1
00:00:03,137 --> 00:00:05,275
In the ocean
near Los Angeles...
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00:00:06,413 --> 00:00:08,517
on a lonely mountain
in Japan...
3
00:00:09,551 --> 00:00:11,068
off the East coast
of Canada...
4
00:00:12,551 --> 00:00:14,000
a plane crash can reduce
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00:00:14,103 --> 00:00:17,172
an enormous jet plane
to mangled pieces.
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00:00:17,275 --> 00:00:20,344
The cause is buried
somewhere in the wreckage.
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00:00:20,448 --> 00:00:22,310
In the business, we refer to,
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00:00:22,413 --> 00:00:24,000
often, "finding
the golden nugget."
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00:00:26,551 --> 00:00:28,103
A modern jet plane
is made up of hundreds
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00:00:28,206 --> 00:00:30,172
of thousands of parts.
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00:00:30,275 --> 00:00:33,448
A failure in any one of them
can lead to disaster.
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00:00:34,758 --> 00:00:38,137
A missing screw can jeopardize
the safety of flight.
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00:00:38,241 --> 00:00:40,344
Constant checks
keep planes flying,
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00:00:40,448 --> 00:00:41,862
and passengers safe.
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00:00:43,620 --> 00:00:46,034
A single oversight can
end in tragedy.
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00:00:48,724 --> 00:00:49,793
Mayday!
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00:00:52,862 --> 00:00:54,000
Something exploded.
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00:00:54,931 --> 00:00:55,758
Oh, my God!
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00:00:56,310 --> 00:00:58,137
Oh, my God!
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00:00:58,241 --> 00:01:00,172
Help me,
help me hold it.
Help me hold it!
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00:01:04,724 --> 00:01:05,758
Mayday, mayday.
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00:01:25,793 --> 00:01:28,655
A hot summer night
in Phoenix, Arizona.
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00:01:29,620 --> 00:01:31,620
It's eleven o'clock,
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00:01:31,724 --> 00:01:34,241
but the maintenance workers
at Southwest Airlines
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00:01:34,344 --> 00:01:35,517
are just getting started.
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00:01:37,862 --> 00:01:39,206
Tonight, they're going
to open up
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00:01:39,310 --> 00:01:42,517
a state-of-the-art
Boeing 737-700.
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00:01:43,827 --> 00:01:46,344
Almost 40 inspectors
and mechanics are going
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00:01:46,448 --> 00:01:49,206
to spend the night making sure
the plane is fit to fly.
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00:01:51,103 --> 00:01:53,827
Without proper maintenance,
airplanes don't fly.
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00:01:53,931 --> 00:01:56,034
Pilots are usually the focus
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00:01:56,137 --> 00:01:58,448
for the operation
of the airplane.
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00:01:58,551 --> 00:02:02,000
But maintenance has
an equally high priority role
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00:02:02,103 --> 00:02:04,655
in the safe operation
of any aircraft.
35
00:02:04,758 --> 00:02:07,241
To keep airplanes
in peak condition,
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00:02:07,344 --> 00:02:10,586
they get more health checks
than most passengers.
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00:02:10,689 --> 00:02:14,103
It's a very intricately
weaved web
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00:02:14,206 --> 00:02:15,965
between the operation
of the airplane
39
00:02:16,068 --> 00:02:17,103
and the maintenance
of the airplane
40
00:02:17,206 --> 00:02:18,827
and the management
of the airplane.
41
00:02:20,448 --> 00:02:22,000
Passenger planes
are examined
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00:02:22,103 --> 00:02:23,862
every time they come
to a stop.
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00:02:24,620 --> 00:02:26,137
This is the A-check.
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00:02:26,241 --> 00:02:28,517
A brief walk-around inspection
turns up
45
00:02:28,620 --> 00:02:30,137
the most obvious problems.
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00:02:31,482 --> 00:02:34,241
The more intensive work is
done at set intervals.
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00:02:34,344 --> 00:02:36,586
These are the B and C checks.
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00:02:40,034 --> 00:02:42,517
Tonight, workers are
performing a C-check.
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00:02:44,103 --> 00:02:46,344
From start to finish,
it can require
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00:02:46,448 --> 00:02:48,000
hundreds of man-hours of work.
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00:02:51,448 --> 00:02:53,103
It all has
to get finished tonight,
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00:02:53,206 --> 00:02:55,551
so the plane is
back flying in the morning.
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00:02:59,551 --> 00:03:01,000
It's a massive challenge
54
00:03:01,103 --> 00:03:02,551
because modern jets are made
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00:03:02,655 --> 00:03:05,275
of hundreds of thousands
of individual pieces.
56
00:03:13,724 --> 00:03:15,103
In 1903,
57
00:03:15,206 --> 00:03:17,758
when the Wright Brothers took
their historic first flight
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00:03:17,862 --> 00:03:20,000
near Kitty Hawk,
North Carolina,
59
00:03:20,103 --> 00:03:22,620
their plane had
some 1,500 parts.
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00:03:23,482 --> 00:03:27,965
A 737 has more than 360,000.
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00:03:28,068 --> 00:03:30,965
You have to ensure that
every one of those components
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00:03:31,068 --> 00:03:33,000
is doing its respective job.
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00:03:34,000 --> 00:03:36,034
It doesn't matter
how big the part is.
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00:03:36,137 --> 00:03:39,517
A missing screw can jeopardize
the safety of flight.
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00:03:40,965 --> 00:03:42,862
It's a lesson
the aviation industry has
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00:03:42,965 --> 00:03:44,275
learned the hard way.
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00:03:47,482 --> 00:03:49,310
January 31st, 2000.
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00:03:52,344 --> 00:03:54,862
On board Alaska Airlines
flight 261,
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00:03:54,965 --> 00:03:56,379
the situation is desperate.
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00:03:57,689 --> 00:03:59,310
Operating a damaged plane,
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00:03:59,413 --> 00:04:02,517
the captain is trying to land
at Los Angeles airport.
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00:04:02,620 --> 00:04:05,620
But the aircraft is not
responding to controls.
73
00:04:05,724 --> 00:04:08,758
The MD-83 is plunging
towards the Pacific Ocean.
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00:04:09,482 --> 00:04:11,482
Holy!
75
00:04:11,586 --> 00:04:13,724
Other pilots
flying nearby report
76
00:04:13,827 --> 00:04:16,344
the nightmare scene back
to L.A. Air Traffic Control.
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00:04:30,758 --> 00:04:32,448
Push the blue sign up!
78
00:04:35,758 --> 00:04:36,827
Here we go!
79
00:04:54,793 --> 00:04:58,103
Flight 261 crashed
off the coast of California
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00:04:58,206 --> 00:05:00,275
at over 400 kilometers
an hour.
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00:05:01,965 --> 00:05:04,689
All 88 passengers
and crew are killed.
82
00:05:14,172 --> 00:05:17,482
Investigators from
the National Transportation
Safety Board
83
00:05:17,586 --> 00:05:19,551
begin their work quickly.
84
00:05:19,655 --> 00:05:22,793
The cockpit voice recordings
provide some
of the earliest clues.
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00:05:23,862 --> 00:05:25,344
We have a jammed stabilizer
86
00:05:25,448 --> 00:05:28,517
and we're maintaining altitude
with difficulty.
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00:05:28,620 --> 00:05:29,689
We immediately suspected
88
00:05:29,793 --> 00:05:32,689
some problem in the tail
of the airplane,
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00:05:32,793 --> 00:05:34,241
which is where
the controls are.
90
00:05:34,344 --> 00:05:36,137
Something was
wrong back there.
91
00:05:39,000 --> 00:05:40,379
Investigators examine
92
00:05:40,482 --> 00:05:42,827
the MD-83's
horizontal stabilizer.
93
00:05:45,137 --> 00:05:47,827
The stabilizer controls
the plane's pitch,
94
00:05:47,931 --> 00:05:49,965
its ability to tilt
up and down.
95
00:05:51,310 --> 00:05:53,344
As the stabilizer moves up,
96
00:05:53,448 --> 00:05:55,689
the plane's nose tilts down.
97
00:05:55,793 --> 00:05:57,517
As the stabilizer moves down,
98
00:05:57,620 --> 00:05:58,655
the nose moves up.
99
00:06:01,310 --> 00:06:03,000
In the MD-83,
100
00:06:03,103 --> 00:06:05,482
a motorized jackscrew
on the tail moves
101
00:06:05,586 --> 00:06:07,068
the stabilizer up and down.
102
00:06:11,482 --> 00:06:14,655
When investigators recover
the tail from the crash site,
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00:06:14,758 --> 00:06:16,172
they make
a puzzling discovery.
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00:06:17,310 --> 00:06:20,034
The jackscrew wasn't mated
105
00:06:20,137 --> 00:06:22,137
with the nut
that it screws into.
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00:06:22,241 --> 00:06:24,137
It was just by itself.
107
00:06:24,241 --> 00:06:26,620
And the nut was found
in another piece of structure
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00:06:26,724 --> 00:06:28,896
a few feet away
from where the jackscrew was.
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00:06:29,000 --> 00:06:32,896
To have a screw
separate itself from a nut
110
00:06:33,000 --> 00:06:35,000
with very thick threads
surprised us.
111
00:06:36,344 --> 00:06:37,586
Without the jackscrew,
112
00:06:37,689 --> 00:06:40,137
the stabilizer was
beyond control.
113
00:06:40,241 --> 00:06:43,034
Without the stabilizer,
the plane was doomed.
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00:06:47,862 --> 00:06:49,793
The investigators
very quickly figured out
115
00:06:49,896 --> 00:06:51,241
how the accident happened.
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00:06:52,034 --> 00:06:54,241
Now they want to know why.
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00:06:54,344 --> 00:06:56,724
The answer is tragically simple.
118
00:06:56,827 --> 00:07:00,068
There was no lubrication
or visible grease
119
00:07:00,172 --> 00:07:02,275
on the working area
of the screw.
120
00:07:02,379 --> 00:07:05,413
That was surprising
and strange.
