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narrator: the boeing 737 is one
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00:00:10,678 --> 00:00:15,449
of the most popular
passenger jets in the world.
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00:00:15,483 --> 00:00:17,351
around the globe,
the plane has carried
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00:00:17,385 --> 00:00:20,721
more than 12 billion passengers.
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it's the backbone
of the aviation industry.
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[passengers screaming]
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but in 1991, something happened
on board a 737
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that sent shudders
through the world of aviation.
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man: oh, my lord.
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narrator: a deadly crash
has investigators scrambling.
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man: there was a time
when i had doubts
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that we'd be able to solve it.
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man: it was like he was
tracking a serial killer.
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narrator: the hunt for answers
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will take ten long,
grueling years.
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the fate of the airline industry
hangs in the balance.
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and the mystery isn't solved
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until more than 150 people
are dead.
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flight attendant:
ladies and gentlemen,
we are starting our approach.
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pilot: we lost both engines!
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flight attendant:
put the mask over your nose.
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emergency descent.
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pilot: mayday, mayday.
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flight attendant:
brace for impact!
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controller: i think i lost one.
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man: investigation starting...
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man: he's gonna crash!
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narrator: 9:40 a.m.,
march 3, 1991.
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after a short 17-minute trip
from denver,
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united airlines flight 585
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is on final approach
into colorado springs.
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it looks like a perfect day
for flying.
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but there's trouble in the air.
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harold green: nice-looking day.
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hard to believe the skies
are unfriendly.
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narrator: there's been heavy
turbulence during the flight,
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and violent gusts of wind are
forecast over colorado springs.
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green: never driven
to colorado springs
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and not gotten sick.
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narrator: at the controls
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is 52-year-old captain
harold green,
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a pilot with
20 years' experience
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and a sterling reputation.
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green's co-pilot
is patricia eidson.
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at 42, she is one of the first
female flight officers
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in united's history.
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green: flight attendants,
prepare for landing.
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narrator: at colorado springs
municipal airport,
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air traffic controller
james rayfield
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is ready to bring flight 585 in.
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00:03:07,721 --> 00:03:12,393
james rayfield: united 585,
report the airport in sight.
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patricia eidson: got it?
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green: yup.
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eidson: airport in sight,
united 585.
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green: lower landing gear.
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rayfield: united 585 is cleared
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for a visual approach
to runway 35.
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weather conditions,
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wind 320 degrees at 16,
gusting to 29.
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narrator:
as its speed decreases,
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flight 585 becomes more
vulnerable to the turbulence.
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eidson wants to know
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what other planes
have experienced on landing.
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eidson: any reports lately of
any loss or gain of airspeed?
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rayfield: yes, ma'am.
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500 feet, a 15-knot loss,
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at 400 feet, a 15-knot gain,
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and at 150 feet
a gain of 20 knots.
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eidson: sounds adventurous.
thank you.
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green: starting on down.
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narrator:
just a mile from the airport,
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retired policeman harold darnell
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is on his way
to a local flea market.
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half a mile overhead,
green and eidson focus
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on keeping their speed constant
as they descend.
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eidson: we had
a 10-knot change here.
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green: yeah, i know.
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awful lot of power
to hold that airspeed.
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narrator: as united 585
approaches the runway,
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darnell feels something strange.
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harold darnell: whoa!
what the heck was that?
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narrator: out of nowhere,
a powerful gust of wind
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strikes his vehicle,
almost blowing him off the road.
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eidson: another 10-knot gain.
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green: 30 flaps.
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narrator:
from the control tower,
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james rayfield can now see
flight 585's final approach.
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as the aircraft closes in
on the airport,
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the ride gets even bumpier.
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eidson: wow.
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we're at 1,000 feet.
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narrator: then, without warning,
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the 737 starts to spin
out of control.
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eidson: oh, god. flip!
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[passengers screaming]
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green: 15 flaps!
eidson: 15!
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green: oh, no.
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eidson: oh, my god!
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[screaming]
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oh, my god!
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oh, my god!
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[screaming]
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[explosion]
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darnell: oh, my lord!
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rayfield: crash! crash!
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narrator: rescue workers arrive
within minutes,
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but there is almost no sign
of the 737.
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the shattered remains
of the 38-ton jet lie buried
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in a fire-blackened
impact crater.
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man: the plane didn't, it didn't
skate or bounce, you know,
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like when a plane comes in
normally and lands?
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it just nosed right in,
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and where it hit
is where it stayed.
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narrator:
there are no survivors.
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all 20 passengers
and 5 crew members
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are killed instantly
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by the high-speed impact
and exploding jet fuel.
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in 10 violent seconds,
colorado springs has become
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the site of one of the most
mysterious air crashes
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in aviation history.
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by nightfall, investigators
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from the national
transportation safety board
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descend on colorado springs.
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known to insiders
as tin kickers,
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ntsb investigators examine over
2,000 aviation accidents a year,
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at times by picking through the
metal debris of fallen aircraft.
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00:07:40,728 --> 00:07:44,598
while coroners mark the location
of human remains in red,
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00:07:44,632 --> 00:07:48,201
ntsb investigators mark
scraps of metal in yellow,
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looking for clues to help them
solve the mystery of flight 585.
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like investigating
a mass murder,
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it's a tough job walking
onto a crash site.
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00:08:05,819 --> 00:08:09,657
among the investigators assigned
to the case is malcolm brenner,
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a specialist
in human performance.
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his job will be to find out
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if the crash was caused
by pilot error.
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malcolm brenner: the area
was cordoned off by police,
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and there were
salvation army trucks.
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i got a cup of coffee, a cup
of hot chocolate or something,
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and i thanked them for it,
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and they said no, no, thank you,
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and they had this look
in their eyes,
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like my god, you have to go
into this site.
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narrator: clues to the fate
of united 585
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lie mangled
in a deep, black hole.
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the fuselage is crushed
like an accordion
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in the impact crater.
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the rest of the plane
is in pieces
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spread over an area
smaller than a football field.
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brenner:
there was a lot of fire damage.
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there'd been a fire afterwards.
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and it was all contained
in a relatively small area,
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which, just initial impression,
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it can be a sign that
the airplane was intact.
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if there was a midair explosion
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00:09:06,213 --> 00:09:07,681
or something
came off the airplane,
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you would expect that
to be a much larger site.
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00:09:11,084 --> 00:09:13,721
greg phillips:
my first sense that it was
going to take some time
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to investigate the accident
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was the damage that we saw
in the parts.
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when they're burnt and broken,
the process always takes longer.
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narrator: the national
transportation safety board
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begins a painstaking
investigation into the crash.
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engine turbines,
hydraulic pressure gauges,
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the cockpit voice recorder
and inflight data recorder
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are all carefully extracted
from the site, photographed,
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and sent to the lab
for analysis.
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an important step
in the investigation
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is the analysis of
the cockpit voice recorder.
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with pilot error a factor
in 70% of air disasters,
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malcolm brenner's job
is to see what role
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pilots green and eidson
played in the crash.
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brenner: this crew was,
and i felt this at the time,
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was one of the more impressive
crews i had ever dealt with.
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there was a little bit
of tension release,
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a little bit of humor.
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the captain said...
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green:
never driven to colorado springs
and not gotten sick.
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brenner:
the first officer suggested
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that they add extra speed
as a safety margin.
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the captain agreed with it.
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it was good interaction.
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eidson: got it?
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green: yup.
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eidson: airport in sight,
united 585.
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green: lower landing gear.
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brenner: this was a sense
of an excellent crew
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caught randomly, if anything.
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so again that was
my first impression
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is that this would be consistent
more with a hardware situation.
