Mayday (2013) s18e03 Episode Script

Deadly Distraction

Hurry! Oh, god! It was so dark, so black and so thick I could not breathe.
I was on my last breath.
Please.
VOICEOVER: Paul Verheyden fights for his life inside a burning plane.
I was on the go team.
It was terrible when I got there.
The wreckage was strewn over a large area.
JIM CASH: The plane is going down the runway but it can't get in the air.
Investigators must now solve the mystery of what went wrong aboard Delta flight 1141.
Is this it? It won't be easy.
This FDR is outdated.
It makes it difficult when you don't have many parameters to work with.
It will require all their insight, expertise and determination.
We had to do a lot more digging.
VOICEOVER: It's another hectic morning at Dallas/Fort Worth International, the third busiest airport in America.
American 1056, fly heading one-eight-five, runway one-eight-left, cleared for take-off.
Controllers here handle more than 670,000 take-offs and landings every year.
1141, push off of 15.
Let's go tail straight back, prepare to taxi, call me when you're ready.
OK.
- Brakes off and tail straight back.
- Roger.
The pilots of Delta Airlines flight 1141 started their day together in Jackson, Mississippi.
After a brief stopover in Dallas, they're now getting ready to pilot their Boeing 727 to Salt Lake City, Utah.
Captain Larry Davis has been a Delta pilot for 23 years.
I forgot to get my pay-check.
Did you get yours? Yeah, I got mine.
First Officer Wilson Kirkland has been with the airline for nine years.
Larry and Wilson knew each other very well and they were very comfortable with each other.
I also have to check what my upcoming schedule is.
Excuse me.
Can I have a coffee? I'm sorry.
You'll have to wait until we're in the air.
Paul Verheyden is an architect flying to Utah on business.
I had a project just outside Salt Lake City.
I had to go up there to make some field surveys and measurements.
Basically, you know, a routine trip.
GROUND CREW: Clear to start engines.
- Beacon? - It's on.
- Parking brake.
- It's off.
40 psi.
VOICEOVER: The third crewman is the newest Delta employee on the team.
Oil pressure rising.
Flight engineer, Steven Judd.
Start valve closed.
40 psi.
The engineer has his start sequence, which is a little complicated.
So he's busy with his switches and his, uh, gauges.
Start valve open.
Oil pressure rising.
Start valve closed.
40 psi.
GROUND CREW: Brakes set.
You guys have a great trip.
Brakes are set, thank you.
As the flight attendants begin securing the cabin, the 727's progress onto the taxiway is stalled.
Delta 1141, give me a right turn, bring it between south ramp and 30, hold short of enter.
1141, roger.
They have to wait for other planes to pass.
Hopefully we'll get out of here while we still have teeth in our mouths.
Growing grey at the south ramp, that's Delta 1141.
I guess we should, uh, shut down engine number three, save a few thousand dollars.
Shutting down one of the 727's three engines will save fuel while they wait.
Ask him to give us a two minute warning to start our engines.
OK.
I should have brought something else to read.
I'll be finished this before we get off the ground.
It's very common to be trapped on a taxiway for long periods of time.
Frequently it's 10, 20, 30 minutes uh, on the taxiway, especially during the big push at the big airports where they schedule the airplanes to go out at the same time.
Dixie Dunn is a senior flight attendant with more than 30 years in the job.
Gentlemen, how's it going in here? We're gonna go all the way down there, and once all those planes are gone we can go too.
What kind of birds are those? Egrets or whatever you call 'em.
- Are they? - I think so.
They're cousins to the ones by the sea.
1141, come south on the inner until taxiway 21, then move to the outer, hold short of 19.
1141, roger.
VOICEOVER: Now cleared to taxi, the 727 will have to join a long line of planes waiting to take-off.
So what else are we gonna talk about? Well we could discuss the dating habits of our flight attendants.
That way we have it on the recorder, you know, in case we crash.
We gotta leave something for our wife and children to listen to.
FIRST OFFICER KIRKLAND: Good morning, ladies and gentlemen.
We are number four for departure.
Flight attendants prepare the cabin, please.
- We are ready.
- Thank you.
Well, might as well start.
- 40 psi.
- Number three.