121
00:07:09,620 --> 00:07:12,103
The Federal
Aviation Administration orders
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00:07:12,206 --> 00:07:15,482
an immediate check
on all MD-80s in the USA.
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00:07:17,827 --> 00:07:19,068
At Alaska Airlines,
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00:07:19,172 --> 00:07:21,172
the jackscrews on six
of its fleet
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00:07:21,275 --> 00:07:24,482
of 34 MD-80s fail inspection.
126
00:07:27,827 --> 00:07:30,551
Investigators discover
even more alarming evidence
127
00:07:30,655 --> 00:07:33,068
as they go through
the carrier's
maintenance records.
128
00:07:34,413 --> 00:07:37,034
Mechanics at Alaska Airlines
report that they are
129
00:07:37,137 --> 00:07:38,379
under tremendous pressure
130
00:07:38,482 --> 00:07:40,758
to cut corners
to keep the planes flying.
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00:07:42,206 --> 00:07:44,724
We interviewed
all the mechanics
132
00:07:44,827 --> 00:07:46,517
who had worked
on these airplanes.
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00:07:46,620 --> 00:07:49,896
We knew that they had
been falsifying records
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00:07:50,000 --> 00:07:51,827
or not doing the work
they had indicated.
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00:07:53,793 --> 00:07:55,482
To survive
an economic recession
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00:07:55,586 --> 00:07:57,448
in the 1990s,
137
00:07:57,551 --> 00:08:00,172
Alaska Airlines slashed
their maintenance regime.
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00:08:01,034 --> 00:08:02,448
With air carriers,
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00:08:02,551 --> 00:08:05,551
especially those that may
be economically strapped,
140
00:08:05,655 --> 00:08:07,413
they're going to stretch
inspection cycles
141
00:08:07,517 --> 00:08:09,724
to the maximum.
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00:08:09,827 --> 00:08:12,172
The FARs, the Federal
Aviation Regulations,
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00:08:12,275 --> 00:08:15,172
set a minimum level of safety.
144
00:08:15,275 --> 00:08:17,689
Now if you're going
to operate on a shoestring,
145
00:08:17,793 --> 00:08:21,000
you're only going to meet
that minimum level of safety.
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00:08:21,103 --> 00:08:24,275
If I'm a good carrier,
or I want to be a good carrier
147
00:08:24,379 --> 00:08:26,793
and I want to show
that we're going to operate
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00:08:26,896 --> 00:08:28,655
at the highest levels
of safety,
149
00:08:28,758 --> 00:08:31,551
I'm going to typically
exceed the minimums.
150
00:08:31,655 --> 00:08:33,896
It's going to cost more,
but I'm going to exceed it.
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00:08:34,000 --> 00:08:35,206
A lot of companies that say,
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00:08:35,310 --> 00:08:37,034
"Wait, the regulations
only say
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00:08:37,137 --> 00:08:39,413
"I only have to go to here.
That's what I'm going to do."
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00:08:43,000 --> 00:08:44,793
Jackscrews in
the company's fleet had been
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00:08:44,896 --> 00:08:48,344
inspected every 500
to 700 flight hours.
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00:08:48,448 --> 00:08:51,034
But in 1996, to cut costs,
157
00:08:51,137 --> 00:08:53,551
Alaska Airlines began
checking the jackscrews
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00:08:53,655 --> 00:08:55,896
every 2,500 hours.
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00:08:56,000 --> 00:08:57,482
At the same time, they doubled
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00:08:57,586 --> 00:08:59,379
the average daily use
of their fleet.
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00:09:00,620 --> 00:09:03,827
If you had 600 hours
between inspection points
162
00:09:03,931 --> 00:09:04,965
and greasing points,
163
00:09:05,068 --> 00:09:07,103
we have no chance
of ever having
164
00:09:07,206 --> 00:09:08,965
a metal-to-metal
contact situation.
165
00:09:09,068 --> 00:09:12,275
But if you put that up
to 2,000 hours
or 2,500 hours,
166
00:09:12,379 --> 00:09:14,137
now what you do is eat into
167
00:09:14,241 --> 00:09:16,344
some of these
protective stages,
168
00:09:16,448 --> 00:09:19,827
these barriers that we have
towards catastrophic failure.
169
00:09:22,000 --> 00:09:24,068
Proper maintenance
becomes even more critical
170
00:09:24,172 --> 00:09:26,965
when there is no backup
to a component.
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00:09:27,068 --> 00:09:29,586
On the MD-83,
there was no alternative
172
00:09:29,689 --> 00:09:31,620
if the jackscrew failed.
173
00:09:31,724 --> 00:09:34,448
So proper maintenance was
a matter of life and death.
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00:09:35,655 --> 00:09:37,379
But in the aviation industry,
175
00:09:37,482 --> 00:09:41,137
it's also a matter
of dollars and cents.
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00:09:41,241 --> 00:09:42,931
There's a lot of pressure
in the airline industry,
177
00:09:43,034 --> 00:09:45,379
when you look at it,
whether you're hauling boxes
178
00:09:45,482 --> 00:09:46,827
or hauling people.
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00:09:46,931 --> 00:09:51,448
The fact of the matter is, is
that competition is stiff
180
00:09:51,551 --> 00:09:53,827
and how do you get
the competitive advantage
181
00:09:53,931 --> 00:09:54,793
against the next guy?
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00:09:56,689 --> 00:09:58,379
How am I gonna
get more for less?
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00:09:58,482 --> 00:10:00,000
And a lot of times,
it's labor.
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00:10:00,103 --> 00:10:01,793
The other times,
it's maintenance.
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00:10:03,172 --> 00:10:05,241
If I can stretch
the inspection
186
00:10:05,344 --> 00:10:08,068
to 500 hours
instead of 400 hours,
187
00:10:08,172 --> 00:10:09,655
that saves me a lot of money.
188
00:10:10,931 --> 00:10:12,862
To stay afloat financially,
189
00:10:12,965 --> 00:10:15,896
Alaska Airlines put
countless lives at risk.
190
00:10:18,206 --> 00:10:21,000
But disaster can erupt
even when an airline doesn't
191
00:10:21,103 --> 00:10:23,310
cut back
on its maintenance regime.
192
00:10:23,413 --> 00:10:24,620
We're going
to hit the mountain!
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00:10:24,724 --> 00:10:26,482
Keep trying!
194
00:10:31,413 --> 00:10:34,827
It's past midnight
in Phoenix, Arizona.
195
00:10:34,931 --> 00:10:38,310
A maintenance crew works
through a 737-700.
196
00:10:39,448 --> 00:10:42,241
They're performing
a so-called C-check,
197
00:10:42,344 --> 00:10:44,448
one of the most
detailed inspections
198
00:10:44,551 --> 00:10:46,896
any plane can go through.
199
00:10:47,000 --> 00:10:51,206
We work overnight because
that's when nobody flies.
200
00:10:51,310 --> 00:10:53,103
It's better for the airline
to keep the airplanes
on ground overnight
201
00:10:53,206 --> 00:10:54,344
to fix them up.
202
00:10:54,448 --> 00:10:57,413
Tonight, 339
individual inspections are
203
00:10:57,517 --> 00:10:58,655
set to be made.
204
00:10:58,758 --> 00:11:01,241
Each one of these is
tracked by computer.
205
00:11:01,344 --> 00:11:04,275
Anything that comes up yellow
is an unscheduled procedure,
206
00:11:04,379 --> 00:11:06,551
a problem that's
just been spotted.
207
00:11:06,655 --> 00:11:09,172
Unscheduled maintenance are
those kinds of things
208
00:11:09,275 --> 00:11:11,620
typically that people
experience with their car
209
00:11:11,724 --> 00:11:13,620
where they're driving
down the highway
210
00:11:13,724 --> 00:11:15,448
and, all of a sudden,
the air conditioner
doesn't work.
211
00:11:15,551 --> 00:11:17,448
Well, the same
with an airplane.
212
00:11:17,551 --> 00:11:19,068
Tonight,
the inspectors discover
213
00:11:19,172 --> 00:11:22,620
a tire on one of
the main landing gears
is worn out.
214
00:11:22,724 --> 00:11:26,034
They add it the list
of unscheduled
maintenance items.
215
00:11:26,137 --> 00:11:27,275
It has to be replaced
216
00:11:27,379 --> 00:11:29,310
before the plane goes
back into service.
217
00:11:30,724 --> 00:11:32,896
Obviously, the stakes
are extremely high.
218
00:11:33,000 --> 00:11:34,275
Every night, we come to work
219
00:11:34,379 --> 00:11:36,482
and try to do
our best job possible,
220
00:11:36,586 --> 00:11:38,758
make sure everything's
in working order
221
00:11:38,862 --> 00:11:41,275
so people get
to where they need to go.
222
00:11:41,379 --> 00:11:43,896
But sometimes,
despite all the maintenance,
223
00:11:44,000 --> 00:11:46,827
the worst-case scenario
comes true.
224
00:11:46,931 --> 00:11:50,379
A simple repair can
unexpectedly lead to disaster.
225
00:11:54,241 --> 00:11:58,448
August 13th, 1985.
Mount Osutaka, Japan.
226
00:12:00,793 --> 00:12:03,827
This is the wreckage
from the deadliest
single plane disaster
227
00:12:03,931 --> 00:12:05,241
in aviation history.
228
00:12:06,448 --> 00:12:10,655
JAL Flight 123 crashed
the night before,
229
00:12:10,758 --> 00:12:12,965
killing 520 passengers
and crew.
230
00:12:14,931 --> 00:12:16,793
Only four people survived.
231
00:12:20,137 --> 00:12:23,931
Because the 747 jet was
built in the United States,
232
00:12:24,034 --> 00:12:26,413
the National Transportation
Safety Board joins
233
00:12:26,517 --> 00:12:28,000
the investigation.
234
00:12:28,103 --> 00:12:30,241
When I arrived in Tokyo,
235
00:12:30,344 --> 00:12:33,793
the atmosphere in Japan was
extremely stressful.
