Original subtitles

NARRATOR: At one of the busiest airfields on Earth...

CPT. HASLER: Okay. He's clear. Let's get going.

NARRATOR: ...a 747 cargo plane

is transporting a load of military equipment.

Within seconds, things go horribly wrong.

CPT. HASLER: Get the nose down!

FO. BROKAW: I'm trying!

STEVEN: It completely foundered and stalled.

I remember thinking he's lost all his engines.

NARRATOR: The accident is caught on camera.

TIM: Holy cow. There it is.

NARRATOR: Leading investigators

to what seems like an obvious conclusion.

TIM: Looks like a problem with the cargo load.

TIM: We really thought that we had the cause of the accident.

But later we found out there was more to the story.

NARRATOR: It takes one piece of overlooked evidence

to tell investigators they were wrong.

Flight attendant: LADIES AND GENTLEMEN, WE ARE STARTING OUR APPROACH.

Pilot: WE LOST BOTH ENGINES!

Flight attendant: PUT THE MASK OVER YOUR NOSE.

EMERGENCY DESCENT.

Pilot: MAYDAY, MAYDAY.

Flight attendant: BRACE FOR IMPACT!

Controller: I THINK I LOST ONE.

Man: INVESTIGATION STARTING INTO THIS TRAGEDY...

Man: HE'S GONNA CRASH!

♪

NARRATOR: Bagram Airfield in northeastern Afghanistan.

It's a hive of activity.

FO. BROKAW: Bagram ground, ISAF nine-five-alpha-Quebec

ready to taxi.

NARRATOR: The crew of National Airlines Flight 102

is on the last leg of a grueling shift.

FO. BROKAW: The air is just billowing outta here.

CPT. HASLER: Yeah. Sure is.

NARRATOR: They're flying cargo in a converted Boeing 747

and are parked on the tarmac waiting to depart.

CPT. HASLER: Please tell the flight attendant

I'm ready for my lobster dinner.

FO. BROKAW: I think she's in First Class

handing out caviar at the moment.

DON: Joking and humor among air crews

is probably more prevalent in times of stress

when you get into these off-line unusual situations.

NARRATOR: The crew members are all American.

Captain Brad Hasler is heading home to his pregnant wife.

Beside him is First Officer Jamie Brokaw.

Augment Captain Jeremy Lipka is in the jump seat.

CPT. HASLER: Is Sheets back there? I haven't seen him.

I hope he's in the back.

AC. LIPKA: Yeah, he's back there.

NARRATOR: In a cabin behind the cockpit

is loadmaster Michael Sheets, along with two technicians

and an augment first officer.

With the additional pilots, the plane can be flown

long distances non-stop.

NARRATOR: The crew members are all civilians

on contract for the US Department of Defense.

The United States military and its allies

built more than fifty bases across Afghanistan

during the war there. Bagram was by far the biggest.

STEVEN: It's got gyms and seven dining facilities

of enormous sizes. It's got stores. It had a Burger King.

NARRATOR: At its peak, more than 40,000 people lived here.

Now, after twelve years of fighting,

the military is scaling back their operation.

Troops, weapons and heavy machinery are all on the move.

Every day, air traffic control handles several hundred flights

coming in and out of the airport.

Today, National Airlines Flight 102 is just one piece

of a hugely complex puzzle.

♪

The flight plan has taken it from Chateauroux, France,

to Camp Bastion, Afghanistan, where the crew loaded up

207,000 pounds of cargo.

They were supposed to take it straight to Dubai

but were rerouted via Bagram.

The crew has been waiting more than an hour to depart.

AIR TRAFFIC CONTROLLER: Five Alpha Quebec,

I have your clearance. Advise when ready to copy.

CPT. HASLER: Yeah, let's do it.

NARRATOR: Finally, they get clearance to go.

FO. BROKAW: Ready to copy, Nine Five Alpha Quebec.

AIR TRAFFIC CONTROLLER: Nine Five Alpha Quebec,

taxi to runway three.

NARRATOR: Controllers need to keep a sharp eye

on the crowded taxiway that the 747 freighter shares

with other military aircraft.

AIR TRAFFIC CONTROLLER: Nine Five Alpha Quebec,

give way to the C-17.

CPT. HASLER: Let him go first.

FO. BROKAW: Roger. We'll let him go first.

NARRATOR: A C-17 military cargo plane moves to the runway

ahead of them.

