CPT WATERS: Thank you
for flying Cathay Pacific. NARRATOR: A crowded flight en
route to Hong Kong is suddenly in trouble over
the South China Sea. CPT WATERS: What the hell
was that? Engine two stall? FO HAYHOE: Relying on one engine
to get us safely on the ground. ♪ ♪ NARRATOR: Then, the
situation gets worse. CPT WATERS: We now
have two engines stalled. This is not fair. FO HAYHOE: Approach,
mayday, mayday, mayday. CPT WATERS: Damn it! NARRATOR: The 200-ton jet with
309 passengers is free-falling toward disaster. CPT WATERS: I felt fear. CPT WATERS: This
cannot be happening. FO HAYHOE: It looks like this
aircraft could end up ditching into the water. NARRATOR: Unless the captain
can come up with a better plan. [♪ theme music ♪] ♪ ♪ MADELINE:
Seatbelt, please. Thank you. NARRATOR: Cathay Pacific Flight
780 is cruising at 38,000 feet over the South China Sea. CPT WATERS: This is
your captain speaking. We'll be starting our
descent into Hong Kong shortly. Local weather is 29
degrees with scattered clouds, so it should be a
lovely spring day. Thank you again for
flying Cathay Pacific. NARRATOR: Captain Malcolm Waters
and his crew are nearing the end of a four-and-a-half hour flight
from Indonesia to Hong Kong. Touchdown is in 30 minutes. CPT WATERS: It's a
crisp morning, clear skies, a light wind. It was a nice day to go flying. NARRATOR: It's only the
second time Captain Waters and his first officer, David
Hayhoe, have flown together. FO HAYHOE: So how long
have you lived in Hong Kong? CPT WATERS: Twelve years.
I moved there when I was 23. NARRATOR: Waters is
one of Cathay Pacific's youngest captains. Hayhoe is an ex-fighter pilot with the Royal
Australian Air Force. CPT WATERS: So what's
it like flying F-18s? FO HAYHOE: Oh,
there's nothing to it, but the in-flight
service is terrible. [laughter] NARRATOR: Flight 780 originated
in Suribaya, Indonesia. It'll travel more than
2,000 miles to reach Hong Kong. The Airbus A330 is powered by two
Rolls-Royce Trent 700 engines with advanced
computers aiding every aspect of flight operations. FO HAYHOE: The engineering and
complexity that goes into them, and the science that
presents the information, they're incredible machines. MADELINE: Seatbelts, please. NARRATOR: Madeline Avisado is
the in-flight service manager responsible for overseeing
10 cabin crew members and the plane's 309 passengers. MADELINE: We
carried out the service and prepared for landing. It was a normal flight. NARRATOR: One
hundred and sixty-five miles from Hong Kong Airport, the Airbus leaves cruising
altitude and begins its descent. FO HAYHOE:
Airspeed's, uh, 295 knots. Rate of descent
700 feet per minute. It's looking good. NARRATOR: The aircraft
is performing perfectly. And, then, something goes wrong. [warning tone] CPT WATERS: What
the hell was that? FO HAYHOE: That's strange. CPT WATERS: I describe
it as a low thumping noise and airframe vibration. So, you know, David
and myself kind of looked at each other like, that's unusual. NARRATOR: The flight
computer is alerting the pilots to a problem. CPT WATERS: Okay,
let's see what we got. FO HAYHOE: Engine two stall. NARRATOR: The plane's
monitoring system indicates there's an issue with the right
engine -- engine number two. Captain Waters checks to see
what's happened to the engine, but the monitoring
system gives him no answers. CPT WATERS: Now when we
were checking the parameters, they were relatively normal. CPT WATERS: Okay. Thrust
lever number two, confirm? FO HAYHOE: Confirm. NARRATOR: With no
explanation for the incident, Captain Waters reduces
power on the engine to idle to protect it from damage... CPT WATERS: Idle. NARRATOR: ...the
lowest possible power level while still keeping it running. It has an immediate effect. The engine noises disappear. FO HAYHOE: That's better. FO HAYHOE: All the
symptoms went away. CPT WATERS: We've got
fuel flow. We've got rotation. NARRATOR: The bigger concern
is that the engine at idle isn't providing any thrust. They must now rely
on their other engine to get them to Hong Kong. CPT WATERS: A single engine
approach is not a big deal. We practice it a
lot in the simulator. The aircraft are
certified to fly on one engine. CPT WATERS: Hong Kong, Cathay
780. Pan pan. Pan pan. Pan pan. NARRATOR: The crew
