Mayday (2013) s18e10 Episode Script
Dead of Winter
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left, cleared for take-off.
NARRATOR: A commercial flight from Denver, Colorado FIRST OFFICER BRUECHER: Damn it! crashes on take-off.
JASON KEMPER: The plane was on top of me.
I was like, okay, maybe I am gonna die here today.
NARRATOR: Rescuers struggle for hours in the bitter cold to free trapped passengers.
BOB WERNER: Stay strong! We'll be there soon.
You're never gonna be able to save everybody.
BOB BENZON: What's going on here? BOB BENZON: After we determined that safe flight was technically possible, we had to determine what else went wrong.
NARRATOR: But that job proves more difficult than anyone imagines.
JOHN COX: There's a lot more to it, and that's what the investigators had to understand.
# # NARRATOR: It's just past two in the afternoon in Denver, Colorado.
There are 77 passengers onboard Continental Airlines flight 1713.
They're headed to Boise, Idaho.
It's been snowing all morning.
Controllers are busy trying to get a line-up of planes off the ground.
AIR TRAFFIC CONTROLLER: Continental 6-5, runway three-five-left, cleared for take-off.
Wind is zero-one-zero at one-five.
CONTINENTAL 65 PILOT: Cleared for take-off three-five-left, Continental 65.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, taxi into position and hold runway three-five-left.
Report in position.
NARRATOR: The controllers have no ground radar to help them track the planes at the airport.
They're struggling to keep departures on schedule.
JOHN COX: The air traffic controllers when they can't physically see the airplanes depend on the pilots reporting known positions to them so that the taxi clearances will be, "Taxi via this taxiway to this point, report when you get there.
" They have to keep a mental image of where all the airplanes are without physically being able to see them.
NARRATOR: The pilots of flight 1713 are waiting for their turn to get off the ground.
The winter weather has already delayed them by nearly 1.
5 hours.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, tower.
NARRATOR: The captain is 43-year-old Frank Zvonek.
He's been flying for Continental for almost 19 years.
CAPTAIN ZVONEK: You might want to tell them we're number one here on the north side.
FIRST OFFICER BRUECHER: Denver tower, Continental 1713 is number one.
DC-9 for Continental.
NARRATOR: The first officer, Lee Bruecher, has only been with the airline for a few months.
The pilots are at the controls of a McDonnell Douglas DC-9, an extremely popular and economical short to medium haul airplane.
JOHN COX: The airlines could, could fly it several legs in a day, do it economically, do it reliably.
AIR TRAFFIC CONTROLLER: Continental 8-7-5, taxi into position and hold.
CONTINENTAL 875 PILOT: Continental 8-75, position and hold.
JASON KEMPER: Great trip, Dad.
Thanks.
MR KEMPER: It was fun, wasn't it? But it will be good to get back home.
NARRATOR: Among the passengers on the two-hour flight to Boise are teenager Jason Kemper and his father.
They're headed home.
JASON KEMPER: We were traveling from Nebraska, where our family farm is, back to Boise.
I feel like we've been here forever.
I know what you mean, buddy.
JASON KEMPER: I remember just sitting and waiting and waiting and waiting and being like, are we ever gonna take off? FIRST OFFICER BRUECHER: Ladies and gentlemen, we have been cleared to taxi into position and hold on the runway.
We will be airborne very shortly.
Flight attendants, prepare the cabin for departure.
NARRATOR: At 2:14 in the afternoon, flight 1713 moves into take-off position.
Before take-off.
Brake selector.
Ignition is override.
CONTINENTAL 875 PILOT: Continental 8-75 is airborne.
There is a little clutter on the runway.
AIR TRAFFIC CONTROLLER: Continental 8-75, thank you.
For anyone who asks there's a bit of crud on the runway.
FIRST OFFICER BRUECHER: A little crud.
VR speed one-forty-five.
CAPTAIN ZVONEK: Don't slide.
NARRATOR: The pilots set their take-off speed: 145 knots.
JOHN COX: When there's a contaminant on the runway, be it wet snow, dry snow or slush, they all differently affect the acceleration and the stopping capability of the airplane.
FIRST OFFICER BRUECHER: Continental 17-13 is in position.
AIR TRAFFIC CONTROLLER: Uh, all right.
Thank you.
Got the brakes on.
You've got the airplane.
FIRST OFFICER BRUECHER: Okay.
NARRATOR: First Officer Bruecher will pilot the plane during the take-off from Denver.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left, cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13, cleared for take-off.
Lights on.
JOHN COX: As the airplane starts to accelerate, the biggest thing is maintaining control of the airplane and keeping it on the center line.
CAPTAIN ZVONEK: Okay.
Power set left and right.
We got 95 knots.
JASON KEMPER: You hear the engines thrust up.
We're finally rolling down the runway.
That was the exciting part of the trip.
AIR TRAFFIC CONTROLLER: United 2-27, taxi into position and hold.
NARRATOR: As flight 1713 speeds down the runway, the controller has already turned his attention to the next flight in line.
CAPTAIN ZVONEK: V-1.
JASON KEMPER: All right.
JASON KEMPER: We, you know, are picking up speed and then, uh, lift-off.
CAPTAIN ZVONEK: Rotate.
Positive rate.
FIRST OFFICER BRUECHER: Damn it.
NARRATOR: The plane is barely off the ground.
But there are signs of serious trouble.
JASON KEMPER: What's happening? MR KEMPER: Don't worry, Jason.
We lifted off the ground and then there was a sharp bank.
A very short time later it banked back the other direction.
I was just like, what's going on? Everybody is screaming at this point.
I'm just like, something's wrong.
NARRATOR: In the tower, controllers have no idea that anything is wrong.
AIR TRAFFIC CONTROLLER: United 2-27, please advise when at runway.
UNITED 227 PILOT: Tower, somebody just crashed on three-five-left.
A big fireball.
AIR TRAFFIC CONTROLLER: Continental 17-13, tower.
Emergency.
All fire and rescue to three-five-left.
I think we had a crash, a DC-9.
NARRATOR: City firefighter Bob Werner is one of the first to answer the call.
BOB WERNER: My first thoughts were that it wasn't a commercial airliner.
It was a small general aviation, maybe two or three souls onboard.
We had no idea what we were actually responding into.
(SIRENS APPROACHING) JASON KEMPER: The plane was on top of me.
There was just, you know, fuselage and scrap metal and broken up pieces all around me.
(SIRENS IN DISTANCE) I was like, okay, maybe I am gonna die here today.
NARRATOR: Darkness has fallen over the Denver crash site of Continental 1713.
Firefighter Bob Werner quickly realizes the accident is much worse than he imagined.
BOB WERNER: When I looked and saw Continental written upside down on the side of the plane my plans changed immediately.
NARRATOR: Of the 82 people on board, more than half are still alive.
But many of the survivors, like Jason Kemper, are trapped in the twisted wreckage.
I remember being very, very, very cold.
To my left was a woman and she was hysterical.
She was, "I'm not gonna make it to Thanksgiving.
" BOB WERNER: We gotta cut away some of this fuselage.
There were some victims that were able to move away from the scene.
But the ones that we were dealing with were basically trapped in the aircraft.
NARRATOR: Rescuers work frantically to free the trapped passengers.
But Werner is worried about sparking a catastrophic fire.