Although the military effort is winding down in Afghanistan,

this is not the kind of place a civilian wants to linger.

Bagram is still a favorite target of the Taliban.

STEVEN: It's a dangerous place. I mean, it's not JFK airport.

It's JFK airport surrounded by terrorists.

NARRATOR: For the crew of Flight 102,

every delay means more risk.

CPT. HASLER: Okay, he's clear. Let's get going.

FO. BROKAW: Following the C-17 for Nine Five Alpha Quebec.

♪

Before-takeoff checklist. Flaps?

CPT. HASLER: Ten, ten, checked.

DON: You're certainly thinking:

What do I do if somebody started firing at us on the ground?

Well, that's a great deal of mental pressure.

NARRATOR: The C-17 ahead has cleared the runway.

CPT. HASLER: How are we looking on that wing?

Everything look clear?

FO. BROKAW: Everything's great.

CPT. HASLER: We all happy with that?

FO. BROKAW: Yeah, I'm good.

NARRATOR: They must now wait for takeoff clearance.

They've been on duty for more than twenty straight hours.

Once in Dubai, they'll get a rest break.

CPT. HASLER: We earned it as far as I'm concerned, man.

Without minimum rest, I'd be dead tomorrow.

FO. BROKAW: I think I'd have to agree with that sentiment.

DON: It's a real stress situation.

They were rightfully ready for their day to be over.

NARRATOR: Finally, at 3:25 pm, they are cleared for takeoff.

AIR TRAFFIC CONTROLLER: Nine Five Alpha Quebec,

runway three full length.

CPT. HASLER: Runway three is verified.

FO. BROKAW: Prepare for departure.

NARRATOR: The first officer is at the controls

for this final leg.

They're scheduled to arrive in Dubai in two and a half hours.

DON: When you've been in a long delay situation, when

you finally get the clearance to go,

it's a great relief.

NARRATOR: At that same moment,

military journalist Steven Hartov

is on the base's perimeter road, returning from

a day's work taking photographs for a magazine.

STEVEN: We decided we were gonna go get something to eat

and I saw off to the left of the truck

a white and purple 747.

And I remember thinking, this is a beautiful airplane,

because it looked brand new.

CPT. HASLER: V-1. Rotate.

Positive climb.

FO. BROKAW: Gear up. CPT. HASLER: Gear up.

STEVEN: He pulled away from us and started to rotate

and in this case there was something immediately not right.

NARRATOR: The climb is unusually steep.

STEVEN: What's going on with that aircraft?

STEVEN: It was almost stuttering in the air.

And I immediately said to Chris,

what's going on with that aircraft? Is he taking fire?

♪

CPT. HASLER: Keep on that! Get the nose down!

FO. BROKAW: I'm trying!

NARRATOR: The plane is suddenly uncontrollable.

The nose won't drop.

CPT. HASLER: My airplane!

NARRATOR: In a matter of seconds,

the crew is in emergency mode.

If they can't get the nose down fast, the plane will stall.

DON: They're not very high above the ground,

therefore don't have very much time to try very many things.

AUTOMATION: Bank angle. Bank angle.

Bank angle.

NARRATOR: For a moment, the plane hangs in the air, suspended.

STEVEN: And then the aircraft seemed to sort of careen

in our direction.

Now you're looking at a big 747 coming at ya.

STEVEN: Stop the car.

♪

STEVEN: And then it completely foundered and stalled,

and I remember thinking, he's lost all his engines.

AUTOMATION: Don't sink. Don't sink.

STEVEN: And in very slow motion it just went straight down

and pancaked into the ground.

The explosion was enormous.

It was a mushroom cloud like a small atom bomb. It was huge.

The entire base, you know,

thundered under our feet.

NARRATOR: The controller also watches helplessly

as the aircraft comes down.

It is the worst civilian aviation accident ever

at Bagram Airfield.

STEVEN: And I just pulled a camera out with the lens

and just shot some pictures.

Instinct, you know, trigger instinct.

Watching those people die was tough. It was tough.

I still think about it.

Sometimes I wake up thinking about it.

NARRATOR: Has a US cargo plane been shot down?

The safety of thousands of people now hinges on the answer.

NEWS ANCHOR (Archive): Today officials identified

seven Americans killed Monday in the crash of a cargo plane

in Afghanistan.

