilian aviation decoration

awarded for exceptional airmanship and heroic actions.

We got the airplane to the runway.

That's the most we could hope for,

even more than most people thought we could hope for.

And to say that we were heroes in doing that? No, no.

We were just fortunate that the things we tried worked.

I was willing to give up my life.

No, I mean that's not being heroic.

I mean I was willing to give up my life

because to me, that's my responsibility as an airline captain.

You trust me. I don't want to fail that trust.

NARRATOR: Al Haynes and Bill Records were back in the cockpit

within a year of the accident.

For Denny Fitch, it took a bit more time.

Doctors...

God love 'em, they fixed me,

but they didn't believe I'd ever make the captain seat again.

They didn't think I'd ever be able to fly.

I think it was 16 or 18 months later. It was Flight 187 to Honolulu.

And if you'd been in the cabin, you would have heard this announcement,

"Today in command of your flight is Captain Denny Fitch."

Never give up.