Mayday (2013) s07e04 Episode Script

(CRASH!) NARRATOR: Outside one of India's busiest airports, the early evening sky ignites into a fireball.
MAN: This cloud just lit up.
It felt like you could feel the heat.
Flaming wreckage falls from the sky.
It's a horrifying crash.
I realised that the clumps that I saw all around me were either the remnants of the aircraft or dead bodies.
When investigators arrive, they find the twisted remains of two passenger jets.
349 people are dead.
Vital clues are buried deep underground.
Investigators must piece together the day's events.
Saudi 763.
We'll maintain 1-4-0.
Kazakh 1907 now reach 150.
How had two crews who should have known each other's positions ended up in the world's deadliest midair collision? (THEME MUSIC) Indira Gandhi International Airport, New Delhi.
A gateway to India.
November 12, 1996.
Air traffic controller VK Dutta arrives for the late afternoon shift.
There was a watch supervisor.
There was one person who was sitting beside me and he was assisting me.
And, uh, things were all normal.
But normal at Indira Gandhi doesn't mean calm.
This is becoming one of the most congested airports in the world.
In 1990, the government of India signed open skies agreements with several different countries.
Those pacts have made it easier for foreign airlines to land at Indian airports.
Many airlines are taking advantage of the new policy.
MAN: The open sky policy acted as a catalyst in the air traffic group.
The volume of traffic grew from, I believe, 175 movement a day to around 225 movement a day.
Just past six o'clock, Saudi Arabian Airlines Flight 763 takes off into the sunset.
Gear up.
- Gear up.
- Clear on left.
Captain Khalid Al Shoubaili powers the Boeing 747 away from the runway.
His copilot, Nazir Khan, handles all radio communication.
MAN: (OVER RADIO) Saudi 763, airborne 03.
Contact radar 127.
9.
While flight 763 was on the runway, its movements were tracked and directed by an air traffic controller in the airport's tower.
279.
Good day.
But shortly after the plane takes off, the tower passes the pilots over to approach controller VK Dutta, who's in another room at the airport.
Approach controllers at Indira Gandhi guide planes through the airspace beyond the runways.
DUTTA: The approach controller normally is responsible for arrival and departures of aircraft which are coming in.
They are safely and expeditiously, you know, they are brought to the final approach.
Tonight, Dutta is controlling five flights.
Some of these are leaving the airport while others are coming in.
His task is to keep those planes spaced safely apart, but not so far apart as to cause any delays.
Saudi 763 approaching flight level 1-0-0.
Roger.
Climb flight level 1-4-0.
Clear to climb 1-4-0, Saudi 763.
This evening, a United States Air Force cargo plane is coming in for a landing.
Even though it's an air force jet, this flight is Dutta's responsibility.
MAN: I think we probably had three or four back-and-forths with the controller where he was verifying our altitude or checking on our altitude, telling us about other traffic in the vicinity.
Saudi 763 approaching 1-4-0 higher.
Saudi Flight 763 reaches its last assigned altitude of 14,000ft.
The pilots request permission to fly higher.
Roger.
Maintain flight level 1-4-0.
Stand by for higher.
In order to coordinate incoming and outgoing traffic, Dutta wants the Saudi flight to stop climbing.
Saudi 763 will maintain 1-4-0.
Dutta is concerned with another plane now flying east for a landing at Indira Gandhi Airport.
It's a passenger jet operated by Kazakhstan Airlines.
The Ilyushin 76 is a massive Russian plane.
Originally built for the military, a modified version is now widely used as a commercial airliner.
Dutta wants it to pass over the top of the Saudi flight before landing.
After that, he'll let the Saudis continue their climb.
They were supposed to cross maintaining 1,000ft of separation.
Kazakh 1907 now reaching 1-5-0, 46 miles from Delta Papa November.
Roger.
Maintain flight level 1-5-0.
Identify traffic 12 o'clock reciprocal, Saudi Boeing 747.
Dutta doesn't want the Kazakh flight to be surprised to see the Saudi jet.
Since planes don't have radar to track other aircraft, they rely on controllers to warn them about other planes nearby.
How many miles? All pilots tuned to the approach control radio frequency are able to hear one another as they communicate with the ground.
How many miles? Eight miles now.