NARRATOR: National Airlines Flight 102 crashed

at America's biggest Air Force base in Afghanistan.

Remarkably, no one on the ground was hit,

but the entire flight crew is dead.

STEVEN: You think about these poor seven people

who were there on a contract job, you know, never went home.

DON: The loss of life is tragic under any circumstance,

but when it's a fellow pilot it's,

it's, it's really hard to deal with.

NARRATOR: Within hours, the Taliban claims responsibility.

♪

Amid the specter of a terrorist attack,

the NTSB is assigned to lead the US investigation.

♪

TIM: Although it wasn't ideal, it was one of those things

that we had a job to do, and so let's go get it done.

NARRATOR: Tim LeBaron heads up the team of five investigators.

TIM: This investigation was a lot different

because we were flying into a war zone.

When we first got there, we were given bulletproof vests

and Kevlar helmets to wear into the accident site.

NARRATOR: As this is an American base,

the civilian NTSB will have to work closely with the military.

TIM: So what have you got for me?

NARRATOR: A military sweep of the crash site

has already turned up the black boxes.

TIM: The US military had found the flight data recorder

and the cockpit voice recorder before we arrived

and had sent them back to the United States

to the NTSB laboratory,

and so we were very hopeful that we would get good information

from those recorders that would help explain

why the airplane had crashed.

TIM: Is there a report for me?

NARRATOR: But there's another surprising piece of news.

The sweep has uncovered no evidence of a missile attack.

TIM: You're sure?

NARRATOR: The Taliban claim was purely opportunistic.

TIM: Let's see what we have here, okay?

NARRATOR: With the most obvious explanation

for the crash eliminated, the team must now take a new look

at the wreckage.

BRIAN: The damage to this aircraft was

some of the most extensive fire damage I've had to work with

in my career.

So we really didn't have much to work with.

NARRATOR: Seventy-five percent of the plane

has been consumed by fire or destroyed by impact forces.

But the crucial tail section is still almost intact.

The tail wings hold the plane's flight control surfaces,

including the all-important elevators,

which the pilots move up or down to control the plane's pitch.

And pitch was a problem from the start of Flight 102.

BRIAN: We had that structure remaining,

so we did have something of value to look at

with regards to a possible scenario for the accident.

NARRATOR: They take a close look at the tail wing mechanics.

TIM: We looked at the hydraulic actuators for the elevators

and really couldn't find any problems with that.

TIM: So everything seems to check out. No problem here.

Why couldn't those guys get that nose down?

NARRATOR: If the flight controls were working,

then something else must have made the plane uncontrollable.

♪

Every last scrap of evidence is collected, including

a number of unidentified parts found on the runway

more than a mile from the crash site.

TIM: Anybody know what this is? Let's find out.

TIM: Our team was in Afghanistan one time and one time only.

So it was very important for our team

that we document what we could, find what we could,

because we knew that we'd never be able to return

and see the wreckage again.

TIM: Let's get those photos to Boeing right away.

NARRATOR: The pieces of wreckage will be sent

to the United States, where the manufacturer

will have to identify them.

♪

With all the evidence now collected from the crash site,

investigators move their operations indoors.

TIM: Our headquarters was in the basement

of an old control tower.

TIM: Okay. Let's clean this place up. Okay. I'll set up there.

TIM: Yeah, there really was no workspace down there.

There were a bunch of computers.

There were signs that warned of asbestos.

And it was a pretty rough environment.

NARRATOR: As they are settling into

their temporary headquarters, a video of the accident

appears on the Internet.

TIM: Holy cow. There it is.

♪

NARRATOR: Shot from an unknown vehicle on the perimeter road,

it reveals a huge clue about the plane's erratic climb

and fall.

♪

TIM: Looks like a problem with the cargo load.

NARRATOR: The aircraft's movement in the video

suggests it was carrying too much weight

and that the load threw the plane off balance.

BRIAN: The weight is very important in a cargo accident

more so than a passenger accident per se

because passengers have assigned weights. It's very standard.

There's much more room,

margin of error to work with passenger weights and baggage

than when you're flying cargo.

NARRATOR: A 747 freighter plane can carry

just about any type of load.

It is the cargo company's responsibility to ensure

that the aircraft is not overweight.

DON: I've heard it frequently in the cargo business

about you call, we haul, and sometimes the crew knows

in advance what they're gonna be doing.

