Original subtitles

NARRATOR: After losing their electric generators--

OK, beacons off.

NARRATOR: The pilots of Air Illinois flight 710

shut down one system after another

to conserve their battery power.

It was probably the most sickening

feeling for both of them.

NARRATOR: But efforts proved futile.

All the passengers and crew are killed.

NTSB investigators examine the plane's electrical components

for clues.

There was no short circuit.

What about the batteries?

No signs of arcing.

NARRATOR: The cockpit voice recording

raises more questions.

Are you using these lights here?

I'll get that one down.

Well, they're doing the right thing, turning

things off to reduce the load.

So what happened?

You got a flashlight?

Yep.

CREW (ON RADIO): Mayday, mayday.

NARRATOR: Air Illinois flight 710

departs from capital airport in Springfield, Illinois.

Gear up.

NARRATOR: 32-year-old Captain Lester Smith has been with Air

Illinois almost five years.

He's one of its most experienced pilots.

Gear is up.

NARRATOR: First Officer Frank Tudor has been with the airline

for three years.

He's considered one of its top first officers.

1,000 feet.

The pilots are flying a Hawker Siddeley 748.

The rugged turboprop is designed to land on shorter runways.

DAVE MINTY: These Hawker Siddeley 748

was one of a number of aircraft built to replace the DC3

as a commuter slash cargo slash military-type aircraft

but primarily used as a commuter aircraft.

NARRATOR: It's the ideal plane for a regional airline

that connects big cities to small towns in Illinois.

Illinois 710, radar identified.

Continue to 3,000 feet, clear to Carbondale.

TUDOR: Illinois 710, 3,000 feet cleared for Carbondale.

Thank you and good night.

Heading 175.

NARRATOR: Less than two minutes after takeoff--

It's the generator again.

NARRATOR: A generator warning light comes on.

The aircraft is equipped with two nine-kilowatt generators

that supply power to the battery banks and electrical systems.

One of the generators has failed.

Isolating it now.

NARRATOR: The first officer disconnects the right generator

to protect the rest of the aircraft's electrical system.

SHAWN PRUCHNICKI: When something like this

happens and you have a generator failure,

one of the most important steps is

to disconnect that generator from the system

as quickly as possible.

Jeanene Urban is a former Air Illinois

pilot who landed the pain in Springfield

three hours earlier.

JEANENE URBAN: The generators are each

rated to be able to carry the entire load,

so if one generator goes down, you can

continue to your destination.

It is not an emergency.

NARRATOR: Tonight's 40-minute flight

is taking seven passengers 146 miles from Springfield

to Carbondale, Illinois.

Springfield, Illinois 710, we've experienced

a slight electrical problem.

We'll keep you advised.

Illinois 710, do you intend to return to Springfield.

SMITH: Negative.

Continuing to Carbondale, 3,000 feet.

NARRATOR: The captain decides it's

safe to continue the flight.

I understand you are continuing to Carbondale.

Roger.

NARRATOR: There's dense cloud cover this evening.

JEANENE URBAN: The conditions at Carbondale

were what is called IFR, instrument flight rules.

They would have been operating in the clouds,

needed their instruments to be able to fly the airplane.

DAVE MINTY: They were flying into deteriorating weather

conditions.

It's something that every airline pilot

is trained to handle, but it doesn't

give you much room for error.

NARRATOR: Four minutes after takeoff,

the first officer checks the status of the generators.

Zero voltage in amps on the left side.

NARRATOR: He discovers that the left generator is dead.

TUDOR: The right generator's putting out 27.5 volts.

NARRATOR: The right generator now appears to be working,

but the first officer is unable to reconnect

it to the electrical system.

Can't get it to come online.

NARRATOR: The right generator is as good as dead.

DAVE MINTY: With both generators out,

all the systems are feeding off the batteries

instead of the generators.

It's not a good situation.

NARRATOR: The aircraft has four nickel cadmium batteries.

With no generators, the batteries

are now powering lights, instruments,

navigational equipment, and everything

in the passenger cabin.