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narrator: as more about
flight 585 becomes known,
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mechanical failure becomes
a serious suspect.
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just seconds before it crashed,
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the plane rolled onto its back
and spun wildly out of control.
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investigators wonder
if the sudden motion was caused
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00:11:12,973 --> 00:11:16,009
by the plane losing
an engine or a wing.
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00:11:19,112 --> 00:11:21,749
from the state
of the aircraft on site,
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it's clear that it was intact
at the time of the crash.
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what investigators don't know
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00:11:27,220 --> 00:11:30,758
is if the engines
were still working at impact.
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00:11:36,897 --> 00:11:40,167
technicians examine
the engine turbines.
201
00:11:40,200 --> 00:11:44,738
they discover dirt has been
drawn deeply into every crevice.
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00:11:44,772 --> 00:11:47,440
these blades were clearly
spinning and sucking in air
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00:11:47,474 --> 00:11:51,244
at the time of impact.
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00:11:51,278 --> 00:11:53,446
the engines
may have been running,
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00:11:53,480 --> 00:11:56,116
but technicians
aren't sure how well.
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00:11:56,149 --> 00:11:59,119
the plane's hydraulic pressure
dials are destroyed,
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00:11:59,152 --> 00:12:01,521
their glass covers broken.
208
00:12:01,554 --> 00:12:03,824
the indicator needles
have been snapped off
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00:12:03,857 --> 00:12:05,492
by the force of the impact.
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00:12:05,525 --> 00:12:09,362
but even these ravaged dials
tell a tale.
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green: 15 flaps!
eidson: 15!
212
00:12:15,302 --> 00:12:16,870
narrator: on close inspection,
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00:12:16,904 --> 00:12:19,773
investigators find
a critical mark.
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00:12:19,807 --> 00:12:22,976
at the moment of impact, a dent
was made on the faceplate
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00:12:23,010 --> 00:12:25,813
by the jarred indicator needle.
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00:12:25,846 --> 00:12:28,882
it proves that
when flight 585 crashed,
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00:12:28,916 --> 00:12:31,218
its engines
were running normally.
218
00:12:41,228 --> 00:12:43,230
with engine failure ruled out,
219
00:12:43,263 --> 00:12:46,099
there seems to be only one other
mechanical explanation
220
00:12:46,133 --> 00:12:49,236
for why flight 585
suddenly rolled over
221
00:12:49,269 --> 00:12:53,140
and then fell out of the sky.
222
00:12:53,173 --> 00:12:55,042
it appears increasingly likely
223
00:12:55,075 --> 00:12:57,444
that the plane had suffered
a catastrophic problem
224
00:12:57,477 --> 00:12:59,880
with its flight controls.
225
00:12:59,913 --> 00:13:02,482
investigators quickly
become suspicious of the rudder
226
00:13:02,515 --> 00:13:04,151
at the back of the tail.
227
00:13:04,184 --> 00:13:05,485
phillips: we focused in
228
00:13:05,518 --> 00:13:08,555
after eliminating other
flight control surfaces
229
00:13:08,588 --> 00:13:11,458
that we thought could
contribute to the roll.
230
00:13:11,491 --> 00:13:14,394
we started looking
into the rudder.
231
00:13:14,427 --> 00:13:16,496
bring that up
so i can take a look at it.
232
00:13:16,529 --> 00:13:18,331
narrator: investigators
begin their examination
233
00:13:18,365 --> 00:13:20,367
of the rudder on site.
234
00:13:20,400 --> 00:13:21,902
but the violence of the crash
235
00:13:21,935 --> 00:13:23,871
makes the job
extremely difficult.
236
00:13:23,904 --> 00:13:25,505
phillips: almost nothing left.
237
00:13:27,374 --> 00:13:29,376
narrator:
most of the plane's parts
238
00:13:29,409 --> 00:13:32,445
are too crushed or burned
for testing.
239
00:13:32,479 --> 00:13:35,482
but a vital component
is still reasonably intact:
240
00:13:35,515 --> 00:13:38,818
the power control unit, or pcu.
241
00:13:40,921 --> 00:13:44,591
used constantly during flight,
especially during landings,
242
00:13:44,624 --> 00:13:48,962
the pcu performs
like a car's power steering.
243
00:13:48,996 --> 00:13:51,431
when the pilot pushes
on a rudder pedal,
244
00:13:51,464 --> 00:13:53,366
the pcu uses hydraulic fluid
245
00:13:53,400 --> 00:13:56,003
to convert gentle movements
of a pilot's foot
246
00:13:56,036 --> 00:14:00,040
into the pressure needed to move
the 737's enormous rudder.
247
00:14:03,010 --> 00:14:04,311
the heart of the pcu
248
00:14:04,344 --> 00:14:07,847
is something called
the dual servo valve.
249
00:14:09,449 --> 00:14:12,152
shaped like a soda can,
it has two slides,
250
00:14:12,185 --> 00:14:13,987
which glide past one another,
251
00:14:14,021 --> 00:14:16,289
directing the flow
of pressurized hydraulic fluid
252
00:14:16,323 --> 00:14:18,325
that moves the rudder.
253
00:14:20,327 --> 00:14:23,130
bill adair: the servo valve
is very unique,
254
00:14:23,163 --> 00:14:28,168
that it is in effect
two valves in one,
255
00:14:28,201 --> 00:14:32,139
and that that creates
a whole range of interactions
256
00:14:32,172 --> 00:14:37,010
that don't occur in a more
conventional hydraulic valve.
257
00:14:39,679 --> 00:14:42,515
narrator: when a technician
opens the power control unit,
258
00:14:42,549 --> 00:14:47,054
chips of metal are found
floating in the hydraulic fluid.
259
00:14:47,087 --> 00:14:49,256
it's a disturbing find.
260
00:14:49,289 --> 00:14:52,592
these particles could cause
the servo valve to jam,
261
00:14:52,625 --> 00:14:57,564
making it impossible
to work the plane's rudder.
262
00:14:57,597 --> 00:14:59,566
it's a chilling prospect.
263
00:14:59,599 --> 00:15:04,204
could a microscopic fault
bring down a 38-ton jet?
264
00:15:04,237 --> 00:15:06,606
it's difficult
for phillips to tell.
265
00:15:06,639 --> 00:15:09,342
while more intact
than much of the wreck,
266
00:15:09,376 --> 00:15:13,213
the pcu and dual servo valve
are both damaged.
267
00:15:16,483 --> 00:15:18,185
to test what he does have,
268
00:15:18,218 --> 00:15:21,554
phillips travels to california
to the labs of parker hannifin
269
00:15:21,588 --> 00:15:24,457
where the rudder control unit
is made.
270
00:15:31,398 --> 00:15:34,601
the curious metal chips
floating in the pcu's chambers
271
00:15:34,634 --> 00:15:36,669
are dismissed.
272
00:15:36,703 --> 00:15:38,471
phillips is told
that filters keep them
273
00:15:38,505 --> 00:15:40,273
out of the delicate servo valve
274
00:15:40,307 --> 00:15:43,010
that directs fluid
and moves the rudder.
275
00:15:46,546 --> 00:15:49,382
nothing else is found that could
explain any sudden movement
276
00:15:49,416 --> 00:15:53,720
of the rudder on flight 585.
277
00:15:53,753 --> 00:15:55,989
phillips: we didn't have
any absolute indication
278
00:15:56,023 --> 00:15:57,690
or information
that we could point to
279
00:15:57,724 --> 00:16:00,027
that said
the rudder power control unit,
280
00:16:00,060 --> 00:16:03,330
the servo valve or any, any part
of that flight control system
281
00:16:03,363 --> 00:16:06,766
caused that accident.
