Original subtitles

Stabilizer motion.

Help me back.

Okay.

The pilots of Alaska Airlines,

flight 261, wrestle with an M.D. 83 nosediving

toward the Pacific Ocean.

We got it under control, here.

No, we don't.

The airplane pitched down and rolled.

Mayday!

It actually gets inverted, upside down.

Amazingly, the pilots managed

to keep the aircraft flying.

This is like an air show maneuver.

Speed brakes.

Just seconds from impact, the pilots

right their aircraft.

They had one shot to save the plane,

are all would be lost.

Here we go!

Mayday, mayday!

Alaska Airlines, flight 261, takes flight.

Climbing into sunny skies over Puerto Vallarta, Mexico.

You're up.

Gears' up.

Captain Ted Thompson is an Air Force veteran.

He's flown with Alaska Airlines for 17 years.

Thank you, sir.

First Officer Bill Tansky has been

flying for almost four decades.

He's the one flying, today.

The pilots on 261

were highly regarded by their fellow pilots

these were really top notch aviators

Flaps up

Flaps.

The M.D. 83 is flying North to San Francisco,

for a stopover.

From there, it's a short hop to its final destination,

Seattle, Washington.

Three flight attendants tend to the 83 passengers on board.

Fifteen minutes after takeoff

That's strange.

The pilots become aware of a problem.

Planes out a trim.

Trim refers to small adjustments

to the horizontal stabilizer that maintains

the pitch of the aircraft.

When that light goes on, it tells the crew

you're going to have a problem adjusting the nose up or down,

which is of course, crucial for flight.

The Warning light indicates

the horizontal stabilizer is jammed,

pushing the nose down slightly.

Let's check this out.

Autopilot off.

Good idea.

-Whoa. -What's it doing?

It's pushing down.

First Officer Tansky uses all his physical strength

to keep the plane's nose on.

The first officer is hand flying the airplane.

So he's manually got his hands on the control yoke.

And increasingly, there's more and more pressure

that he's having to hold.

He's using a lot of arm muscle.

So this is something that they want to fix.

Yeah, well we're still climbing, that's good.

Let's get to 3-1-0 Let's figure this out.

By pulling back on the control column,

the pilots can deflect the plane's

elevators enough to enable the aircraft to continue climbing.

Twenty minutes after takeoff,

flight 261 levels off at 31,000 feet.

Manual says to try the pickle switch.

Pickle switches are literally just

a little toggle switch on the control column.

And it moves the horizontal stabilizer,

such that it will push the nose up or down.

Controls in the cockpit activated

a two foot jack screw in the tail.

As the Jack screw turns,

it moves the stabilizer up or down.

They were having to go through the manuals,

and they were asking each other, "What do you know?

What can we do? What can we try?"

Nothing, why don't you try.

Captain Thompson tries to activate

the horizontal stabilizer, using what pilots call,

the suitcase handles.

No dice.

It's like trying to start your car.

They were trying everything they could think of

to get their plane to respond.

Let's try it on autopilot.

They hope the autopilot

can keep the plane level.

The plane is steady.

I'm thinking we get this plane on the ground sooner,

rather than later.

Yep, maybe LAX?

Call dispatch.

If you have a control problem,

you have to get that plane on the ground.

Dispatch 261, requesting a diversion to LAX.

Are longitudinal trim system is inoperative.

Captain Thompson contacts Alaska Airlines

flight dispatcher, in Seattle.

Dispatch 261, copy that.

If you want to land in LA, for safety reasons

we'll be looking at over an hour delay

because of a flow problem right now.

I didn't really want to hear about the flow,

I'm concerned about suitable airports.

Do you have a wind at LAX?

It's two, six, zero, at nine.

The pilots compare the wind conditions

at Los Angeles and San Francisco airports.

The pilots on this flight took such care considering

all their options on runways.

There's a headwind at LAX,

but at San Francisco, there's a crosswind.

Two six at nine versus a direct crosswind,

for safety reasons, I think...

something that lowers the ground speed makes sense.

The headwind at LAX

will help make it a safer landing.

Once you're lined up for the LAX runway,

you've got perfect winds

coming right at your nose.