The plane was carrying almost 17,000 pounds of fuel.
BOB WERNER: I smell the vapors.
I smell the fumes.
With the saw that I was using, it was throwing sparks and I didn't want to become an ignition source.
BOB WERNER: Toss me that pry bar.
NARRATOR: Bob Werner struggles for five-and-a-half hours straight, working to save lives.
BOB WERNER: Stay strong! We'll be there soon.
BOB WERNER: You're cutting things and they're not moving and you're thinking, "Uh-oh, what do I do now?" So we just had to chip away a little bit at a time.
That 5.
5 hours seemed to fly by.
NARRATOR: Finally, after hours spent trapped in the bitter cold, Jason Kemper is freed from the wreckage.
JASON KEMPER: I remember the snow falling in my face and, uh, I looked at, you know, the wreckage from outside of the wreckage for the first time.
NARRATOR: Rescuers save 54 lives.
But 28 people die in the crash, including Jason's father.
I remember thinking in my head like, "I don't want to leave here.
" NARRATOR: It's the worst accident ever at Stapleton International Airport.
BOB WERNER: We do what we can.
And we work as quickly and effectively as possible, but you're never gonna be able to save everybody.
NARRATOR: Bob Benzon will lead the investigation for the National Transportation Safety Board.
BOB BENZON: It was my first big accident for a major airline, and I was a little intimidated.
So I wanted to do everything right.
BOB BENZON: Let's see the weather records for the time of the crash.
Visibility three-eighths of a mile, moderate snow and fog.
RICHARD RODRIGUEZ: Not the best conditions for flying, that's for sure.
BOB BENZON: I wanna know about the runway conditions and the de-icing protocols.
BOB BENZON: It was snowing at the time of the accident.
It was below freezing, and these aren't ideal conditions for aviation operation.
But then again, we couldn't focus on that immediately, because other aircraft were taking off and landing routinely.
So there had to be something more than simply bad weather.
NARRATOR: Investigators know that flight 1713 barely got off the ground.
The lack of lift points to a possible cause: wing flaps.
Richard Rodriguez is the investigator looking into the operation of the airplane.
RICHARD RODRIGUEZ: We had had a recent accident involving an MD-80 that had not configured the aircraft properly for take-off.
The flaps were left up instead of take-off position.
And so that was on our mind and one of the things we looked toward first of all.
RICHARD RODRIGUEZ: Flaps are out, no question.
NARRATOR: They quickly discover that the flaps on flight 1713 were in the correct position for take-off.
RICHARD RODRIGUEZ: The flaps were down when we got there, so that indicated that they had set it properly.
NARRATOR: Investigators will need help from the plane's two black boxes if they hope to crack this case.
Luckily, they're both found intact.
BOB BENZON: Cockpit voice recorders record more than just, uh, the voices in the cockpit.
We can determine an engine rotation speed.
We can hear switches being thrown, aural warnings that the aircraft gives off, buzzers or noises and things like that.
NARRATOR: What clues do the flight 1713 recorders hold? Investigators won't know until NTSB technicians While investigators wait for the black box data, they hope to learn more about flight 1713 from the controller on duty at the time of the accident.
INVESTIGATOR: Okay, let's take it from the top.
Look, the first I heard from them they were already at the runway.
I mean, it kind of took me by surprise actually.
Continental 5-9-4, tower.
NARRATOR: The controller thought the next flight in line was Continental 5-9-4, but he was unable to make contact with that plane.
FIRST OFFICER BRUECHER: Uh, Denver Tower, the number one on the runway is Continental 1713.
1713, are you an MD-80? FIRST OFFICER BRUECHER: Negative, sir.
DC-9.
I don't know how 1713 got there, but there he is.
NARRATOR: The controller explains that all of a sudden flight 1713 reported being at the runway.
AIR TRAFFIC CONTROLLER: He should have gone from the gate to the de-icing facility, then taxied to the runway, but the first I heard from him he was already in position at the runway.
NARRATOR: The revelation leaves investigators with a crucial question.
Did flight 1713 neglect to de-ice before heading for the runway? Ice on the surface of a wing can be deadly.
It can disrupt the wing's ability to produce lift, leading to an aerodynamic stall.
That's why in winter conditions planes must be de-iced before every take-off.
JOHN COX: For aerodynamic reasons, you don't want any ice adhering.
It distorts the air flow and has an adverse effect on lift or the airplane's ability to fly.
NARRATOR: Investigators check with the de-icing supervisor.
RICHARD RODRIGUEZ: So it was fully de-iced and out to the runway? His records show that flight 1713 did de-ice before going to the runway.
Investigators are no closer to understanding why the plane couldn't climb out safely.
But they are very close to hearing the final moments inside the cockpit.
The recording is intact.
CAPTAIN ZVONEK: It's like going through a car wash.
BOB BENZON: Unmistakably de-icing spray.
BOB BENZON: In this particular case, the cockpit voice recorder even picked up the, uh, the sound of de-icing fluid hitting the fuselage.
JASON KEMPER: The de-icing was something that I'd never seen before.
You know, you see foam just getting shot all over the plane and the windows.
BOB BENZON: That's it.
De-icing complete at 1:47.
So we knew exactly when that de-icing procedure began and exactly when it stopped.
CAPTAIN ZVONEK: Start 'em both.
FIRST OFFICER BRUECHER: Okay.
NARRATOR: Investigators now know exactly when the pilots re-started their engines and left the de-icing bay.
They wonder if there were any other factors that could have affected the plane before take-off.
BOB BENZON: Stapleton was down to two runways, 35-left for take-offs, 35-right for landings.
NARRATOR: They consider the layout of the Denver Airport.
The two runways were only 1,600 feet apart.
JOHN COX: They were able to use one side for arrivals and one side for departures, and that let the flow run as well as it could considering the weather.
Let's see who was landing beside our plane.
NARRATOR: Large airplanes can create dangerous wake vortices.
Swirling winds coming off the wing tips can travel great distances.
How far depends on the weight of the plane and the weather conditions.
Investigators now wonder Did a powerful vortex from another plane upset flight 1713 just as it was attempting to take off? CONTINENTAL 875 PILOT: Tower, Continental 8-75 is in position.
AIR TRAFFIC CONTROLLER: it's gonna be a few more minutes for the runway, guys.
We are running them a bit tight to the right.
NARRATOR: Because the runways are so close together, controllers usually call for a two-minute gap between each landing and take-off.
But, on the day of the accident, there was so much traffic that the time between landings and take-offs was sometimes as short as one minute.
The last plane to land before the accident was this one, Delta flight 3-6-7.
NARRATOR: Three minutes before flight 1713 was cleared for take-off, a Delta Airlines 767 touched down on the neighbouring runway.
Continental 17-13, runway three-five-left cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13 cleared for take-off.
NARRATOR: Was flight 1713 allowed to take off too soon after the Delta flight's landing? A 767, weighing 300,000 pounds, creates a wake vortex that can drift 1,700 feet to the side and linger for up to 3.
5 minutes.
Such a wake vortex could have disrupted flight 1713's take-off.
BOB BENZON: Okay.
Let's start with the weights.
Using flight records, investigators calculate the weight of the landing Delta plane.
They factor in passengers, baggage and fuel load and come up with a number: 232,000 pounds.
BOB BENZON: Tough to generate much of vortex at that weight.