282
00:16:06,799 --> 00:16:09,702
narrator: phillips still
suspects a mechanical problem,
283
00:16:09,736 --> 00:16:11,571
but with no conclusive evidence
284
00:16:11,604 --> 00:16:14,641
that the pcu or servo valve
caused the crash,
285
00:16:14,674 --> 00:16:17,610
he is forced to sign off
on the tests.
286
00:16:17,644 --> 00:16:19,646
phillips: it's a pass.
287
00:16:24,751 --> 00:16:26,619
narrator:
with phillips at a dead end,
288
00:16:26,653 --> 00:16:31,691
only bad mountain weather
remains a primary suspect.
289
00:16:31,724 --> 00:16:34,694
an expert on weather-related
aviation accidents,
290
00:16:34,727 --> 00:16:38,398
greg salotollo is trying
to determine if heavy winds
291
00:16:38,431 --> 00:16:40,733
on the day of the crash
were a factor.
292
00:16:40,767 --> 00:16:43,403
greg salotollo:
there is a history of events
293
00:16:43,436 --> 00:16:44,771
where there've been
airplane accidents
294
00:16:44,804 --> 00:16:47,440
attributed to mountain waves
or rotors.
295
00:16:47,474 --> 00:16:55,582
in 1966, a boac 707
near mount fuji disintegrated
296
00:16:55,615 --> 00:16:57,717
in a mountain wave and rotor.
297
00:16:57,750 --> 00:17:00,387
narrator: high winds crashing
over mountain peaks
298
00:17:00,420 --> 00:17:03,423
leave so-called wind rotors
in the lee side--
299
00:17:03,456 --> 00:17:05,725
invisible,
highly turbulent downdrafts
300
00:17:05,758 --> 00:17:08,628
that come plunging down
with devastating power
301
00:17:08,661 --> 00:17:11,364
and are extremely dangerous
to aircraft.
302
00:17:11,398 --> 00:17:15,802
salotollo: we found
a great deal of evidence,
303
00:17:15,835 --> 00:17:18,438
looking at the surface,
upper air data
304
00:17:18,471 --> 00:17:20,607
and talking to witnesses
in the area
305
00:17:20,640 --> 00:17:22,575
that rotors were a possibility.
306
00:17:22,609 --> 00:17:23,710
darnell: an explosion.
it was right over there.
307
00:17:23,743 --> 00:17:26,479
narrator: salotollo hears
several eyewitness reports
308
00:17:26,513 --> 00:17:30,250
of bizarre mountain weather
on the day of the crash.
309
00:17:30,283 --> 00:17:33,753
one of the most intriguing
is from harold darnell...
310
00:17:33,786 --> 00:17:36,723
darnell: oh, what the heck
was that?
311
00:17:36,756 --> 00:17:39,326
narrator:
...whose truck was struck
by a powerful gust of wind
312
00:17:39,359 --> 00:17:43,563
just moments before 585 crashed.
313
00:17:43,596 --> 00:17:47,200
but as greg salotollo
combs through his evidence,
314
00:17:47,234 --> 00:17:50,103
the theory that a wind rotor
knocked the plane from the sky
315
00:17:50,137 --> 00:17:52,372
is getting less and less likely.
316
00:17:58,611 --> 00:17:59,512
green: nice-looking day.
317
00:17:59,546 --> 00:18:02,715
hard to believe
the skies are unfriendly.
318
00:18:02,749 --> 00:18:03,883
narrator: wind rotors are areas
319
00:18:03,916 --> 00:18:07,154
of extremely low
barometric pressure,
320
00:18:07,187 --> 00:18:10,323
so if flight 585
did pass through one,
321
00:18:10,357 --> 00:18:12,292
its altimeter reading
would have spiked
322
00:18:12,325 --> 00:18:15,162
as the plane was blown
suddenly upwards.
323
00:18:19,766 --> 00:18:22,835
salotollo: there was no evidence
that we saw that
324
00:18:22,869 --> 00:18:26,739
on the flight data recorder
of 585.
325
00:18:26,773 --> 00:18:28,641
narrator:
what the flight recorder
did show
326
00:18:28,675 --> 00:18:31,678
was a fast and deadly drop
in altitude
327
00:18:31,711 --> 00:18:34,113
as the plane fell to earth.
328
00:18:47,960 --> 00:18:50,597
it's been 21 months
since the investigation
329
00:18:50,630 --> 00:18:54,634
into the crash
of united flight 585 began--
330
00:18:54,667 --> 00:18:59,606
almost two years, in which
the ntsb has studied the crew,
331
00:18:59,639 --> 00:19:01,608
the weather, the rudder,
332
00:19:01,641 --> 00:19:04,577
and thousands of other
pieces of evidence.
333
00:19:04,611 --> 00:19:07,447
they've come up empty-handed.
334
00:19:07,480 --> 00:19:09,649
for only the fourth time
in its history,
335
00:19:09,682 --> 00:19:14,654
the ntsb releases a report which
doesn't reach a conclusion.
336
00:19:14,687 --> 00:19:19,926
the cause of the crash
of flight 585 is undetermined.
337
00:19:19,959 --> 00:19:22,395
phillips: we had put a lot
of time and effort in
338
00:19:22,429 --> 00:19:23,596
into the investigation,
339
00:19:23,630 --> 00:19:25,898
and we just weren't sure
what had happened.
340
00:19:25,932 --> 00:19:28,768
adair: it was like he was
tracking a serial killer.
341
00:19:28,801 --> 00:19:33,206
he was frustrated
that they had not solved 585.
342
00:19:33,240 --> 00:19:35,908
he did not want that
to happen again.
343
00:19:38,878 --> 00:19:40,380
narrator: but almost two years
344
00:19:40,413 --> 00:19:43,216
after the report on 585
is released,
345
00:19:43,250 --> 00:19:45,685
the killer strikes again.
346
00:19:48,421 --> 00:19:51,458
at 7 p.m. on a clear,
windless day,
347
00:19:51,491 --> 00:19:55,828
u.s. air flight 427
is nearing pittsburgh.
348
00:19:55,862 --> 00:19:58,798
captain peter germano
and first officer chuck emmett
349
00:19:58,831 --> 00:20:02,669
are getting ready
for their final approach.
350
00:20:02,702 --> 00:20:04,604
chuck emmett:
folks, from the flight deck,
351
00:20:04,637 --> 00:20:07,374
we should be on the ground
in about ten more minutes.
352
00:20:07,407 --> 00:20:09,742
sunny skies, a little hazy.
353
00:20:09,776 --> 00:20:11,578
flight attendants,
please prepare for landing.
354
00:20:11,611 --> 00:20:13,012
i ask you to check the security
of your seatbelts.
355
00:20:13,045 --> 00:20:14,647
thank you.
356
00:20:14,681 --> 00:20:20,320
controller: u.s. air 309,
descend and maintain 6,000.
357
00:20:20,353 --> 00:20:22,355
narrator: as they close in
on the airport,
358
00:20:22,389 --> 00:20:24,391
the pilots are on the lookout
for another flight
359
00:20:24,424 --> 00:20:28,395
about six miles ahead of them.
360
00:20:28,428 --> 00:20:31,664
peter germano:
looking for the traffic.
361
00:20:31,698 --> 00:20:38,271
turning 1-0-0, u.s. air 427.
362
00:20:40,673 --> 00:20:42,675
emmett:
i see zuh jet stream.
363
00:20:45,011 --> 00:20:46,779
narrator: as they pass
through the turbulence
364
00:20:46,813 --> 00:20:48,781
left behind the other flight,
365
00:20:48,815 --> 00:20:53,320
their jet suddenly
and alarmingly rolls left.