How were the bats there?

We're down to 22.5 volts.

SHAWN PRUCHNICKI: So now that we're operating on only battery

power, the primary problem is that the batteries are only

designed to operate for about 30 minutes

under the best case scenario.

NARRATOR: Illinois 710 is now 32 minutes from its destination.

If they don't reduce the drain on the batteries,

it will be almost impossible to land without lights,

instruments, or a radio.

OK, beacons off.

OK.

SMITH: Nav lights are off.

Are you using these lights here?

I'll get that one down.

NARRATOR: The pilots quickly shut down nonessential systems.

JEANENE URBAN: The sooner they start shutting things down,

the longer the battery is going to last.

How are the batteries?

Pretty good.

We're at 21.5.

NARRATOR: The efforts to conserve battery

power seem to be paying off.

Should last to Carbondale.

Yeah.

NARRATOR: Midway to their destination,

the weather deteriorates.

JEANENE URBAN: The weather that Frank and Les encountered

trying to get down to Carbondale was

much stormier than Springfield.

There were level two and three thunderstorms.

Want me to tune in to cabby real quick?

Sure.

Not gonna use that much power.

NARRATOR: 45 miles from Carbondale, the crew

tunes into a signal that will provide a precise bearing

to the airport.

Meanwhile, air traffic control transfers

the flight to the approach frequency

for Southern Illinois.

Air Illinois flight 710, contact Kansas

City center on frequency 125.3.

25.3, Roger.

Air Illinois 710.

They were getting close to the airport,

and that approach control facility would have lined them

up for an instrument approach.

NARRATOR: After contacting approach control,

the situation worsens.

I don't know if we have enough juice to get out of this.

NARRATOR: The radios and transponder on flight 710

have shut down.

The pilots are now on their own.

Illinois 710, I've lost radar contact.

NARRATOR: Flight 710 has disappeared from air

traffic control's radar.

Illinois 710, Kansas City.

They had no capability at this point to like help.

It was probably the most sickening

feeling for both of them that you or I could imagine.

Watch my altitude.

Going down to 2,400 feet.

NARRATOR: Concerned their instruments are about to fail,

the captain attempts to get below the clouds.

JEANENE URBAN: He was desperately

hoping that he could see the airport

beacon or some runway lights and land that airplane visually.

DAVE MINTY: Just eight minutes from landing--

SMITH: You got a flashlight?

Yeah.

NARRATOR: The batteries are almost depleted.

Here we go.

You want to shine it up here.

Trying to illuminate the instruments with a flashlight

in a dark cockpit, that is very abnormal,

and is he pointing it at an instrument that's functioning

or one that's not?

We're losing everything down to 13 volts.

Watch my altitude, Frank.

JEANENE URBAN: It would have been a total panic situation

and realizing that they were out of options.

OK, 2,400.

NARRATOR: Rapidly losing electrical power

and operating in total darkness, the pilots of Illinois flight

710 desperately try to land their plane.

DAVE MINTY: The conditions Carbondale were such

that one mile visibility in light rain

and fog, his chances of seeing anything were minimal at best.

Do you have any instruments?

Do you have a horizon?

DAVE MINTY: They're in a dark cockpit.

Instruments are failing.

They can't see anything outside.

They were now into a critical emergency.

TUDOR: OK, you're banking left six degrees.

OK, correcting to the right.

A little more.

Illinois 710, Kansas City, do you read?

DAVE MINTY: I would be very surprised that they knew

that they were going to hit.

I would be very surprised they saw the ground at all.

NARRATOR: Air Illinois flight 710 crashes 25 miles north

of Carbondale airport.

The wreckage is scattered across farmland

near the town of Pinckneyville.

All seven passengers and three crew members are dead.

The National Transportation Safety Board, or NTSB,

begins an investigation to determine

what happened to flight 710.

Let's see what we got here.

NARRATOR: They begin by reviewing the debris pattern.

That's a half a mile long and roughly 200 feet wide.