And sometimes it's all last-minute.

BRIAN: Some of the early questions were, you know,

what was the cargo in the airplane? Was it full?

How heavy was the cargo?

NARRATOR: By examining the cargo manifest,

investigators discover that the plane was carrying

an unusual load: armored vehicles called MRAPs,

or Mine-Resistant Ambush Protected vehicles.

These massive, heavily armored cars can sustain roadside bombs.

They even have bulletproof wheels.

DON: The crew had never flown these type of vehicles

in this charter.

In fact, the airline had not carried these kind of vehicles

that were loaded on the airplane.

NARRATOR: The plane was carrying five MRAPs

weighing between twelve and eighteen tons.

Each vehicle was chained to a custom-built pallet

and secured with straps to the plane's main deck.

BRIAN: The cargo in this particular case was very heavy.

It was the first time they'd ever flown

five vehicles this heavy.

FO. BROKAW: Ready to put some numbers in there?

CPT. HASLER: Yeah. Go ahead.

NARRATOR: The crew landed at Bagram Air Base

with a full cargo load of 207,000 pounds.

Then they refueled, increasing the fuel load

to 106,000 pounds.

FO. BROKAW: Zero fuel weight is 2-5-9-2.

♪

NARRATOR: Investigators calculate the precise weight

being carried.

TIM: Max takeoff weight is 870,000 pounds.

We have 207,000 pounds of cargo, plus fuel.

NARRATOR: They learn that

even with the heavy cargo and fuel load,

the plane was not overweight.

It was almost 200,000 pounds under the safe limit.

TIM: Weight was definitely not an issue.

NARRATOR: Something else must have brought

the 747 cargo plane down.

♪

NARRATOR: Even if the weight of the cargo was not responsible

for the crash of Flight 102, the balance of the load

could be the problem.

DON: If the aircraft is loaded from the outset out of balance,

then that affects the performance of the airplane.

TIM: Bring up the schematics.

NARRATOR: Investigators map out the placement of the MRAPs

in the hold to study the balance of the load.

TIM: Fill it with our cargo.

NARRATOR: Three MRAPs weigh 18 tons each.

On the ends are similar versions that weigh 12 tons apiece.

TIM: The center of gravity with their vehicles in position

looks like 30.4 percent.

NARRATOR: After a few calculations,

they determine the balance of the load.

TIM: The airplane actually could carry the weight

and, as loaded, was within the center of gravity.

NARRATOR: It's a puzzling assessment.

But there's another possibility.

Even if the load was balanced before takeoff,

it could have shifted as the plane was lifting off.

The focus now turns to the loading procedures.

Specifically, were the MRAPs properly secured?

Standard cargo containers are locked into a hardware system

built on tracks in the floor.

But oddly shaped oversized cargo, like the MRAPs,

can't use these locks.

Heavy nylon straps are secured to tie-down points

around the hold.

BRIAN: What became critical to me was the process

of calculating the number of straps necessary

to restrain these five vehicles.

NARRATOR: The loadmaster on board the plane

used a National Airlines manual to calculate

how many straps were needed to secure the vehicles.

BRIAN: Based on their cargo operations manual,

the numbers were determined to be 24 straps

for the 28,000-pound MATVs

and 26 straps for the three 40,000-pound Cougars.

And seeing his rationale for calculating those numbers,

all seemed to make sense to me.

NARRATOR: Despite the appearance of the dash cam video,

analysis has shown that the plane was not overweight,

it was properly balanced, and the load was secured

according to company standards.

Investigators need to find out what was going on

inside the plane.

Information from the black boxes will be crucial.

CPT. HASLER: My airplane!

TIM: Flight data recorders record

what the elevator and the ailerons

and what the control pitches are doing.

And so we were very hopeful that we would get good information

from those recorders that would help explain

why the airplane had crashed.

TIM: Hello?

NARRATOR: A call comes in from the NTSB's head office

in Washington, D.C.

TIM: Hey. You have the readouts?

NARRATOR: The black box data is in.

TIM: That's great!

NARRATOR: But there's a problem.

TIM: Really?

TIM: I got a call from our director, John DeLisi.

And he informed me that unfortunately the flight data

recorder and the cockpit voice recorder had quit working

shortly after takeoff.

NARRATOR: Things started to go wrong shortly after liftoff,

known as the point of rotation, but this is precisely

the moment when the black boxes stopped recording.