366
00:20:53,353 --> 00:20:55,688
emmett: hold on, hold on.
367
00:20:55,722 --> 00:20:56,889
hold on.
368
00:20:56,923 --> 00:20:58,090
germano: shoot!
369
00:20:58,124 --> 00:21:03,730
narrator: nothing the pilots do
seems to have any effect.
370
00:21:03,763 --> 00:21:06,366
[screaming]
371
00:21:09,602 --> 00:21:12,739
germano: what the hell
is this?
372
00:21:12,772 --> 00:21:14,707
what the hell?
373
00:21:14,741 --> 00:21:16,008
shoot!
374
00:21:22,449 --> 00:21:24,784
427, emergency!
375
00:21:25,785 --> 00:21:28,688
[screaming]
376
00:21:29,822 --> 00:21:31,724
emmett: oh, shoot!
377
00:21:31,758 --> 00:21:33,893
germano: pull! pull!
378
00:21:35,762 --> 00:21:36,763
emmett: oh, god, no!
379
00:21:36,796 --> 00:21:37,864
no!
380
00:21:37,897 --> 00:21:43,503
[screaming]
381
00:21:53,580 --> 00:21:55,515
narrator:
rescue crews arrive quickly,
382
00:21:55,548 --> 00:22:00,086
but the fate of flight 427
is tragically clear.
383
00:22:00,119 --> 00:22:04,624
there is no hope for the 132
passengers and crew.
384
00:22:04,657 --> 00:22:06,593
the human carnage is so bad
385
00:22:06,626 --> 00:22:10,763
authorities declare
the crash site a biohazard.
386
00:22:10,797 --> 00:22:13,666
john cox: u.s. air 427 accident
was the first u.s. accident
387
00:22:13,700 --> 00:22:19,005
where biohazard suits were used,
and it made it more difficult.
388
00:22:19,038 --> 00:22:20,740
they were uncomfortable,
they were hot,
389
00:22:20,773 --> 00:22:23,710
and to this day when i put on
a pair of rubber gloves
390
00:22:23,743 --> 00:22:24,911
for any reason,
391
00:22:24,944 --> 00:22:29,749
i'm instantly transformed back
to the site in pittsburgh.
392
00:22:29,782 --> 00:22:31,384
narrator: captain john cox,
393
00:22:31,418 --> 00:22:34,487
a 737 pilot and
flight systems specialist
394
00:22:34,521 --> 00:22:36,756
with the air line pilots
association,
395
00:22:36,789 --> 00:22:38,057
is asked to join the team
396
00:22:38,090 --> 00:22:41,628
investigating the crash
of flight 427.
397
00:22:42,895 --> 00:22:47,767
as coroners attempt
to collect human remains,
398
00:22:47,800 --> 00:22:50,570
ntsb lead investigator
tom haueter
399
00:22:50,603 --> 00:22:55,475
already knows his hunt for clues
will be long and painstaking.
400
00:22:55,508 --> 00:22:58,811
tom haueter: when we first
arrived at the crash site,
401
00:22:58,845 --> 00:23:00,747
well, first of all,
there was no aircraft there.
402
00:23:00,780 --> 00:23:02,915
there were only bits and pieces
of the airplane.
403
00:23:02,949 --> 00:23:06,653
it wasn't really recognizable
as an airplane.
404
00:23:06,686 --> 00:23:08,020
narrator: with the help
of eyewitnesses,
405
00:23:08,054 --> 00:23:10,022
information from
the flight data recorder
406
00:23:10,056 --> 00:23:12,058
and the cockpit voice recorder,
407
00:23:12,091 --> 00:23:15,795
investigators begin to quickly
see some striking similarities
408
00:23:15,828 --> 00:23:20,900
between 427 and the unsolved
case of united 585.
409
00:23:24,036 --> 00:23:28,641
in fact, they seem to be
mirror images of each other.
410
00:23:28,675 --> 00:23:32,879
on final approach,
united 585 rolls right,
411
00:23:32,912 --> 00:23:37,650
while u.s. air 427 rolls
to the left.
412
00:23:37,684 --> 00:23:40,019
both crews are caught
by surprise.
413
00:23:40,052 --> 00:23:42,822
and after just a few
terrifying seconds,
414
00:23:42,855 --> 00:23:47,760
both aircraft plummet
straight to the ground.
415
00:23:47,794 --> 00:23:52,665
as the investigation continues,
the list of similarities grows:
416
00:23:52,699 --> 00:23:56,035
427's engines were also
attached and functioning
417
00:23:56,068 --> 00:23:59,706
at the time of impact.
418
00:23:59,739 --> 00:24:01,140
but for all the similarities,
419
00:24:01,173 --> 00:24:03,776
there is one
important difference.
420
00:24:03,810 --> 00:24:06,245
unlike united 585,
421
00:24:06,278 --> 00:24:09,215
as u.s. air 427
approached pittsburgh,
422
00:24:09,248 --> 00:24:13,486
weather conditions
were dead calm.
423
00:24:13,520 --> 00:24:15,488
emmett: folks,
from the flight deck
424
00:24:15,522 --> 00:24:18,057
we should be on the ground
in about ten more minutes.
425
00:24:18,090 --> 00:24:21,160
sunny skies, a little hazy.
426
00:24:21,193 --> 00:24:24,564
narrator: as he did in the case
of united 585,
427
00:24:24,597 --> 00:24:26,966
greg phillips will once again
lead the investigation
428
00:24:26,999 --> 00:24:30,803
into the mechanical aspects
of the crash.
429
00:24:30,837 --> 00:24:34,140
almost immediately, he makes
a promising discovery.
430
00:24:35,942 --> 00:24:39,846
miraculously, much of
u.s. air 427's tail and rudder
431
00:24:39,879 --> 00:24:42,081
appear intact.
432
00:24:47,253 --> 00:24:49,789
the hydraulic devices
inside the tail
433
00:24:49,822 --> 00:24:53,760
have also sustained
very little damage.
434
00:24:53,793 --> 00:24:56,262
phillips and haueter prepare
to send the parts
435
00:24:56,295 --> 00:24:58,798
to the manufacturer
parker hannifin for testing
436
00:24:58,831 --> 00:25:00,867
as soon as possible.
437
00:25:00,900 --> 00:25:02,869
they need answers.
438
00:25:02,902 --> 00:25:06,906
pressure on the ntsb to solve
the accident is growing quickly.
439
00:25:09,776 --> 00:25:13,746
not only are the crashes
of flights 585 and 427
440
00:25:13,780 --> 00:25:15,782
disturbingly similar,
441
00:25:15,815 --> 00:25:18,551
both of them involve
the same kind of airplane--
442
00:25:18,585 --> 00:25:21,220
a boeing 737.
443
00:25:21,253 --> 00:25:24,991
but with serious questions being
raised about the plane's safety,
444
00:25:25,024 --> 00:25:28,561
billions of dollars,
untold lives
445
00:25:28,595 --> 00:25:33,299
and perhaps the airline industry
itself are at risk.
446
00:25:33,332 --> 00:25:35,802
cox: we couldn't live
with the fact, as investigators,
447
00:25:35,835 --> 00:25:39,038
of having two unsolved
737 accidents.
448
00:25:39,071 --> 00:25:42,141
the airplane is in too much use,
too wide a use around the world.
449
00:25:42,174 --> 00:25:44,143
it carries too many people
every day.
450
00:25:44,176 --> 00:25:48,915
unsolved was not
an acceptable answer.
451
00:25:48,948 --> 00:25:50,282
narrator: to find their killer,
452
00:25:50,316 --> 00:25:53,720
the ntsb can't afford
to rule anything out...