It was strictly visual and trying to pick up on the radios where everyone else is at and what they're up to.
Suddenly, a massive explosion shatters the evening's calm.
All at once out of the right side of the window - the right side of the cockpit - this cloud just lit up.
Are those missiles? In my mind's eye they were missiles kind of corkscrewing.
Picking up speed was what they looked like and they looked like they were coming right at us.
We actually started veering the aircraft away before it became apparent that they weren't coming at us.
(YELLS IN ARABIC) (SCREAMING) The Saudi Airline's jet spirals towards the ground.
This is 1815.
1815, say again? Got on the radio right away, called the controller.
I saw something that looks like a big explosion.
On Dutta's radar screen, both the Saudi jet and the Kazakh plane have simply vanished.
I then heard the controller call for the Saudi air jet and the Ilyushin.
Saudi 763? But no response.
That was obviously very bone chilling.
Something tragic has happened in the skies near New Delhi's airport.
VK Dutta is about to become the target of an investigation into one of the deadliest plane crashes of all time.
Kazakh 1907.
Report your position.
At New Delhi's airport, a sense of dread is growing.
Two planes have vanished from approach control's radar.
DUTTA: The worst nightmare an air traffic controller has is the midair collision.
Saudi 763? Together, the two missing planes were carrying 349 people.
Kazakh 1907.
Report position.
US Air Force pilot Captain Tim Place soon confirms the worst.
- PLACE: Delhi, this is 1815.
- 1815.
- What did you see? - Two distinct fires on the ground.
Two fires on the ground.
- Confirm? - Confirm.
Confirm.
Roger.
Charkhi Dadri is a town 65km west of New Delhi.
(CRASH!) Its mustard and grain fields are now burning with the twisted wreckage of two ruined aeroplanes.
(SPEAKS FOREIGN LANGUAGE) TRANSLATION: One plane started to come towards us.
There was fire and parts of the plane were flying everywhere.
People were running.
The plane's engine broke off and the plane started to spin out of control and fell into the field.
MAN: I was told that there's been a midair collision.
Apparently there's a jumbo jet which may be involved and why don't you just head out? There was this adrenalin rush in that sense.
I was very new in the business and I knew I had to get that story.
Vishnu Som is assigned to report on the crash for New Delhi Television.
He arrives in the darkness of night a few hours after the crash.
We parked our vehicle on the side of the road and it was there was a fair bit of moonlight.
He and his cameraman are one of the first media crews to arrive on the scene.
Hey, turn off the light.
Don't want to attract attention.
Police have likely cordoned off the area.
I stepped onto the field and I thought it was a fallow field.
Nothing was growing over there because it was just sand.
And, you know, because it was dark and our only visual reference was the moonlight, we just sort of kept going and then I remember seeing clumps around me, you know, just these little piles on all sides.
Because there wasn't enough light, I didn't know what exactly it was, and then I stopped because I said, you know, something's terribly wrong over here.
Turn on your light.
Turn on your light! I realised that the clumps that I saw all around me were either the remnants of the aircraft or dead bodies.
There was a tree, just maybe 15 feet away from me to my right.
There was this burnt corpse on that tree and that's an image which, you know, which comes back and continues to haunt me even after so many years.
349 people are dead.
It's the worst midair collision of all time.
MAN: We have two very separate wreckage fields.
Captain KPS Nair is one of the first investigators on the scene.
MAN: I was aghast.
Horrified.
I can't explain it because I have never seen anything like that before.
It was something .
.
which I can't explain.
The Kazakh flight and the Saudi Airlines jet have fallen seven kilometres from each other.
Investigators have two separate crash sites to examine, but they know one cause will explain both accidents.
How had two planes that were supposed to be 1,000ft apart collided? Investigators consider three possibilities - an error on the part of the air traffic controller, an error by one of the crews or the failure of an instrument on one of the planes.
Although fire has ravaged the wreck sites, the black boxes from both planes are found on the first day of the investigation.
But for the moment, they hold their secrets.
It will take several months for experts to extract data from the recorders.
In the meantime, investigators focus on conversations between the two planes and the air traffic controller.
Without onboard radar, the planes around Delhi's airport rely on air traffic controllers to guide them.
VK Dutta comes under enormous pressure.
Did he make mistakes that caused the worst midair collision ever? Hi.