Start valve open.
In preparation for take-off, the pilots restart the third engine.
As the air traffic controller juggles the many flights he's handling this morning, he spots an opportunity to get Delta 1141 back on track.
1141, taxi to position runway one-eight-left and hold.
OK.
1141's position and hold.
It's an unexpected but welcome change of plans.
Instead of having to wait for three other planes to take off, Delta 1141 is told to move to the head of the line.
- Shoulder harness? - They're on.
Flaps? 15, 15 green light.
Flight control? - Tops and bottoms checked.
- Nav instruments? They're set.
- Take-off briefing.
- Is complete.
Ugh.
Finally.
Delta 1141, fly heading one-eight-five, runway one-eight-left, cleared for take-off.
1141, one-eight-five, cleared to go.
Power set.
Engine instruments look good.
Finally, Delta flight 1141 is on the roll.
Before we took off it was pretty normal.
Um, I don't remember anything unusual.
Airspeed's coming up on both sides.
The most difficult part of being an airline pilot Eighty knots.
.
.
is that last five seconds before the decision speed.
Tension grows up to that moment.
VR.
V-2.
- (ALARM) - Something's wrong.
I think we got engine failure.
PAUL: As the plane got off the ground it kind of dipped and then it kind of went up and then there was a big bang and it kind of tilted to one side and then the other.
We're not gonna make it.
Full power! Captain Davis and first officer Kirkland struggle to get their plane in the air.
And then it just dropped.
And it hit the ground shaking, you know, shake, shake and everything kind of flying around and people hollering and screaming.
And then it stopped.
You know, I thought, we have crashed.
108 people are now desperately trying to get out of a plane that's filling up with smoke and fire.
Every passenger and crew member, including the pilots, onboard Delta flight 1141 have survived a crash on take-off at Dallas/Fort Worth airport.
But now they're fighting for their lives inside the burning cabin.
And then I looked over the aisle.
There's all these people and the cabin was filling with smoke, and the fire I could see outside the window.
I thought, I may not get off of this thing 'cause of all these people.
Hurry! Oh god.
(COUGHING) I just was feeling people's backs and they were moving so I just followed along.
Oh, god.
Oh, god! It was so dark, so black and so thick I could not breathe.
I was on my last breath.
Flashing through my mind was my wife and two kids and this is it.
Please.
And then the smoke cleared and there was sky and we were at the door.
VOICEOVER: An airport rescue team is at the crash site in less than five minutes.
News crews aren't far behind.
I looked back and I could see tattered clothes and some blood on some, some of the stewardesses.
Meanwhile, you know, the plane was burning up.
Along with the pilots, Paul Verheyden is one of 94 people who make it off the burning plane alive.
14 others, including flight attendant Dixie Dunn, die, unable to escape the smoke and flames.
Something that I realized was life is not guaranteed.
None of us really know what's gonna happen.
Investigators from the National Transportation Safety Board are quick to arrive on the scene.
JIM CASH: The smell is the first thing that jumps out at you, and it's the smell that gets to you most, more than anything.
Specialist, Jim Cash is one of the first investigators to get to Dallas/Fort Worth Airport.
I was there while it was still smoking.
I've never been to an accident that early on before.
I was on the go team so my instructions were to just go to the accident site.
It was terrible when I got there.
The wreckage was strewn over a large area.
Investigators begin examining the scorched remains of the Boeing 727.
They need to understand why it failed to get airborne.
It is a long runway.
There was no weather at the time.
There's was no reason he shouldn't have gotten off.
So we knew there was something wrong with either the airplane or configuration.
Now we're getting somewhere.
Within hours, workers recover the plane's black boxes and send them to an NTSB lab.
Make sure you get those to D.
C.
ASAP.
The flight data recorder or the cockpit voice recorder are the most important things.
Both of them provide pieces to the puzzle that the investigators need to kind of get the whole picture of what's going on.
With the recorders on their way for analysis, investigators continue searching for clues at the crash site.
We want to walk the accident site because we want to see if there's any evidence that, that would help us understand what happened.
Take a look at this! The back of the wing here.
It's really ground down.
Get some shots of that.
The skid shoe looks like it hit the ground too.