453
00:25:53,753 --> 00:25:55,822
from the possibility
that a collision with birds
454
00:25:55,855 --> 00:25:57,890
brought flight 427 down
455
00:25:57,924 --> 00:26:00,693
to strange,
even bizarre theories.
456
00:26:00,727 --> 00:26:03,195
adair: they looked at
electromagnetic interference.
457
00:26:03,229 --> 00:26:04,664
they got calls from people
458
00:26:04,697 --> 00:26:07,133
saying it might be
russian death rays.
459
00:26:07,166 --> 00:26:08,835
they considered everything.
460
00:26:08,868 --> 00:26:10,770
haueter: there were a couple
of witnesses who gave reports
461
00:26:10,803 --> 00:26:13,172
of the aircraft suddenly
descending and hovering
462
00:26:13,205 --> 00:26:14,206
before it blew up.
463
00:26:14,240 --> 00:26:17,276
we discounted those.
464
00:26:17,309 --> 00:26:21,313
narrator:
but the investigation's primary
suspect is the dual servo valve,
465
00:26:21,347 --> 00:26:25,284
part of the power control unit
that moves the 737's rudder
466
00:26:25,317 --> 00:26:30,757
and a suspect in the crash
of united 585.
467
00:26:30,790 --> 00:26:32,925
parker hannifin made the valve.
468
00:26:32,959 --> 00:26:34,894
at its lab in california,
469
00:26:34,927 --> 00:26:37,329
investigators look
inside the main cavity
470
00:26:37,363 --> 00:26:40,733
of the u.s. air
power control unit.
471
00:26:40,767 --> 00:26:42,702
just like in the earlier crash,
472
00:26:42,735 --> 00:26:47,874
they find tiny chips of metal
floating in the hydraulic fluid.
473
00:26:47,907 --> 00:26:51,744
but once again, parker and
boeing repeat their claim.
474
00:26:51,778 --> 00:26:53,846
filters designed
to stop any debris
475
00:26:53,880 --> 00:26:56,649
from interfering with
the delicate metal slides
476
00:26:56,683 --> 00:27:00,853
have done their job.
477
00:27:00,887 --> 00:27:04,891
investigator greg phillips
wants to be absolutely sure.
478
00:27:04,924 --> 00:27:07,393
if the chips were blocking
the slides,
479
00:27:07,426 --> 00:27:09,762
they would have left
tiny scratch marks behind
480
00:27:09,796 --> 00:27:13,700
where they rubbed
against the metal.
481
00:27:13,733 --> 00:27:16,102
but phillips can't find any.
482
00:27:16,135 --> 00:27:18,838
phillips: another pass.
483
00:27:18,871 --> 00:27:20,807
okay.
484
00:27:22,374 --> 00:27:25,945
narrator:
phillips has technicians put
the servo valve from flight 427
485
00:27:25,978 --> 00:27:28,280
through as many tests
as he can think of,
486
00:27:28,314 --> 00:27:30,717
trying to find a weakness.
487
00:27:30,750 --> 00:27:32,852
if he can find one,
it could explain
488
00:27:32,885 --> 00:27:37,256
why two planes were ripped
from the sky.
489
00:27:37,289 --> 00:27:40,326
but he comes up empty.
490
00:27:40,359 --> 00:27:42,895
phillips: that unit passed
all its operational tests.
491
00:27:42,929 --> 00:27:45,732
there wasn't any indication
that it had failed,
492
00:27:45,765 --> 00:27:50,369
and it operated within the
parameters we expected it to.
493
00:27:52,772 --> 00:27:54,841
narrator: once again,
the investigators are forced
494
00:27:54,874 --> 00:27:57,810
to shift their focus
back to the pilots.
495
00:28:01,413 --> 00:28:04,083
by studying the plane's
flight data recorder,
496
00:28:04,116 --> 00:28:06,285
investigators know
that the jet's rudder
497
00:28:06,318 --> 00:28:10,890
was deployed fully to one side,
what's called rudder hard-over.
498
00:28:13,125 --> 00:28:15,862
brenner: we were definitely
focused on a rudder,
499
00:28:15,895 --> 00:28:23,002
on hard-over rudder, full rudder
input for about 20 seconds.
500
00:28:23,035 --> 00:28:24,737
it can be caused
either by hardware,
501
00:28:24,771 --> 00:28:25,905
something unknown
in the hardware,
502
00:28:25,938 --> 00:28:27,506
or it can be caused
by pilot input.
503
00:28:31,778 --> 00:28:34,747
narrator:
first officer chuck emmett,
who was flying 427,
504
00:28:34,781 --> 00:28:37,316
did indeed step down hard
on his rudder
505
00:28:37,349 --> 00:28:38,751
and then held it there
506
00:28:38,785 --> 00:28:41,821
while the plane plummeted
toward the earth.
507
00:28:41,854 --> 00:28:43,856
it raised a grisly question--
508
00:28:43,890 --> 00:28:47,827
was he trying to fly the plane
into the ground?
509
00:28:47,860 --> 00:28:51,363
haueter: in looking at this,
and being a pilot myself,
510
00:28:51,397 --> 00:28:55,501
it's like this doesn't seem
like rational behavior.
511
00:28:55,534 --> 00:28:58,504
germano: what the hell is this?
512
00:28:58,537 --> 00:29:00,907
narrator: human performance
specialist malcolm brenner
513
00:29:00,940 --> 00:29:03,810
listens closely for evidence
on the cockpit voice recorder.
514
00:29:03,843 --> 00:29:06,312
germano: what the...no!
515
00:29:06,345 --> 00:29:07,446
shoot.
516
00:29:07,479 --> 00:29:08,848
brenner: in this case,
517
00:29:08,881 --> 00:29:09,949
they had microphones
right by their mouths,
518
00:29:09,982 --> 00:29:12,384
and you can hear as well
as in real life, or better.
519
00:29:12,418 --> 00:29:14,887
you can hear breathing sounds.
520
00:29:14,921 --> 00:29:16,355
emmett: hmm, yeah.
521
00:29:16,388 --> 00:29:17,857
i see zuh jet stream.
522
00:29:17,890 --> 00:29:22,428
narrator:
the cockpit recordings indicate
that flight 427's troubles began
523
00:29:22,461 --> 00:29:24,897
at the moment it flew
through the jet wake
524
00:29:24,931 --> 00:29:29,969
of a delta airlines 727 that had
just passed in front of them.
525
00:29:30,002 --> 00:29:32,504
brenner: both pilots
are startled by the wake.
526
00:29:32,538 --> 00:29:34,807
emmett: i see zuh jet stream.
527
00:29:34,841 --> 00:29:36,542
brenner:
the first officer breaks off
at the end of a sentence.
528
00:29:36,575 --> 00:29:39,511
i see the jet stream.
zuh.
529
00:29:39,545 --> 00:29:40,880
and there's no more discussion
of the jet stream
530
00:29:40,913 --> 00:29:41,747
or anything else.
531
00:29:41,780 --> 00:29:42,915
they both focus.
something happened here.
532
00:29:42,949 --> 00:29:44,550
captain says "sheez."
533
00:29:44,583 --> 00:29:45,918
germano: sheez.
534
00:29:45,952 --> 00:29:47,854
haueter: it was
such a smooth flight
535
00:29:47,887 --> 00:29:50,156
that it was a momentary jolt
536
00:29:50,189 --> 00:29:52,258
that they just hadn't
anticipated.
537
00:29:52,291 --> 00:29:55,461
and, with that, the pilots
got on the controls
538
00:29:55,494 --> 00:29:57,529
and immediately, you know,
put in a rudder input.
539
00:30:01,868 --> 00:30:03,102
germano: sheez.