What about the winds? NARRATOR: A wake vortex will travel furthest when the atmosphere is calm and stable.
Even mild winds can help dissipate wake vortices.
BOB BENZON: Moderate snow.
Winds gusting to 17 knots.
NARRATOR: Based on the weather reports at Stapleton Airport, investigators calculate the distance a wake vortex could have traveled.
BOB BENZON: There's no way a vortex traveled 1,600 feet that day.
BOB BENZON: In the end when we took everything into consideration - wind speeds, wind direction, aircraft weights, etcetera, etcetera, the wake vortex encounter simply could not have occurred.
NARRATOR: What doomed Continental flight 1713 is still a mystery.
BOB BENZON: Okay.
De-icing is completed at 1:47.
NARRATOR: Investigators are still hunting for the cause of the failed take-off of Continental 1713.
They begin a detailed analysis of the plane's various movements around Denver's Stapleton airport.
They need to get off the ground in the next 20 minutes.
JOHN COX: Continental at that time in their flight operations manual said that the crew needed to be airborne within 20 minutes of de-icing.
NARRATOR: After 20 minutes, the melting ice and snow on the wing can start to freeze again, forming a new layer of ice.
BOB BENZON: Let's see what happens.
NARRATOR: Did flight 1713 get off the ground within the mandated 20 minutes? CAPTAIN ZVONEK: Before start.
NARRATOR: The CVR shows that it took the pilots four minutes to restart their engines.
FIRST OFFICER BRUECHER: Hydraulics? CAPTAIN ZVONEK: Check.
On high.
BOB BENZON: So far so good.
Plenty of time to get to the runway and off the ground.
FIRST OFFICER BRUECHER: Engine anti-ice.
CAPTAIN ZVONEK: Is on.
NARRATOR: It takes the crew another three minutes to run the pre-taxi checklist.
CAPTAIN ZVONEK: Go ahead and run the taxi.
BOB BENZON: And they're on the move.
NARRATOR: Eleven minutes after de-icing, Continental 1713 is taxiing towards the runway.
FIRST OFFICER BRUECHER: Bug is set.
145.
NARRATOR: It should only take about a minute to reach the runway from the de-icing bay.
The de-icing array was as close as practical to the runway for obvious reasons.
You want to de-ice and then take off as soon as possible.
There are two flights ahead of them: Continental 1617, Continental 65.
There are 8 minutes until the clock runs out.
NARRATOR: Flight 1713 should be able to get off the ground within the 20-minute deadline.
AIR TRAFFIC CONTROLLER: Continental 1617, runway 3-5-left cleared for take-off.
Okay.
Continental 1617 is off.
Continental 65 is up next.
And they have one plane in front of them with five minutes left on the clock.
CAPTAIN ZVONEK: This stuff just may not go anywhere.
It may hang in for a couple of days.
FIRST OFFICER BRUECHER: Uh-huh.
AIR TRAFFIC CONTROLLER: Cleared for take-off 3-5-left, Continental 65.
NARRATOR: Eighteen minutes after leaving the de-icing bay, there are no more planes between flight 1713 and the runway.
The pilots expect to hear their number next.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, taxi into position and hold runway 3-5-left.
Report in position.
BOB BENZON: Continental 594? What's going on here? NARRATOR: For some reason, the controller isn't clearing flight 1713 for take-off.
BOB BENZON: It was very, very confusing trying to figure out where several aircraft were on the ground at the same time.
I mean, it was so complicated, and I ended up going to a toy store and buying a bunch of little plastic airplanes, getting a big map of the airport and we were pushing these little plastic planes around just so we could get a handle on, on where everybody was.
NARRATOR: They check the flight records of 5-9-4 to determine its position at the time.
INVESTIGATOR: Continental 5-94 is an MD-80 back at the de-ice bay.
So why is the tower trying to get him on the runway? AIR TRAFFIC CONTROLLER: Can anybody see an MD-80 going into position out there? The controller seems to have lost track of the planes in line for the runway.
CAPTAIN ZVONEK: You might want to tell him we're number one here on the north side.
The crew of flight 1713 tries to clear up the confusion.
FIRST OFFICER BRUECHER: Denver tower, Continental 1713 is number one, DC-9 for Continental.
NARRATOR: Closing in on the 20-minute limit, they report that they're next in line to take off.
But the controller thinks the next plane in line is flight 5-9-4.
INVESTIGATOR: The controller thinks 1713 is flight 594.
But flight 5-9-4 is back here being de-iced.
RICHARD RODRIGUEZ: He was in the de-icing pad, radio shut off, engine shut down and wasn't even listening.
AIR TRAFFIC CONTROLLER: Continental 8-7-5, can you get around an MD-80 for the runway? CONTINENTAL 875 PILOT: Continental 8-75, affirmative.
Who's this now? INVESTIGATOR: He's moving planes around what he thinks is 5-9-4.
NARRATOR: The controller isn't getting an answer from what he believes is the next plane in line, flight 5-9-4.
So he starts moving planes around it.
That confusion was on the part of the controller because he had three or four Continental aircraft he was talking to and he didn't know where each of them was.
As flight 1713 passes the 20-minute mark, the crew is busy trying to sort out the controller's confusion.
Denver tower, number one at the runway is Continental 1713.
AIR TRAFFIC CONTROLLER: 1713, are you an MD-80? FIRST OFFICER BRUECHER: Negative, sir.
DC-9.
The controller doesn't have a flight strip for flight 1713, which only adds to his confusion.
I don't know how 17-13 got there, but there he is.
All right.
Thank you.
Okay.
I think we've got him straightened out.
We'll see.
BOB BENZON: Then 8-75 takes off ahead of them.
In all the confusion, flight 1713 is still on the ground well past the 20-minute limit.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13, cleared for take-off.
NARRATOR: The DC-9 spent 27 minutes waiting in the snow.
RICHARD RODRIGUEZ: That's a pretty long time when you're having continuous precipitation at freezing temperatures.
BOB BENZON: So they start their take-off roll at 2:14:31, but never get more than 20 feet off the ground.
NARRATOR: The critical question now: Did a seven-minute delay turn a routine take-off into a fatal disaster? Investigators need to know how much snow could have accumulated on flight 1713's wings after de-icing.
Passengers say they saw patches of ice on the wings while they were waiting to take off.
JASON KEMPER: Snow was accumulating on the wing.
I was kind of uneasy about it.
Is this normal? I'm sure the pilots know what they're doing.
You trust your father and the people that are running a plane.
Okay.
What do we have between 1:47 and 2:14? BOB BENZON: We had to look at the amount of precipitation that was falling, the rate that it was accumulating on airplanes.
NARRATOR: They study data from the National Weather Service.
BOB BENZON: Less than a third of an inch of snow? Can you print that up for me? NARRATOR: Investigators now need to figure out how much of that snow could have turned into ice on the wings of the DC-9.
The de-icing solution is supposed to melt the snow accumulating on the plane's wings.
But, if it's cold enough, that melted snow can dilute the solution and then refreeze as ice.
BOB BENZON: Twenty-eight degrees.
It's cold enough for water to freeze.
NARRATOR: Benzon calculates exactly how much ice accumulated on the wings in the 27 minutes before take-off.
Melt 0.
292 inches of snow and you get 0.
036 inches of water.