236
00:12:33,896 --> 00:12:36,275
The news media
were everywhere.
237
00:12:36,379 --> 00:12:38,344
There was a tremendous
amount of anger.
238
00:12:41,068 --> 00:12:42,310
Soon after the crash,
239
00:12:42,413 --> 00:12:45,275
experts get a helping hand
from an amateur photographer.
240
00:12:46,241 --> 00:12:47,586
He managed to take a picture
241
00:12:47,689 --> 00:12:50,310
of the 747
minutes before it crashed.
242
00:12:54,517 --> 00:12:57,724
The picture reveals
that JAL Flight 123 was
243
00:12:57,827 --> 00:13:00,551
flying without
its massive tail fin.
244
00:13:00,655 --> 00:13:03,517
The tail fin houses
critical control surfaces
245
00:13:03,620 --> 00:13:04,689
like the rudder,
246
00:13:04,793 --> 00:13:07,862
as well as tubes that carry
the hydraulic fluids.
247
00:13:07,965 --> 00:13:09,586
What force could be
strong enough
248
00:13:09,689 --> 00:13:11,206
to tear off the tail fin?
249
00:13:14,551 --> 00:13:17,206
Digging through
the 747's maintenance history,
250
00:13:17,310 --> 00:13:20,241
investigators discover that,
seven years earlier,
251
00:13:20,344 --> 00:13:22,896
the jet had landed
with its nose too high.
252
00:13:25,172 --> 00:13:27,965
The tail hit the ground
and scraped along the runway.
253
00:13:33,586 --> 00:13:36,068
The rear part of the plane
had to be repaired,
254
00:13:36,172 --> 00:13:37,896
including the pressure bulkhead.
255
00:13:41,000 --> 00:13:43,413
Japan Airlines called in
Boeing technicians
256
00:13:43,517 --> 00:13:45,310
to help repair
the cracked bulkhead.
257
00:13:49,758 --> 00:13:51,620
After this
unscheduled maintenance,
258
00:13:51,724 --> 00:13:54,379
the 747 was given
a clean bill of health
259
00:13:54,482 --> 00:13:56,310
and flew
for another seven years.
260
00:13:57,896 --> 00:13:59,344
But this bulkhead becomes
261
00:13:59,448 --> 00:14:01,724
a prime suspect
for the investigators.
262
00:14:03,103 --> 00:14:05,517
We had an idea
that we wanted to find
263
00:14:05,620 --> 00:14:07,206
the rear pressure bulkhead,
264
00:14:07,310 --> 00:14:09,068
because we had
a flight attendant
265
00:14:09,172 --> 00:14:12,310
who had been interviewed,
that described an explosion
266
00:14:12,413 --> 00:14:14,551
in the back of the airplane
and she could see out.
267
00:14:14,655 --> 00:14:16,827
So we wanted to focus
on the bulkhead.
268
00:14:19,000 --> 00:14:20,413
During his investigation,
269
00:14:20,517 --> 00:14:22,344
Schleede finds
a piece of the panel
270
00:14:22,448 --> 00:14:24,068
that had been spliced
into the bulkhead
271
00:14:24,172 --> 00:14:25,413
seven years before.
272
00:14:27,517 --> 00:14:30,689
The mystery
of Flight 123 is solved.
273
00:14:30,793 --> 00:14:35,000
The 747 went down
because of a faulty repair.
274
00:14:35,103 --> 00:14:37,793
The repair had,
in fact, not been
done correctly.
275
00:14:37,896 --> 00:14:39,827
There was only
one row of rivets
276
00:14:39,931 --> 00:14:41,931
holding that joint together,
277
00:14:42,034 --> 00:14:44,413
uh, where there should
have been two rows
278
00:14:44,517 --> 00:14:46,310
of rivets holding
the joint together.
279
00:14:46,413 --> 00:14:48,655
With only one row
of rivets straining to hold
280
00:14:48,758 --> 00:14:50,862
the repaired panel in place,
281
00:14:50,965 --> 00:14:53,862
this was a disaster
waiting to happen,
282
00:14:53,965 --> 00:14:56,551
especially because this
was such a busy jet.
283
00:14:56,655 --> 00:14:58,655
This particular airplane was
284
00:14:58,758 --> 00:15:01,896
used in Japan
on a domestic operation.
285
00:15:02,000 --> 00:15:04,793
So, it made
multiple takeoffs and landings
286
00:15:04,896 --> 00:15:06,275
on domestic operations,
287
00:15:06,379 --> 00:15:10,413
unlike most 747s
that make long-range hauls.
288
00:15:10,517 --> 00:15:13,068
So, this was considered
a high cycle airplane.
289
00:15:15,413 --> 00:15:17,000
Investigators calculate
290
00:15:17,103 --> 00:15:19,310
that, with the repair job,
the bulkhead would survive
291
00:15:19,413 --> 00:15:22,517
approximately 10,000 flights
or cycles.
292
00:15:24,344 --> 00:15:25,793
But on the day of the crash,
293
00:15:25,896 --> 00:15:29,689
the 747 had already racked up
over 12,000 cycles.
294
00:15:34,758 --> 00:15:39,034
On 747 jets, the cabin is
pressurized, but not the tail.
295
00:15:41,000 --> 00:15:43,758
During flight,
the pressurized cabin air
presses against
296
00:15:43,862 --> 00:15:45,724
the repaired bulkhead.
297
00:15:45,827 --> 00:15:47,965
After some 12,000 cycles,
298
00:15:48,068 --> 00:15:50,103
this pressure stretched
the faulty repair
299
00:15:50,206 --> 00:15:51,206
to breaking point.
300
00:15:55,172 --> 00:15:56,551
The highly-pressurized air
301
00:15:56,655 --> 00:15:58,448
blasted into
the hollow tail fin
302
00:15:58,551 --> 00:15:59,758
and blew it off.
303
00:16:00,827 --> 00:16:02,413
Flap up! Flap up!
304
00:16:02,517 --> 00:16:04,241
Losing part
of the tail crippled
305
00:16:04,344 --> 00:16:05,965
the plane's hydraulic systems.
306
00:16:07,448 --> 00:16:08,862
The Boeing 747 had
307
00:16:08,965 --> 00:16:11,620
four independent
hydraulic systems
308
00:16:11,724 --> 00:16:13,068
to power its systems.
309
00:16:13,172 --> 00:16:15,482
So it had
quadruple redundancy.
310
00:16:15,586 --> 00:16:18,310
Unfortunately,
these four lines
came together
311
00:16:18,413 --> 00:16:19,827
in the lower part of the spar,
312
00:16:19,931 --> 00:16:23,344
and when it separated,
it sheared those four lines.
313
00:16:23,448 --> 00:16:25,517
All four hydraulic systems
were depleted.
314
00:16:25,620 --> 00:16:26,551
Both hands!
315
00:16:26,655 --> 00:16:27,965
For some 30 minutes,
316
00:16:28,068 --> 00:16:32,000
the crew tried to fly
their 747 using only thrust.
317
00:16:32,103 --> 00:16:33,275
This is like trying to drive
318
00:16:33,379 --> 00:16:35,586
a car using
only the accelerator,
319
00:16:35,689 --> 00:16:37,896
no steering wheel, no brakes.
320
00:16:40,413 --> 00:16:42,068
Despite their heroic efforts,
321
00:16:42,172 --> 00:16:43,551
it was a losing battle.
322
00:16:54,896 --> 00:16:57,413
All this death
and destruction boils down
323
00:16:57,517 --> 00:16:59,137
to a missing row of rivets.
324
00:17:00,862 --> 00:17:02,482
Why had
the growing metal fatigue
325
00:17:02,586 --> 00:17:04,724
in the bulkhead
remained undetected
326
00:17:04,827 --> 00:17:07,068
through seven years
of scheduled maintenance
327
00:17:07,172 --> 00:17:08,172
and inspections?
328
00:17:09,793 --> 00:17:13,241
The primary inspection method
for the bulkhead area
329
00:17:13,344 --> 00:17:15,586
and the seams was
a visual inspection.
330
00:17:15,689 --> 00:17:17,931
And at heavy maintenance
periods when they...
331
00:17:18,034 --> 00:17:20,482
they would take
the insulation out,
332
00:17:20,586 --> 00:17:24,137
uh, off the walls
and everything
and off the bulkhead,
333
00:17:24,241 --> 00:17:26,793
they would do
a detailed visual inspection.
334
00:17:28,689 --> 00:17:31,137
And during
subsequent maintenance checks,
335
00:17:31,241 --> 00:17:33,310
the faulty repair was
never found.
336
00:17:39,862 --> 00:17:43,379
Two decades
after JAL Flight 123,
337
00:17:43,482 --> 00:17:46,068
airlines are constantly
looking for hidden flaws
338
00:17:46,172 --> 00:17:48,103
that aren't visible
from the outside.
339
00:17:50,896 --> 00:17:52,965
Back at the Southwest
maintenance hangar,
340
00:17:53,068 --> 00:17:55,620
inspectors are
using a borescope,
341
00:17:55,724 --> 00:17:58,896
a tiny flexible camera,
to inspect the engines.
342
00:18:01,068 --> 00:18:03,827
Engines are the heart
of passenger planes.
343
00:18:03,931 --> 00:18:06,413
If they stop working,
pilots don't have the option
344
00:18:06,517 --> 00:18:08,206
of pulling over
to the side of the road.
345
00:18:09,275 --> 00:18:10,310
Yeah, there we go.
346
00:18:12,344 --> 00:18:15,034
In this area,
we're looking for cracks.
347
00:18:15,137 --> 00:18:18,034
Looking at the, uh, blades,
the rotor blades,
348
00:18:18,137 --> 00:18:20,172
and we're looking
for missing material
off of them.
349
00:18:20,275 --> 00:18:21,620
You know, any hot spots
350
00:18:21,724 --> 00:18:24,206
that have worn
through the metal cracks,
351
00:18:24,310 --> 00:18:25,758
radial and axial cracks.