TIM: Having the FDR, CVR after the point of rotation

would have been very helpful. We had none of that information.

TIM: Thank you.

TIM: We really had to revert back to old methods

of investigating. So I call it old-school methods.

NARRATOR: Investigators decide to contact eyewitnesses

who might have seen the plane take off.

TIM: Okay. What else did you see?

NARRATOR: On a base of this size,

there may be thousands of people who could provide

potential clues.

TIM: All right, well, thanks very much.

TIM: You need really to interview many different witnesses

and listen for the common thread that's the same

through all of the witness statements.

TIM: Sorry. What did you see?

NARRATOR: One witness reports an unusual sight.

A runway sweeper is sure he saw puffs of smoke

trailing behind the airplane after liftoff.

TIM: And it wasn't coming off the wings or out of the engines?

NARRATOR: His testimony raises the possibility

that a fire inside the plane may have caused the crash.

♪

If a fire had started inside the cargo hold during liftoff,

there would be evidence of this on the pieces of wreckage

from the interior of the plane.

TIM: The interesting thing was, the tail portion,

the aft pressure bulkhead, which is white in its color,

did not have any evidence to support

that we had a fire on board the airplane before the impact.

TIM: There's no sign of any smoke residue.

There couldn't have been a fire on board.

NARRATOR: Investigators are at another impasse.

They still have no hard evidence about the final fatal moments

of Flight 102.

TIM: When you go to an accident scene

where everything appears to be burned up

and there's not a lot left,

how in the world can you do an investigation?

One thing for sure is there's always evidence.

TIM: Bring up the CVR. Stand by.

NARRATOR: In a search for answers,

investigators turn to the cockpit voice recorder.

It cut out just three seconds after liftoff.

But it was recording during the crew's hour-long wait

on the tarmac.

TIM: What the heck. Let's hear the whole two hours.

There might be something there.

FO. BROKAW: There's your trouble, Brad.

CPT. HASLER: What is it?

TIM: Sounds like the first officer

is showing something to the captain.

FO. BROKAW: There's your trouble, Brad.

CPT. HASLER: What is it?

FO. BROKAW: One of the damn straps is busted.

TIM: Pause it there.

NARRATOR: The CVR suggests the first officer

found a broken strap inside the cargo hold.

TIM: Play.

CPT. HASLER: So are you gonna be throwing more straps on that thing?

FO. BROKAW: Well, it just shifted apparently.

CPT. HASLER: Did the truck move?

FO. BROKAW: Yeah. I just tightened up on the straps.

TIM: Holy crap. One of those things actually moved?

TIM: So we're hearing the crew talk about

that the load had shifted, also that a strap had broken.

Definitely piqued our interest.

TIM: Go again. FO. BROKAW: All the straps

that were keeping them from moving backwards were loose.

TIM: Those things shouldn't budge an inch.

NARRATOR: Despite investigators' earlier conclusion

that the heavy load was properly secured

and therefore could not shift, the CVR recording indicates

that the opposite was true.

TIM: So from that information we know

that they had a load shift when they came in and landed,

and that was very important to us in our investigation.

FO. BROKAW: All the straps that were keeping them

from moving backwards were loose.

AC. LIPKA: What the hell do you think's gonna happen

when you slam it on the runway, slam on the brakes

and don't use reverse?

FO. BROKAW: Well, there ain't nothing you coulda done

about that.

AC. LIPKA: I'm getting off this plane. I'm scared!

TIM: They have no idea how serious this really is.

DON: Really the crew is not trained or equipped

to actually be involved in knowing whether the restraints

are proper for the load.

CPT. HASLER: I hope instead of just replacing that strap

he's beefing the strap up more.

FO. BROKAW: Yeah, he's cinching them all down.

TIM: Stop. "He" would be Loadmaster Michael Sheets.

DON: The loadmaster in a cargo operation

is the one that's responsible for the security of the load.

So everyone is depending upon them.

CPT. HASLER: What's up, dude?

FO. BROKAW: Did you throw that other strap away?

CPT. HASLER: Did you put a couple more on? How far did it move?

A couple inches?

LOADMASTER: Yeah. They just moved a couple inches

'cause it's nylon, you know?

CPT. HASLER: Those things are so heavy you'd think

they probably wouldn't hardly move no matter what.

LOADMASTER: They always move. Everything moves.