That can't be enough to bring down a DC-9, can it? BOB BENZON: It would be the equivalent of, of 30 to 40 grit sandpaper, which is about like sprinkling salt on the wing.
NARRATOR: Investigators look into the wing accumulation tolerance of a DC-9.
The manufacturer, McDonnell Douglas, provides them with some stunning data.
Higher stall speed? Wow! That's incredible.
Calculations show that the very small amount of ice on the wings was enough to degrade performance, increasing the speed needed for take-off.
RICHARD RODRIGUEZ: When I found out that, uh, just the equivalent of thirty grit sandpaper of contamination on the wing can degrade the performance by a good 20 knots, that's significant and so I was kind of shocked.
Damn it! NARRATOR: Investigators may have finally solved the mystery of flight 1713's failed take-off.
They turn to the flight data, looking for confirmation that ice contamination caused a fatal stall.
BOB BENZON: Wait a minute.
Look at this.
But right away, they spot something that suggests there is more to it than just ice.
The plane sped past the target take-off speed of 145 knots.
They kept accelerating to 165 right before the crash.
JASON KEMPER: All right.
NARRATOR: The data shows the plane did reach a speed where it could have overcome the loss of performance caused by icing.
That's close, but it looks like they could have climbed out.
BOB BENZON: We determined that, even with the contamination and the type of aircraft, etcetera, etcetera, flown correctly, the aircraft probably would have been able to get off the ground and fly away safely.
So icing was a factor but not the only one.
After we determined that a safe flight was technically possible, we had to determine what happened.
What else went wrong? Show me the angle of attack.
Now what is going on here? NARRATOR: Investigators are intrigued by the plane's pitch-up attitude on take-off.
To keep drag to a minimum, airliners normally take off at a shallow angle of about five or six degrees.
When you get to the flying speed where you pull back on the yoke and the nose starts to rise, you wanna do that somewhat gently to let the wings start producing lift and make that transition in a smooth way.
NARRATOR: Data reveals that flight 1713 pitched up steeply, at twice the normal rate.
V-1.
Rotate.
JOHN COX: The problem is that then you create a large amount of drag, and if there's any contamination on the wing you drive the airplane into a stalled condition right as it breaks ground, which is in fact what occurred.
CAPTAIN ZVONEK: Positive rate.
Damn it! It seems the first officer took a bad situation and made it worse by pulling back too severely on his control column.
JASON KEMPER: What's happening? MR KEMPER: Don't worry, Jason.
NARRATOR: How a trained pilot could make such a lethal mistake is the next important question.
BOB BENZON: Once we determined that the rotation rate and the degrees that the aircraft obtained very quickly on rotation, were so high, we needed to try to figure out why.
BOB BENZON: Thank you.
Let's see what we can figure out about these guys.
NARRATOR: Investigators dig into the crew training records.
BOB BENZON: Well the training records became quite important once we began to suspect that one crew member wasn't quite up to snuff, so to speak.
NARRATOR: What they uncover about the first officer is troubling.
BOB BENZON: Hardly a stellar performance at that airline.
But then he gets hired again.
The first officer had a checkered history, to say the least.
He wasn't really the ace of the base.
BOB BENZON: And then in May '86 he fails a flight exam.
And get this, he flew right past a holding fix and then botched his approach.
JOHN COX: The first officer had failed some check rides and had had some issues in the turboprops.
BOB BENZON: Guess who hires him next? JOHN COX: He was not fully up to speed with all the jobs that he had to do flying this new airplane.
This was a big step for him.
NARRATOR: Investigators scour Lee Bruecher's employment records, trying to understand how he ever got hired by Continental Airlines.
Wait, stop! This is from the guys who fired him.
They soon learn that although Continental did perform a background check on Bruecher, the airline was kept in the dark about his poor performance.
JOHN COX: The previous employer informed Continental this pilot had left there to pursue other opportunities but he left of his own choosing.
BOB BENZON: Uh we think the, the reason the previous employer wasn't quite truthful about the skills of the first officer was they frankly were afraid of a lawsuit, afraid of getting sued by the first officer.
NARRATOR: Four months after being hired, and with only 36 hours flying large passenger jets, he over-rotates a DC-9, leading to a fatal stall that claims 28 lives.
That young man never belonged in a large aircraft.
NARRATOR: The revelations about the first officer raise an important question about the captain of the flight.
Why did he allow him to attempt a challenging take-off on a snow-covered runway? - You've got the airplane.
- Okay.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left cleared for take-off.
Cleared for take-off, Continental 17-13.
NARRATOR: Investigators learn that Frank Zvonek had been with the airline for almost 19 years, but he'd only been a captain for less than a month.
To make matters worse, the two pilots had never flown together before, and neither one had ever flown a DC-9 in icing conditions.
BOB BENZON: It was just a bad combination from the get-go.
No real check and balance there.
RICHARD RODRIGUEZ: The weather was very poor.
The captain was really in error to let the first officer make that take-off.
NARRATOR: Investigators conclude the inexperienced captain was ill-prepared for what came next.
V-1 Rotate.
Positive rate.
Damn it! NARRATOR: Captain Zvonek does nothing to counteract his first officer's catastrophic actions.
The combination of a new captain, a rookie first officer and a thin layer of ice proves lethal.
JOHN COX: Had the rotation rate been at the normal or even slightly below rate, it is quite likely that the airplane would have accelerated normally, produced lift normally and that the take-off would have proceeded normally.
NARRATOR: Investigators are left with one final mystery to solve.
FIRST OFFICER BRUECHER: Uh, Denver tower, number one at the runway is Continental 17-13.
AIR TRAFFIC CONTROLLER: 17-13, are you an MD-80? FIRST OFFICER BRUECHER: Negative, Sir.
DC-9.
NARRATOR: The delay in getting flight 17-13 off the ground was a critical factor in the crash.
Why didn't the controller know there was a DC-9 waiting at the foot of the runway? BOB BENZON: They never asked for permission to taxi.
CAPTAIN ZVONEK: Continental 17-13 at Delta 18 going to Boise.
AIR TRAFFIC CONTROLLER: Continental 17-13, cleared to Boise.
Okay.
Ready to push.
NARRATOR: Investigators discover that the pilots began taxiing to the de-ice bay without proper clearance, creating confusion for the controllers.
From that point on, no one had a clear picture of the plane's whereabouts.
BOB BENZON: The fact that the accident aircraft 17-13 was taxiing around almost at will with no true idea of where he was going, he wasn't telling people where he was, that's a very serious thing.
I mean, they could have overcome a couple of these, but combined they didn't have a chance.
BOB BENZON: In the end, uh, we actually had to have two major reasons to make the accident occur.
If you take one away, the icing, then the rapid rotation wouldn't have mattered too much at all.
If you take away the rapid rotation, then the icing wouldn't have mattered much at all.
So you had to have both to have this accident.
NARRATOR: The NTSB recommends strict new guidelines for the de-icing of DC-9 airplanes.
They also call on airlines to establish new rules to prevent inexperienced pilots from being paired together on the same flight.
BOB BENZON: We recommended that a crew such as the one on Continental flight 17-13 would never exist again.
A not very experienced crew member on the right seat, coupled with an inexperienced captain in the left seat.
And Continental and the other airlines and the FAA bought off on that very quickly.
So that was a big lesson learned.