352
00:18:29,620 --> 00:18:32,137
Any kind of crack
or trace of metal fatigue
353
00:18:32,241 --> 00:18:34,965
in any of the fan blades
could spell disaster.
354
00:18:40,758 --> 00:18:44,275
- Take-off, check.
Below the line.
- I'll clear your lights.
355
00:18:44,379 --> 00:18:47,000
August 21st, 1995.
356
00:18:48,448 --> 00:18:51,862
Atlantic Southeast Airlines
Flight 529,
357
00:18:51,965 --> 00:18:54,724
an Embraer Brasilia,
is about to take off
358
00:18:54,827 --> 00:18:57,586
with 29 people on board.
359
00:18:57,689 --> 00:18:59,620
It's bound
for Gulfport, Mississippi.
360
00:19:00,862 --> 00:19:02,758
It was, at the time,
361
00:19:02,862 --> 00:19:06,000
the fastest, sleekest
turbo-prop around.
362
00:19:08,206 --> 00:19:09,655
Before the plane
even reaches
363
00:19:09,758 --> 00:19:11,137
its cruising altitude,
364
00:19:11,241 --> 00:19:13,758
something seems
to explode outside.
365
00:19:15,172 --> 00:19:17,655
Autopilot, engine control...
366
00:19:17,758 --> 00:19:20,448
The sound of that
was tremendous.
367
00:19:20,551 --> 00:19:24,586
It was as if someone
had taken a baseball bat
368
00:19:24,689 --> 00:19:27,551
and hit
an aluminum garbage can
as hard as they could.
369
00:19:27,655 --> 00:19:31,724
It was just a...
gigantic crashing sound.
370
00:19:31,827 --> 00:19:34,241
The airplane immediately
lurched to the left.
371
00:19:36,310 --> 00:19:39,000
No matter what
the flight crew tries to do,
372
00:19:39,103 --> 00:19:41,206
the plane pulls violently
to the left.
373
00:19:41,310 --> 00:19:42,896
Autopilot. Engine control.
374
00:19:46,068 --> 00:19:48,241
Help me hold it.
Help me hold it!
375
00:19:48,344 --> 00:19:49,448
Over there!
376
00:19:53,068 --> 00:19:54,931
The captain
and co-pilot are pushed
377
00:19:55,034 --> 00:19:56,724
to the brink
of their experience.
378
00:19:58,344 --> 00:20:00,103
Help me. Help me!
379
00:20:00,206 --> 00:20:01,793
Help me hold it.
Help me hold it!
380
00:20:19,827 --> 00:20:22,896
Atlantic Southeast
Flight 529 crashes
381
00:20:23,000 --> 00:20:24,310
near the small
farming community
382
00:20:24,413 --> 00:20:25,724
of Carrollton, Georgia.
383
00:20:27,206 --> 00:20:28,620
Emergency.
Yes,
384
00:20:28,724 --> 00:20:30,965
we have a plane crashed
in our backyard.
385
00:20:31,068 --> 00:20:32,827
A plane crash?
386
00:20:32,931 --> 00:20:35,965
All 29 people
survive the violent landing.
387
00:20:41,620 --> 00:20:44,379
But ten passengers
eventually die
from their injuries.
388
00:20:58,068 --> 00:21:01,103
Called into action,
the NTSB creates teams
389
00:21:01,206 --> 00:21:03,310
to examine various parts
of the plane.
390
00:21:05,758 --> 00:21:08,310
Jim Hookey,
an aerospace engineer,
391
00:21:08,413 --> 00:21:10,586
is in charge of the Propeller
Maintenance Group.
392
00:21:11,793 --> 00:21:14,551
We came along a lot of pieces
of the wing,
393
00:21:14,655 --> 00:21:17,068
came along the, um...
394
00:21:17,172 --> 00:21:18,379
the propeller assembly
395
00:21:18,482 --> 00:21:21,000
that was missing
one part of the blade.
396
00:21:21,103 --> 00:21:23,827
The blade broke
in a very specific fashion,
397
00:21:23,931 --> 00:21:26,241
leaving behind
all the telltale signs
398
00:21:26,344 --> 00:21:28,482
of a fatigue fracture.
399
00:21:28,586 --> 00:21:32,862
A fatigue fracture tends to be
a very flat fracture.
400
00:21:32,965 --> 00:21:35,275
It also has
what we call beach marks
401
00:21:35,379 --> 00:21:37,344
radiating out from the origin.
402
00:21:37,448 --> 00:21:40,965
So you see these radiating
concentric rings
403
00:21:41,068 --> 00:21:44,137
coming from the origin
of the crack.
404
00:21:45,103 --> 00:21:46,413
Hookey had good reason
405
00:21:46,517 --> 00:21:48,448
to focus
on the broken propeller blade.
406
00:21:49,586 --> 00:21:52,758
Seventeen months
before ASA 529,
407
00:21:52,862 --> 00:21:54,586
identical propeller
blades broke
408
00:21:54,689 --> 00:21:57,275
on separate flights
over Canada and Brazil.
409
00:22:02,793 --> 00:22:04,275
Fortunately, in both cases,
410
00:22:04,379 --> 00:22:06,310
the aircraft managed
to land safely.
411
00:22:08,344 --> 00:22:11,275
The manufacturer
of the propeller was
Hamilton Standard.
412
00:22:12,620 --> 00:22:14,517
Hookey and his team
start combing
413
00:22:14,620 --> 00:22:17,586
through Hamilton Standard's
maintenance records.
414
00:22:17,689 --> 00:22:19,724
They're looking for anything
out of the ordinary.
415
00:22:20,793 --> 00:22:22,172
It's
whatever's abnormal.
416
00:22:22,275 --> 00:22:24,689
You really don't know
what you're looking for
until you find it.
417
00:22:24,793 --> 00:22:27,206
But you just go through,
418
00:22:27,310 --> 00:22:29,241
and there's a lot
of routine maintenances done,
419
00:22:29,344 --> 00:22:33,517
regular inspections, A-checks,
B-checks, C-checks.
420
00:22:33,620 --> 00:22:35,931
And there's
the non-routine maintenance
that's occurred.
421
00:22:36,034 --> 00:22:38,862
If something is broken,
or a truck hits the airplane
422
00:22:38,965 --> 00:22:41,275
or they have a bird strike
or something like that.
423
00:22:41,379 --> 00:22:43,517
And it's those
that you look for.
424
00:22:45,275 --> 00:22:46,689
The maintenance records reveal
425
00:22:46,793 --> 00:22:50,137
that the broken propeller blade
had earlier problems.
426
00:22:50,241 --> 00:22:52,448
We found out that
that propeller blade had
427
00:22:52,551 --> 00:22:55,310
actually been removed
from service once already,
428
00:22:55,413 --> 00:22:57,689
uh, for a crack indication.
429
00:22:57,793 --> 00:23:00,620
And that became the first clue
about there may be a problem
430
00:23:00,724 --> 00:23:03,379
with that propeller blade
and those inspections.
431
00:23:05,241 --> 00:23:07,448
Deep inside
the hollow propeller,
432
00:23:07,551 --> 00:23:09,724
investigators find
what they're looking for.
433
00:23:12,034 --> 00:23:15,068
In the hollow interior,
or taper bore,
434
00:23:15,172 --> 00:23:17,896
weights are inserted
to balance the prop.
435
00:23:18,000 --> 00:23:20,344
They're kept in place
by a cork.
436
00:23:20,448 --> 00:23:22,275
This simple cork
was the trigger
437
00:23:22,379 --> 00:23:24,655
in a deadly chain of events.
438
00:23:24,758 --> 00:23:28,586
About 95% of the cork
that's produced in the world
439
00:23:28,689 --> 00:23:31,137
is used by
the medical industry.
440
00:23:31,241 --> 00:23:35,000
And, for aesthetic purposes
and for sterilization,
441
00:23:35,103 --> 00:23:37,793
they like to have
the light color.
442
00:23:37,896 --> 00:23:40,620
So, the cork is
bleached with chlorine.
443
00:23:42,655 --> 00:23:44,103
The NTSB discovers
444
00:23:44,206 --> 00:23:46,586
that moisture
inside the propeller caused
445
00:23:46,689 --> 00:23:48,620
the chlorine in the cork
to leach out
446
00:23:48,724 --> 00:23:51,206
and corrode the propeller's
aluminum alloy.
447
00:23:53,482 --> 00:23:56,103
They also notice
something else
on the broken blade.
448
00:23:57,068 --> 00:23:58,344
On the inner surface,
449
00:23:58,448 --> 00:24:00,137
extending about
four centimeters
450
00:24:00,241 --> 00:24:03,586
from the fracture, there are
a series of sanding marks.
451
00:24:05,655 --> 00:24:07,689
Going through
the blade's repair records,
452
00:24:07,793 --> 00:24:10,413
Hookey notices
the initials "CSB".
453
00:24:11,413 --> 00:24:12,862
Christopher Scott Bender.
454
00:24:13,620 --> 00:24:14,689
This technician worked
455
00:24:14,793 --> 00:24:16,965
at a Hamilton Standard
repair facility.
456
00:24:18,896 --> 00:24:21,827
When Christopher Bender
watches news of the accident,
457
00:24:21,931 --> 00:24:23,206
he learns that
the investigators
458
00:24:23,310 --> 00:24:26,275
are examining
the Hamilton propeller.
459
00:24:26,379 --> 00:24:27,689
As soon as I heard that,
460
00:24:27,793 --> 00:24:30,000
my heart just sank.
I was like...
461
00:24:30,103 --> 00:24:31,793
you know, I think I might
have even cried a little bit
462
00:24:31,896 --> 00:24:33,724
'cause I was just, you know,
just emotionally overwhelmed
463
00:24:33,827 --> 00:24:35,862
that, you know, something
I had put my hands on,
464
00:24:35,965 --> 00:24:38,620
a procedure somebody
trusted me to do, failed.
465
00:24:38,724 --> 00:24:40,448
Uh, and because of it,
somebody had died.
