Original subtitles

A 737 vanishes from radar

over one of the most remote jungles on earth

The crash pushes investigators to the limit.

On the first day, we had 8 snake-bites, 3 broken legs and one cardiac arrest

It is the worst accident in history of Panama.

A commercial aircraft just don't fall out of the sky

Dark theories emerge

Drug runner airplanes out there?

What about a bomb

They saw a big ball of fire

It was highly suspicious

An entire nation is demanding answers

With this massive spreads of parts that made no logical sense

Only one stunning conclusion can explain it

It was a big surprise to everybody

Air Crash Investigation Season 14, Edition 04

This is a true story

It is based on official reports and eyewitness accounts

SIDESWIPED

Tocumen International Airport in Panama City

V1

Copa Airlines Flight 201 takes off for a short flight to Cali, Colombia

Gear up

Captain Rafael Chial is Copa's most senior pilot

Today, he is monitoring the instruments

First Officer Cesareo Tejada is flying the plane.

40 passengers are on board, mostly business travellers heading to Colombia

The flight usually takes about an hour.

But tonight, there is a hitch that could add some time.

We got some heavy weather moving in from the Gulf.

Flight 201 is heading straight for a storm

In Panama, out over the water 8 or 10 miles out

because over the Gulf, there is a lot of convective activity and thunderstorms.

The weather was unusually terrible

It was a big big storm,

It looks like we have to take the long way around

If you fly through a powerful thunderstorm, there are up and downdrafts

They can overcome the airplane

so, you don't fly through them.

The pilots need to find a way to fly around the bad weather

you look at the weather and you decide if you can do it

If you can't, you ask for a vector around the thunderstorms,

Panama CENTER Copa 201,

we'd like to get around these weather, requesting a new heading for 090

Copa 201, copy that we are clear to heading 090

Cleared to heading 090.

Ladies and gentlemen, we are going to take a short detour to avoid some bumpy weather

It may delay our arrival in Cali, I will keep you posted.

The new flightpath will take the 737 East around the storm

before heading South again to Cali.

Panama CENTER, Copa 201.

It has been 12 minutes since take off

The Captain tells controllers he has reached cruising altitude, 25.000 ft.

Minutes later, the plane disappears from radar.

The Controller tries the radio,

but gets no response.

If you are close to thunderstorms a lot of rain will be static on the radio

and sometimes you may not be able to talk for a few minutes.

Garcia Orcana is one of the Controllers on duty.

The flight was leaving Panama airspace, entering Colombian airspace.

When the signal disappeared from the radar, I was worrying what happened

The plane's last known location was over Panama's remote Darién Gap

The plane has vanished over an almost impenetrable jungle

If Copa 201 crashed here,

just getting to the crash site will be a huge struggle.

Graciela Ocana reports the missing flight to aviation authorities

Then comes the news she has been dreading.

Early in the morning, I received a call from a radio station in Darién

Witnesses on the ground have reported a terrifying site.

During the night, they saw a big ball of fire

falling from the sky.

We had to find out where the aircraft was

and if there was any one alive they could save.

The next day, searchers make their way to the crash site,

but all 47 people on board

are dead.

Even if it is one person, it is a big loss

and it is a plane full of passengers.

It is really terrible

In Panama City, air-crash investigators set up a command post at a local flight school.

Panama's Deputy Director of civil aviation, Jorge Rodriguez,

is under enormous pressure to figure out what happened.

The loss of such a large aircraft has left his country in shock.

At that time, it was the first big accident of an air carrier of Panama.

We lost 47 people on board, all dead.

The bad weather leads to immediate speculation

that the Copa pilots may have been overcome by a deadly storm.

They reported nasty weather in the Gulf of Panama that time.

I want any weather-data for this entire area.

In the Darien Province,

Panamanian firemen say a prayer for the 47 people who died aboard flight 201.

The search to understand why they died

brings NTSB investigator Tom Haueter to Panama City.

It is a lot of pressure in all investigations in terms of the cause of the accident

We want to know what happened, and why and we want to prevent another accident

That is our main mission.

Tom Haueter, NTSB How do you do?

But there is added pressure on Haueter,

because of the type of plane involved in the tragedy

a Boeing 737.

I'd really like to get a look at the rudder on this one.

The rudder is a critical control surface in the tail

that helps to turn the plane.