This paint, from the runway? Along with a scraped wing section, they find that the plane's tail skid shoe also suffered damage.
On the Boeing 727, it has a tail skid in the very aft part of the fuselage.
And it's a little metal shoe that rides below the fuselage in case the airplane's nose is rotated up too high you would actually hit this tail skid before you would hit the bottom of the fuselage.
Let's find out where it hit.
What we're really interested in is what was going on before the airplane got to its final resting point.
Bingo.
First impact with the skid shoe, right there.
Mark and measure, please.
If you just look at the geometry of the 727 to strike the tail skid, it works out to roughly a ten degree nose up pitch attitude.
So when we looked at that mark, we knew that the airplane was at a ten degree nose up pitch attitude at that point along the runway.
It's a puzzling discovery.
Ten degrees nose up should allow a 727 to climb out safely.
Why didn't it this time? It looks like we have a match.
Wing tip there, fiberglass nav light beside it.
Impact number two.
We found where the right wing tip had actually struck the runway, and it had deposited quite a bit of aluminum along a segment of the runway.
And so that told us that there was a problem as far as the attitude of the airplane.
OK.
Let's take some measurements, get this runway open.
We knew that the pilot was having some kind of controllability problem at that point.
OK so.
.
the plane is going down the runway.
It can't get in the air.
Its tail starts to drag and the right wing hits the ground.
As they wait for crews to recover all the aircraft wreckage, investigators try to eliminate as many possible causes for the failed take-off as they can.
What was the weight of the plane? RON SCHLEEDE: One of the critical things for departure of an airplane is to get the weight calculated.
If the calculations are wrong, say two, three thousand pounds, the airplane may rotate but it may not fly.
DON SMITH: The actual weight was 157,683 pounds, well below maximum.
Records show that flight 1141 was 18,000 pounds below its maximum take-off weight, well within the limits for the runway at Dallas.
OK, so if weight wasn't an issue maybe they had a fuel imbalance.
Let's check the fuel logs.
The Boeing 727 is equipped with three fuel tanks.
By managing how the fuel is consumed during flight, the pilot is able to properly balance the aircraft.
Initial information that our guys got was that there might have been a fuel imbalance, that the refueling numbers were a little bit confusing.
If the 727 was fueled improperly, it may have been dangerously unbalanced on take-off.
If there was more fuel in the right wing that might account for the right wing scraping the runway that we saw in the accident.
So we go check the refueling records to see how many pounds, how many gallons of fuel were put on.
When they run the numbers So what have we got? It's all fine, no imbalance in the fuel tanks.
.
.
they can find nothing out of the ordinary.
The weight and balance was correct.
It was not a factor in the take-off accident.
It's another dead end.
Air crash investigators in Dallas are trying to figure out why Delta Airlines flight 1141 crashed on take-off.
There was a lot of traffic at Dallas/Fort Worth.
We could be looking at a wing tip vortex.
Wing tip vortices are spirals of air that trail off the tips of an airplane's wings.
The heavier the plane, the bigger the vortex.
These tornado-like winds can sometimes be strong enough to pose an invisible hazard to other planes.
One of the things that can cause an accident on take-off, such as 1141, is if it's behind another aircraft and it happens to encounter the wing tip vortices, fly into those, it can upset the airplane.
Did the plane in front of Delta 1141 create dangerous vortices? Was flight 1141 cleared for take-off too soon, bringing it too close to the plane ahead? Air traffic records show that the plane that took off just before flight 1141 was Delta Airlines flight 1486, another Boeing 727.
They get take-off clearance at 8:59:17.
In this case, we did calculate the probable location of the wing tip vortices for the airplanes that were nearest to the accident airplane.
By then, the other Delta plane was off the ground and already 7,000 feet ahead of them.
Investigators know that the minimum Federal Aviation Authority requirements for separation between flights is 6,000 feet.
We found that even assuming the vortices stayed as strong as they could possibly stay and that they moved in a manner that put them as close as possible to the accident airplane, that they would still be a significant distance away from the accident aircraft.
More than enough clearance.
So, it wasn't wing tip vortex.
We determined there was no effect of the wake vortex on this airplane to cause it to crash.
Excess weight, fuel imbalance and wing tip vortices, three potential causes are now off the table.