alerts air traffic control about the situation. CPT WATERS: Pan
pan. Pan pan. Pan pan. AIR TRAFFIC CONTROLLER:
Sir, we have a pan pan call. CPT WATERS: We declared
a pan, which is sort of the first level of urgency. CPT WATERS: We're operating
engine two at idle thrust at the moment, but operation
is normal apart from that. AIR TRAFFIC CONTROLLER:
Cathay 780, roger your pan. CPT WATERS: If we could
just get priority, thanks. FO HAYHOE: You
declare a pan in order to let air traffic control know
that we need a bit of help to get us on the ground quickly, and it gives them the
authority to push people out of our way and
help us achieve that goal. AIR TRAFFIC CONTROLLER:
Cathay 780, understood. NARRATOR: The
controller goes into action. AIR TRAFFIC CONTROLLER:
We have a pan pan call from an incoming flight. Please put emergency
services on standby. [sirens wailing] NARRATOR: Airport firefighters
rush to take up positions near the runway. Flight 780 is 115 miles
from Hong Kong Airport. The plane will be on
the ground in 22 minutes. MADELINE: In
preparation for landing, please stow tray
tables and return your seats to the upright position. Madz here. MADELINE: It's not
normal for captains to call during a
pre-landing announcement by the in-flight
service manager. CPT WATERS: Madz,
we're having a problem with engine number two. I need you to keep an
eye on it from the cabin. MADELINE: Roger. MADELINE: He requested to
check the engine number two, if there's something unusual, or if you can smell any smoke. I checked the engine
and it was pretty normal, nothing unusual going on. ♪ ♪ NARRATOR: The pilots
prepare to land the Airbus with only one engine. CPT WATERS: I'll
take the landing. FO HAYHOE:
Understood. You have control. NARRATOR: Captain
Waters will fly the plane from this point on. CPT WATERS: I have control. CPT WATERS: In an
emergency situation, the most senior crew
member assumes the flying role. Now I have to actually do
what I've been trained to do. So it's not a normal day
anymore and you have to be on your game. NARRATOR: Everything is
set for an emergency landing. ♪ ♪ [alert sounds] But then, another
alert, and more vibrations. FO HAYHOE: Engine one stall. CPT WATERS: Engine
one stall confirmed. NARRATOR: Things have
gone from bad to worse. The monitoring system
indicates they've just lost the other engine -- the
one they were counting on to get the plane to Hong Kong. CPT WATERS: We now
have two engines stalled. This is not fair. NARRATOR: Twenty
minutes from landing, Cathay Pacific Flight
780 is in serious trouble. FO HAYHOE: We were relying on
this one engine to get us safely on the ground and now it
had exactly the same symptoms and noises and
sounds as the other engine. NARRATOR: If they can't get
engine one back up and running, the plane is
headed for disaster. FO HAYHOE: Engine one to idle. NARRATOR: The monitoring
system tells the pilots to put the malfunctioning
engine number one into idle. Just like engine number two, it's still running
but producing no thrust. The plane is now gliding. CPT WATERS: Damn it! Our descent
rate is not looking good. NARRATOR: Without thrust, they can't make it to Hong
Kong -- or any other airport. Captain Waters faces
a desperate situation. CPT WATERS: We were still
about 60 miles out to sea at that time. With the aircraft descending
at 1300 feet per minute, we've only got five, six minutes
before we're at sea level. I felt fear. And you have all those
human responses to fear -- the hair standing up
on the back of your neck, the tightening of your stomach,
the dryness in your mouth. FO HAYHOE: It was
a sense of disbelief that we might
end up in the water. This can't be happening. ♪ ♪ NARRATOR: Though
the cabin is quiet prior to the expected landing, the passengers have no
idea of the danger they're in. MADELINE: Everything was calm. Everything was
like normal to them. ♪ ♪ FO HAYHOE: There's an
initial moment of that shock and how are we going to
start overcoming this problem. NARRATOR: Without power
to make it to Hong Kong, the pilots now face an
emergency water landing, or ditching, in
the South China Sea. CPT WATERS: What do you think? FO HAYHOE: I'll start
the ditching checklist. CPT WATERS: Good idea. FO HAYHOE: I suggested carrying
out a checklist procedure to prepare the aircraft