The NTSB suspects a rudder failure caused a recent crash of another 737

United Airlines Flight 585.

There had previously been an accident with a 737 at Colorado Springs

It was on approach, when it suddenly rolled over

and dove into the ground at high speed killing all aboard.

A possible connection between the two crashes

makes it critical to figure out what brought down Flight 201.

Because that was an unsolved accident we were very anxious to know

Is there other evidence out there that will help us solve that case?

If rudder failure brought down both flights

there could be a fatal flaw in every 737,

the most popular airliner in the sky.

Passengers all over the world could be at risk.

In Panama's Darien Province,

investigators begin the painstaking task of try to find all the wreckage of Copa Flight 201

The dense vegetation makes it almost impossible to spot small pieces from the air

The team must search on foot with the help of local guides.

It wasn't laid out as we normally see in a crash

where the airplane comes in and you know:

here is the nose, here is the CENTER section, here is the tail

it turned out there were parts all over.

we were trying to determine where they were and so it became a major search

They need to find as much of the plane as they can

but they quickly realize it is going to be a daunting task.

The Darien jungle is probably the remotest section of Latin America you can think of

The Pan American highway does not go through there

There are no roads, nothing.

It is like one of the worst jungles in the world

I probably saw insects that National Geographic hasn't even seen yet

It was just very tough.

On the first day, we had 8 snake bites, 3 broken legs and one cardiac arrest.

As they work,

they map the location of every fragment of the plane

Tracking where the pieces landed could hold clues about why the plane crashed.

Most of the pieces are small

but a trail of scorched vegetation leads to the first large piece of the plane.

There was a large cleared area there was a fire that took place from the fuel

This is the CENTER section of the wing

the main landing gear is right there below you feet down the hill

It is an important find

but many more parts are still missing, including the rudder, and the cockpit.

The wreckage is spread across more than a 100 mile²

For investigators, the large area is a critical clue

There had been some type of high speed event where the airplane had broken up

it rained parts down on the jungle

Because the break up, we didn't know, so we did take a look at the wreckage

and tried to determine how all these pieces of the puzzle fit.

The crash site's proximity to the Colombian border suggests an obvious theory

It is an air-corridor for drugs

It is a busy one.

The Darien jungle is right on the border between Panama and Columbia

and there is a fair amount of drug activity coming back and forth across the jungle.

The remote jungle of the Darien Gap is a haven for drug-cartels

flying illicit merchandise, North from secret air-strips

In that gap, we don't have no radar to patrol the route of the drug-smuggle

Drug-runners usually fly at night when they are less likely to be spotted.

Unlike commercial crews, smuggles avoid radar detection

by switching OFF their radar transponder

and they never check in with Air Traffic Control.

If he does not report, who will know that they are there?

It is really dangerous, especially if there is not good visibility.

Cleared heading 090

We will let you know when we are getting clear from this weather

Perhaps the unsuspecting pilots suddenly crossed paths with drugs runners

It would have been the last thing they ever saw.

We thought at drug running who were going out there

Everything was open for consideration.

If Flight 201 did hit another aircraft,

investigators should be able to find some trace of the 2nd plane among the wreckage.

If a red airplane hits a blue airplane,

the paint is going to transfer from the one to the other

They scrutinize each piece carefully

hunting for any speck of paint that could have come from a covert drug plane,

But they come up empty.

Even more telling,

there is no wreckage that could have come a 2nd plane

We didn't find any other wreckages , old or new

and looking at the wreckage we found from the Copa airplane

we didn't find any evidence of a mid air collision.

There is another possibility:

What about a bomb?

Flight 201 was bound for Cali, Colombia,

home of a violent drug cartel.

Investigators know that a bomb on board could explain the eye-witness reports of fire in the sky

Certainly, we were interested in the possibility of an explosion

we brought an FAA explosive expert with us

a possible bomb went off and caused to break up of the airplane

We needed to take a look at everything.

Commercial aircraft just don't fall out of the sky

so those individuals put in a team together

felt that it was highly suspicious and might be something in my area of expertise

Explosive expert Calvin Walbert begins his search for evidence of an on board bomb

There is a tremendous amount of pressure because everybody wants that answer yesterday

He is looking for signature blast marks, caused by the superheated gasses from an explosion

There are indicators that you look for,

that will tell you that this is caused from an explosive event

it is not caused from just a fire or fuel erupting or something like that

If there were a bomb, the tell tale marks will most likely be found on metal debris.