The failed take-off of Delta 1141 is still a mystery.
Hey, take a look at that photo.
It looks like the flaps weren't extended.
All commercial airliners must have their wing flaps extended for take-off.
Without the flaps, the wings cannot generate enough lift to carry the plane skyward.
We had to do a lot more digging.
Investigators finally have their hands on critical performance data, the readouts from the plane's flight data recorder.
They hope these can confirm their suspicion that the flaps on this flight were not extended on take-off.
Is this it? But as they scan the numbers, they soon realize the data they need simply isn't there.
This FDR is outdated.
The flight data recorder is an older model, a Lockheed 109-D.
It captures very little information.
The recorder is kind of basic and, uh, it just has your basic flight parameters: airspeed, altitude, heading, basic engine parameters.
There's no information regarding the flaps at all.
The data available can't help them prove the only working theory they have.
It makes it difficult when you don't have many parameters uh to work with.
We need to speak to the crew.
Human factors interviews, when you're fortunate enough to have surviving pilots in a serious accident, we hope to uncover something that's more intuitive than was evident on the flight data recorder or the cockpit voice recorder.
Investigators meet with Delta Captain Larry Davis and his lawyer, along with a representative from the Pilots' Union.
Thank you for coming, everyone.
As a Delta person I was terribly embarrassed that we had let down the traveling public with this accident.
So I can only imagine what the, the pilots of 1141 must have felt like.
It must have been terrible.
OK.
Everyone ready? Let's try and figure this thing out.
Part of the union rep's job is to defend the pilots from any unjust accusation.
Now Captain Davis, just tell me what happened.
Back in the '80s, Airline Pilots' Association had, had seen many of the investigations quickly dismissed as pilot error.
Why would you want to blame it on the pilot? It's real simple.
We're the cheapest guys to nail.
If you had an engine or an airframe that was found to be at fault, airlines could go bankrupt, manufacturers could go bankrupt.
The price would be untold billions.
Nail a pilot and he goes away and case over.
We'd been waiting for some time trying to get permission to taxi.
Hopefully we'll get out of here while we still have teeth in our mouths.
Growing grey at the south ramp, that's Delta 1141.
Investigators want to get as many details as they can from the captain, including what he recalls about the wing flaps.
Lots of traffic waiting to get out.
Definitely a hurry up and wait kind of day.
Now, do you remember if you uh extended the flaps? Of course we did! OK, great.
Now is there anything else you might remember? There was something.
Just when the main gear left the ground I heard two explosions.
A revelation from the captain of Delta flight 1141 about hearing explosions on take-off takes the investigation in a new direction.
Explosions? That's right.
It felt like we were experiencing reverse thrust.
Engine thrust reversers are devices deployed on landing to slow the plane.
If a reverser were to somehow activate on take-off, the results could be catastrophic.
That'll cause an airplane not to fly and it'll stagger down the runway and crash 'cause of wing stall.
OK.
Uh, I think we're done for today.
Thank you all very much for your time.
There have been cases where a thrust reverser has come out inadvertently.
There's been a malfunction.
And so this is always in the back of our mind this is a possibility.
Investigators are chasing a new lead, the possibility that a faulty thrust reverser brought down the plane.
So show me that thrust reverser.
What they need now is hard evidence that can prove or disprove the theory.
We were able to look at the engine thrust reversers in the wreckage after the accident.
We thoroughly examined the mechanisms to make sure what position they were in when this airplane crashed.
What they find leaves no doubt.
They're still stowed.
They were all stowed in their proper position and could not have been extended and then pushed back in by the impact.
That was ruled out totally.
Captain Davis must have been mistaken about the sound he heard on take-off.
The thrust reversers had nothing to do with the accident.
What if the captain is wrong? What if he just thinks they extended the flaps? Wing flaps are still a possible culprit.
Time to see what that recording has to offer.
Crash site wreckage suggests the 727 may not have been properly configured for take-off.
OK.
You ready? But is there anything on the recording that can back up that theory? I forgot to get my pay-check.
Did you get yours? Yeah, I got mine.
They should be focused on the flight, not talking about pay-checks.
When we finally listened to the voice recorder that, that afternoon there was some extraneous conversations on their long taxi out.