I'm VK Dutta.
- I'm sorry to keep you waiting.
- Have a seat.
Investigators want to know everything that Dutta did on the night of the crash.
- Was traffic heavy? - Evenings are always busy.
Dutta's radar doesn't track a plane's altitude.
Instead, controllers in New Delhi write a plane's last reported position on a strip of paper.
The strips are continually updated.
It's the only way for controllers to keep track of the altitude of planes under their control.
This is the Kazakh one.
And this is the Saudi one.
Investigators learn that Dutta was in charge of five flights at the time of the accident and the Saudi and Kazakh flights were flying in opposite directions of the same aerial pathway.
The area that Dutta manages is divided into a network of air corridors.
Controllers use them to channel flights in and out of the airport.
But many of the corridors are used for military flights.
In fact, even at such a busy airport, there's only one main corridor for commercial planes.
When aircraft fly through the sky, they leave turbulence in their wake, like boats on the water.
It can affect the planes around them.
Air traffic controllers deal with this by keeping planes at different altitudes.
Roger.
Maintain flight level 1-4-0.
Stand by for higher.
Dutta was supposed to ensure that the two planes were 1,000 feet apart as they approached each other.
He planned to do what he'd done many times before, have the incoming plane pass 1,000 feet over top of the outbound plane.
It was a routine procedure.
but somehow the two planes had ended up on a collision course.
One of the two planes was not where it should've been.
Investigators wonder if Dutta made a mistake that led to the horrific crash.
Poring through the ATC transcripts, investigators quickly learn that Dutta had given the two planes the proper directions but since his radar doesn't display altitude, there was no way for him to tell if the planes followed those instructions.
Investigators are so convinced that Dutta did nothing wrong, that three days after the crash he's back on duty.
Investigators return to the crash site.
They're hoping to recover certain instruments from the two aircraft.
Perhaps a mechanical failure had led one of the planes off course.
But the Saudi cockpit has plunged deep into the ground.
The accident investigation becomes an excavation.
Machines had to be brought in.
Excavators to dig up and lift the cockpit of the Saudi aircraft.
The altimeters of the Kazakh flight are easier to find.
That plane didn't crash nose first.
Mostly there and there.
As close as you can get it.
Investigators need to discover which of the two planes was at the wrong altitude.
The pattern of the damage on the two planes may help answer a critical question.
What was the relative angle between the two aircraft at the time of their contact? Most of the pieces from the two planes are kilometres apart but a large section of the tail from the Saudi aircraft is found near the beginning of the debris field.
This suggests it was one of the first pieces to come off that plane.
The tail of the Kazakh plane appears to have pierced through the left wing of the Saudi jet.
If that's the case, the Kazakh flight hadn't been above the Saudi jet when they collided, as air traffic controllers thought.
It must've been below it.
It's a puzzling discovery that adds to the mystery.
Investigators still don't know which plane was in the wrong airspace.
What they do know is that once the two planes hit, there was no hope for either crew.
After hitting the other plane's wing, the Kazakh plane's tail tore through the horizontal stabiliser at the rear of the Saudi 747.
Five and a half metres of it is torn off.
Without it, the Saudi crew can't control their plane.
Almost two weeks after the accident, Captain Ashok Verma joins investigators at the scene.
By that time the operations for taking the Saudi cockpit had been completed.
Whatever equipment was recoverable had been recovered.
Like the rest of the evidence uncovered so far, the instruments from the Saudi plane don't help explain what happened.
The force of the crash has completely destroyed them.
I can't find anything.
- Too much damage.
- I agree.
Look at this.
They've learned all they can at the crash site.
The case now depends on what they can find out from the black boxes.
Investigators hope that somewhere on the cockpit recordings or buried in the flight data are the clues they need.
Where were the planes when they collided? And how had they ended up on a deadly collision course? (YELLS) It's been three months since the midair collision of two passenger jets near New Delhi.
Investigators have been frustrated by a lack of conclusive evidence.
They hope the planes' black boxes will help them solve the case.
In order to avoid any suggestion of bias, the boxes from the Saudi flight are being analysed in England.
Technicians from the Air Accidents Investigation Branch try to extract valuable data.
Each plane was equipped with two black boxes, a flight data recorder and a cockpit voice recorder.