On something like aircraft aluminium, you would be looking for pitting and cratering

like the surface of the moon

He carefully examines each piece.

He finds burn marks , evidence of a fire

but there is no sign of an explosive detonation.

The bomb theory is looking less likely

but it cannot be ruled out completely until they carry out one final test.

Transport to Panama city where the bodies will be X Rayed

to check for embedded shrapnel

I am looking for something that would be foreign to human remains

that is not part of the aircraft that is not part of the personal facts

that is something that would indicate that it was a bomb.

Base camp, come in, please

A call from the jungle search team brings some much needed good news

We got the black boxes.

The exhausting effort has paid off:

they found Flight 201's Black boxes

This could be the break through investigators need.

At least we got something to analyze what was the cause of the accident

Without those Black boxes you are blind, you don't get nothing.

There is no lab in Panama, equipped to analyze the recorders.

They need to go to the NTSB in Washington DC.

We were anxious to look at the FDR

The Flight Data Recorder is the only data we have from the flight up to the time of the break up.

NTSB technicians work quickly to download the information, stored on the two recorders.

The FDR tracks information like airspeed and heading.

The CVR captures the sound of the pilots' conversation in the cockpit.

We are hoping with the CVR

we get more information in terms of what the crew was saying, what was happening

right at the time of impact

The FDR is in good condition...

...but the same can not be said for the CVR.

It was a big surprise to everybody

Somehow, the tape has snapped and come unspooled

My God, what a mess.

the tape was broken completely like black spaghetti.

Jorge had a ball of Mylar tape.

Investigators won't know what answers the tape holds

unless they can somehow repair it.

If the people of the NTSB can not put that tape to work

there was no way.

Battling a 120° F heat in the Panamanian jungle

investigators struggle to learn what they can from the wreckage of Copa Flight 201.

Another big find could be a crucial lead in two investigations

They have recovered a key part from the rudder: the PCU

The PCU is a hydraulic ram that moves the rudder back and forth.

It is the same part investigators suspect may have failed during the recent crash of a UA 737

If there is a failure mode out there that is affecting thousands of airplanes

we want to document what happened

work with the FAA, the main factories to correct the problem, so the accident cannot happen again.

If they find evidence that the critical component malfunctioned

it will send shock-waves through the entire industry

The Boeing company will stop all those airplanes

They will not be flying.

Investigators test the mechanism.

They need to know if it jammed in flight

a failure that could easily put a 737 into a sudden dive,

but it is another dead end.

There is no evidence of pre existing damage it appeared to be working normally

The team hopes the engines will provide a better lead

In rare cases,

turbine engines have been known to overheat and catch fire.

If you got a fire in the engine, there is a lot of things that you can do about it

If there was an engine fire on Flight 201

investigators should be able to find scorch-marks on fan blades and other internal parts.

But again, their inspection turns up nothing.

There wasn't a problem at all with the engines that flight

The engines were working normally when the plane broke apart.

Investigators are still no closer to understand what happened in the skies over Panama

Medical X Rays eliminate yet another theory

All of the victim's remains were X Rayed to see if there is any evidence of an explosion.

The images show no sign of any foreign debris that could have come from an explosion on board

There is nothing that I saw or that I observed

that would indicate to me that there was a device on board Copa flight 201.

Investigators now believe the flames witnesses saw ignited after the plane broke apart.

It wasn't a bomb.

There is enormous pressure on the investigation.

Panamanians want to know what caused their nations deadliest air disaster.

How could that happen, we could not imagine

We needed an answer.

In Washington, there is renewed hope of finding answers in the CVR

Technicians have managed to repair the broken tape

Well, it took a lot of effort,

but they slowly found an end and straight it out rolled it back up, get it on a reel

Rodriguez can finally listen to the sounds, captured in the cockpit.

Copa 4129, you are cleared for take off

But what he hears reveals a stunning new problem

Cleared for take off, 4129

OKAY, here we go

The recording is not from flight 201

It is from a flight, days earlier.

It seems that the tape was already broken when Flight 201 took off.

The tape was broken 7 days before that accident.

and that was the reason that the recorder wasn't working at all.