It blows off the Pacific Ocean,

it's predictable, it's constant,

and it slows down your plane.

You the guys with the horizontal situation?

Ten minutes after rerouting,

a mechanic at Alaska Airlines maintenance facility

in Los Angeles contacts the crew.

Yeah, affirmative.

The maintenance facility can talk directly to the pilots

to provide them the expertise on the problem

that they're dealing with.

Did you try the suitcase and pickle switches?

Yeah, we tried just about everything.

If you've got any hidden circuit breakers,

we'd love to know about them.

Yeah, I'll look into the circuit breaker guide,

as a double check.

And the alternates in operative two, huh?

Yep, our horizontal stabilizer appears

to be jammed, the whole thing.

Okay, Thank you, sir.

I'll see you when you get to LAX.

The response from Alaska Airlines maintenance

was basically no response, at all.

They provided them no help.

Really, the most they ever said to them,

did you try the pickle switches and the suitcase handles?

Which is one of the first things that they did.

All right, let's, uh,

let's try the pickle switches, again.

You got it?

The captain is warning the first officer, as a reminder,

when we click the autopilot off, be ready,

because it's going to require

a lot of effort from you, right then.

Yeah, so click the autopilot off.

Stabilizer motion,

stabilizer motion.

The nose of the plane drops,

far more than the pilots anticipated.

Holy crap.

The airplane is pitched down, significantly.

And the air frame is shaking, violently.

They know something is very, desperately,

wrong with the airplane.

The problem is suddenly, much worse.

Flight 261 begins to nosedive.

What are you doing?

It got worse.

They have to get the nose back up,

or they'll have an unarrested descent

all the way to the ocean.

Help me back.

Help me back.

Okay.

The crew of Alaska Airlines, flight 261,

struggles to regain control of their M.D. 83.

They pulled back on the control yoke,

holding a lot of force.

Center Alaska, 261,

we are in a dive, here.

I've lost control of vertical pitch.

Alaska 261, say again, sir.

We are in a vertical dive, at 26,000.

They are now three minutes from impact.

Speed brakes!

The pilots deploy the speed brakes,

control surfaces on the wings of the plane,

that increase drag.

And he wanted to slow the plane down,

and it would also give them more of a chance, physically,

to pull the plane out of the dive.

The speed brakes arrest the dive.

Using all their strength,

the pilots bring the aircraft

back under control at 24,000 feet.

All right, once we get this speed slowed,

maybe we'll be okay.

In 80 seconds,

the plane has dropped 8,000 feet.

The pilots pulled out of the dive

with pure, brute force.

I got it back

under control, here.

No, we don't.

Even though they've managed

to pull out of the dive, it requires extreme effort

to keep the nose of the plane level.

Okay, it really wants to pitch down.

They're really having to work, physically,

at holding the nose up on this jet.

They're in a fight for control of the airplane.

It's a lot worse than it was.

Yeah, we are in much worse shape, now.

This is a very experienced crew,

these aviators have had problems in flights before,

but nothing like this.

Maintenance 261, are you on?

Twenty two miles from Los Angeles,

Captain Thompson updates Alaska Airlines maintenance,

hoping hope advice on how to land, safely.

Yeah, 261, this is maintenance.

Yeah, we've tried both the pickle switch

on the suitcase handles, and it ran away, full nose trim down.

Oh, it ran away full trim?

And now we're worse than we were.

He's explaining that when he commanded

"nose up trim,"

the trim system moved nose down,

moved in opposite direction of the way he commanded it.

And it did so very quickly,

and it did so with a lot of force.

And you're getting full nose trim down,

and no nose trim up, correct?

That's affirmative.

We went full nose down.

And now I'm afraid to try it again

to see if we can get it to go back in the other direction.

He is reluctant to try to move it again,

for the concern that if it gets worse yet,

that they could lose control of the airplane, entirely.

If you want to try it, that's okay with me.

If not, that's fine,

see you at the gate.

After the maintenance base, at LAX, said,

"Oh, we'll see you at the gate,"

the pilots knew they were on their own.

All they had left was, they had themselves,

their physical strength, and their wits.

To land the plane, the pilots need to figure out

how to control their descent,

without using the plane's trim system.