TIM: So if those straps weren't fixed right then

the back vehicle could have come loose on takeoff.

BRIAN: If that cargo shifts during rotation

you'll wind up with a potential pitch problem.

NARRATOR: Did the MRAPs shift after takeoff?

To answer this question, the team must find a way

to piece together events in the cargo hold

in the moments before the crash.

TIM: So there's no evidence of a...

NARRATOR: Investigators need to prove that

one of the heavy Mine-Resistant Ambush Protected vehicles

shifted during the flight.

Clues might be hard to find

in the minimal and scattered remains of the aircraft.

TIM: But the one thing as investigators that we do

is we go into a very chaotic environment

and we bring order to it.

TIM: Okay guys, great.

Just put that down right in the center there.

BRIAN: So I gathered as much

of the aft pressure bulkhead structure as I could,

and I believe we came up with at least 90 to 95% of it.

NARRATOR: The aft pressure bulkhead is an airtight wall.

It protects the cargo area

from the non-pressurized tail section of the aircraft.

♪

Investigators sort out pieces of the liner

that covers the cargo hold side of the bulkhead.

TIM: You definitely go with this guy here. Take a look at this.

I can guess what that is.

BRIAN: And you could read the words Goodyear.

What became obvious was that the tire from the aft MATV

had impacted the aft pressure bulkhead

and left that tire impact on the liner.

TIM: Bam!

TIM: It looked as if that tire had pressed up

like a rubber stamp on the aft pressure bulkhead.

TIM: Only one tire capable of doing that.

NARRATOR: The mark matches the spare tire

in the top right corner of the rear vehicle.

The vehicle itself was found tipped over in the wreckage,

damaged but not destroyed by fire.

TIM: Pass me that flashlight, will you? Thanks.

NARRATOR: The metal antenna box from the rear of the same MRAP

is damaged and provides another big clue.

♪

TIM: Look at that, paint transfer!

NARRATOR: The box sits up high at the back of the MRAP.

TIM: That looks like a direct hit.

TIM: The only place that we could think of

where there was orange paint was the cockpit voice recorder

and the flight data recorder.

NARRATOR: To hit the flight recorders, the MRAP

would have had to shift at least twelve feet.

Could it have moved that far?

NARRATOR: A few quick measurements show that

the height of the paint transfer on the antenna box

lines up neatly with the location of the orange recorders

inside the plane.

BRIAN: The antennae box sat about 104 inches above floor level,

and where the CVR and FDR are located is 104 inches

above the floor of the aircraft.

Now you're starting to see a chain of events

that this vehicle had to be moving in an aftward direction.

NARRATOR: Both black boxes stopped recording

seconds after takeoff because a twelve-ton MRAP

knocked them out.

But even if the heavy vehicle damaged the flight recorders,

would it have been able to somehow bring down a huge 747?

NARRATOR: Investigators turn to the only wreckage

left to examine, the collection of unidentified parts

found on the runway.

BRIAN: These items were all recovered from the runway

in the area near the point of rotation for the flight.

CPT. HASLER: Rotate.

♪

NARRATOR: At Bagram Airfield, the runway stretches

for over two miles.

The parts were discovered at the spot

where the aircraft lifted off, one mile

from the site of the crash.

It is uncertain what relevance, if any, they have.

BRIAN: Where were these parts on the airplane?

Did they come from the nose section?

Did they come from the aft section of the airplane?

What function did they serve on the airplane?

NARRATOR: Experts at Boeing have been able to identify them.

TIM: There we go. Hydraulic return tubing.

NARRATOR: One of the parts, a broken piece of tubing,

comes from Hydraulic System Number Two.

TIM: Bring up the hydraulic system schematic.

NARRATOR: The 747 has four hydraulic lines

that power the control systems of the aircraft.

Hydraulic System Number Two carries fluid

along the deck floor and through the aft pressure bulkhead

at the back of the plane.

TIM: The tube runs through here.

TIM: The number two hydraulic system operates

one of the four airplane elevator panels.

NARRATOR: The elevator panels control pitch

from the tail of the aircraft.

If the rear vehicle shifted backwards through the bulkhead,

it could have hit the hydraulic tubing,

affecting control of the airplane.

TIM: Okay, let's play it.

NARRATOR: Investigators decide to take a closer look

at the dash cam video.

♪

♪

TIM: Play it again, this time in slow motion.