It is very unusual that it does not operate.

I flew the airplane for many years I don't recall ever having a CVR not working

The first funeral is for one of the 5 flight attendants

Many mourners are asking the same questions as investigators:

'Why did this tragedy happen?'

It was like a nightmare that you wish you could wake up

You do not expect that to happen at least not in your country

The flight data is finally in the hands of investigators

It paints a terrifying picture

Flight 201 suddenly went into a catastrophic dive.

The airplane coming from 25,000 ft

until it disintegrate at 9,195 ft

10,000 ft /min

The extreme speed of the dive solves the mystery of the mid-air break up

It is not designed for flying inverted with speeds approaching the speed of sound

And so, we were trying to understand how it got from a level flight to be inverted

coming down at high speeds.

That few seconds is really the focus of the investigation.

The fierce weather over the Gulf of Panama may have been a factor

We had reports that the storm extended more than 100 miles from East to West.

If the Copa crew flew into a severe storm

there is a chance that the pilots were confused by what experts call spatial disorientation.

Flying in bad weather at night, thunderstorms can be disorienting.

You can't really trust your own senses

The inner ear will not lead you to the right conclusion

the G-forces you are feeling may lead you think you are turning left while you are turning right.

Investigators use radar information, captured in the tower to plot Flight 201's path.

They want to compare it to the path of the storm.

We could go back and look at the weather data and the long range radar data

We knew where the storm was we knew where the airplane was, by the impact

and so we could piece together their flight path and where they were going.

The results are conclusive:

Flight 201 wasn't anywhere near the storm.

I said that the weather wasn't an issue in that accident.

Investigators still can't explain what happened to Copa Flight 201.

They need a better approach.

The data we had, the take off, the climb out, the cruise,

everything looked like a normal flight

They delved deeper into the last 2 minutes of flight data

and discover some very unusual flight manoeuvres

Tom Haueter: OKAY, it looks like it turned right, and then left

and then right again until they spiralled into a dive.

It doesn't make any sense.

The flight data seems completely baffling.

Could it hold the key to explaining why 47 people died?

Investigators zero in on the final 2 minutes

They create an animation of the flight data...

That was normal, That was abrupt

...hoping it will shed some light on how the 737 could have made such strange manoeuvres...

Tom H. It should be correcting, it is not correcting

What the heck is going on?

...but it only adds to the mystery.

We saw the aircraft roll over into a bank angle then a sudden snap back to level vice versa.

The strange motion is unlike anything an airliner usually does during flight

It is strange to understand how can the airplane manoeuvre the way it is doing

That was causing quite a bit of problems, because we couldn't make a fit.

The aircraft is normally flown very gentle

As if your grandmother is in the back and she does not like to fly

because you are trying to make a happy customer and make them come back and fly with you again.

Could the pilots have been incapacitated by drugs or a medical emergency?

We've got to find that cockpit.

There is no way to answer that question unless they can find the pilots' bodies

and carry out forensic tests.

That was one of the main parts of the investigation

We have to get the cockpit.

Investigators are prepared for the hunt.

Before going into the jungle, they examine the 737 just like the one that crashed.

We hurry and go to the jungle looking for parts and pieces

it might be nice to see what they look like intact

So, we came across in the jungle we had an idea what we were really seeing.

The meticulous search finally pays off.

We found the cockpit in the base of the big tree.

Like it hit the tree and stopped there.

In Panama City, pathologists examine the bodies.

During the autopsies, we found no evidence of heart seizure at that time

or any medical event with eyes of the pilots at the time of the impact

Toxicology tests also confirm that neither pilot was impaired by drugs

There must be another explanation for the bizarre manoeuvres

We are trying to understand what happened here, the cause of the upset

It was quite a mystery for a long time.

With little else to go on investigators focus on the cockpit debris.

It provides some intriguing details about the last moments of the flight

We certainly did piece together what may have been going on in the cockpit at the time

The delicious food makes up for the long hours.

The First Officer is flying the airplane,

the Captain is back from the controls

He is having his meal, everything seems like a very normal flight.

Investigators study the flight instruments and cockpit controls that pilots rely on.

The position of a switch raises an immediate red flag.

The vertical GYRO-switch affects the most important flight instrument:

The attitude indicator

Each pilot has his own attitude indicator.