540
00:30:03,135 --> 00:30:06,305
narrator: the cockpit recorder
even records the thumping sound
541
00:30:06,338 --> 00:30:10,576
of the jet stream turbulence
as 427 flies through it.
542
00:30:10,609 --> 00:30:13,880
as flight 427 encounters
the turbulence,
543
00:30:13,913 --> 00:30:16,615
brenner hears something unusual.
544
00:30:16,648 --> 00:30:20,386
first officer emmett
begins to grunt.
545
00:30:20,419 --> 00:30:22,021
[grunts]
546
00:30:24,590 --> 00:30:27,860
brenner: the grunting
is unusual.
547
00:30:27,894 --> 00:30:30,863
the controls are designed so
that pilots don't need to grunt.
548
00:30:30,897 --> 00:30:33,332
they're specially designed
around human capabilities,
549
00:30:33,365 --> 00:30:34,533
so to have someone grunting
550
00:30:34,566 --> 00:30:37,636
is typically a sign
of an emergency.
551
00:30:37,669 --> 00:30:39,538
narrator: by matching data
from the flight recorder
552
00:30:39,571 --> 00:30:41,373
with the crew's voices,
553
00:30:41,407 --> 00:30:44,343
brenner is able to confirm
that emmett's grunts begin
554
00:30:44,376 --> 00:30:47,579
a split second after he pushed
down on the rudder pedal
555
00:30:47,613 --> 00:30:50,282
and 3 to 4 seconds
after the wake turbulence
556
00:30:50,316 --> 00:30:52,885
affected flight 427.
557
00:30:52,919 --> 00:30:53,886
germano: what the...
558
00:30:53,920 --> 00:30:54,987
help!
559
00:30:57,289 --> 00:30:58,524
narrator: on their own,
560
00:30:58,557 --> 00:31:01,260
the cockpit voice recordings
prove very little.
561
00:31:01,293 --> 00:31:03,395
but it seems clear that the crew
562
00:31:03,429 --> 00:31:06,332
wasn't trying to crash
their plane.
563
00:31:06,365 --> 00:31:09,535
something happened
which took them by surprise.
564
00:31:09,568 --> 00:31:12,939
but nothing they did
seemed to help.
565
00:31:12,972 --> 00:31:14,540
germano: what the hell is this?
566
00:31:16,608 --> 00:31:18,344
narrator:
it's been almost two years
567
00:31:18,377 --> 00:31:20,980
since the crash of flight 427,
568
00:31:21,013 --> 00:31:23,382
and the investigation
has stalled.
569
00:31:23,415 --> 00:31:28,487
now, two 737s have gone down
in startlingly similar ways,
570
00:31:28,520 --> 00:31:31,290
and investigators
still don't know why.
571
00:31:31,323 --> 00:31:36,662
cox: we were all frustrated
as months wore into years.
572
00:31:36,695 --> 00:31:38,130
what were we missing?
573
00:31:38,164 --> 00:31:39,966
haueter: we were going
up against an aircraft
574
00:31:39,999 --> 00:31:42,468
that had an incredible
safety history.
575
00:31:42,501 --> 00:31:46,105
it was really...everything
you could see for 30 years,
576
00:31:46,138 --> 00:31:48,707
this has been a great airplane.
577
00:31:48,740 --> 00:31:52,378
we were trying to prove
that there was something wrong
578
00:31:52,411 --> 00:31:55,714
with the straight-a student.
579
00:31:55,747 --> 00:31:57,549
narrator:
unsure of where to look next,
580
00:31:57,583 --> 00:32:00,019
and with the trail of evidence
getting colder,
581
00:32:00,052 --> 00:32:04,623
investigators need a break
in the case, and fast.
582
00:32:04,656 --> 00:32:07,659
controller: eastwind 517,
you're clear for landing.
583
00:32:13,065 --> 00:32:15,667
narrator: on june 9, 1996,
584
00:32:15,701 --> 00:32:18,137
captain brian bishop
is on final approach
585
00:32:18,170 --> 00:32:20,639
to richmond, virginia,
when, without warning,
586
00:32:20,672 --> 00:32:24,443
his eastwind jet rolls
sharply to the right.
587
00:32:30,649 --> 00:32:32,218
brian bishop: we didn't know
to what extent,
588
00:32:32,251 --> 00:32:34,620
but we knew we had a problem
with the rudder.
589
00:32:34,653 --> 00:32:36,688
i turned the yoke
the opposite direction
590
00:32:36,722 --> 00:32:38,991
and stood on the opposite
rudder pedal.
591
00:32:39,025 --> 00:32:42,594
the pedal didn't move for me.
592
00:32:42,628 --> 00:32:44,330
narrator: for over 30 seconds,
593
00:32:44,363 --> 00:32:47,599
the 737 flies
in a precarious right bank
594
00:32:47,633 --> 00:32:52,571
as bishop fights to keep it
from rolling over.
595
00:32:52,604 --> 00:32:57,509
then suddenly, the unknown
forces holding the jet let go...
596
00:33:00,612 --> 00:33:03,215
snapping the wings
back to horizontal.
597
00:33:06,285 --> 00:33:08,654
bishop: in a matter of seconds,
598
00:33:08,687 --> 00:33:12,524
it released itself
and went back to normal.
599
00:33:12,558 --> 00:33:15,427
we had started the checklist.
600
00:33:15,461 --> 00:33:17,329
almost before i could finish
the sentence,
601
00:33:17,363 --> 00:33:19,698
all of a sudden
there was just a wham.
602
00:33:25,637 --> 00:33:31,410
narrator:
for a second time, the 737
is pushed on its side again.
603
00:33:31,443 --> 00:33:33,679
for 30 more harrowing seconds,
604
00:33:33,712 --> 00:33:37,449
the 737 takes on
a life of its own.
605
00:33:37,483 --> 00:33:42,654
then, once again, as quickly
as it began, the rollover stops.
606
00:33:45,357 --> 00:33:47,459
bishop: after the second time,
i looked at the first officer
607
00:33:47,493 --> 00:33:49,595
and i said declare an emergency.
608
00:33:49,628 --> 00:33:52,764
tell the controller we have
flight control problems.
609
00:33:52,798 --> 00:33:56,268
[sirens]
610
00:33:59,405 --> 00:34:03,309
narrator: as they slow down
to land, the risks increase.
611
00:34:07,113 --> 00:34:08,814
if a third rollover occurs,
612
00:34:08,847 --> 00:34:11,650
they won't have enough airspeed
to recover.
613
00:34:11,683 --> 00:34:13,719
bishop: i did, at some point,
tell my first officer
614
00:34:13,752 --> 00:34:17,389
to look out the window
and find a dark spot.
615
00:34:17,423 --> 00:34:18,757
it was nighttime,
616
00:34:18,790 --> 00:34:20,192
and we were looking to avoid
a neighborhood
617
00:34:20,226 --> 00:34:22,328
or a populated area,
618
00:34:22,361 --> 00:34:24,263
and he very calmly responded
619
00:34:24,296 --> 00:34:26,565
that hey, here's a spot
over here.
620
00:34:34,373 --> 00:34:37,143
narrator: but there is
no third rollover.
621
00:34:37,176 --> 00:34:42,414
bishop brings flight 517 in
high and fast and lands safely.
622
00:34:44,883 --> 00:34:49,455
bishop: taxiing in is when
i realized my legs were shaking.
623
00:34:49,488 --> 00:34:51,557
we got the aircraft to the gate,
624
00:34:51,590 --> 00:34:53,792
and i did pick up the p.a.
to make an announcement
625
00:34:53,825 --> 00:34:58,664
to try to explain what had
just happened to these people.