NARRATOR: A commercial flight from Denver, Colorado FIRST OFFICER BRUECHER: Damn it! crashes on take-off.
JASON KEMPER: The plane was on top of me.
I was like, okay, maybe I am gonna die here today.
NARRATOR: Rescuers struggle for hours in the bitter cold to free trapped passengers.
BOB WERNER: Stay strong! We'll be there soon.
You're never gonna be able to save everybody.
BOB BENZON: What's going on here? BOB BENZON: After we determined that safe flight was technically possible, we had to determine what else went wrong.
NARRATOR: But that job proves more difficult than anyone imagines.
JOHN COX: There's a lot more to it, and that's what the investigators had to understand.
# # NARRATOR: It's just past two in the afternoon in Denver, Colorado.
There are 77 passengers onboard Continental Airlines flight 1713.
They're headed to Boise, Idaho.
It's been snowing all morning.
Controllers are busy trying to get a line-up of planes off the ground.
AIR TRAFFIC CONTROLLER: Continental 6-5, runway three-five-left, cleared for take-off.
Wind is zero-one-zero at one-five.
CONTINENTAL 65 PILOT: Cleared for take-off three-five-left, Continental 65.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, taxi into position and hold runway three-five-left.
Report in position.
NARRATOR: The controllers have no ground radar to help them track the planes at the airport.
They're struggling to keep departures on schedule.
JOHN COX: The air traffic controllers when they can't physically see the airplanes depend on the pilots reporting known positions to them so that the taxi clearances will be, "Taxi via this taxiway to this point, report when you get there.
" They have to keep a mental image of where all the airplanes are without physically being able to see them.
NARRATOR: The pilots of flight 1713 are waiting for their turn to get off the ground.
The winter weather has already delayed them by nearly 1.
5 hours.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, tower.
NARRATOR: The captain is 43-year-old Frank Zvonek.
He's been flying for Continental for almost 19 years.
CAPTAIN ZVONEK: You might want to tell them we're number one here on the north side.
FIRST OFFICER BRUECHER: Denver tower, Continental 1713 is number one.
DC-9 for Continental.
NARRATOR: The first officer, Lee Bruecher, has only been with the airline for a few months.
The pilots are at the controls of a McDonnell Douglas DC-9, an extremely popular and economical short to medium haul airplane.
JOHN COX: The airlines could, could fly it several legs in a day, do it economically, do it reliably.
AIR TRAFFIC CONTROLLER: Continental 8-7-5, taxi into position and hold.
CONTINENTAL 875 PILOT: Continental 8-75, position and hold.
JASON KEMPER: Great trip, Dad.
Thanks.
MR KEMPER: It was fun, wasn't it? But it will be good to get back home.
NARRATOR: Among the passengers on the two-hour flight to Boise are teenager Jason Kemper and his father.
They're headed home.
JASON KEMPER: We were traveling from Nebraska, where our family farm is, back to Boise.
I feel like we've been here forever.
I know what you mean, buddy.
JASON KEMPER: I remember just sitting and waiting and waiting and waiting and being like, are we ever gonna take off? FIRST OFFICER BRUECHER: Ladies and gentlemen, we have been cleared to taxi into position and hold on the runway.
We will be airborne very shortly.
Flight attendants, prepare the cabin for departure.
NARRATOR: At 2:14 in the afternoon, flight 1713 moves into take-off position.
Before take-off.
Brake selector.
Ignition is override.
CONTINENTAL 875 PILOT: Continental 8-75 is airborne.
There is a little clutter on the runway.
AIR TRAFFIC CONTROLLER: Continental 8-75, thank you.
For anyone who asks there's a bit of crud on the runway.
FIRST OFFICER BRUECHER: A little crud.
VR speed one-forty-five.
CAPTAIN ZVONEK: Don't slide.
NARRATOR: The pilots set their take-off speed: 145 knots.
JOHN COX: When there's a contaminant on the runway, be it wet snow, dry snow or slush, they all differently affect the acceleration and the stopping capability of the airplane.
FIRST OFFICER BRUECHER: Continental 17-13 is in position.
AIR TRAFFIC CONTROLLER: Uh, all right.
Thank you.
Got the brakes on.
You've got the airplane.
FIRST OFFICER BRUECHER: Okay.
NARRATOR: First Officer Bruecher will pilot the plane during the take-off from Denver.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left, cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13, cleared for take-off.
Lights on.
JOHN COX: As the airplane starts to accelerate, the biggest thing is maintaining control of the airplane and keeping it on the center line.
CAPTAIN ZVONEK: Okay.
Power set left and right.
We got 95 knots.
JASON KEMPER: You hear the engines thrust up.
We're finally rolling down the runway.
That was the exciting part of the trip.
AIR TRAFFIC CONTROLLER: United 2-27, taxi into position and hold.
NARRATOR: As flight 1713 speeds down the runway, the controller has already turned his attention to the next flight in line.
CAPTAIN ZVONEK: V-1.
JASON KEMPER: All right.
JASON KEMPER: We, you know, are picking up speed and then, uh, lift-off.
CAPTAIN ZVONEK: Rotate.
Positive rate.
FIRST OFFICER BRUECHER: Damn it.
NARRATOR: The plane is barely off the ground.
But there are signs of serious trouble.
JASON KEMPER: What's happening? MR KEMPER: Don't worry, Jason.
We lifted off the ground and then there was a sharp bank.
A very short time later it banked back the other direction.
I was just like, what's going on? Everybody is screaming at this point.
I'm just like, something's wrong.
NARRATOR: In the tower, controllers have no idea that anything is wrong.
AIR TRAFFIC CONTROLLER: United 2-27, please advise when at runway.
UNITED 227 PILOT: Tower, somebody just crashed on three-five-left.
A big fireball.
AIR TRAFFIC CONTROLLER: Continental 17-13, tower.
Emergency.
All fire and rescue to three-five-left.
I think we had a crash, a DC-9.
NARRATOR: City firefighter Bob Werner is one of the first to answer the call.
BOB WERNER: My first thoughts were that it wasn't a commercial airliner.
It was a small general aviation, maybe two or three souls onboard.
We had no idea what we were actually responding into.
(SIRENS APPROACHING) JASON KEMPER: The plane was on top of me.
There was just, you know, fuselage and scrap metal and broken up pieces all around me.
(SIRENS IN DISTANCE) I was like, okay, maybe I am gonna die here today.
NARRATOR: Darkness has fallen over the Denver crash site of Continental 1713.
Firefighter Bob Werner quickly realizes the accident is much worse than he imagined.
BOB WERNER: When I looked and saw Continental written upside down on the side of the plane my plans changed immediately.
NARRATOR: Of the 82 people on board, more than half are still alive.
But many of the survivors, like Jason Kemper, are trapped in the twisted wreckage.
I remember being very, very, very cold.
To my left was a woman and she was hysterical.
She was, "I'm not gonna make it to Thanksgiving.
" BOB WERNER: We gotta cut away some of this fuselage.
There were some victims that were able to move away from the scene.
But the ones that we were dealing with were basically trapped in the aircraft.
NARRATOR: Rescuers work frantically to free the trapped passengers.
But Werner is worried about sparking a catastrophic fire.
The plane was carrying almost 17,000 pounds of fuel.
BOB WERNER: I smell the vapors.
I smell the fumes.
With the saw that I was using, it was throwing sparks and I didn't want to become an ignition source.