You want to try the trim switch again, or not?

Uh...

No. I don't know.

It's up to you, man.

They're literally test pilots,

and they're having to utilize decades of experience

to try to work their way through to a solution.

We better talk to the people back there.

Yeah, I know.

Captain Thompson

tries to reassure the passengers.

Folks, we've had a flight control problem.

We're intending to go to Los Angeles.

We're working on it, and I don't anticipate

any problems once we get a couple

systems back on the line.

With Los Angeles in sight,

the pilots prepare for an emergency landing.

You try flaps, 15, 11?

Let's go to 11.

The pilots test the plane

in a landing configuration.

Okay, we're pretty stable, here.

But we got to get down to 180 knots.

The jet is very badly damaged,

and they need to understand

and find a way to control the pitch of the jet,

all the way through the landing.

If it's controllable, we ought to just try and land it.

First Officer Tansky suggests a risky,

high speed landing.

Okay, let's head for LA.

Their predicament was dire.

They would not be able to pull the plane up,

and do a go around.

The only chance they had was one shot

to get it on the ground, or all would be lost.

But as soon as they come up with a plan...

Do you feel that?

Yeah.

...the pilots hear thumps

at the back of the plane,

then disaster strikes.

The airplane pitched down in roll,

they know that they are in a life threatening situation.

This is a pilot's nightmare.

You're running out of time,

if they do not control the jet very quickly,

they'll lose the airplane.

Mayday!

Push and roll!

Push and roll!

18,000 feet above the Pacific Ocean,

flight 261 rolls left, and goes into a dive.

And this is like an air show maneuver.

The Blue Angels do this, the Thunderbirds do this.

Dropping at 160 feet per second,

time is running out.

Okay, we are inverted,

now we got to get it up.

When the airplane was inverted,

this is a very difficult situation,

because they've got to try to determine

if they can maintain control of it

and get the airplane back, right side up.

The plane starts responding.

They're pushed on the control column to prevent

the possibility of the stall.

And then they roll the airplane toward wings level,

in an attempt to maintain control of it.

Push the blue side up.

The top side of an attitude indicator is blue,

like the sky.

And so, they need to get the blue side

of the attitude indicator, back on the top.

On the ground,

LAX controllers have lost contact with flight 261.

SkyWest 5154, traffic at your one o'clock, is Alaska M.D. 80.

Do you see him up there?

They look for help from other pilots.

Yes, sir.

Definitely in a nose down position.

Descending quite rapidly, he's inverted.

Okay, keep your eye on them.

Alaska 261, are you with us yet, sir?

13,000 feet over the ocean,

the pilot's efforts seem to pay off.

The plane's nose starts to rise,

but it's still inverted.

Okay, let's kick rudder.

Left rudder, left rudder.

The pilots are, kind of, hanging upside down like bats.

And it was very difficult to reach the rudder pedal.

-Left rudder! -I can't reach it.

-Okay, right rudder. -Right rudder!

There one hope is if they could kick that rudder,

they could flip the pain back over.

Okay,

we got to get it over, again.

At least upside down, we're flying.

As the pilots fight to get the plane

the right way up,

the engines on flight 261 fail.

There was a disruption in the airflow into the engines

and it caused a loss of thrust.

Speed brakes!

Got it.

Their demeanor was determined, collected,

they were giving everything they had.

The windscreens full of the ocean,

they're not going to solve this.

Here we go!

He's hit the water, he's down.

Search and rescue helicopters

are immediately dispatched from Coast Guard stations.

Search teams find debris, floating 2.7 miles North

of Anacapa Island,

off the coast of California.

In addition to pieces of the plane,

searchers are finding personal effects,

a shoe, a passport, a postcard.

Aviation safety advocate, Mary Schiavo,

represents the families of six passengers from flight 261.

I remember this person's possessions,

all the pictures were still in the wallet,

in the pants pocket.

Except for the picture of his wife.

And so, we knew, by that,

and by how they found things, that he had been clutching.

That was really important to her.

Rescuers search for survivors throughout the night,

none are found.

All 88 passengers and crew on board flight 261,

are dead.

It's a terrible, tragic thing, of course.