The flight data recorder contains information on dozens of aspects of a plane's performance, among them, the altitude, the airspeed and the changes pilots make to the flight controls.
The cockpit voice recorder picks up all the conversations in the cockpit.
279 to Delhi.
As investigators try to learn more about the collision near New Delhi, they use the information stored on the black boxes to make a chronology of events.
Peter Sheppard is head of the recorder section of the Air Accidents Investigation Branch.
He'll work backwards from the moment of impact The point of collision is reasonably well defined by rapid changes in parameters on each aircraft.
If we make that our time-zero point, we can then relate that to the individual times and build up, you know, a common time base.
First, Sheppard and his team concentrate on the Saudi 747.
Saudi 763 approaching 1-4-0 higher.
Roger.
Maintain flight level 1-4-0.
Stand by for higher.
Saudi 763 will maintain 1-4-0.
The CVR reveals that the Saudi pilots received clear instructions about their altitude and seemed to have understood them.
After being told to hold at 14,000 feet, there was no discussion of climbing to a higher altitude, which would've taken them into the path of the Kazakh flight.
Next, Sheppard looks at the flight data recorder to confirm that the Saudi flight actually followed the instructions it was given.
The recorder from the Saudi flight showed us that the altitude had been normal during climbing.
The Saudi pilots levelled off at 14,108 feet, well within their safe corridor.
It had levelled at its assigned altitude of 14,000 feet and continued to fly level.
The Saudi pilots followed the ATC instructions meticulously, which is borne out by their confirmatory calls back to the ATC.
Air traffic controllers wanted the two planes separated by 1,000 feet and wanted the Saudi plane to fly below the Kazakh jet.
If the Saudi pilots did nothing unusual, suspicion is growing that somehow it was the Kazakh plane that was in the wrong place.
Alarmingly, when investigators examine the information from the Kazakh jet's flight data recorder .
.
they discover that it descended far below the 15,000 feet it was supposed to stay at.
Moments before the collision, the Kazakh plane is at 14,100 feet, almost 1,000 feet lower than its assigned altitude, and less than 10 feet below the Saudi flight.
It then powered directly into the Saudi jet.
The Kazakh crew had not stopped descending at the altitude they were cleared to that was 15,000ft.
But why had the Kazakh flight dropped so badly off course? Kazakh 1907, report position.
Kazakhstan Airlines presents one theory for their plane's dramatic loss of altitude.
The Kazakhstan defence mainly relied on presence of turbulence.
Perhaps a sudden burst of turbulence had forced the plane lower.
The data recorder of the Kazakh flight does seem to indicate that the crew had a bumpy ride.
It shows two distinct and sudden drops of more than 400ft.
The airline claims both of these drops were caused by turbulence.
But Peter Sheppard isn't so sure.
When we saw the jumps - 250ft-500ft - our initial response was that these can't be right.
I mean, you know - it was .
.
the rate at which they changed was beyond that that an aircraft could actually perform.
What else could cause the plane to drop so quickly - or at least seem to drop so quickly.
Sheppard searches for an explanation.
We tried to resolve the inaccuracies in the Kazakh recording by looking at the other parameters that were recorded and trying to derive altitude using these other recordings.
It's intricate math.
By using information including the speed and rate of descent from the flight data recorder, Sheppard determines that the plane was on a steady downward approach.
The reason for the apparent sharp drops is simple.
Sheppard learns that the sensor that sends altitude information to the flight data recorder was faulty.
It would stick and temporarily stop sending information.
When it got unstuck, it would wrongly appear as though the plane had lost considerable altitude.
It's as if there was a bit of glue on one area and it stuck in that .
.
and eventually it the altitude changed so much that the force on it made it jump again and it stuck there for a little while.
Investigators can now conclusively dismiss turbulence as a factor in the collision.
So there's no sudden descent.
It's been months since the midair collision of two passenger jets near New Delhi.
Investigators have been frustrated by a lack of conclusive evidence.
To understand why the Kazakh plane kept descending after it was told to hold, investigators turn to the cockpit voice recorder.
It begins long before the crash itself.
Initially, there are no hints that anything is wrong.
MAN: (ON RECORDING) Kazakh 1907.
Report level passing.
Passing 2-4-0.
Kazakh 1907.