BOB WERNER: Toss me that pry bar.
NARRATOR: Bob Werner struggles for five-and-a-half hours straight, working to save lives.
BOB WERNER: Stay strong! We'll be there soon.
BOB WERNER: You're cutting things and they're not moving and you're thinking, "Uh-oh, what do I do now?" So we just had to chip away a little bit at a time.
That 5.
5 hours seemed to fly by.
NARRATOR: Finally, after hours spent trapped in the bitter cold, Jason Kemper is freed from the wreckage.
JASON KEMPER: I remember the snow falling in my face and, uh, I looked at, you know, the wreckage from outside of the wreckage for the first time.
NARRATOR: Rescuers save 54 lives.
But 28 people die in the crash, including Jason's father.
I remember thinking in my head like, "I don't want to leave here.
" NARRATOR: It's the worst accident ever at Stapleton International Airport.
BOB WERNER: We do what we can.
And we work as quickly and effectively as possible, but you're never gonna be able to save everybody.
NARRATOR: Bob Benzon will lead the investigation for the National Transportation Safety Board.
BOB BENZON: It was my first big accident for a major airline, and I was a little intimidated.
So I wanted to do everything right.
BOB BENZON: Let's see the weather records for the time of the crash.
Visibility three-eighths of a mile, moderate snow and fog.
RICHARD RODRIGUEZ: Not the best conditions for flying, that's for sure.
BOB BENZON: I wanna know about the runway conditions and the de-icing protocols.
BOB BENZON: It was snowing at the time of the accident.
It was below freezing, and these aren't ideal conditions for aviation operation.
But then again, we couldn't focus on that immediately, because other aircraft were taking off and landing routinely.
So there had to be something more than simply bad weather.
NARRATOR: Investigators know that flight 1713 barely got off the ground.
The lack of lift points to a possible cause: wing flaps.
Richard Rodriguez is the investigator looking into the operation of the airplane.
RICHARD RODRIGUEZ: We had had a recent accident involving an MD-80 that had not configured the aircraft properly for take-off.
The flaps were left up instead of take-off position.
And so that was on our mind and one of the things we looked toward first of all.
RICHARD RODRIGUEZ: Flaps are out, no question.
NARRATOR: They quickly discover that the flaps on flight 1713 were in the correct position for take-off.
RICHARD RODRIGUEZ: The flaps were down when we got there, so that indicated that they had set it properly.
NARRATOR: Investigators will need help from the plane's two black boxes if they hope to crack this case.
Luckily, they're both found intact.
BOB BENZON: Cockpit voice recorders record more than just, uh, the voices in the cockpit.
We can determine an engine rotation speed.
We can hear switches being thrown, aural warnings that the aircraft gives off, buzzers or noises and things like that.
NARRATOR: What clues do the flight 1713 recorders hold? Investigators won't know until NTSB technicians While investigators wait for the black box data, they hope to learn more about flight 1713 from the controller on duty at the time of the accident.
INVESTIGATOR: Okay, let's take it from the top.
Look, the first I heard from them they were already at the runway.
I mean, it kind of took me by surprise actually.
Continental 5-9-4, tower.
NARRATOR: The controller thought the next flight in line was Continental 5-9-4, but he was unable to make contact with that plane.
FIRST OFFICER BRUECHER: Uh, Denver Tower, the number one on the runway is Continental 1713.
1713, are you an MD-80? FIRST OFFICER BRUECHER: Negative, sir.
DC-9.
I don't know how 1713 got there, but there he is.
NARRATOR: The controller explains that all of a sudden flight 1713 reported being at the runway.
AIR TRAFFIC CONTROLLER: He should have gone from the gate to the de-icing facility, then taxied to the runway, but the first I heard from him he was already in position at the runway.
NARRATOR: The revelation leaves investigators with a crucial question.
Did flight 1713 neglect to de-ice before heading for the runway? Ice on the surface of a wing can be deadly.
It can disrupt the wing's ability to produce lift, leading to an aerodynamic stall.
That's why in winter conditions planes must be de-iced before every take-off.
JOHN COX: For aerodynamic reasons, you don't want any ice adhering.
It distorts the air flow and has an adverse effect on lift or the airplane's ability to fly.
NARRATOR: Investigators check with the de-icing supervisor.
RICHARD RODRIGUEZ: So it was fully de-iced and out to the runway? His records show that flight 1713 did de-ice before going to the runway.
Investigators are no closer to understanding why the plane couldn't climb out safely.
But they are very close to hearing the final moments inside the cockpit.
The recording is intact.
CAPTAIN ZVONEK: It's like going through a car wash.
BOB BENZON: Unmistakably de-icing spray.
BOB BENZON: In this particular case, the cockpit voice recorder even picked up the, uh, the sound of de-icing fluid hitting the fuselage.
JASON KEMPER: The de-icing was something that I'd never seen before.
You know, you see foam just getting shot all over the plane and the windows.
BOB BENZON: That's it.
De-icing complete at 1:47.
So we knew exactly when that de-icing procedure began and exactly when it stopped.
CAPTAIN ZVONEK: Start 'em both.
FIRST OFFICER BRUECHER: Okay.
NARRATOR: Investigators now know exactly when the pilots re-started their engines and left the de-icing bay.
They wonder if there were any other factors that could have affected the plane before take-off.
BOB BENZON: Stapleton was down to two runways, 35-left for take-offs, 35-right for landings.
NARRATOR: They consider the layout of the Denver Airport.
The two runways were only 1,600 feet apart.
JOHN COX: They were able to use one side for arrivals and one side for departures, and that let the flow run as well as it could considering the weather.
Let's see who was landing beside our plane.
NARRATOR: Large airplanes can create dangerous wake vortices.
Swirling winds coming off the wing tips can travel great distances.
How far depends on the weight of the plane and the weather conditions.
Investigators now wonder Did a powerful vortex from another plane upset flight 1713 just as it was attempting to take off? CONTINENTAL 875 PILOT: Tower, Continental 8-75 is in position.
AIR TRAFFIC CONTROLLER: it's gonna be a few more minutes for the runway, guys.
We are running them a bit tight to the right.
NARRATOR: Because the runways are so close together, controllers usually call for a two-minute gap between each landing and take-off.
But, on the day of the accident, there was so much traffic that the time between landings and take-offs was sometimes as short as one minute.
The last plane to land before the accident was this one, Delta flight 3-6-7.
NARRATOR: Three minutes before flight 1713 was cleared for take-off, a Delta Airlines 767 touched down on the neighbouring runway.
Continental 17-13, runway three-five-left cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13 cleared for take-off.
NARRATOR: Was flight 1713 allowed to take off too soon after the Delta flight's landing? A 767, weighing 300,000 pounds, creates a wake vortex that can drift 1,700 feet to the side and linger for up to 3.
5 minutes.
Such a wake vortex could have disrupted flight 1713's take-off.
BOB BENZON: Okay.
Let's start with the weights.
Using flight records, investigators calculate the weight of the landing Delta plane.
They factor in passengers, baggage and fuel load and come up with a number: 232,000 pounds.
BOB BENZON: Tough to generate much of vortex at that weight.
What about the winds? NARRATOR: A wake vortex will travel furthest when the atmosphere is calm and stable.
Even mild winds can help dissipate wake vortices.
BOB BENZON: Moderate snow.