But, you know, we have a real well,

established procedure here for how

these tragedies are handled.

Investigators from the NTSB,

the National Transportation Safety Board,

are assigned to find an explanation for the crash.

LAX maintenance is saying the pilots

reported a jam stabilizer.

NTSB systems investigator, Jeff Guzzetti,

joins the investigation.

We knew quite a lot, just from the transmissions

between the flight crew and Los Angeles.

Maybe they had a mechanical problem.

It looks like they tried both switches, no luck.

The plane pitched, full for nose trim down.

We immediately began to research

the horizontal stabilizer trim system,

to see how it was designed, how it functioned,

and how the crew operated it, normally.

The leading edge of the horizontal stabilizer

is raised or lowered by a jacks screw.

When activated, it moves up or down through an acme nut,

changing the angle of the horizontal stabilizer.

We need to see the jack screw assembly.

Let's hope it's all in one piece.

Investigators wonder how the horizontal trim system

could have failed.

I'll get this to the Navy.

Recovering parts of the stabilizer system

could give investigators important clues.

But the wreckage field lies on the bottom of the ocean,

at a depth of 700 feet,

well beyond the reach of scuba divers.

We were able to tell the Navy what to look for,

what the high priority targets were.

US Navy crews use side scan sonar

to pinpoint the location of the wreckage.

Remotely operated vehicles equipped with robotic arms

are used to recover pieces of flight 261.

The Black boxes are retrieved two days after the crash.

Nine days into the investigation,

essential parts of the horizontal stabilizer

are also recovered.

We got the jack screw.

And with the brainpower we had, that we had a fighting chance

to find out exactly what went wrong, during this flight.

What's this stuff?

Investigators wonder if recovered parts

from the horizontal stabilizer of flight 261

can provide clues about why it failed.

It's some kind of metal.

What they see is puzzling.

We saw this, this little, thin piece of metal,

that we thought looked like a slinky.

That really struck us is something very odd.

Why isn't the nut attached to the jack screw?

Normally, the lower end of the jack screw

is threaded through an acme nut.

When we looked at that, and the jack screw

wasn't part of the acme nut,

we asked ourselves, "How can that happen?"

That really just blew our mind.

The jack screw and the acme were found a few feet apart.

They must have separated mid-flight.

Threads an 1/8 of an inch thick, inside the nut,

should hold it securely to the jack screw.

Look at this.

There's something unusual about the nut.

Incredible.

It's completely stripped.

When we finally looked inside the acme nut,

it revealed that there were no threads inside of it.

Let's talk to metallurgy.

It was shocking and stunning to us

to see something like this.

No one thought that you could get

those thick threads to rip out.

Interesting.

Metallurgist, Joe Epperson,

examines the stripped nut and the jack screw.

It became immediately apparent

that what we were looking at

was actually the remainder of the threads

that were inside the nut.

Looks like the jack screw stripped

the threads of the acme nut.

The next step in the process was to figure out

how the threads were reduced

to such an extreme degree,

and then stripped out of the nut.

There's some grease here, on the bottom.

The team studies residue

observable on the jack screw.

The way to prevent wear is by lubrication,

with grease,

and in the case of an extreme wear event,

you want to look at,

is there grease where it's supposed to be?

And there's some, here, at the top.

In flight,

the jack screw rotates inside the nut.

To prevent wear, it needs to be lubricated regularly.

There should be more grease, here in the middle.

That's the working area where it rotates the most.

When we first looked at the jack screw,

there was very minimal signs

that there was any grease on it, at all.

It was in the ocean for a week,

did the water wash the grease away?

No, I don't think so.

Grease doesn't wash off that easily.

There's still some remnants here,

but none in the middle.

We did find a little bit of a remnant of a grease,

at the very upper end.

And at the very lower end.

It was very easy to conclude that being in the ocean

had not washed away the grease from the working area of

of the jack screw.

How could it be that there so little grease

on this jack screw?

Grease goes through here, during the lubrication process.

During maintenance,

grease is applied to the interior of the nut,

through a small valve called a Zerk fitting.

So the Zerk fitting is this fitting, right here.

And what mechanics have to do is

put a grease gun hose in here,

and then squirt grease into this little grease fitting

that goes inside this passage.