Because the Ilyushin 76 is a modified military plane, it has another unusual feature - a position for a radio operator in the cockpit.
Egor Repp mans that position and handles all communications for the Kazakh flight.
Roger.
Over to Delhi approach 127.
9.
127.
9.
Bye-bye Kazakh 1907.
As the aircraft nears the airport, Repp gets in touch with approach controller Dutta.
Delhi approach, good evening.
Kazakh 1907 passing 2-3-0 to 1-8-0.
I told Kazakh to descend and maintain flight level 1-5-0.
That is 15,000ft.
Roger, Kazakh 1907.
Descend flight level 1-5-0.
Report reaching.
1,000ft vertical separation is sufficient and that was granted to the two aircraft.
Kazakh 1907, now reach 1-5-0.
The Kazakhstan radio operator had at one time stated reaching flight level 1-5-0.
It's just one minute before the impact, and at this point, the Kazakh plane appears to be right where it's supposed to be - 1,000ft higher than the Saudi plane.
But investigators know that instead of levelling off, the plane continued to descend.
This is where the trouble starts.
As investigators compare the flight data information to the cockpit voice, they notice something disturbing.
Kazakh 1907 now reach 1-5-0.
When Repp calls out that they've descended to 15,000ft, he's actually over 1,000ft higher than he thinks he is.
Investigators wonder how he could make such an enormous mistake.
Why would he say he was at 15,000ft when, in fact, he was at 16,000ft? They consider the layout of the cockpit.
A radio operator does not have an independent altimeter.
There are two metric altimeters fitted in front of .
.
one each in front of the pilots.
With some effort, the radio operator could also see this.
Whatever the reason, Repp is mistaken about his plane's height and he's the only one in contact with the ground.
Despite being told to remain at 15,000ft, the plane continues to descend.
As it does, Dutta issues a warning to the Kazakh pilots.
Identify traffic.
12 o'clock reciprocal.
Saudi Boeing 747 and 10 miles.
Likely to cross in another 5 miles.
Report if in sight.
He tells them to watch out for the Saudi flight, but the Kazakh jet just keeps flying lower.
- Ahead? - Ahead.
Just before the crash, Egor Repp seems to have recognised that the plane is now flying dangerously low.
But his warning doesn't come in time.
Keep to 150.
Do not descend! Accelerate! The cockpit voice recorder proves what investigators found in the flight data - at the time of the crash, the Kazakh jet was trying desperately to get back on course.
Keep to the 150! (YELLS) But investigators are still puzzled.
Why had the Kazakh plane kept descending? After ruling out controller's error, ruling out mechanical failure, you have to go further into details of human behaviour during the operation of a flight.
Kazakhstan is one of several now independent republics that used to be part of the Soviet Union.
The national airline has a reputation at Indira Gandhi Airport.
There was always a sense that, you know, these were small fly-by-night operators essentially doing the charter business and they didn't necessarily follow the conventions of modern western aviation.
We examined the background of knowledge of English language.
The crew in the Soviet states - they pass English examination but they're not fluent in spoken English.
Verma now listens more closely to the cockpit voice recorder, looking for an indication that the crew misunderstood their instructions.
Had a language barrier caused the crash? How many miles? Traffic is at eight miles, level 1-4-0.
Did the Kazakh pilots confuse their own altitude with that allocated to the Saudi aircraft? Report eight miles.
Verma finds that members of this crew weren't communicating clearly with each other.
Egor Repp was responsible for communication with the ground, but there's no indication that the pilot and copilot were listening to his instructions.
Switch on engine inlet heating.
While the rest of the crew was busy discussing arrival procedures, Repp alone seemed to be occupied with their altitude.
Now locking 1907.
It is a usual practice that the briefing for the arrival is completed before start of descent so that all crew can pay full attention to the radio.
While the radio operator appears to have understood that the Saudi plane was at 14,000ft, investigators believe the copilot thought that he was cleared to 14,000ft and continued his descent.
Hold the level! What level were we given? When the pilot does respond, he seems confused.
I think pilots did not pay that much attention and relied too much on the radio operator to navigate the aircraft during this critical phase.
The decision to increase power and stop descending ends in tragedy.
Keep to 150.
Do not descend! Accelerate! Descend to 140! (YELLS) (ALARMS BEEP) The final report points a finger squarely at the crew of the Kazakh plane.