Winds gusting to 17 knots.
NARRATOR: Based on the weather reports at Stapleton Airport, investigators calculate the distance a wake vortex could have traveled.
BOB BENZON: There's no way a vortex traveled 1,600 feet that day.
BOB BENZON: In the end when we took everything into consideration - wind speeds, wind direction, aircraft weights, etcetera, etcetera, the wake vortex encounter simply could not have occurred.
NARRATOR: What doomed Continental flight 1713 is still a mystery.
BOB BENZON: Okay.
De-icing is completed at 1:47.
NARRATOR: Investigators are still hunting for the cause of the failed take-off of Continental 1713.
They begin a detailed analysis of the plane's various movements around Denver's Stapleton airport.
They need to get off the ground in the next 20 minutes.
JOHN COX: Continental at that time in their flight operations manual said that the crew needed to be airborne within 20 minutes of de-icing.
NARRATOR: After 20 minutes, the melting ice and snow on the wing can start to freeze again, forming a new layer of ice.
BOB BENZON: Let's see what happens.
NARRATOR: Did flight 1713 get off the ground within the mandated 20 minutes? CAPTAIN ZVONEK: Before start.
NARRATOR: The CVR shows that it took the pilots four minutes to restart their engines.
FIRST OFFICER BRUECHER: Hydraulics? CAPTAIN ZVONEK: Check.
On high.
BOB BENZON: So far so good.
Plenty of time to get to the runway and off the ground.
FIRST OFFICER BRUECHER: Engine anti-ice.
CAPTAIN ZVONEK: Is on.
NARRATOR: It takes the crew another three minutes to run the pre-taxi checklist.
CAPTAIN ZVONEK: Go ahead and run the taxi.
BOB BENZON: And they're on the move.
NARRATOR: Eleven minutes after de-icing, Continental 1713 is taxiing towards the runway.
FIRST OFFICER BRUECHER: Bug is set.
145.
NARRATOR: It should only take about a minute to reach the runway from the de-icing bay.
The de-icing array was as close as practical to the runway for obvious reasons.
You want to de-ice and then take off as soon as possible.
There are two flights ahead of them: Continental 1617, Continental 65.
There are 8 minutes until the clock runs out.
NARRATOR: Flight 1713 should be able to get off the ground within the 20-minute deadline.
AIR TRAFFIC CONTROLLER: Continental 1617, runway 3-5-left cleared for take-off.
Okay.
Continental 1617 is off.
Continental 65 is up next.
And they have one plane in front of them with five minutes left on the clock.
CAPTAIN ZVONEK: This stuff just may not go anywhere.
It may hang in for a couple of days.
FIRST OFFICER BRUECHER: Uh-huh.
AIR TRAFFIC CONTROLLER: Cleared for take-off 3-5-left, Continental 65.
NARRATOR: Eighteen minutes after leaving the de-icing bay, there are no more planes between flight 1713 and the runway.
The pilots expect to hear their number next.
AIR TRAFFIC CONTROLLER: Continental 5-9-4, taxi into position and hold runway 3-5-left.
Report in position.
BOB BENZON: Continental 594? What's going on here? NARRATOR: For some reason, the controller isn't clearing flight 1713 for take-off.
BOB BENZON: It was very, very confusing trying to figure out where several aircraft were on the ground at the same time.
I mean, it was so complicated, and I ended up going to a toy store and buying a bunch of little plastic airplanes, getting a big map of the airport and we were pushing these little plastic planes around just so we could get a handle on, on where everybody was.
NARRATOR: They check the flight records of 5-9-4 to determine its position at the time.
INVESTIGATOR: Continental 5-94 is an MD-80 back at the de-ice bay.
So why is the tower trying to get him on the runway? AIR TRAFFIC CONTROLLER: Can anybody see an MD-80 going into position out there? The controller seems to have lost track of the planes in line for the runway.
CAPTAIN ZVONEK: You might want to tell him we're number one here on the north side.
The crew of flight 1713 tries to clear up the confusion.
FIRST OFFICER BRUECHER: Denver tower, Continental 1713 is number one, DC-9 for Continental.
NARRATOR: Closing in on the 20-minute limit, they report that they're next in line to take off.
But the controller thinks the next plane in line is flight 5-9-4.
INVESTIGATOR: The controller thinks 1713 is flight 594.
But flight 5-9-4 is back here being de-iced.
RICHARD RODRIGUEZ: He was in the de-icing pad, radio shut off, engine shut down and wasn't even listening.
AIR TRAFFIC CONTROLLER: Continental 8-7-5, can you get around an MD-80 for the runway? CONTINENTAL 875 PILOT: Continental 8-75, affirmative.
Who's this now? INVESTIGATOR: He's moving planes around what he thinks is 5-9-4.
NARRATOR: The controller isn't getting an answer from what he believes is the next plane in line, flight 5-9-4.
So he starts moving planes around it.
That confusion was on the part of the controller because he had three or four Continental aircraft he was talking to and he didn't know where each of them was.
As flight 1713 passes the 20-minute mark, the crew is busy trying to sort out the controller's confusion.
Denver tower, number one at the runway is Continental 1713.
AIR TRAFFIC CONTROLLER: 1713, are you an MD-80? FIRST OFFICER BRUECHER: Negative, sir.
DC-9.
The controller doesn't have a flight strip for flight 1713, which only adds to his confusion.
I don't know how 17-13 got there, but there he is.
All right.
Thank you.
Okay.
I think we've got him straightened out.
We'll see.
BOB BENZON: Then 8-75 takes off ahead of them.
In all the confusion, flight 1713 is still on the ground well past the 20-minute limit.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left cleared for take-off.
CAPTAIN ZVONEK: Continental 17-13, cleared for take-off.
NARRATOR: The DC-9 spent 27 minutes waiting in the snow.
RICHARD RODRIGUEZ: That's a pretty long time when you're having continuous precipitation at freezing temperatures.
BOB BENZON: So they start their take-off roll at 2:14:31, but never get more than 20 feet off the ground.
NARRATOR: The critical question now: Did a seven-minute delay turn a routine take-off into a fatal disaster? Investigators need to know how much snow could have accumulated on flight 1713's wings after de-icing.
Passengers say they saw patches of ice on the wings while they were waiting to take off.
JASON KEMPER: Snow was accumulating on the wing.
I was kind of uneasy about it.
Is this normal? I'm sure the pilots know what they're doing.
You trust your father and the people that are running a plane.
Okay.
What do we have between 1:47 and 2:14? BOB BENZON: We had to look at the amount of precipitation that was falling, the rate that it was accumulating on airplanes.
NARRATOR: They study data from the National Weather Service.
BOB BENZON: Less than a third of an inch of snow? Can you print that up for me? NARRATOR: Investigators now need to figure out how much of that snow could have turned into ice on the wings of the DC-9.
The de-icing solution is supposed to melt the snow accumulating on the plane's wings.
But, if it's cold enough, that melted snow can dilute the solution and then refreeze as ice.
BOB BENZON: Twenty-eight degrees.
It's cold enough for water to freeze.
NARRATOR: Benzon calculates exactly how much ice accumulated on the wings in the 27 minutes before take-off.
Melt 0.
292 inches of snow and you get 0.
036 inches of water.