626
00:34:58,697 --> 00:35:00,166
and on picking up
the microphone,
627
00:35:00,199 --> 00:35:02,801
i realized there was
nothing i could say
628
00:35:02,834 --> 00:35:05,804
to make this any better.
629
00:35:05,837 --> 00:35:08,174
and probably for the first time
in a long time
630
00:35:08,207 --> 00:35:09,908
i was at a loss of words.
631
00:35:09,941 --> 00:35:14,313
so i simply put the microphone
down and let it go at that.
632
00:35:16,182 --> 00:35:19,151
narrator: but bishop won't
remain speechless for long.
633
00:35:19,185 --> 00:35:20,419
by the next day,
634
00:35:20,452 --> 00:35:24,756
the investigation team
has arrived in richmond.
635
00:35:24,790 --> 00:35:27,393
bishop: there were a lot of faa,
a lot of ntsb,
636
00:35:27,426 --> 00:35:30,296
and they all wanted
to talk to us very badly.
637
00:35:30,329 --> 00:35:33,699
adair: it gave the ntsb
a tremendous break
638
00:35:33,732 --> 00:35:37,769
because suddenly they had a 737
that had had a rudder incident,
639
00:35:37,803 --> 00:35:39,438
that was intact,
640
00:35:39,471 --> 00:35:41,307
and they had a pilot
who was alive
641
00:35:41,340 --> 00:35:43,342
and who could talk about it.
642
00:35:43,375 --> 00:35:45,777
narrator: ntsb investigators
quickly determine
643
00:35:45,811 --> 00:35:49,415
that what happened
on board eastwind flight 517
644
00:35:49,448 --> 00:35:54,553
is alarmingly similar to events
on flights 427 and 585.
645
00:35:54,586 --> 00:35:58,490
if they can discover
why bishop's 737 rolled over,
646
00:35:58,524 --> 00:36:02,761
they may be able to crack two
mysterious and fatal accidents.
647
00:36:02,794 --> 00:36:03,995
brenner: and when we said
"what happened?"
648
00:36:04,029 --> 00:36:06,832
they said there was something
wrong with the rudder pedal.
649
00:36:06,865 --> 00:36:08,567
the pedal wouldn't go down.
650
00:36:08,600 --> 00:36:10,669
i was standing
on the rudder pedal,
651
00:36:10,702 --> 00:36:14,873
and i couldn't get it
to go down.
652
00:36:14,906 --> 00:36:16,875
my god!
653
00:36:16,908 --> 00:36:18,710
[passengers screaming]
654
00:36:18,744 --> 00:36:20,946
narrator: with bishop's
first-person testimony,
655
00:36:20,979 --> 00:36:22,948
investigators
immediately zero in
656
00:36:22,981 --> 00:36:25,451
on eastwind's rudder controls.
657
00:36:28,920 --> 00:36:31,757
the power control unit
is removed, inspected
658
00:36:31,790 --> 00:36:37,229
and then tested again and again.
659
00:36:37,263 --> 00:36:43,235
to the frustration of everyone,
the unit performs perfectly.
660
00:36:43,269 --> 00:36:45,571
after a five-year hunt
for clues,
661
00:36:45,604 --> 00:36:48,674
a third mysterious rudder event
on a 737,
662
00:36:48,707 --> 00:36:50,942
and a live pilot as a witness,
663
00:36:50,976 --> 00:36:53,712
tom haueter still lacks
the evidence he needs
664
00:36:53,745 --> 00:36:56,948
to crack his case.
665
00:36:56,982 --> 00:36:59,485
he decides to push
his chief suspect,
666
00:36:59,518 --> 00:37:03,389
flight 427's rudder controls,
a little harder.
667
00:37:08,494 --> 00:37:09,728
haueter: one fellow mentioned
668
00:37:09,761 --> 00:37:11,897
a test they had done
in the military
669
00:37:11,930 --> 00:37:14,500
of a thermal shock,
670
00:37:14,533 --> 00:37:18,304
where if you had the actuator
be very cold
671
00:37:18,337 --> 00:37:20,572
and put in very hot
hydraulic fluid,
672
00:37:20,606 --> 00:37:25,944
it would cause it to react
in strange ways.
673
00:37:25,977 --> 00:37:28,680
so we put together
a thermal shock test.
674
00:37:28,714 --> 00:37:31,517
and this test was extreme,
to say the least.
675
00:37:34,820 --> 00:37:38,790
narrator: on august 26, 1996,
in valencia, california,
676
00:37:38,824 --> 00:37:42,294
ntsb investigators gather
to watch the torture test
677
00:37:42,328 --> 00:37:45,664
of u.s. air 427's pcu.
678
00:37:47,799 --> 00:37:49,835
after soaking it in dry ice,
679
00:37:49,868 --> 00:37:52,638
the pcu is blasted
with nitrogen gas
680
00:37:52,671 --> 00:37:54,706
to simulate the minus 40-degree
temperatures
681
00:37:54,740 --> 00:37:57,309
at 32,000 feet.
682
00:37:59,711 --> 00:38:03,582
then it's quickly injected with
super-heated hydraulic fluid
683
00:38:03,615 --> 00:38:06,452
and given the command
to start working.
684
00:38:08,754 --> 00:38:11,657
cox: as we were standing there
listening to the actuator
685
00:38:11,690 --> 00:38:14,760
move left and right,
left and right...
686
00:38:17,829 --> 00:38:21,800
it stopped, and it was not
commanded to stop.
687
00:38:21,833 --> 00:38:24,603
narrator: systems investigator
greg phillips now asks
688
00:38:24,636 --> 00:38:28,574
that the valve be taken apart
and scanned for scratches.
689
00:38:32,711 --> 00:38:34,680
they find none.
690
00:38:34,713 --> 00:38:36,648
phillips: look at that.
691
00:38:36,682 --> 00:38:38,850
doesn't leave a trace.
692
00:38:38,884 --> 00:38:43,355
narrator:
it is a crucial breakthrough to
solving an almost perfect crime.
693
00:38:43,389 --> 00:38:45,891
they have proven that the valve
which controls the rudders
694
00:38:45,924 --> 00:38:49,961
can jam, but no evidence
is left behind.
695
00:38:52,764 --> 00:38:54,900
tom haueter and his team
have now found
696
00:38:54,933 --> 00:38:57,869
that a small hydraulic valve
that controls the rudder
697
00:38:57,903 --> 00:39:00,606
of the world's most popular
commercial jetliner
698
00:39:00,639 --> 00:39:03,542
can jam in the right
circumstances.
699
00:39:05,511 --> 00:39:07,413
it's an ominous discovery,
700
00:39:07,446 --> 00:39:10,682
but incredibly there's another
shocking surprise in store
701
00:39:10,716 --> 00:39:13,985
for the investigators.
702
00:39:14,019 --> 00:39:17,523
adair: the most important
breakthrough came
703
00:39:17,556 --> 00:39:19,625
when a boeing engineer,
704
00:39:19,658 --> 00:39:22,861
examining the data
from that test,
705
00:39:22,894 --> 00:39:25,697
discovered some numbers
that indicated
706
00:39:25,731 --> 00:39:30,536
the valve at that point
had actually reversed.
707
00:39:33,071 --> 00:39:34,773
germano: whoa. sheez.
708
00:39:34,806 --> 00:39:36,842
narrator:
it is a stunning revelation.
709
00:39:36,875 --> 00:39:39,110
not only can
the servo valve jam,
710
00:39:39,144 --> 00:39:42,047
but it can then function
in reverse.