NARRATOR: Upon close examination, they notice something odd.

TIM: Freeze.

Something's not right. Advance a few frames.

A little more. A little more. Stop.

What's going on?

Something's wonky with the landing gear.

DON: Large aircraft like the 747

have a very complicated landing gear system

to carry the loads that they carry.

They come down together and they go up together,

and it takes several hydraulic systems to make that happen.

NARRATOR: The hydraulic systems that control landing gear

also regulate various other parts of the plane,

including control surfaces that affect pitch.

♪

Using animation software, the investigators create

a match for the 747 with its five sets of landing gear.

TIM: Now let's compare the model to the video.

♪

These are down and this one here is up.

That shouldn't happen.

CPT. HASLER: Positive climb.

NARRATOR: On National Airlines Flight 102, one of the last commands

recorded refers to the landing gear.

FO. BROKAW: Gear up. CPT. HASLER: Gear up.

NARRATOR: But after that exchange, not all the gear retracted.

DON: When I see a configuration of an airplane

with part of the landing gear up, part of it down,

I immediately think that they've had a hydraulic failure

of one or more of the hydraulic systems.

NARRATOR: It looks like damage

to one of the four hydraulic lines

may have happened in the air.

TIM: Now, which systems are out?

Body landing gear.

TIM: Now which systems are out? Body landing gear.

The nose and body landing gear didn't retract.

It must have been system one.

TIM: We were able to determine

that the number one hydraulic system had been damaged

at some point before the airplane hit the ground.

NARRATOR: The discovery of the broken hydraulic line

explains the eyewitness account of smoke.

TIM: As hydraulic fluid vaporizes behind the airplane,

it appears to look like smoke.

NARRATOR: Investigators think

they have finally cracked the mystery.

The heavy armored vehicle came loose,

smashed through the back of the plane

and took out the hydraulic lines,

making the plane uncontrollable.

♪

NARRATOR: After eleven days in Bagram,

the investigators are ready to head home.

All that's left to do is wrap up the case

with a simulation test back in Washington.

TIM: We really thought that we had the cause of the accident,

but there was more to the story.

♪

NARRATOR: At NTSB headquarters in Washington, D.C...

TIM: Glad to be back.

NARRATOR: ...investigators are preparing to finalize the case.

All they have to do is to verify their theory

that damaged hydraulics made it impossible

for the pilots to recover from the steep climb.

TIM: So once we got back to the United States,

the next step was to do simulations,

reenact the accident scenario.

NARRATOR: First, they model the 747

with two broken hydraulic systems

to test the cargo shift.

Airplane performance group chairman Tim Burtch

oversees the simulations.

TIM: If I had one of these armored vehicles move back

and there was an associated center of gravity shift,

is the airplane controllable?

TIM: Okay. What else do we know?

Let's try the new balance numbers.

TIM: Let's take what we know up to a point

and then start doing the what-if scenarios with the simulation

to see if we can put together a story that makes sense.

TIM: Okay, plane. Let's see what you do now.

NARRATOR: But when they run the simulation

of the rear vehicle coming loose,

something totally unexpected happens.

TIM: Nose comes down and flies out of trouble.

Let's shift even more weight back.

♪

Let's push the center of gravity even further. Let's try that.

♪

NARRATOR: Even with two hydraulic systems broken

and an MRAP crushed into the back of the plane,

the simulations show that the aircraft can be controlled.

TIM: All right. We're missing something.

NARRATOR: The theory that seemed so solid in Afghanistan

is now a bust.

TIM: So we started scratching our heads.

There was something more that we were missing.

NARRATOR: Most of the airplane wreckage now lies buried near

the crash site in Afghanistan, thousands of miles away.

Only selected parts have been sent to the United States

for analysis.

Investigators must sift through photographs from the site

to search for new evidence that might explain

what caused the crash.

♪

TIM: Hmm. I wonder.

BRIAN: So we needed to look further, and the next thing

behind the aft pressure bulkhead

that control pitch on the aircraft is the jackscrew.

♪

TIM: Hey. Where'd that stabilizer jackscrew end up?

NARRATOR: The horizontal stabilizer is a large control surface

that helps balance the plane in the air.

The jackscrew, about six feet tall, lowers and raises

the edge of the stabilizer

in response to the pilot's commands.

The jackscrew found at the crash site

was bent and severed right near its base.