NARRATOR: Investigators get a sense of the vast impact area,

which extends across two small wooded areas,

a field, and a pond.

They came in at a shallow angle.

RON SCHLEEDE: The wreckage pattern gave us the idea

that this was a fairly high speed, low angle

impact to be able to spread the wreckage

like this over a half a mile.

First point of impact is right here with ground

scars and debris heading north.

Carbondale airport is 25 miles to the south.

NARRATOR: Investigators determined

that at the time of the crash, flight

710 was flying in the opposite direction to its destination.

ROBERT WATSON: With the aircraft traveling the way it was

at that speed and in a wrong direction,

it made us wonder was the aircraft actually

under control.

So first ground scar here followed by a few

more and then 200 feet in front of that, the right wing tip.

NARRATOR: Near the first impact marks,

investigators discover fragments of a green navigation

light from the plane's right wing tip.

It was banked to the right when it hit the ground.

RON SCHLEEDE: We had the right wing tip.

We knew that was the first thing to hit the ground,

and we could measure approximately 30 degree right

bank.

Did the crew report any issues to air traffic control?

Yeah, they did.

Springfield, Illinois 710, we have experienced

a slight electrical problem.

We'll keep you advised.

NARRATOR: Investigators learned that 90 seconds after taking

off from Springfield, the crew reported an electrical problem.

Anything else?

That's it, just the electrical problem.

We'll need to take a good look at all

the electrical components.

RON SCHLEEDE: The pilot reported a slight electrical problem,

and it was up to us to figure out what his problem was

and why they crashed.

Is this everything?

NARRATOR: Investigators examine electrical components

for evidence of malfunctions.

The wires are clean.

There's no short circuit.

This inverter's in bad shape.

Hard to tell if they were working or not.

What about the batteries?

NARRATOR: Four NiCad batteries are powered by two generators.

Each battery contains 18 individual battery cells.

No signs of arcing or short circuit as a result of impact.

ROBERT WATSON: We were able to recover a total of 10 cells

from the batteries, and they were all in decent shape.

Well, let's see if they can hold a charge.

NARRATOR: Under normal conditions,

the battery should be fully charged.

Wow, they're dead.

ROBERT WATSON: The batters are able to hold a charge,

but for some reason, they were run down.

NARRATOR: Did the generators malfunction

and fail to charge the batteries?

Now the left generator.

NARRATOR: Aircraft engines power a generator

shaft to rotate a metal core wrapped in copper coil.

This is known as an armature.

The armature spins rapidly between the poles of a magnet

to generate electricity.

Banding wire's come off.

NARRATOR: Banding wire is used to hold

the armature together as it spins inside the assembly.

If the banding wire comes loose, the armature could jam.

The soldering is melted.

The motor must have overheated.

NARRATOR: Investigators discover evidence

that the left generator failed.

This happened before the crash.

ROBERT WATSON: We know that there was

no fire on the aircraft, so we believe that the solder

melted due to internal heating.

But we don't know why.

NARRATOR: They then inspect the right generator.

Well, the banding wire's intact on this one.

Looks fine.

ROBERT WATSON: We did a resistance test, checked

the brushes, and we looked at all the mechanical workings

of the generator.

We were not able to find any reason why the right generator

would not charge the batteries.

How did they crash with four working batteries

and one working generator?

RON SCHLEEDE: From examination of the wreckage,

we were not able to find any reason for the accident.

We were hoping that the voice recorder would give us clues

as to what really happened.

The recording starts around four minutes after takeoff.

NARRATOR: Investigators turn to flight 710's cockpit voice

recorder to determine how an aircraft

with one functioning generator crashed

short of its destination.

Zero voltage and amps on the left side.

Just like we suspected.

NARRATOR: The CVR recording confirms

that the left generator failed shortly after takeoff.

The right generator's putting out 27.5 volts,

but I can't get it to come online.

NARRATOR: Investigators can't understand

why the right generator was disconnected

from the electrical system if it was operational.

Then they hear an astonishing statement

from the first officer to the captain.