It shows him how the plane is positioned with respect to the horizon

The attitude indicator is like a ball

It shows bank angle, it shows pitch

It is the sole control of the aircraft

And without it, it would be very, very difficult to fly the airplane.

Each attitude indicator is connected to its own sensor, called a vertical gyro

Or VG

The gyros constantly measure the plane's attitude

If the gyro's don't match, the pilots get a warning.

Normally, you will have the captain's attitude indicator powered by one gyro,

and the First Officer's attitude indicator powered by another gyro.

If there is a problem with one gyro,

the pilots can switch both indicators onto the other one.

If one gyro goes bad, you don't want to have a pilot looking at bad data

So you switch them both over to the good data.

It appears that is what happened:

the gyro control switch has been positioned to feed both indicators from VG1,

the Captain's gyro.

It is like they are having troubles with the FO's gyro

Both of them are reading data from the same gyro source

which make you think that at some point

either it was selected that way or they didn't realize it was selected that way

but they are both feeding data from the same source, which is unusual.

Investigators could be on the verge of an important break-through

but they won't know for sure,

until they can test the flight-instruments for any kind of malfunction.

We removed all the components from the cockpit and shipped those back to the U.S. for examination

This could be their last chance to understand what happened to Flight 201.

Investigators need to know if a faulty cockpit instrument was giving the crew

misleading data about the position of their plane.

What we were going to look at:

Is there anything here that would show us what happened

Is there a failure on one of the gyros or the failure is added to the indicator

They test the displays and the gyros that feed them.

This one seems to work fine.

There is nothing wrong with the First Officer's instrument.

They run the same test on the Captain's attitude indicator.

At first, the Captain's instrument seems fine, too

We put them on a bench, we powered them up they actually worked quite well.

Then, they notice something odd.

Hang on, it seems to be stuck

Occasionally, the display momentarily freezes in place.

The attitude indicator stops moving even though the gyro is still in motion

Yeah, there it goes, now it is circling.

Investigators need to know what is causing the failure.

They test every wire, connecting the display to the gyro.

Finally, they find the culprit.

This wire is hanging by a thread

We found a break in the wire

Intermittent, it was close enough: Sometimes it touches and sometimes it won't.

The discovery gives new meaning to the bizarre rolling motion, captured by the FDR

The Captain's instrument and the Flight recorder are both fed by the same gyro.

The way the airplane is wired is:

what the Captain is seeing on his indicator is what is been recorded on the FDR

Since the Captain's gyro was broken, it was sending faulty roll data to the recorder.

Copa 201 didn't really make any quick rolling manoeuvres at all.

OKAY, let us see what the plane is really doing.

By carefully analyzing other parameters on the FDR,

they managed to calculate its actual movements and reveal the plane's true motion.

Making it visual, we could see what the data is showing and the plane is doing.

That is extraordinary helpful.

The red image shows the bad data the pilots were seeing,

while the solid image shows how the Copa 201 was actually flying.

They were trying to level the plane, but they are making it worse.

You have the attitude indicator here, stuck

Now, the airplane is going in the other direction and sends suddenly

the attitude indicator is powered to unstuck it goes back and moves the airplane again

The pilots' ability to troubleshoot the problem

was likely complicated by the intermittent nature of the failure.

If they are totally confused by their attitude indicator

they are making improper control inputs.

When it sticks, the pilot is trying to correct that problem

so, he is trying to get that airplane 'level' again

and he doesn't realize that he is going in the wrong direction

He is looking at an instrument providing bad data,

and unfortunately in the period of time, he lost control of the aircraft.

The plane rolls so far to the right, it becomes unrecoverable.

Though the pilots don't know it,

they are now falling from the sky.

When they got to this point, they didn't have a chance.

But a puzzling question remains

It was the Captain's gyro that failed in flight

and started sending bad data.

So, why did the pilots select it?

The question is:

why they believed the Captain's gyro is the good one?

Why is it switched to that position?

Because of that mistake, both pilots were seeing the wrong information.

The accident wouldn't have happened had they've been on VG-2

What could have led the pilots to make such a lethal error?

You want to know, how are they trained for unusual events?

What is their level of skill?

How would they handle an unusual situation? are they trained for gyro failures?

OKAY, let us start

Investigators go into the type of flight-simulator the Copa crew used for their 737 training.

Climb to 25,000 ft and turn right.