So that Zerk fitting should have preserved

and kept the remnants of whatever grease it saw, last.

What's that?

It's packed with dried grease.

I've been around grease long enough to know

that if you don't replenish it,

and if you just leave it,

eventually it dries up and gets hard,

and it basically says

that it had not been replenished.

How long has it been clogged like this?

At least a year, maybe more.

Finding this blockage suggests long term abuse to the grease.

I'd say we have a maintenance issue, here.

Time to talk to the airline.

We were very suspicious

about how well

this component was lubricated.

Or whether it was lubricated, at all.

And so, we had our doubts as to whether or not

this component was being properly

maintained by the airline.

NTSB investigators travel

to the Alaska Airlines operation facility,

in San Francisco.

You worked on the plane in September 1999, that true?

Yes, I did.

They tracked down the mechanic

who was responsible for the last lubrication

of the jack screw assembly,

four months before the accident.

Could you walk us through how you lubricate

the jack screw assembly?

I'll tell you this, it's not my favorite job.

The team learns that jack screw lubrication are done

most often on the night shift, outside the hangar,

sometimes in the rain.

You're working off high lift trucks,

which will sometimes move with a gust of wind,

the airplane moves with a gust of wind,

you're up and 30 feet off the ground,

some mechanics don't like that job.

They're not stable up there.

To reach the jack screw assembly,

remove a panel first.

How do you apply the grease?

I use the paint brush, sometimes I put a big glob in my hand

to make sure it's on there.

Aircraft, especially large aircraft, need grease.

They need to have lubricants,

and it's messy.

The most effective way

is to fill your hand with grease

and actually move it up and down on the jack screw,

filling all the screw grooves,

filling them with grease.

What about greasing the acme nut?

Investigators focus on how the mechanic greased

the acme nut on the jack screw.

We use a grease gun to the Zerk fitting.

And you pump grease in,

until you see fresh grease coming out.

Well, how do you know whether the lubrication

is being done properly and when to stop

pumping the grease gun?

I don't.

Would you be able to see the grease

coming out from the top of the acme nut during lubrication?

No, I can't remember looking to see if there was.

One of the first things that tells me,

is that he couldn't have known that Zerk fitting

has taken grease.

You have no idea that it's clogged.

So we found a variety of ways in which mechanics

lubricated this component.

And that gave us some pause,

because it's a very critical component,

and if you don't lubricate it properly,

you could end up with an accident

like the one that just happened.

The team discovers that the methods Air Alaska

mechanics used to lubricate the jack screw assembly,

don't follow maintenance standards.

The last time the jack screw was lubricated

was about four months before the accident.

But it's not just the way that jack screw assembly

is being lubricated that bothers investigators,

it's also the frequency.

And before that?

January 1999.

They're doing it every...

...2,500 hours.

They can see there's a long period

between lubrications.

Is that even within regulations?

I'll find out.

We knew we had, kind of,

a research project on our hands.

Some of the documents that we requested

from the manufacturer, from the FAA, from the airline,

came in the form of Internal memorandums

from engineering departments

or requests from maintenance

to extend an interval.

It really began to paint a picture

of how the lubrication intervals were extended.

Check that out.

The airline made multiple requests

to extend the intervals on the lubrications.

In 1987,

the interval between lubrications

it was 500 hours.

The intervals between lubrication

are measured by the number of hours the plane is in the air.

In 1991,

it goes up to 1,200 hours.

By 1996,

increases all the way up

to 2,500 hours.

They just continued to extend, extend, extend.

Approved by the FAA?

Yeah, every one of them was approved.

Investigators conclude

that the lubrication of jack screws

was not only conducted poorly,

it was also performed less and less frequently.

If you're going to extend these lubrication functions,

then you better be doing something

to make sure that what you're doing is correct.

But even if the lubrication, wasn't being done properly

regular inspections should have caught

the wear on that acme nut.

True, they should have inspected it regularly.

Was the jack screw assembly on flight 261,

inspected when and how it should have been?

We looked at the maintenance records for information

about the last check.

I've got something.

Investigators dig deeper into the records

of flight 261,

to find out how the jack screw assembly was inspected.