TUDOR: When we lost the left one,

I reached up and shut off the right generator

because I assumed the problem was the right side.

Isolating it now.

NARRATOR: There are two shutoff switches for the generators,

one for the left generator and one for the right.

The first officer disconnects the right one

to protect the rest of the aircraft's electrical system,

but he soon realizes that it's the left one that

has the issue, not the right.

Why doesn't he just reconnect it?

He tries, but it doesn't work.

ROBERT WATSON: The right generator

was not charging the battery so that we know all they had

to power the aircraft was the charge remaining on the battery

shortly after takeoff.

Maybe there was a problem with the switching unit?

ROBERT WATSON: If the generator switching unit is not working,

then the generator will not come back online.

So we were quite interested in learning what

we could about this component.

It's in pretty rough shape.

NARRATOR: Looking for signs of a malfunction,

investigators examine the right generator control switch.

I can't tell 100%.

It's possible it failed before the crash.

ROBERT WATSON: The switching unit was

heavily damaged from the crash.

We were not able to determine if that's even why the generator

would not come online.

Even if the switch was broken, it doesn't

explain the pilot's actions.

The first officer says I assumed the problem

was with the right side.

Why would he assume something like that?

ROBERT WATSON: Made us wonder if there

was a problem with that generator in the past.

Take a look at these maintenance reports.

NARRATOR: The team reviews the maintenance

records for the Hawker Siddeley's generators.

Check it out.

No less than eight separate pilot complaints and repairs

on the right generator.

There were voltage fluctuations and recurring

problems at the regulator.

Causing the right generator shut down.

NARRATOR: Two weeks before the crash,

there were issues with a right generator almost every day.

RON SCHLEEDE: They were doing maintenance,

they were troubleshooting it, they were changing parts,

and they couldn't fix it.

Air Illinois had one Hawker Siddeley and three

flight crews flying that plane.

ROBERT WATSON: I'm sure that they all

knew that the right generator had had problems in the past,

and they probably all experienced

it at one time or another.

JEANENE URBAN: The first officer had

been on some of those flights where the right generator

had actually disconnected.

Thank goodness I was not.

The most I ever saw it do was flicker a time or two.

That would explain why the first officer

disconnected the right generator instead of the left one.

NARRATOR: Investigators suspect that

on the night of the crash--

It's the generator again.

NARRATOR: The first officer made the immediate assumption

that the right generator had malfunctioned.

ROBERT WATSON: The reaction that the first officer had

about taking the right generator offline

probably falls into a phenomenon that's called expectation bias.

He has experienced this in the past

and assumed that that was going to be the problem

without really looking at the indications

they had available to him.

Still doesn't explain the crash.

NARRATOR: Even though both generators were offline,

investigators know the aircraft's batteries

were in working order.

How are the batteries?

Pretty good.

They're at 21.5.

Should last to Carbondale.

Yeah.

ROBERT WATSON: It was really important to know

did the batteries have enough endurance

to get to the airport.

Let's see how they manage their battery power.

NARRATOR: Investigators return to the cockpit voice recorder

to determine why flight 710 ran out of battery power

before reaching Carbondale.

SMITH: How are the bats there?

We're down to 22.5 volts.

OK, beacons off.

OK.

SMITH: Nav lights are off.

NARRATOR: Just minutes after discovering both generators

are down, the pilots turn off nonessential systems

to save their batteries.

They were doing the right thing turning

things off to reduce the load.

But is it enough?

According to the manufacturer, they needed to reduce

their load to 70 amps.

NARRATOR: Amps measure the strength

of an electrical current.

The more amps drawn on a battery,

the faster the battery will discharge.

ROBERT WATSON: If the crew would have reduced the load to 70

amps, that would have given them a minimum

of 30 minutes of endurance.

That might have been enough time to get

them to the Carbondale airport.

Let's see if they got their load down to 70 amps.

Well, we know they turned off the beacons,

navigation lights--

NARRATOR: Investigators make an inventory of the instruments

the crew turned off and what they

left on in order to calculate the load on the batteries.