466
00:24:43,344 --> 00:24:45,103
After discovering
that it was Bender
467
00:24:45,206 --> 00:24:47,827
who last worked
on the deadly propeller blade,
468
00:24:47,931 --> 00:24:50,862
the NTSB now has to find out
how the blade had
469
00:24:50,965 --> 00:24:52,827
passed inspection
at Hamilton Standard.
470
00:24:56,689 --> 00:24:58,620
Investigators ask Bender
to perform
471
00:24:58,724 --> 00:25:00,551
his standard
maintenance technique
472
00:25:00,655 --> 00:25:02,931
on the propeller.
473
00:25:03,034 --> 00:25:06,655
He demonstrated how he would
go down into the barrel
474
00:25:06,758 --> 00:25:08,068
of the taper bore
475
00:25:08,172 --> 00:25:12,620
with a fiberoptic borescope
and look for cracks.
476
00:25:12,724 --> 00:25:15,344
And therein lied one
of the primary problems.
477
00:25:15,448 --> 00:25:17,965
The borescope
that he was using
478
00:25:18,068 --> 00:25:19,620
had a bright white light
479
00:25:20,517 --> 00:25:22,344
that would put
a lot of glare
480
00:25:22,448 --> 00:25:24,586
back into
the inspector's eyes.
481
00:25:24,689 --> 00:25:26,000
It really did not lend itself
482
00:25:26,103 --> 00:25:29,000
to the inspection
that was required.
483
00:25:31,724 --> 00:25:33,931
And investigators
also find a gap
484
00:25:34,034 --> 00:25:36,310
in Bender's training.
485
00:25:36,413 --> 00:25:39,551
He had never been shown
what a crack would look like.
486
00:25:39,655 --> 00:25:41,862
He was just told
to find a crack,
487
00:25:41,965 --> 00:25:43,310
and he would look for a crack.
488
00:25:45,344 --> 00:25:47,413
When he was
examining the propeller blade,
489
00:25:47,517 --> 00:25:49,137
Bender had been
unable to detect
490
00:25:49,241 --> 00:25:50,689
any evidence of corrosion.
491
00:25:52,172 --> 00:25:54,620
He then did what
he had been told to do,
492
00:25:54,724 --> 00:25:57,034
polish the inside
of the blade.
493
00:25:57,137 --> 00:26:02,448
He was given a directive
to use a repair
494
00:26:02,551 --> 00:26:06,034
to blend out the inside
of the taper bore.
495
00:26:06,137 --> 00:26:09,034
He blended it out,
he did an inspection.
496
00:26:09,137 --> 00:26:10,655
And the blending
that he had done
497
00:26:10,758 --> 00:26:12,068
had roughened the surface,
498
00:26:12,172 --> 00:26:15,034
so it actually masked
the indication of the crack
499
00:26:15,137 --> 00:26:17,000
in the subsequent inspection.
500
00:26:17,103 --> 00:26:18,827
And the blade was
returned to service,
501
00:26:18,931 --> 00:26:21,586
where the crack continued
to propagate
502
00:26:21,689 --> 00:26:25,655
until it ultimately reached
critical length and separated.
503
00:26:25,758 --> 00:26:28,103
The draft accident report
we present to you today
504
00:26:28,206 --> 00:26:32,000
involves Atlantic
Southeast Airlines Flight 529.
505
00:26:32,103 --> 00:26:33,551
According to the NTSB,
506
00:26:33,655 --> 00:26:36,172
by polishing the blade,
Hamilton Standard had
507
00:26:36,275 --> 00:26:38,931
unwittingly removed
all traces of the crack.
508
00:26:40,275 --> 00:26:43,275
Even a later, more thorough
ultrasound examination
509
00:26:43,379 --> 00:26:44,965
could not detect it.
510
00:26:46,689 --> 00:26:50,034
The company that manufactured
Flight 529's propeller is
511
00:26:50,137 --> 00:26:53,241
now renamed
Hamilton Sundstrand.
512
00:26:53,344 --> 00:26:55,896
Its inspection
and repair process was made
513
00:26:56,000 --> 00:26:59,517
more stringent, in some cases
exceeding FAA requirements.
514
00:27:02,310 --> 00:27:04,413
Flight 529 was the last time
515
00:27:04,517 --> 00:27:06,517
one of its propellers
failed in flight.
516
00:27:12,655 --> 00:27:14,724
You know, I wish
this had never happened.
517
00:27:14,827 --> 00:27:17,034
I wish I could go back
in time and fix it
518
00:27:17,137 --> 00:27:18,896
and take care of it
and that it didn't happen.
519
00:27:21,137 --> 00:27:23,000
Out of the thousands
of parts on board
520
00:27:23,103 --> 00:27:26,103
an Embraer Brasilia,
a simple small cork was
521
00:27:26,206 --> 00:27:28,000
the key to
a horrific accident.
522
00:27:29,551 --> 00:27:32,379
ASA Flight 529 underlines
523
00:27:32,482 --> 00:27:34,551
the critical need
for proper maintenance.
524
00:27:36,758 --> 00:27:38,344
But sometimes maintenance can
525
00:27:38,448 --> 00:27:40,620
create the potential
for disaster
526
00:27:40,724 --> 00:27:41,931
when a new component is
527
00:27:42,034 --> 00:27:44,172
installed into
an older airplane.
528
00:27:44,275 --> 00:27:46,724
Moncton center, Swiss Air 111
heavy is declaring
529
00:27:46,827 --> 00:27:49,551
Pan Pan Pan. We have
smoke in the cockpit.
530
00:27:55,758 --> 00:27:58,965
It's early morning
in Phoenix, Arizona.
531
00:27:59,068 --> 00:28:01,620
Southwest Airlines engineers
are continuing
532
00:28:01,724 --> 00:28:04,034
their scheduled maintenance
of a 737.
533
00:28:05,965 --> 00:28:08,724
Southwest is unique
among larger airlines.
534
00:28:08,827 --> 00:28:13,344
It flies just one kind
of plane, the 737.
535
00:28:13,448 --> 00:28:15,862
Tonight, engineers are
working on a 700 model,
536
00:28:15,965 --> 00:28:17,862
one of the newest 737s.
537
00:28:19,137 --> 00:28:21,724
But the company's
very first 300 model,
538
00:28:21,827 --> 00:28:24,379
bought in the mid-1980s,
is still flying.
539
00:28:26,413 --> 00:28:28,379
You can
still operate an old airplane,
540
00:28:28,482 --> 00:28:31,103
as long as you have
inspection protocols.
541
00:28:31,206 --> 00:28:32,965
When you look at some
of the cargo carriers,
542
00:28:33,068 --> 00:28:35,241
they're operating airplanes
that are 30 and 40
543
00:28:35,344 --> 00:28:37,241
and even 50 years old.
544
00:28:37,344 --> 00:28:39,206
They're still
reliable airplanes.
545
00:28:39,310 --> 00:28:40,517
They've been maintained,
546
00:28:40,620 --> 00:28:43,310
they've been retrofitted
with modern day equipment.
547
00:28:44,586 --> 00:28:45,827
Updating older planes is
548
00:28:45,931 --> 00:28:48,275
a standard part
of maintenance.
549
00:28:48,379 --> 00:28:50,586
But sometimes,
installing a new component
550
00:28:50,689 --> 00:28:52,758
in an older plane can
lead to tragedy.
551
00:28:55,689 --> 00:28:58,517
Inside this makeshift lab
are the shattered remains
552
00:28:58,620 --> 00:29:00,413
of Swiss Air Flight 111.
553
00:29:02,000 --> 00:29:04,793
On September 2nd, 1998,
554
00:29:04,896 --> 00:29:06,586
the passenger jet crashed
off the coast
555
00:29:06,689 --> 00:29:08,103
of Nova Scotia, Canada,
556
00:29:08,206 --> 00:29:09,931
killing everyone on board.
557
00:29:11,965 --> 00:29:15,206
Recovered from the seabed,
the debris is overwhelming.
558
00:29:18,482 --> 00:29:22,379
There is almost 250 kilometers
of wiring alone.
559
00:29:22,482 --> 00:29:26,000
In Swiss Air, we'd had
about two million pieces
of airplane.
560
00:29:26,103 --> 00:29:28,517
And we pretty much almost
had to look at them all.
561
00:29:28,620 --> 00:29:30,000
In the business, we refer
562
00:29:30,103 --> 00:29:33,000
to often "finding
the golden nugget."
563
00:29:33,103 --> 00:29:35,689
That's saying, "A-ha, there's
the cause of the accident."
564
00:29:38,413 --> 00:29:39,931
Somewhere in this wreckage,
565
00:29:40,034 --> 00:29:43,034
investigators hope to find
that golden nugget,
566
00:29:43,137 --> 00:29:45,241
the one piece that will
reveal the reason
567
00:29:45,344 --> 00:29:48,206
why Swiss Air 111 crashed
into the Atlantic ocean.
568
00:29:55,379 --> 00:29:57,000
The cockpit
voice recorder gives
569
00:29:57,103 --> 00:29:59,482
investigators their
first critical clues.
570
00:30:01,448 --> 00:30:03,034
Do you smell something?
571
00:30:03,137 --> 00:30:04,827
Yeah. What is that?
572
00:30:04,931 --> 00:30:06,275
Go have a look.
I'll take the controls.
573
00:30:06,379 --> 00:30:07,517
Roger. You have control.
574
00:30:10,724 --> 00:30:11,931
The First Officer checks
575
00:30:12,034 --> 00:30:14,172
the area around
the air conditioning vent.
576
00:30:15,068 --> 00:30:16,379
Nothing seems wrong.
577
00:30:19,000 --> 00:30:20,413
Don't see anything there.
578
00:30:20,517 --> 00:30:21,758
And there's nothing
up there now.
579
00:30:24,620 --> 00:30:25,965
Captain Zimmerman
is troubled
580
00:30:26,068 --> 00:30:27,241
by the smell of smoke.