Hopefully we'll get out of here while we still have teeth in our mouths.
Growing grey at the south ramp, that's Delta 1141.
The conversation sounds casual.
Investigators are surprised to hear it continue.
Gentlemen, how's it going in here? Is that the flight attendant? And what is she doing in there now? What kind of birds are those? Egrets, or whatever you call 'em.
Are they? I think so.
They're cousins to the ones by the sea.
Sitting in the cockpit talking about birds.
The pilots are not allowed to have non-pertinent conversations from taxi, take-off, up to 10,000 feet.
In this case we were pretty amazed at the lack of discipline in the cockpit during taxi prior to take-off.
That way we have it on recording, you know, in case we crash.
We gotta leave something for our wife and children to listen to.
Good morning, ladies and gentlemen.
We are number four for departure.
Flight attendants, prepare the cabin please.
- We are ready.
- Thank you.
So far, they've heard nothing about the flap configuration.
But what they hear next is another surprise.
We might as well start.
Number three, start valve open.
1141 taxi to position runway one-eight-left and hold.
OK.
1141's position and hold.
Hold up a minute.
Stop.
Here's where the controller bumps them into first position and they've just restarted the engine.
They're gonna have to rush to get airborne.
In the course of about 90 seconds they were to start the engine, finish the taxi checklist, do the before take-off checklist and take off.
That's a rush.
Play it.
Were the pilots so rushed that they overlooked an essential item on their checklist: Investigators need to know if the pilots of Delta flight 1141 missed a critical item on their take-off checklist.
Shoulder harness.
They're on.
Flaps.
15, 15 green light.
Wait.
Stop.
Clear as day - flaps extended to 15 for take-off.
What's going on here? So they did get a little rushed there and, and it was attributed to having the flight attendant in the cockpit and the casual conversations that were going on.
They hit all the items on the checklist.
You could go right down the checklist and they, they got 'em all.
Once again, the no flaps theory is in question.
But investigators may have a way to resolve the flap issue once and for all.
Let's dig up the jackscrews.
Oh perfect.
A device called a jackscrew is an integral part of the flap system.
As it turns, it moves a nut that extends or retracts the flaps.
We like those because most of the time they don't move during impact.
If we want to determine the position of flaps, we go measure the jackscrew.
If the flaps were extended this nut would have been here.
We find the jackscrew, we can determine where the flaps were at take-off.
That seals it.
Those flaps were never extended.
Everything that we examined on the flaps, the mechanisms and everything, reveal that they were all in the retracted position at impact.
It's the conclusive proof they need.
The flaps were not extended before take-off.
But the finding leaves them with another puzzling question.
So why did the pilots think they were extended? Let's go back to the start of the take-off checklist.
The team returns to the cockpit recording, hoping to hear something that might explain the discrepancy.
- Shoulder harness.
- They're on.
- Flaps.
- 15, 15 green light.
Flight controls.
Tops and bottoms are checked.
- Nav instruments.
- They're set.
Take-off briefing.
Is complete.
That was fast.
- Shoulder harness.
- They're on.
- Flaps.
- 15, 15 green light.
Is he, is he checking or just answering? When you have a crew going through the checklist and you can listen to it on the cockpit voice recording, one of the things that you don't typically know is whether they're just confirming a setting that's already been made or if they're actually moving, say, the flap handle to a position that it needs to be in.
- Flaps.
- 15, 15 green light.
There was less than one second between the flaps call and his response.
There's no way he had time to check and see if the flaps were actually out.
No way.
The speed of the first officer's response is an important clue.
It would have been very difficult to actually move the flap lever from, say, zero to 15 degree detent that rapidly.
Investigators are convinced, despite his response, the first officer could not have extended or even checked the flaps in the time available.
Flaps.
15, 15 green light.
But we didn't hear the flap handle being moved.
I don't know what he was doing when the flight engineer read the challenge for flaps.
Uh he gave the correct response.
That's all I can tell you is that he gave the correct response.
You have to be totally focused on the task at hand.
If you're doing the checklist in the middle of other conversations that aren't related to operating the airplane then it's easy to get distracted and it's easy to miss things.