What else?

SMITH: Are you using these lights here?

TUDOR: I'll get that one down.

RON SCHLEEDE: We were not able to determine

what was powered up or on or off based on the flight recorder.

TUDOR: Should last the Carbondale.

RON SCHLEEDE: So we had to rely on the conversations

between the two pilots what to leave on and what to turn off.

Want me to tune into cabby real quick?

Sure.

Not gonna use that much power.

The DME instruments, weather radar, main cabin lights, one

of the main radios, cooling fan, and the transponder.

RON SCHLEEDE: The weather radar and the radios

draw a lot of power, and so shedding those if you

can is a prudent thing to do.

Looks like they kept the rest of the flight instruments on

and that's it.

They used 110 amps.

NARRATOR: Investigators discover the crew

did not properly reduce the draw on their batteries.

No wonder they didn't make it to Carbondale.

SHAWN PRUCHNICKI: This importance with load shedding

and getting down to 70 amps seems to be lost on the crew

as there seems to be no discussion whatsoever

about amperage to determine if their changes

in the electrical system were actually

making a difference in the longevity of the batteries.

NARRATOR: So why did the pilots believe they had enough power

to reach their destination?

The team checks to see how the pilots monitored

the state of their batteries.

It says here fully charged, the batteries are 24 volts.

Let's see how they did.

SMITH: How are the bats there?

We're down to 22.5 volts.

Eight minutes into the flight, they used up 1.5 volts.

Seven minutes later--

SMITH: How are the batteries?

Pretty good.

We're at 21.5.

The battery charge drops another volt to 21.5.

The first officer says the battery

should last to Carbondale.

They're halfway through the flight, he's feeling good.

And then nine minutes later, he checks again.

It's 20 volts.

So they think they're doing all right.

And then minutes later, the radios go dead.

We're losing everything down to 13 volts.

SHAWN PRUCHNICKI: They're talking about having 20 volts,

and then they all of a sudden, they have 13 volts.

So they're monitoring the volts,

but it's as if the sudden drop caught them by surprise.

SHAWN PRUCHNICKI: The reason this is significant is

because NiCad batteries will maintain

their voltage almost right until the end

that the batteries are dead.

Much different than lead acid type

batteries, which is where you see

a gradual decline in voltage.

NARRATOR: That characteristic of NiCad batteries

may explain why there was such a sudden drop

in the battery voltage.

I don't know if we have enough juice to get out of this.

ROBERT WATSON: If they would have known the characteristic

of a NiCad battery, it might have sent them a message

saying we better get on this right

away and get this load reduced.

NARRATOR: Investigators find another reason why

the crew may have missed how fast their batteries were

discharging.

They never mentioned their amps.

Looks like the only thing they monitored were the volts.

NARRATOR: Volts measure the potential output of a battery,

not how long it will last.

Amps tell you how much electricity is being drawn.

ROBERT WATSON: It was very surprising that they weren't

monitoring the amperage because that

was going to tell them how much longer they

had on the batteries.

NARRATOR: Did the crew have the proper training to monitor

the endurance of the batteries?

Investigators interview other Air Illinois pilots--

So what'd you find out.

NARRATOR: To determine their ability

to monitor and calculate battery endurance.

Well, we know that they're all trained on battery management

for a dual generator problem.

But when I asked them how long they thought the batteries

would have lasted on the flight, some calculated 30 minutes,

others less than an hour.

Five pilots gave us five different answers,

and they were not all correct.

ROBERT WATSON: It became obvious to us

there was definitely a training issue involved here.

Are you using these lights here?

I'll get that one down.

NARRATOR: The lack of training explains why the pilots thought

they had enough power to reach Carbondale,

but that doesn't solve a bigger mystery.

This is their flight path.

NARRATOR: Why didn't the pilots land the pain

at another airport before completely

running out of battery power?

1, 2, 3, 4, 5 different airports.