581
00:30:27,344 --> 00:30:28,586
There it is again.
582
00:30:28,689 --> 00:30:30,000
He starts
to divert the plane
583
00:30:30,103 --> 00:30:31,551
to the nearest airport.
584
00:30:31,655 --> 00:30:33,896
Find the closest place
to land, Stefan.
585
00:30:34,000 --> 00:30:35,551
He radios
air traffic control
586
00:30:35,655 --> 00:30:37,344
in Moncton, New Brunswick.
587
00:30:37,448 --> 00:30:39,724
Moncton Center,
Swiss Air 111 heavy is
588
00:30:39,827 --> 00:30:43,344
declaring Pan Pan Pan.
We have smoke in the cockpit.
589
00:30:43,448 --> 00:30:45,724
"Pan Pan Pan" is
an international term used
590
00:30:45,827 --> 00:30:48,896
to notify air traffic control
of an urgent situation.
591
00:30:49,000 --> 00:30:50,310
...to fly to the threshold.
592
00:30:50,413 --> 00:30:52,379
It's one step below
declaring Mayday.
593
00:30:55,206 --> 00:30:57,827
Uh, I guess Boston, we need...
594
00:30:57,931 --> 00:31:00,344
Swiss Air 111
is directed to Halifax
595
00:31:00,448 --> 00:31:02,482
and starts its descent.
596
00:31:02,586 --> 00:31:06,137
Can I vector you to set up
for runway zero-six
at Halifax?
597
00:31:07,655 --> 00:31:10,241
The pilots appear
calm and in control.
598
00:31:10,344 --> 00:31:13,310
Halifax is just
20 minutes away.
599
00:31:13,413 --> 00:31:16,068
They want us
to turn to the south.
600
00:31:16,172 --> 00:31:18,896
At that point,
everything was normal.
601
00:31:19,000 --> 00:31:21,482
I gave the pilot
an initial descent
602
00:31:21,586 --> 00:31:24,137
and he requested to level off
603
00:31:24,241 --> 00:31:25,620
at an intermediate altitude
604
00:31:25,724 --> 00:31:27,275
to get the cabin in order
for the landing,
605
00:31:27,379 --> 00:31:28,931
which took to mean
that they needed
606
00:31:29,034 --> 00:31:32,103
to pack away dinner trays
and things like that.
607
00:31:33,034 --> 00:31:34,413
Cabin bus off.
608
00:31:34,517 --> 00:31:35,517
Cabin bus off. Roger.
609
00:31:37,758 --> 00:31:39,724
But the seemingly
controlled situation
610
00:31:39,827 --> 00:31:42,482
on board
Swiss Air Flight 111 escalates
611
00:31:42,586 --> 00:31:44,344
into a full scale emergency.
612
00:31:46,137 --> 00:31:47,620
Autopilot, disconnect.
613
00:31:52,379 --> 00:31:54,068
We are declaring
emergency now!
614
00:31:54,172 --> 00:31:57,586
Swiss Air 111 at time 0-1-2-4!
615
00:32:00,241 --> 00:32:01,965
All my screens are down!
616
00:32:02,068 --> 00:32:03,931
I'm planning
on steering by instruments.
617
00:32:04,034 --> 00:32:06,275
Maintaining 300!
618
00:32:06,379 --> 00:32:08,517
Shortly after declaring an emergency,
619
00:32:08,620 --> 00:32:10,206
the plane goes silent.
620
00:32:19,827 --> 00:32:22,689
It was probably one
of the most helpless feelings
621
00:32:22,793 --> 00:32:24,793
that any individual can have,
622
00:32:24,896 --> 00:32:26,551
not being able to do anything
623
00:32:26,655 --> 00:32:28,413
but just sit
and watch the target
624
00:32:28,517 --> 00:32:31,000
and hope that it would turn
back toward the airport.
625
00:32:32,068 --> 00:32:33,275
And of course, it didn't.
626
00:32:37,724 --> 00:32:40,275
At 10:31 p.m. Atlantic time,
627
00:32:40,379 --> 00:32:43,620
residents of Peggy's Cove hear
a devastating explosion.
628
00:32:54,758 --> 00:32:56,344
From the cockpit
voice recorder,
629
00:32:56,448 --> 00:32:58,896
investigators know
they are dealing with a fire
630
00:32:59,000 --> 00:33:01,137
and not a plane
that was malfunctioning.
631
00:33:01,965 --> 00:33:03,482
We found no anomalies
632
00:33:03,586 --> 00:33:06,448
or no problems
in any of that flight data
633
00:33:06,551 --> 00:33:08,379
that suggested there was
a problem with the aircraft.
634
00:33:10,413 --> 00:33:13,034
Investigators work
their way through the hangar
635
00:33:13,137 --> 00:33:15,482
of wreckage recovered
from the Atlantic Ocean.
636
00:33:22,034 --> 00:33:24,620
Finally, they find
scorch marks,
637
00:33:24,724 --> 00:33:26,620
which reveal that the source
of the fire was
638
00:33:26,724 --> 00:33:28,000
in the back of the cockpit,
639
00:33:29,482 --> 00:33:31,448
directly behind
the First Officer.
640
00:33:35,034 --> 00:33:38,206
Following this trail
leads the team to
an unlikely suspect,
641
00:33:38,310 --> 00:33:40,827
the entertainment system
in First Class.
642
00:33:44,517 --> 00:33:47,482
The Swiss Air MD-11s
provided First Class
643
00:33:47,586 --> 00:33:51,206
with one of the world's
most sophisticated
entertainment systems.
644
00:33:51,310 --> 00:33:52,689
Passengers in first class
645
00:33:52,793 --> 00:33:54,310
could choose
their own movies,
646
00:33:54,413 --> 00:33:56,793
access the Internet,
and even gamble.
647
00:33:58,517 --> 00:34:00,586
This entertainment system
was not part
648
00:34:00,689 --> 00:34:02,620
of the original MD-11 design.
649
00:34:04,931 --> 00:34:06,931
The system had
some major deficiencies.
650
00:34:07,034 --> 00:34:08,379
It was getting very hot,
651
00:34:09,310 --> 00:34:10,517
it drew a lot of power.
652
00:34:12,241 --> 00:34:14,586
And, uh, thereby,
for example,
653
00:34:14,689 --> 00:34:16,620
raising the cabin temperature
654
00:34:17,758 --> 00:34:20,275
considerably, because it
was always running.
655
00:34:22,206 --> 00:34:25,137
They did not install
a simple "off" switch,
656
00:34:25,241 --> 00:34:27,793
nor did they install
appropriate cooling systems.
657
00:34:30,172 --> 00:34:32,137
Any time you have
an electrical system
658
00:34:32,241 --> 00:34:34,758
where you're putting
an after-market install
659
00:34:34,862 --> 00:34:36,103
into an airplane,
660
00:34:36,206 --> 00:34:38,793
you run the risk
of compromising
661
00:34:38,896 --> 00:34:41,379
the integrity
of the aircraft itself
662
00:34:41,482 --> 00:34:42,896
as it was originally designed.
663
00:34:44,448 --> 00:34:47,034
When informed
about the flaw in the wiring,
664
00:34:47,137 --> 00:34:49,931
Swiss Air immediately disabled
the entertainment system
665
00:34:50,034 --> 00:34:51,413
on the rest of its fleet.
666
00:34:53,068 --> 00:34:54,896
But investigators discover
that another piece
667
00:34:55,000 --> 00:34:56,896
of the jet had helped
the fire spread
668
00:34:57,000 --> 00:34:58,206
with alarming speed.
669
00:35:01,517 --> 00:35:05,068
And in this instance,
we did discover a wire
670
00:35:05,172 --> 00:35:07,517
that arced in that way.
671
00:35:07,620 --> 00:35:12,275
And right next to it was
some very flammable material
672
00:35:12,379 --> 00:35:17,103
called metalized polyethylene
terephthalate covering material
673
00:35:17,206 --> 00:35:20,000
that covers
the insulation blankets.
674
00:35:21,655 --> 00:35:23,586
This polyethylene insulate was
675
00:35:23,689 --> 00:35:25,965
common on commercial airlines
around the world.
676
00:35:27,000 --> 00:35:28,103
It had somehow passed
677
00:35:28,206 --> 00:35:30,137
the industry's
flammability tests,
678
00:35:30,241 --> 00:35:32,724
which require materials
to self-extinguish
679
00:35:32,827 --> 00:35:34,586
after a reasonable period
of time.
680
00:35:39,586 --> 00:35:41,068
This thermo-acoustical material
681
00:35:41,172 --> 00:35:44,206
that was in this aircraft
was very flammable.
682
00:35:44,310 --> 00:35:46,379
Even though it passed a test,
683
00:35:46,482 --> 00:35:48,965
it does sustain
and it does propagate flame.
684
00:35:51,862 --> 00:35:54,310
The fire spread
quickly from the cockpit
685
00:35:54,413 --> 00:35:56,034
back into
the First Class galleys.
686
00:35:57,413 --> 00:35:59,517
Some metals showed heat damage
687
00:35:59,620 --> 00:36:02,241
from temperatures as high
as 1,100 degrees Fahrenheit.
688
00:36:04,620 --> 00:36:06,931
Less than 12 minutes
after the crew declared
689
00:36:07,034 --> 00:36:09,241
a Pan Pan,
the fire disabled
690
00:36:09,344 --> 00:36:11,000
all electronics
in the cockpit.
691
00:36:19,241 --> 00:36:21,241
In the aftermath,
Swissair removed
692
00:36:21,344 --> 00:36:25,862
the flammable insulate
from its entire MD-11 fleet.
693
00:36:25,965 --> 00:36:28,689
The rest of the industry was
required to follow suit.
694
00:36:31,620 --> 00:36:34,551
In Phoenix, Arizona,
flight engineers continue
695
00:36:34,655 --> 00:36:37,379
their C-check on the 737.
696
00:36:37,482 --> 00:36:40,172
It includes testing
the plane's rudder.