In the wrong place, at the wrong time, a simple misunderstanding led to the deaths of 349 people.
The investigation concluded that the primary cause of this midair collision was non-adherence to the authorised altitude allocated to the Kazakhstan aircraft.
Investigators are confident they know what caused the worst midair collision in aviation history.
But there are steps they want the industry to take to help make Indira Gandhi Airport safer.
What they find is that the technology that could have prevented this accident was already at the airport.
Saudi 763.
Investigators have determined that poor cockpit communication and a simple misunderstanding caused a devastating accident which killed almost 350 people.
But technology existed that could have helped avoid this accident - systems that would have helped both the pilots in the air and the controllers on the ground.
Investigators are especially critical of the radar that was being used in New Delhi.
Air traffic controllers did rely on fairly outdated technology at that stage.
There wasn't any secondary radar available at Delhi Airport.
There was only an old primary radar.
Primary radar sends out radio signals to locate aeroplanes in the sky.
The signal bounces off the plane and back to a dish on the ground.
It reads a plane's position but not its altitude.
The primary radar gives you a 2-D picture.
Secondary radar works differently.
A transponder aboard an aircraft sends a message to the ground with key information about the flight, including its altitude.
Saudi 763 approaching flight level 1-0-0.
Roger.
Climb flight level 1-4-0.
On the day of the collision, approach controller VK Dutta could only rely on what the crews told him about their aircrafts' altitudes.
Kazakh 1907, now reach 1-5-0.
The Kazakh radio operator said that they were flying at 15,000ft but Dutta had no way to confirm that.
If he had known the Kazakh flight's actual altitude, he could have diverted the Saudi flight from its path.
DUTTA: That is the 3-D picture.
So you can You have some time to react to it.
You can take the aircraft away.
At the time of the accident, India had ordered a 118-million air traffic control system with secondary radar and more sophisticated communications and navigational equipment.
The system had originally been scheduled to be installed two weeks before the accident.
But on the day of the crash, the system hadn't even been unpacked.
SOM: Secondary radar is an advancement on the primary radar and in this particular case also, by getting the altitude information, it could have been possible that the accident of this nature would have been avoided.
In the year following the accidents, there would be three near misses near Indira Gandhi Airport.
It would take more than two years for the secondary radar system to be installed.
Today, controllers at Indira Gandhi International Airport see an aeroplane's flight number, altitude and heading.
It's far more information than controller VK Dutta had available to him on the day of the accident.
Experts believe another piece of technology could have helped prevent the collision - TCAS.
TCAS equipment generates a caution and warnings for the crew.
It allows them time to react, draws their attention to the situation around and it looks into the vertical separation.
TCAS is a collision avoidance system that can be installed onboard airliners.
In many countries the technology is mandatory.
It alerts pilots when other flights are coming too close.
The system also automatically tells them what evasive action they should take.
Neither plane was equipped with TCAS.
The Indian Airports Authority has also made the airport safer by redesigning the air corridors coming and going from the runways.
At the time of the collision, there was one main air corridor for commercial planes landing and taking off from Indira Gandhi International Airport.
With the increase in air traffic, that single corridor was becoming too crowded.
In the wake of the accident, more air corridors were opened for commercial flights.
In general, aviation safety standards has improved.
The concern for the safety has improved.
Out-of-date technology and poor communication led to this crash.
But like almost every aviation accident, it was a chain of seemingly minor events that ended in disaster.
In retrospect .
.
those were some very unlucky people to meet in the sky that night.
Uhyou know, it's a one in a million chance for that to happen.
Certainly there were other things that could have helped - radar, collision avoidance systems andI think we continue to make advances there.
I don't worry about flying.
Certainly You know, destiny - I don't know.
It was Glad we weren't five minutes in front of where we were at, that's for sure.
VK Dutta went on to have a long career as an air traffic controller.
Today, he works at a college training young controllers.
So I'm chief instructor there so I'm training ATC youths.
I'm addicted to my job.
I love it.
I really love it.
Dutta, who was initially suspected of having caused the crash helped implement the changes to make New Delhi's airport safer.
His efforts have paid off.
The airport now handles 20 million passengers a year.
Since the new radar system was installed and the new corridors opened, there hasn't been a fatal accident at this airport.