The mystery of the flaps is finally solved.
A rushed checklist led to the Delta pilots thinking that their plane was ready for take-off when it was anything but.
They probably didn't know in a true sense that they forgot.
It wasn't intentional, that's for sure.
And they just overlooked it.
For investigators, there's still one critical question.
The take-off warning would have gone off.
The Boeing 727 is equipped with a take-off warning system specifically designed to prevent the kind of accident that killed 14 and injured dozens more in Dallas.
If you apply take-off thrust and you don't have the flaps in take-off position, you would get a warning horn.
There's no sound of the warning on the recording.
It should have been sounding non-stop.
And we didn't hear the take-off warning horn go off.
The alarm would have saved them.
Why didn't it sound? So that made us think that there must have been some kind of a malfunction of the take-off warning system.
The NTSB wants to know why a critically important take-off warning system failed on Delta flight 1141.
Let's see what happens.
Testing the console that houses the alarm mechanism could provide an answer.
They focus on the electronic components that are designed to trigger the cockpit warning.
Here we go.
There's a little switch that, that when they advance the throttles the switch is supposed to activate the circuitry for the take-off warning horn.
OK.
Let's reset it, try it again.
Here we go.
Hmm.
So it only works sometimes.
What gives? Multiple tests reveal that what should be a fail-safe mechanism is instead intermittent and unreliable.
When the take-off warning system doesn't work it is a big deal.
There's a reason that it exists and it's, uh, it's to prevent a catastrophic accident.
Look at this.
They find the reason for the failure on the terminals of the alarm mechanism: Corrosion.
And this.
And we were able to determine that it was the switch on the throttle quadrant that when you advance the throttles didn't activate the system properly.
If that button slipped off the alarm wouldn't have sounded.
The switch failed and thus there was no aural warning.
So it was a technical failure that happens extremely rarely, and, unfortunately, they needed it that day.
Investigators finally know what happened to Delta Airlines flight 1141.
So it's now 08:58am.
Flight 1141 is lined up behind four other planes on the taxiway.
The Delta crew breaks cockpit protocol while awaiting their turn to taxi.
1141 one-eight-five cleared to go.
Instead of setting the flaps for take-off and focusing on the job at hand, they get distracted by idle chat.
There are still three planes ahead of them when they're suddenly told to move past them to the runway.
When air traffic control cleared them for take-off in that surprise clearance, somebody should have said, wait a minute.
We're not ready.
We can't do that.
We need time to run the checklist.
OK.
1141's position and hold.
Now they're in a rush.
- Shoulder harness.
- They're on.
Investigators believe they are so rushed Flaps.
15, 15 green light.
Flight control.
Tops and bottoms checked.
.
.
that they fail to check if their flaps were properly extended.
You don't want to rush through a checklist when it's vital that you methodically perform everything that's on the list or else you're gonna have a problem during the flight.
A mechanical failure with the take-off warning system meant that the pilots were not alerted to their mistake.
The take-off warning system is a great backup system, but those backup systems don't always perform as they should, so it's really up to the pilots to make sure that they're operating the airplane as methodically and professionally as possible.
Without their wing flaps extended, a successful take-off is virtually impossible.
One minute later, at exactly 9am, the plane crashes.
Following the crash, Captain Larry Davis and first officer Wilson Kirkland both lose their jobs at Delta.
For many of the 94 survivors, including Paul Verheyden, what happened at Dallas/Fort Worth that day remains the most traumatic experience of their lives.
29 years later it still is like it was yesterday it happened and it still causes me to, to really appreciate given the opportunity to survive something like that.
The NTSB concludes that a combination of pilot error and mechanical failure doomed flight 1141.
Their final report calls for changes to cockpit procedures.
They recommend that each crew member visually confirm the execution of all checklist items to help ensure that none are missed.
They also call for a study of the reliability of the take-off warning system in all Boeing 727 models.
The reason airplanes are so good today are because of these accidents.
The job of the NTSB is to look at the mistakes that people have made in the past and make recommendations to keep this stuff from happening again.
The lessons learned from this accident on cockpit discipline, proper training, proper uh leadership by the captain, that was positive.
There are a lot of important things came out of this accident, uh, improvements in aviation safety.
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