They recreate the flight of Copa 201

Now, trigger the failure.

Including the malfunction of the Captain's attitude indicator.

Tom Haueter: How do you make the switch?

Wait a minute, let me see that

That is not the same switch that was on Copa 201

Two different configurations for one small control-switch

has overwhelming implications for the investigation.

This is the gyro switch from the simulator where the Captain was trained

Next slide, please

And this is the gyro-switch from Copa 201

Can we get it closer, please?

Alright, now let's see both

Well, that is completely different

The cockpit and the simulator weren't similar and so it is possible to get confused

thinking you are going to independent gyro-source when you weren't.

In the simulator, flipping the toggle to the left switches the Captain's instrument to an AUX gyro,

independent of the other two.

On Flight 201,

flipping the switch to the left puts both instruments on the Captain's malfunctioning gyro.

With no CVR from the cockpit of Copa 201

investigators will never know for certain who flipped the switch the wrong way.

But they finally collected enough evidence

to build a compelling theory of how the flight went so horribly wrong

After diverting around the storm,

the crew of Copa Flight 201 needs to turn right to get back on course.

The delicious food makes up for the long hours.

As the plane levels out,

an error flag warns there is a problem with the Captain's attitude indicator.

They fall back on their training and flip the gyro switch to the left,

thinking they are switching to the AUX gyro.

You may revert to your training and do something inappropriate

because, that is what you are trained to do.

Now, they are both on the bad gyro, neither of them knows about it.

The gyro malfunction causes the AUTOPILOT to switch off.

First Officer Tejada must now fly by hand.

He turns his wheel to level the wings.

His frozen instrument makes it look like the plane isn't responding.

So, he continues to turn the controls sending the plane further and further to the left.

He is trying to correct the problem

He is actually making the problem a lot worse.

The pilots have no way of sensing their error.

It is too dark to see anything outside that could help orient them.

In the middle of the night, you don't have the horizon.

You loose the horizon, you don't know where you are.

As the short circuit cuts in and out,

the instruments start working then suddenly stops again.

Now, he thinks they are banking left he is trying to correct it by banking right

In the cabin, there is little sign of trouble.

The barrel move manoeuvre was fairly smooth with 1 G

I doubt the passengers really realized the impending danger

until the airplane inverted and started to come through

and then it would have happened very quickly.

Altitude

Pull up, pull up!

In-between the two pilots, there is a 3rd standby attitude indicator,

fed by its own independent gyro.

By comparing the 2 main indicators to the standby

pilots can quickly determine which one of the main indicators is faulty.

The standby indicator should have giving them the correct indication.

Why the pilots didn't use the standby, remains a mystery.

Had they looked at the standby, they knew there was something really wrong here

By the time the pilots realized they were in a dive...

Left, left, left!

I am trying, Captain

...it is too late.

It is extraordinary dis-concerning you've gone from a few degrees to the left

to multiple degrees to the right.

Once a usual attitude get out of hand it is much more difficult to recover.

This airplane got so much nose low

and at such a high speed

I can imagine in the cockpit what is going on.

In seconds, massive G forces incapacitated passengers and crew

As the airplane gets faster, components are being over-stressed

and you will start breaking off parts of the aircraft.

In the dive, the airplane got fire because that rupture of the tank...

...and exploded.

We were so sorry...

...that the end was the worst.

It is the worst accident in the history of Panama,

and I hope I never run through one again.

Jorge Rodriguez spends months, helping prepare the final report on Copa 201

for Panama Civil Aviation Authority.

It is very important that you analyze and find out what was the cause of the accident.

Copa Airlines responds with a major overhaul of its fleet,

standardizing the layout of cockpit controls.

Their fleet is fully harmonized,

it is a completely different airline that it was at that time.

Copa also revamps pilot training

to make sure its crews are prepared for any instrument malfunction.

I have been 4.5 years with them and their training is the best I've seen

We will respect them for that.

For the airline industry, Copa 201 is a reminder of how even small problems

can result in catastrophe.

A minor flaw can result in a tragedy,

and so we always have to look for these flaws

we have to train for them we have to challenge ourselves to be the best

whether it is the guy who makes the component on the bench

to the people who maintain the aircraft to the pilots

It takes everybody working together.

Narrator Jonathan Aris

Subtitles Rein Croonen