The most likely explanation seemed to be

that the damage occurred on impact.

But just to make sure, it was sent to the US for testing.

TIM: What we were surprised to find out was that that jackscrew

had actually been pushed aft and had broken loose

from the airplane.

Results show that the jackscrew was bent backwards,

the opposite of how it would have bent in the crash.

TIM: So that raised the big question -- why?

What could have pushed it aft?

♪

TIM: Do we have a printout of this?

NARRATOR: To find out what could have hit the jackscrew,

investigators consult a diagram of the airplane's aft section.

TIM: Okay.

They take some careful measurements

and come up with a match.

TIM: Yep. Straight hit.

BRIAN: I was able to determine that the bumper of the MATV

lines up directly with the motor of the jackscrew

in the area where it detached from the lower fuselage.

NARRATOR: They input the new data.

The simulation now includes a broken jackscrew

that makes the stabilizer free-floating.

TIM: One MRAP at the back.

So two elevators down

equals one uncontrollable plane.

NARRATOR: Investigators finally know that an MRAP

crashing into the jackscrew is what brought the airplane down.

But there's still one major mystery.

TIM: We're not done yet. There's one more question.

How did that MRAP come loose?

NARRATOR: In Bagram, the loadmaster had calculated

the correct number of straps to use on each vehicle.

He based his calculations on the company's

cargo operating manual.

How could the cargo have come loose

if he followed the right procedure?

BRIAN: I immediately began contacting other cargo operators

to understand what is supposed to be done

to restrain free-floating cargo using straps.

NARRATOR: When executives from Boeing review the procedures,

they're less than impressed.

BRIAN: The manufacturers were quite shocked

at how they were interpreting the requirements.

NARRATOR: To get the maximum load capacity out of each strap,

it has to be tied down at a precise angle.

Changing the angle changes the strap's capacity.

The airline had not spelled this out in its manual.

TIM: Boeing, when you look at their manual,

they say that if you pull on a strap directly...

let's say that it's worth 3,500 pounds.

But if you go up on a 45-degree angle, it's worth even less.

And if you pull on it on a 90-degree angle,

it's worth zero.

National Airlines' manual said regardless of angle

each strap could be counted for 5,000 pounds.

NARRATOR: Boeing's own calculations found

that National Airlines Flight 102 took off

with less than half the straps required on each vehicle.

TIM: At the most they could have carried one MATV vehicle.

CPT. HASLER: What's up, dude?

NARRATOR: Investigators find no fault

with flight loadmaster Michael Sheets.

He had little training. He wasn't certified.

Without knowing it,

he'd based his calculations on a faulty manual.

TIM: My heart goes out the loadmaster in this situation.

The data, the manuals that he had to go by were incorrect.

So he was really in a no-win situation.

NARRATOR: But the cargo shift itself

would not have brought down the plane.

The crash ultimately occurred

because the sliding MRAP damaged the horizontal stabilizer.

TIM: You take away the horizontal tail

you're not gonna be able to control this airplane and pitch.

This was an uncontrollable event.

NARRATOR: Without the horizontal stabilizer,

the pilots' inputs made the plane do the exact opposite

of what they wanted.

A command to lower nose suddenly caused the plane to pitch up.

TIM: There's a total disconnect between what you're doing

as a pilot and what the airplane's doing.

DON: And it must have been terrifying.

I can't truthfully imagine it other than just sheer panic.

♪

NARRATOR: The NTSB's final report finds

that the probable cause of the accident

was National Airlines' inadequate procedures

for restraining special cargo loads.

It concludes that the improper restraint of the rear vehicle

allowed it to move back, hit the aft pressure bulkhead,

and knock out the two hydraulic systems

and the horizontal stabilizer,

making it impossible for the crew to regain control

of the airplane.

♪

One of the key recommendations is

for mandatory certification of all cargo handling personnel,

a move that would standardize their procedures, training

and workloads.

DON: I know that there are economics involved

in using more certified people.

But I certainly hope that they end up making loadmasters in

these cargo operations certified just like anybody else.

TIM: So reflecting back on this investigation,

there were many hurdles.

We had went into Afghanistan with a very, very small team.

We had to go back to old school methods.

But at the end we actually came out with safety recommendations

that I believe are going to prevent

an accident like this one from happening again.

I don't forget the tragedy, but I also have a lot of pride

that I believe that we've been able to make a difference.