They were only five minutes away from Springfield,

yet they elected to go 40 minutes to Carbondale.

And there were several airports in between that they missed.

They could have landed any time along the way.

NARRATOR: Their decision not to land

calls the pilots' judgment into question.

It's time to look into their backgrounds.

Here's the captain's file.

NARRATOR: Investigators dig into the backgrounds of flight 710's

pilots for clues that explain their unusual reaction

to an electrical failure.

The captain was perfectly qualified.

Same with the FO.

Gear up.

NARRATOR: The two pilots were among the most experienced

flight crew in the roster--

Gear is up.

NARRATOR: With a combined 5,000 flying hours between them

on the Hawker Siddeley.

Here's something.

The captain lived in Carbondale.

Maybe he wanted to get home.

SHAWN PRUCHNICKI: In aviation, what we

describe as get home itis is when we try to make it

to the destination because of our strong desire to do so,

and it plays a significant role in our decision making.

NARRATOR: Investigators talk to other pilots

at the company including first officer Jeanene Urban.

How well did you know the pilots?

I flew with the captain, and I was good friends

with the first officer.

JEANENE URBAN: I thought very highly

of the first officer Frank.

I knew the flight attendant Barbie and liked her a lot.

It was a very emotional thing to hear that both of them

had been killed.

What sort of pilot was the captain?

I'd say average.

ROBERT WATSON: In the aviation community, when someone is

characterized as an average pilot,

that usually means he's not too good.

Why is that?

The captain really prided himself

on getting there on time.

JEANENE URBAN: It was not uncommon for him to take risks.

Looks like we've got some weather.

Shall I call for deviation?

SMITH: Doesn't look too bad.

We'll be fine.

NARRATOR: According to Air Illinois pilots,

the captain would often fly too close

or through dangerous storms to save flight time.

JEANENE URBAN: If I made any comments or suggestions

about a safety issue like the thunderstorms or anything else,

he would do something spiteful just to prove

that he was the captain.

In order to keep schedule, he'd also speed up, which would

set off the overspeed alarm.

Pull the circuit breaker, would you?

What?

Really?

NARRATOR: Pilots said he would order

them to disable the overspeed warning

so that they could fly faster.

It was always about getting there faster.

NARRATOR: The captain's behavior is troublesome.

RON SCHLEEDE: We wanted to know if the company, the airline,

was putting undue pressure on the pilots

to make the schedule.

This pressure to get there on time, was it from management?

No.

It was all the captain.

The interviews with the other pilots

indicated that there was no undue pressure

to skirt the rules.

In the case of the captain, that pressure was self imposed.

NARRATOR: Investigators conclude that Captain Smith

often stretched the rules.

And what about the first officer?

Frank was the best.

And he knew the plane and its systems really well.

NARRATOR: So why didn't the first officer

speak up when Captain Smith made the decision to carry on.

DISPATCH: Air Illinois 710, do you intend

to return to Springfield?

Negative continuing to Carbondale, 3,000 feet.

ROBERT WATSON: And at no time did

we hear the first officer challenge

the captain's decision to go on to Carbondale.

We found this very perplexing.

I asked how he could fly with the captain

because he took so many chances--

JEANENE URBAN: And he said, oh, I just

try to keep an eye on the situation

and not let him get us into anything

that I can't get us out of.

We're losing everything down to 13 volts.

Watch my altitude, Frank.

JEANENE URBAN: Boy, that didn't work out very well at all.

SHAWN PRUCHNICKI: The captain should have made the decision

to return to the Springfield airport, and if so none of this

would have happened.

Thank you.

NARRATOR: Investigators conclude that the risk-taking captain

and an unassertive first officer was a dangerous combination.

Let's pick it up from where they

realize they don't have enough power to make it to Carbondale.

NARRATOR: The team returns to the cockpit voice recording

to see if they can uncover why the plain

ended up so far off course.

SMITH (ON RECORDING): Watch my altitude.

Going down to 2,400 feet.

OK.

Stop the tape.

Why would the captain decide to drop down to 2,400 feet?