697
00:36:40,275 --> 00:36:43,620
The rudder is one of the jet's
most vital control surfaces.
698
00:36:43,724 --> 00:36:46,344
It allows a plane
to turn left and right.
699
00:36:46,448 --> 00:36:49,310
Okay, C-Bass,
rudder should turn.
700
00:36:49,413 --> 00:36:50,655
All right, go ahead.
701
00:36:50,758 --> 00:36:54,620
A problem here could
have terrifying consequences.
702
00:36:54,724 --> 00:36:56,689
Uh, you're clear on the left.
703
00:36:58,965 --> 00:37:01,758
In fact,
despite years
of proper maintenance,
704
00:37:01,862 --> 00:37:03,551
a problem with
a tiny component
705
00:37:03,655 --> 00:37:08,172
with the 737 rudder killed
more than 100 people.
706
00:37:08,275 --> 00:37:12,068
Not even the most diligent
maintenance workers
could have spotted it.
707
00:37:15,551 --> 00:37:17,241
March 3rd , 1991.
708
00:37:18,517 --> 00:37:20,862
United Flight 585 begins
709
00:37:20,965 --> 00:37:23,517
its final approach
into Colorado Springs.
710
00:37:23,620 --> 00:37:24,655
Another ten-knot gain.
711
00:37:25,620 --> 00:37:26,586
Thirty flaps.
712
00:37:34,620 --> 00:37:36,068
Oh, God, flip!
713
00:37:36,172 --> 00:37:37,862
- Fifteen flaps.
- Fifteen!
714
00:37:39,413 --> 00:37:41,241
Oh, my God!
715
00:37:42,448 --> 00:37:43,275
Oh, my God!
716
00:37:44,551 --> 00:37:46,379
- Oh, God!
- Oh, my God!
717
00:37:56,275 --> 00:37:59,241
All 20 passengers
and five crew are killed.
718
00:38:05,310 --> 00:38:08,551
Investigators from
the National Transportation
Safety Board descend
719
00:38:08,655 --> 00:38:10,241
on Colorado Springs.
720
00:38:18,344 --> 00:38:20,931
My first sense that it was
going to take some time
721
00:38:21,034 --> 00:38:23,172
to investigate
the accident was
722
00:38:23,275 --> 00:38:25,965
the damage that we saw
on the parts.
723
00:38:26,068 --> 00:38:28,172
An aerospace
engineer by training,
724
00:38:28,275 --> 00:38:29,724
Greg Phillips is in charge
725
00:38:29,827 --> 00:38:33,413
of investigating United 585's
flight control systems.
726
00:38:35,413 --> 00:38:38,000
We focused in
after eliminating
727
00:38:38,103 --> 00:38:39,896
other flight control surfaces
728
00:38:40,000 --> 00:38:42,620
that we thought could
contribute to the roll.
729
00:38:42,724 --> 00:38:45,206
We started looking
at the rudder.
730
00:38:45,310 --> 00:38:48,068
But investigators
face a critical obstacle.
731
00:38:48,172 --> 00:38:50,137
Most of the plane's parts
are too crushed
732
00:38:50,241 --> 00:38:51,655
or burned for testing.
733
00:38:53,620 --> 00:38:57,103
Luckily, one vital component
is still reasonably intact.
734
00:38:58,172 --> 00:39:01,034
This is the power control unit
or PCU.
735
00:39:03,413 --> 00:39:05,379
Used constantly during flight,
736
00:39:05,482 --> 00:39:07,068
especially during landings,
737
00:39:07,172 --> 00:39:10,000
the PCU performs like
a car's power steering.
738
00:39:11,137 --> 00:39:13,586
When the pilot pushes
on a rudder pedal,
739
00:39:13,689 --> 00:39:15,827
the PCU uses hydraulic fluid
740
00:39:15,931 --> 00:39:17,413
to convert
the gentle movements
741
00:39:17,517 --> 00:39:20,413
of a pilot's foot into
the pressure needed to move
742
00:39:20,517 --> 00:39:22,620
the 737's enormous rudder.
743
00:39:24,793 --> 00:39:28,655
The heart of the PCU is
the dual servo valve.
744
00:39:28,758 --> 00:39:31,206
This valve is roughly
the size of a soda can.
745
00:39:32,896 --> 00:39:35,206
It contains
two extremely thin slides
746
00:39:35,310 --> 00:39:36,896
that glide past one another.
747
00:39:38,517 --> 00:39:40,896
These slides direct
the flow of hydraulic fluid
748
00:39:41,000 --> 00:39:42,206
which moves the rudder.
749
00:39:44,896 --> 00:39:47,517
When a technician opens up
the power control unit,
750
00:39:49,172 --> 00:39:50,758
it seems to be
in working order.
751
00:39:53,068 --> 00:39:55,482
We didn't have
any absolute indication
752
00:39:55,586 --> 00:39:57,689
or information that we could
point to that said
753
00:39:57,793 --> 00:40:01,241
the rudder power control unit,
the servo valve or any part
754
00:40:01,344 --> 00:40:04,000
of that flight control system
caused that accident.
755
00:40:06,862 --> 00:40:08,000
It's a pass.
756
00:40:11,517 --> 00:40:13,827
For only the fourth
time in its history,
757
00:40:13,931 --> 00:40:16,103
the NTSB releases a report
758
00:40:16,206 --> 00:40:18,689
that does not
reach a conclusion.
759
00:40:18,793 --> 00:40:20,896
We had put
a lot of time and effort in
760
00:40:21,000 --> 00:40:22,275
into the investigation
761
00:40:22,379 --> 00:40:24,241
and we just weren't sure
what had happened.
762
00:40:27,482 --> 00:40:29,137
Less than
two years later,
763
00:40:29,241 --> 00:40:32,034
Greg Phillips and the NTSB
would be brought back
764
00:40:32,137 --> 00:40:33,448
to the mysterious disaster
765
00:40:33,551 --> 00:40:35,620
with the crash of another 737.
766
00:40:35,724 --> 00:40:36,758
Hold on. Hold on.
767
00:40:37,793 --> 00:40:39,827
- Hold on.
- Shoot!
768
00:40:42,068 --> 00:40:43,586
What the hell is this?
769
00:40:45,931 --> 00:40:47,103
Oh, God, no!
770
00:40:52,793 --> 00:40:55,620
September 8th, 1994.
771
00:40:55,724 --> 00:40:59,275
US Air Flight 427 has
crashed near Pittsburgh,
772
00:40:59,379 --> 00:41:00,655
killing everyone on board.
773
00:41:03,862 --> 00:41:06,275
When we first arrived
at the crash site,
first of all,
774
00:41:06,379 --> 00:41:07,689
there was no aircraft there.
775
00:41:07,793 --> 00:41:09,931
There were only bits
and pieces of the airplane.
776
00:41:10,034 --> 00:41:12,793
It wasn't really recognizable
as an airplane.
777
00:41:15,517 --> 00:41:18,000
Investigators begin
to see that this crash is
778
00:41:18,103 --> 00:41:21,137
a mirror image
of United Flight 585.
779
00:41:23,344 --> 00:41:26,689
On final approach,
United 585 rolled right,
780
00:41:26,793 --> 00:41:29,275
while US Air 427 rolled left.
781
00:41:30,827 --> 00:41:32,689
Both crews are
caught by surprise.
782
00:41:34,620 --> 00:41:38,724
After a terrifying struggle,
both crash with no survivors.
783
00:41:44,413 --> 00:41:47,689
Once again, investigators test
the dual servo valve.
784
00:41:48,551 --> 00:41:51,206
But they come up empty-handed.
785
00:41:51,310 --> 00:41:53,517
That unit passed
all its operational tests.
786
00:41:53,620 --> 00:41:55,689
There wasn't any indication
that it had failed.
787
00:41:57,931 --> 00:42:02,310
We were going up against
an aircraft that had
an incredible safety history.
788
00:42:02,413 --> 00:42:05,413
It was really, everything
you could see for 30 years,
789
00:42:05,517 --> 00:42:07,965
this had been
a great airplane.
790
00:42:08,068 --> 00:42:10,586
We were trying to prove that
there was something wrong
791
00:42:10,689 --> 00:42:11,896
with the straight A student.
792
00:42:15,448 --> 00:42:17,379
The team reaches
another dead-end.
793
00:42:19,241 --> 00:42:21,137
But almost two years later,
794
00:42:21,241 --> 00:42:24,413
they get a third chance
to solve this deadly mystery.
795
00:42:36,551 --> 00:42:38,103
In Phoenix, Arizona,
796
00:42:38,206 --> 00:42:40,448
a long night of maintenance is
winding down.
797
00:42:41,275 --> 00:42:42,517
Over 30 mechanics
798
00:42:42,620 --> 00:42:44,724
and some
half-a-dozen inspectors
799
00:42:44,827 --> 00:42:48,379
have combed through
a Southwest Airlines 737.
800
00:42:48,482 --> 00:42:51,862
The team has made more
than 400 separate checks.
801
00:42:51,965 --> 00:42:53,862
Parts have been replaced.
802
00:42:53,965 --> 00:43:00,000
Southwest 737 N427WN is
almost ready to fly again.
803
00:43:00,103 --> 00:43:02,103
Hopefully it'll push back
out of the hangar.
804
00:43:02,206 --> 00:43:04,379
We'll do some leak checks,
make sure
everything's working,
805
00:43:04,482 --> 00:43:05,517
nothing's leaking.
806
00:43:05,620 --> 00:43:07,689
Then it'll go to the gate
for departure time.
807
00:43:09,137 --> 00:43:10,655
But it's a truth
in maintenance
808
00:43:10,758 --> 00:43:13,482
that engineers can only fix
what they know is broken.
809
00:43:15,034 --> 00:43:18,413
For several years,
every 737 that flew had
810
00:43:18,517 --> 00:43:22,413
a hidden danger that not even
the most careful technician
could have spotted.
811
00:43:24,103 --> 00:43:26,275
In the early 1990s,
812
00:43:26,379 --> 00:43:29,517
two 737s crashed
in mysterious accidents.