711
00:39:42,080 --> 00:39:45,651
it means that any time a pilot
tries to correct a rollover
712
00:39:45,684 --> 00:39:47,085
by pushing on the rudder,
713
00:39:47,118 --> 00:39:49,688
the rudder might turn
in the opposite direction,
714
00:39:49,721 --> 00:39:52,190
causing a fatal accident.
715
00:39:52,223 --> 00:39:54,793
haueter: and the reversal
is like driving your car.
716
00:39:54,826 --> 00:39:57,596
you turn to the right,
it goes left.
717
00:39:57,629 --> 00:39:59,197
you're not gonna figure out
this failure mode
718
00:39:59,230 --> 00:40:01,667
until you go off the road.
719
00:40:01,700 --> 00:40:03,902
and, in these cases, that's what
the pilots were faced with,
720
00:40:03,935 --> 00:40:05,971
something so unusual
721
00:40:06,004 --> 00:40:08,774
that they didn't understand
what was happening.
722
00:40:08,807 --> 00:40:11,743
germano: what the hell is this?
723
00:40:11,777 --> 00:40:15,847
adair: they had evidence now
that the valve was unique,
724
00:40:15,881 --> 00:40:20,686
that the valve not only
could jam, but would reverse.
725
00:40:20,719 --> 00:40:22,854
germano: 427, emergency!
726
00:40:25,256 --> 00:40:29,995
adair: that would explain why
the first officer, chuck emmett,
727
00:40:30,028 --> 00:40:32,831
would keep his foot
on the rudder pedal,
728
00:40:32,864 --> 00:40:37,202
because he's thinking why isn't
the plane going right?
729
00:40:37,235 --> 00:40:39,771
and he's feeling the plane
go to the left.
730
00:40:42,574 --> 00:40:45,544
narrator: to the very end,
chuck emmett pushes hard,
731
00:40:45,577 --> 00:40:48,914
hoping his rudder will help him
pull out of his deadly spiral.
732
00:40:48,947 --> 00:40:50,882
tragically, he has
no way of knowing
733
00:40:50,916 --> 00:40:54,686
that he's steering his aircraft
straight into the ground.
734
00:40:54,720 --> 00:40:57,088
[screaming]
735
00:40:59,825 --> 00:41:01,259
green: never driven
to colorado springs
736
00:41:01,292 --> 00:41:03,228
and not gotten sick.
737
00:41:07,866 --> 00:41:10,769
flight attendants,
prepare for landing.
738
00:41:10,802 --> 00:41:12,804
narrator: satisfied that they've
determined the cause
739
00:41:12,838 --> 00:41:15,607
of the crash of u.s. air 427,
740
00:41:15,641 --> 00:41:20,512
the ntsb turns its attention to
the unsolved case of united 585.
741
00:41:24,583 --> 00:41:26,051
eidson: another 10-knot gain.
742
00:41:26,084 --> 00:41:27,753
brenner: going back
to colorado springs,
743
00:41:27,786 --> 00:41:31,122
you could follow a progression
of what the captain was doing.
744
00:41:31,156 --> 00:41:34,526
he's close to the ground, and
suddenly under rudder reversal
745
00:41:34,560 --> 00:41:36,261
he puts in a little bit
of pedal.
746
00:41:36,294 --> 00:41:39,598
the pedal violently pushes
his leg back.
747
00:41:39,631 --> 00:41:40,999
eidson: oh, god, flip.
748
00:41:41,032 --> 00:41:43,068
green: 15 flaps!
eidson: 15!
749
00:41:44,703 --> 00:41:47,138
brenner: rudder reversal
certainly fits what i know
750
00:41:47,172 --> 00:41:48,907
about this crew
and how it fits.
751
00:41:48,940 --> 00:41:51,276
haueter: we were able to show
the failure mode.
752
00:41:51,309 --> 00:41:54,846
it matched the flight data
recorder from each aircraft.
753
00:41:54,880 --> 00:41:57,115
it fit like a glove.
754
00:41:57,148 --> 00:41:59,718
so we now had a lot more
information we could apply
755
00:41:59,751 --> 00:42:02,053
to united 585,
756
00:42:02,087 --> 00:42:04,823
and, based on that, we redid
the accident report.
757
00:42:04,856 --> 00:42:06,291
eidson: oh, my god!
oh, my god!
758
00:42:06,324 --> 00:42:10,729
narrator:
from rudder reversal to impact
took less than ten seconds.
759
00:42:10,762 --> 00:42:12,898
585's flight crew had no chance
760
00:42:12,931 --> 00:42:15,601
to save their plane
or passengers.
761
00:42:17,769 --> 00:42:19,905
in the aftermath
of the investigation,
762
00:42:19,938 --> 00:42:23,942
sweeping changes were made
to improve the safety of the 737
763
00:42:23,975 --> 00:42:27,679
and the entire
aviation industry.
764
00:42:27,713 --> 00:42:29,681
new training protocols
were designed
765
00:42:29,715 --> 00:42:33,218
to help pilots react
to unusual inflight events.
766
00:42:33,251 --> 00:42:35,220
in the 737 fleet,
767
00:42:35,253 --> 00:42:37,222
pilots are now trained
on how to react
768
00:42:37,255 --> 00:42:41,827
to both rudder hard-overs
and reversals.
769
00:42:41,860 --> 00:42:45,330
cox: the scenario
of the u.s. air 427 accident,
770
00:42:45,363 --> 00:42:48,834
if the crew had the information
that we have today,
771
00:42:48,867 --> 00:42:50,068
i believe they would have
landed safely
772
00:42:50,101 --> 00:42:51,502
in pittsburgh that evening.
773
00:42:55,373 --> 00:42:57,809
narrator:
the faa also directed boeing
774
00:42:57,843 --> 00:43:00,078
to redesign the rudder's
dual servo valve
775
00:43:00,111 --> 00:43:03,649
to eliminate the potential
for reversal.
776
00:43:03,682 --> 00:43:05,684
boeing spent hundreds
of millions of dollars
777
00:43:05,717 --> 00:43:06,918
to replace the valves
778
00:43:06,952 --> 00:43:10,756
on thousands of 737s
around the world.
779
00:43:10,789 --> 00:43:12,791
haueter: one thing we don't like
at the safety board
780
00:43:12,824 --> 00:43:14,826
is to have
an undetermined accident,
781
00:43:14,860 --> 00:43:18,329
because then we can't make
a change to improve safety.
782
00:43:18,363 --> 00:43:22,167
so out of us air 427,
united 585,
783
00:43:22,200 --> 00:43:25,671
we have a much safer 737 fleet.
784
00:43:31,943 --> 00:43:34,946
narrator: it took
ntsb tin kickers ten years
785
00:43:34,980 --> 00:43:40,185
to solve the mysterious crashes
of flights 585 and 427,
786
00:43:40,218 --> 00:43:43,889
the longest investigation
in aviation history.
787
00:43:43,922 --> 00:43:45,891
adair: there are still
some people in aviation
788
00:43:45,924 --> 00:43:48,193
who don't think the ntsb
got it right.
789
00:43:48,226 --> 00:43:49,427
but i became convinced
790
00:43:49,460 --> 00:43:53,364
after talking to many, many,
many people, pilots, engineers,
791
00:43:53,398 --> 00:43:55,867
people at boeing,
792
00:43:55,901 --> 00:43:58,770
and spending a lot of time
with the investigators
793
00:43:58,804 --> 00:44:00,638
that they did get it right.
794
00:44:04,275 --> 00:44:07,846
narrator: since the replacement
of the 737 servo valves,
795
00:44:07,879 --> 00:44:09,681
there hasn't been
a similar crash
796
00:44:09,715 --> 00:44:10,548
of the most popular,
797
00:44:10,581 --> 00:44:13,251
most profitable plane
in the world.
63287
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