The cloud ceiling near Carbondale

was almost 2,000 feet, so maybe he

was popping in and out of the clouds

to see something on the ground.

Play on.

SMITH (ON RECORDING): You got a flashlight?

Yeah.

Here we go.

You want to shine it up here.

NARRATOR: Just as the captain tries to see the ground,

the cockpit lights go out and plunge

them into total darkness.

We're losing everything down to 13 volts.

Watch my altitude, Frank.

OK, 2,400.

They make it to 2,400 feet.

The captain plans to level off, spot the runway,

and continue his descent.

But that's not what happens.

OK, you're banking left, six degrees.

OK, correcting to the right.

ROBERT WATSON: Just minutes later

they ended up crashing in completely

the opposite direction.

A little more.

So the question is what happened.

How do you go from leveling off

at 2,400 feet to then hitting the ground

in the opposite direction?

NARRATOR: Investigators examine the final moments of flight 710

to determine what ultimately brought the plane down.

How does the recording end?

NARRATOR: The recording eerily slows down.

And then silence.

Their batteries just died.

NARRATOR: The captain is asking for a horizon reading

on the attitude directional indicator or ADI.

The ADI uses an electrically-powered gyroscope

to indicate the aircraft's pitch and roll relative

to the Earth's horizon.

SHAWN PRUCHNICKI: It's nighttime,

no discernible horizon, low visibility.

Your ADI is everything that you need to be able to keep

the airplane wings level.

They've lost the lights on their instruments.

Some of them are starting to fail.

He asked the first officer to shine a light on their ADI.

TUDOR: OK, you're banking left, six degrees.

OK, correcting to the right.

NARRATOR: Investigators can only surmise what happened next.

Even if all the instruments had failed,

the ADI would still look like it's working.

NARRATOR: The ADI gyroscope spins at about 15,000 RPM.

Even after the power shuts down, it will continue

rotating for several minutes.

So it looks like it's working, but it really is not.

NARRATOR: As the ADI winds down, it slowly tilts to one side.

Imagine that ADI starts slowly falling to the left.

They correct by rolling to the right.

OK, you're banking left six degrees.

OK, correcting to the right.

A little more.

ROBERT WATSON: It may have appeared to them that the ADI

was working correctly, but they're

really banking to the right and losing altitude.

They probably followed that failing

ADI right into the ground.

RON SCHLEEDE: They couldn't see where they were,

they couldn't see any lights, and it

would be over in an instant.

NARRATOR: In their final report, investigators

conclude that the fatal accident was a consequence

of a captain's decision to continue the flight

toward Carbondale instead of returning

to the nearby departure airport after the loss of power.

RON SCHLEEDE: The cause of this accident

was not a catastrophic failure that suddenly

caused the airplane to crash.

It was the decision by the captain

to continue flight on battery power

after they lost the generators.

NARRATOR: Also adding to the problem

was a lack of crew resource management or CRM.

RON SCHLEEDE: Now part of crew resource management training

is that crews are trained to act as a team,

and first officers are taught and encouraged

to question the captain's decision making and actions

if they do not agree.

JEANENE URBAN: Speak up.

Don't worry about if it upsets somebody's ego.

It's not worth dying over.

NARRATOR: Investigators cite inadequate crew

training to assess battery endurance

as another contributing factor.

RON SCHLEEDE: It should have been

discussed in their training.

It should have been in their training materials

and in the flight manual.

NARRATOR: As a result of this accident,

the NTSB also recommends independently powered ADIs

on all transport airplanes.

ROBERT WATSON: So that if all power was lost,

they still had the ability to keep the airplane straight and

level for at least 30 minutes.

NARRATOR: This recommendation was implemented in 1997.

Flight 710 brought national attention

and increased scrutiny of small commuter airlines.

Six months after the accident, Air Illinois

filed for bankruptcy and ceased operations.

DAVE MINTY: It's something where we learn by our mistakes.

The first priority is the safety of the passengers is got to be

the most important factor.