813
00:43:31,482 --> 00:43:34,068
In both cases,
the jets spiraled
out of control.
814
00:43:39,620 --> 00:43:43,206
In 1996, the same malfunction
strikes again.
815
00:43:45,793 --> 00:43:47,172
It's June 9th.
816
00:43:47,275 --> 00:43:50,551
Captain Brian Bishop prepares
to land in Richmond, Virginia.
817
00:43:52,068 --> 00:43:56,344
Then, just like United 585
and US AIR 427,
818
00:43:56,448 --> 00:43:58,379
his plane rolls
out of control.
819
00:44:03,862 --> 00:44:06,000
I turned the yoke
the opposite direction
820
00:44:06,103 --> 00:44:07,931
and stood
on the opposite rudder pedal.
821
00:44:08,034 --> 00:44:09,379
The pedal didn't move for me.
822
00:44:11,275 --> 00:44:12,862
We didn't know to what extent,
823
00:44:12,965 --> 00:44:14,344
but we knew we had
a problem with the rudder.
824
00:44:15,758 --> 00:44:17,206
For over 30 seconds,
825
00:44:17,310 --> 00:44:20,724
Bishop struggles to control
his renegade plane.
826
00:44:20,827 --> 00:44:23,000
And then, just as suddenly,
827
00:44:23,103 --> 00:44:26,482
the 737 calms down
and goes back to horizontal.
828
00:44:31,344 --> 00:44:32,965
We had
started the checklist.
829
00:44:34,448 --> 00:44:36,172
And almost before I could
finish the sentence,
830
00:44:36,275 --> 00:44:38,275
all of a sudden
there was just a 'wham!'
831
00:44:40,482 --> 00:44:43,000
The 737 is
once again out of control.
832
00:44:51,241 --> 00:44:55,000
Then, out of the blue,
Eastwind 517 is back on track.
833
00:44:57,344 --> 00:45:00,379
Wasting no time,
Captain Bishop gets it
onto the tarmac.
834
00:45:04,827 --> 00:45:07,620
Taxiing in is
when I realized
my legs were shaking.
835
00:45:11,172 --> 00:45:12,655
We marched
to the scene.
836
00:45:12,758 --> 00:45:14,310
The airplane
literally didn't move.
837
00:45:14,413 --> 00:45:16,172
Stayed at its location
at the airport
838
00:45:16,275 --> 00:45:18,034
until we got down there.
839
00:45:18,137 --> 00:45:21,689
Suddenly they had a 737
that had had
a rudder incident,
840
00:45:21,793 --> 00:45:23,379
that was intact,
841
00:45:23,482 --> 00:45:26,655
and they had a pilot
who was alive
and who could talk about it.
842
00:45:26,758 --> 00:45:28,827
I think they were much happier
to have the airplane than me.
843
00:45:31,379 --> 00:45:32,827
Investigators zero in
844
00:45:32,931 --> 00:45:35,827
on the 737's rudder controls.
845
00:45:35,931 --> 00:45:39,517
The power control unit is
tested again and again.
846
00:45:39,620 --> 00:45:41,068
But it performs perfectly.
847
00:45:42,793 --> 00:45:45,724
Refusing to give up,
investigator Tom
Haueter decides
848
00:45:45,827 --> 00:45:48,448
to try a different test.
849
00:45:48,551 --> 00:45:51,172
One fellow mentioned a test
they had done in the military
850
00:45:52,034 --> 00:45:53,172
of a thermal shock.
851
00:45:54,482 --> 00:45:57,241
The power control unit
is soaked in dry ice
852
00:45:57,344 --> 00:46:01,103
and blasted with nitrogen gas
at minus 40 degrees Celsius.
853
00:46:04,827 --> 00:46:07,379
Then it's injected
with super-heated
hydraulic fluid.
854
00:46:08,931 --> 00:46:11,068
It's then given a command
to start working.
855
00:46:13,586 --> 00:46:15,482
As we were
standing there listening
856
00:46:15,586 --> 00:46:19,241
to the actuator move left
and right, left and right,
857
00:46:20,793 --> 00:46:23,586
it stopped, and it was not
commanded to stop.
858
00:46:24,241 --> 00:46:25,413
It just jammed.
859
00:46:26,586 --> 00:46:27,965
Stopped working completely.
860
00:46:29,620 --> 00:46:30,862
The team
has discovered
861
00:46:30,965 --> 00:46:33,482
that a small hydraulic valve
that controls the rudder
862
00:46:33,586 --> 00:46:36,689
of the world's
most popular jetliner can jam
863
00:46:36,793 --> 00:46:38,241
in the right circumstances.
864
00:46:40,896 --> 00:46:44,275
And the valve can jam
without leaving behind
any traces.
865
00:46:48,827 --> 00:46:51,172
When investigators
double-check their results,
866
00:46:52,551 --> 00:46:54,620
they discover
another major flaw.
867
00:46:56,724 --> 00:46:58,448
In careful analysis
of the data,
868
00:46:58,551 --> 00:47:00,551
a couple
of the engineers recognized
869
00:47:00,655 --> 00:47:03,379
that it not only
stopped working,
870
00:47:03,482 --> 00:47:06,137
but actually left became right
and right became left.
871
00:47:06,241 --> 00:47:08,310
There was actually a movement
872
00:47:08,413 --> 00:47:13,034
of fluid in... into places
that it shouldn't have gone.
873
00:47:14,586 --> 00:47:16,827
And the reversal is
like driving your car.
874
00:47:16,931 --> 00:47:19,586
You turn to the right,
it goes left.
875
00:47:19,689 --> 00:47:21,482
You're not gonna
figure out this failure mode
876
00:47:21,586 --> 00:47:23,758
until you go off the road.
877
00:47:23,862 --> 00:47:26,172
And in these cases,
that's what the pilots
were faced with,
878
00:47:26,275 --> 00:47:28,344
something so unusual
879
00:47:28,448 --> 00:47:30,068
that they didn't understand
what was happening.
880
00:47:30,758 --> 00:47:33,172
What the hell is this?
881
00:47:33,275 --> 00:47:38,137
That would explain why
the First Officer Chuck Emmett
would keep his foot
882
00:47:38,241 --> 00:47:39,862
on the rudder pedal,
883
00:47:39,965 --> 00:47:41,655
because he's thinking,
884
00:47:41,758 --> 00:47:44,206
"Why isn't
the plane going right?",
885
00:47:44,310 --> 00:47:46,793
and he's feeling
the plane go to the left.
886
00:47:50,103 --> 00:47:52,103
In the aftermath
of these disasters,
887
00:47:52,206 --> 00:47:53,793
pilots received
better training
888
00:47:53,896 --> 00:47:56,931
on how to deal
with sudden rudder problems.
889
00:47:57,034 --> 00:47:59,448
Boeing spent hundreds
of millions of dollars
890
00:47:59,551 --> 00:48:02,655
redesigning and replacing
the rudder's dual servo valve
891
00:48:02,758 --> 00:48:06,068
on thousands of 737s
around the world.
892
00:48:06,172 --> 00:48:09,103
One thing we don't like
at the Safety Board is to have
893
00:48:09,206 --> 00:48:10,448
an undetermined accident,
894
00:48:10,551 --> 00:48:13,275
because then we can't make
a change to improve safety.
895
00:48:14,000 --> 00:48:15,931
So out of US Air 427,
896
00:48:16,034 --> 00:48:17,172
United 585,
897
00:48:17,275 --> 00:48:19,655
we have a much
safer 737 fleet.
898
00:48:22,517 --> 00:48:24,551
It's 7 a.m.
899
00:48:24,655 --> 00:48:27,448
After an eight-hour shift,
the maintenance is finished
900
00:48:27,551 --> 00:48:30,068
on this
Southwest Airlines 737.
901
00:48:32,344 --> 00:48:34,068
According to their
maintenance reports,
902
00:48:34,172 --> 00:48:37,413
the team has conducted
78 unscheduled procedures
903
00:48:37,517 --> 00:48:41,379
and 339 scheduled inspections.
904
00:48:41,482 --> 00:48:43,931
I think each one of us
out here has
905
00:48:44,034 --> 00:48:45,344
a sense of pride
in themselves,
906
00:48:45,448 --> 00:48:49,275
that we do the best job
we possibly can,
day in and day out.
907
00:48:49,379 --> 00:48:52,689
Obviously,
the stakes are high.
Every life is important.
908
00:48:52,793 --> 00:48:55,103
Despite the horror
of airplane disasters,
909
00:48:55,206 --> 00:48:58,482
they are still extremely rare,
910
00:48:58,586 --> 00:49:01,896
especially given how often
passenger planes take off
and land.
911
00:49:03,724 --> 00:49:05,620
Sometimes we obscure the fact
912
00:49:05,724 --> 00:49:07,793
that we fly millions
and millions
913
00:49:07,896 --> 00:49:09,896
and millions of people
day in and day out,
914
00:49:10,000 --> 00:49:12,689
without putting a scratch
on even the airplane,
let alone the people.
915
00:49:13,931 --> 00:49:15,827
This is
the most amazing system.
916
00:49:17,310 --> 00:49:19,689
This system depends
on the dedicated team
917
00:49:19,793 --> 00:49:22,103
of professionals committed
to taking care
918
00:49:22,206 --> 00:49:25,655
of these
21st century masterpieces,
919
00:49:25,758 --> 00:49:28,275
planes so well built
that they could fly
920
00:49:28,379 --> 00:49:30,724
almost as long
as we're willing
to take care of them.
921
00:49:32,103 --> 00:49:35,103
We've learned now
how to inspect
and maintain these things
922
00:49:35,206 --> 00:49:38,137
and even rebuild them
to where they should have
an indefinite life.
923
00:49:38,241 --> 00:49:39,310
They're built tough
924
00:49:39,413 --> 00:49:40,827
and they should be
able to last forever,
925
00:49:40,931 --> 00:49:42,482
if they're
maintained properly.