That can't be enough to bring down a DC-9, can it? BOB BENZON: It would be the equivalent of, of 30 to 40 grit sandpaper, which is about like sprinkling salt on the wing.
NARRATOR: Investigators look into the wing accumulation tolerance of a DC-9.
The manufacturer, McDonnell Douglas, provides them with some stunning data.
Higher stall speed? Wow! That's incredible.
Calculations show that the very small amount of ice on the wings was enough to degrade performance, increasing the speed needed for take-off.
RICHARD RODRIGUEZ: When I found out that, uh, just the equivalent of thirty grit sandpaper of contamination on the wing can degrade the performance by a good 20 knots, that's significant and so I was kind of shocked.
Damn it! NARRATOR: Investigators may have finally solved the mystery of flight 1713's failed take-off.
They turn to the flight data, looking for confirmation that ice contamination caused a fatal stall.
BOB BENZON: Wait a minute.
Look at this.
But right away, they spot something that suggests there is more to it than just ice.
The plane sped past the target take-off speed of 145 knots.
They kept accelerating to 165 right before the crash.
JASON KEMPER: All right.
NARRATOR: The data shows the plane did reach a speed where it could have overcome the loss of performance caused by icing.
That's close, but it looks like they could have climbed out.
BOB BENZON: We determined that, even with the contamination and the type of aircraft, etcetera, etcetera, flown correctly, the aircraft probably would have been able to get off the ground and fly away safely.
So icing was a factor but not the only one.
After we determined that a safe flight was technically possible, we had to determine what happened.
What else went wrong? Show me the angle of attack.
Now what is going on here? NARRATOR: Investigators are intrigued by the plane's pitch-up attitude on take-off.
To keep drag to a minimum, airliners normally take off at a shallow angle of about five or six degrees.
When you get to the flying speed where you pull back on the yoke and the nose starts to rise, you wanna do that somewhat gently to let the wings start producing lift and make that transition in a smooth way.
NARRATOR: Data reveals that flight 1713 pitched up steeply, at twice the normal rate.
V-1.
Rotate.
JOHN COX: The problem is that then you create a large amount of drag, and if there's any contamination on the wing you drive the airplane into a stalled condition right as it breaks ground, which is in fact what occurred.
CAPTAIN ZVONEK: Positive rate.
Damn it! It seems the first officer took a bad situation and made it worse by pulling back too severely on his control column.
JASON KEMPER: What's happening? MR KEMPER: Don't worry, Jason.
NARRATOR: How a trained pilot could make such a lethal mistake is the next important question.
BOB BENZON: Once we determined that the rotation rate and the degrees that the aircraft obtained very quickly on rotation, were so high, we needed to try to figure out why.
BOB BENZON: Thank you.
Let's see what we can figure out about these guys.
NARRATOR: Investigators dig into the crew training records.
BOB BENZON: Well the training records became quite important once we began to suspect that one crew member wasn't quite up to snuff, so to speak.
NARRATOR: What they uncover about the first officer is troubling.
BOB BENZON: Hardly a stellar performance at that airline.
But then he gets hired again.
The first officer had a checkered history, to say the least.
He wasn't really the ace of the base.
BOB BENZON: And then in May '86 he fails a flight exam.
And get this, he flew right past a holding fix and then botched his approach.
JOHN COX: The first officer had failed some check rides and had had some issues in the turboprops.
BOB BENZON: Guess who hires him next? JOHN COX: He was not fully up to speed with all the jobs that he had to do flying this new airplane.
This was a big step for him.
NARRATOR: Investigators scour Lee Bruecher's employment records, trying to understand how he ever got hired by Continental Airlines.
Wait, stop! This is from the guys who fired him.
They soon learn that although Continental did perform a background check on Bruecher, the airline was kept in the dark about his poor performance.
JOHN COX: The previous employer informed Continental this pilot had left there to pursue other opportunities but he left of his own choosing.
BOB BENZON: Uh we think the, the reason the previous employer wasn't quite truthful about the skills of the first officer was they frankly were afraid of a lawsuit, afraid of getting sued by the first officer.
NARRATOR: Four months after being hired, and with only 36 hours flying large passenger jets, he over-rotates a DC-9, leading to a fatal stall that claims 28 lives.
That young man never belonged in a large aircraft.
NARRATOR: The revelations about the first officer raise an important question about the captain of the flight.
Why did he allow him to attempt a challenging take-off on a snow-covered runway? - You've got the airplane.
- Okay.
AIR TRAFFIC CONTROLLER: Continental 17-13, runway three-five-left cleared for take-off.
Cleared for take-off, Continental 17-13.
NARRATOR: Investigators learn that Frank Zvonek had been with the airline for almost 19 years, but he'd only been a captain for less than a month.
To make matters worse, the two pilots had never flown together before, and neither one had ever flown a DC-9 in icing conditions.
BOB BENZON: It was just a bad combination from the get-go.
No real check and balance there.
RICHARD RODRIGUEZ: The weather was very poor.
The captain was really in error to let the first officer make that take-off.
NARRATOR: Investigators conclude the inexperienced captain was ill-prepared for what came next.
V-1 Rotate.
Positive rate.
Damn it! NARRATOR: Captain Zvonek does nothing to counteract his first officer's catastrophic actions.
The combination of a new captain, a rookie first officer and a thin layer of ice proves lethal.
JOHN COX: Had the rotation rate been at the normal or even slightly below rate, it is quite likely that the airplane would have accelerated normally, produced lift normally and that the take-off would have proceeded normally.
NARRATOR: Investigators are left with one final mystery to solve.
FIRST OFFICER BRUECHER: Uh, Denver tower, number one at the runway is Continental 17-13.
AIR TRAFFIC CONTROLLER: 17-13, are you an MD-80? FIRST OFFICER BRUECHER: Negative, Sir.
DC-9.
NARRATOR: The delay in getting flight 17-13 off the ground was a critical factor in the crash.
Why didn't the controller know there was a DC-9 waiting at the foot of the runway? BOB BENZON: They never asked for permission to taxi.
CAPTAIN ZVONEK: Continental 17-13 at Delta 18 going to Boise.
AIR TRAFFIC CONTROLLER: Continental 17-13, cleared to Boise.
Okay.
Ready to push.
NARRATOR: Investigators discover that the pilots began taxiing to the de-ice bay without proper clearance, creating confusion for the controllers.
From that point on, no one had a clear picture of the plane's whereabouts.
BOB BENZON: The fact that the accident aircraft 17-13 was taxiing around almost at will with no true idea of where he was going, he wasn't telling people where he was, that's a very serious thing.
I mean, they could have overcome a couple of these, but combined they didn't have a chance.
BOB BENZON: In the end, uh, we actually had to have two major reasons to make the accident occur.
If you take one away, the icing, then the rapid rotation wouldn't have mattered too much at all.
If you take away the rapid rotation, then the icing wouldn't have mattered much at all.
So you had to have both to have this accident.
NARRATOR: The NTSB recommends strict new guidelines for the de-icing of DC-9 airplanes.
They also call on airlines to establish new rules to prevent inexperienced pilots from being paired together on the same flight.
BOB BENZON: We recommended that a crew such as the one on Continental flight 17-13 would never exist again.
A not very experienced crew member on the right seat, coupled with an inexperienced captain in the left seat.
And Continental and the other airlines and the FAA bought off on that very quickly.
So that was a big lesson learned.