Yeah, this doesn't look right to me.

The team finds paperwork,

which reveals that during a routine inspection,

a mechanic at the airline's Oakland facility

observed that the acme nut was badly worn.

You're sure the reading is 0.040?

A mechanic who did that wear check,

reported that he found it to be at the limit.

This nut was wearing fast and something needed to be done.

The lead mechanic ordered the nut to be replaced.

This was evidence that someone had caught

the fact that this acme nut was worn out.

Most airlines, the decision would be,

we will get the piece to the airplane as soon as possible

and replace it.

But the entry is crossed out.

I don't get it.

Well when we saw that they had

crossed out the first entry,

it was very suspicious.

Something was up.

It was fishy to us.

We have to find out what went on, here.

Do you remember inspecting an M.D. 83 on September 27, 1997?

I remember it well.

Investigators contact John Liotine.

the lead mechanic who reported the worn acme nut

on flight 261.

I wrote up the evaluation,

the nut is worn down, replace it.

It was an alarming discovery,

in order for that aircraft to be safe to fly,

that nut assembly, at the very least,

must be replaced.

There is no doubt in my mind.

It was the end of my shift.

When I came back the next work day,

the plane was closed up.

The plane returned to service with the worn nut.

If the nut had been replaced,

the plane would still be flying,

and 88 people would still be alive.

How could a maintenance facility allow the airplane

to be put back into Revenue Service

with the wear

that it found on the acme nut?

When investigators probed further,

they learn that the amount of wear on the acme nut

was rechecked by other mechanics.

They determined that it was just within minimum limits.

Alaska Airlines maintenance misses a warning sign.

The wear on the nut should, at least, have been monitored,

but it wasn't.

The next time that jack screw was looked at

was in the NTSB laboratory.

The plane flew with the worn nut

for two more years, before it took off from Puerto Vallarta,

on the day of the accident.

You're up.

First Officer Tansky and Captain Thompson,

had no idea that their stabilizer

was on the verge of failure.

That's strange, the planes' out of trim.

The team turns to the voice recorder

to find out how the devastating chain of events

unfolded on board flight 261.

Let's check this out.

Autopilot off?

Good idea.

Whoa.

13 minutes after takeoff from Puerto Vallarta,

the worn threads in the acme nut

caused the jack screw to jam,

preventing movement of the horizontal stabilizer.

I'll try it, again.

The captain's trying to rectify the jam stabilizer.

While cruising at 31,000 feet,

the CVR picks up a sound of a click,

followed by a thump.

We think that the pilot was moving his thumb switch

on his yoke, in an attempt to move

the jack screw through the nut.

The threads finally give way,

and the jammed jack screw pulls up through the nut,

causing the stabilizer to move upwards,

a stopper is all that prevents it from separating, completely.

It got worse.

With the horizontal stabilizer

pushing the nose further down, the plane goes into a dive.

Through sheer brute force,

the pilots hold the jack screw in place,

and recover the plane.

Okay it really wants to pitch down.

- - You feel that?

Stop. Let's hear that again.

But eight minutes later,

there's another series of thumps.

Do you feel that?

The stopper holding the jack screw in place,

finally gives out.

Push and roll!

The damage to the stabilizer makes

flight 261 uncontrollable.

The plane rolls over and dives toward the ocean.

Push, push, push, push the blue side up.

Flying upside down, the crew makes a last ditch

attempt to right their plane.

Speed brakes!

Got it.

The pilots of flight 261

give everything they have to save the plane.

It was just total, professional, fighting

for that plane till the very end.

And they express the realization

that the fight was over.

Here we go!

I was sickened by what I listened on the CVR.

This accident could have been prevented.

They grease that jack screw,

this doesn't happen.

The amount of money,

that would have saved these lives,

it's a cup of coffee.

It's, literally, a few dollars of grease.

I still get angry about it.

In the wake of the accident,

the intervals between jack screw lubrication

at Alaska Airlines is reduced from 2,500 hours,

to 650 hours.

We lost 88 people

because of lack of lubrication.

This is a maintenance accident,

pure and simple.

It is truly a tragedy.

It was just one of those cases that you work on,

that's never going to leave you.

Not ever.

It was tough.