for the correct configuration for the ditching itself. CPT WATERS:
Sitting back allowed me to start thinking rationally. NARRATOR: Captain Waters tries
the throttles one more time. ♪ ♪ He increases
power on engine two. ♪ ♪ Then, he tries engine one. CPT WATERS: Nothing happens. The engines just are
not responding at all. They're just remaining at idle. CPT WATERS: Damn it! FO HAYHOE: I'm calling a mayday. CPT WATERS: Do it. FO HAYHOE: Approach,
mayday, mayday, mayday. Cathay 780 had engine one
stall and engine two stall. NARRATOR: This call is more
urgent than the previous one. FO HAYHOE: Currently we
require a lower descent. We're extending our
glide and trying for relights. AIR TRAFFIC CONTROLLER:
Cathay 780, descend to 3,000 feet. FO HAYHOE: Putting the
mayday call out over the radio, you really feel that
something serious is going on. You can tell in the voice
that comes back to you that it gets everyone's attention
because it's not a word that you hear all the time. ♪ ♪ FO HAYHOE: Restarting number
two. Ram air turbine, on. FO HAYHOE: In between the
ditching checklist itself... FO HAYHOE: Engine
two select ignition. FO HAYHOE: ... my
approach was let's try and restart the engines,
because we're gonna be in no worse a
situation than we are now. FO HAYHOE: No
response. It's still at idle. NARRATOR: Now the pilots consider their
options for ditching. A year earlier, a US
Airways Airbus landed on the Hudson River in New
York without a single casualty. Captain Chesley
"Sully" Sullenberger became an instant hero. CPT WATERS: The
Sully incident had been the first successful
ditching really of an airliner and to show that
it could be done. NARRATOR: But as they drop
towards the South China Sea, the pilots of
Flight 780 are facing far more treacherous conditions. CPT WATERS: Big swells. The South China Sea
is not the Hudson River. CPT WATERS: The
seas looked very rough. It was a lot of white caps. The swells would
be one to two meters. I felt that our engines
would act as two big scoops and would pitch the
aircraft down quite violently, and that would
probably result in us, you know, cartwheeling
and breaking apart. CPT WATERS: This
cannot be happening. NARRATOR: Both pilots know
they're running out of time. Despite the growing
urgency in the cockpit, back in the cabin the
passengers remain unaware of how close
they are to disaster, just minutes from ditching
in the South China Sea. Captain Waters takes
manual control of the aircraft to ensure the safest
water landing possible. CPT WATERS: Turning
off flight director. Flying by hand now. FO HAYHOE: Roger that. CPT WATERS: So I start
maneuvering the aircraft to keep it clear of clouds
so that I can see the ocean and start to make an idea where
I'm gonna put the aircraft. NARRATOR: It's
during these tense moments that Captain
Waters gets an idea. CPT WATERS: Okay.
Try slow movements, go slowly, just ease in fuel. Easy does it. ♪ ♪ FO HAYHOE: I could see Malcolm
manipulating the thrust lever for engine one. CPT WATERS: I was just pinching
the side of the thrust lever just to move it a millimeter. Each time I pinched it, it
would just go up a millimeter. CPT WATERS: Slowly. Slowly. NARRATOR: Incredibly, it
seems to have an effect. FO HAYHOE: Rotation
increasing in engine one. CPT WATERS: It's working. CPT WATERS: The rotation
of the fan was increasing from 28 percent
to 29, to 30 to 32 as I moved this very,
very slowly and gently up. CPT WATERS: Let's
see how far we can get. NARRATOR: He wonders if he can
get the engine to full power. CPT WATERS: I eased the thrust
lever up a little bit more. CPT WATERS: Too much. CPT WATERS: We had surges and
a popping and whumping noise, and I immediately set
the thrust lever back to what thrust we had. NARRATOR: Waters
decides not to push the engine beyond 74 percent power. FO HAYHOE: Seventy-four
percent. That'll have to do. CPT WATERS: We've got a
thrust setting that resulted in us being able to fly level. We weren't descending anymore. And that was like a huge relief. CPT WATERS: You see
that? Altitude is holding. FO HAYHOE: Fantastic.
Okay, approach preparation. Cockpit prepared.
Loose items secured. NARRATOR: One engine is all
they need to attempt a landing at Hong Kong airport. FO HAYHOE: Visual 07 left. FO HAYHOE: I knew we
were gonna make Hong Kong. And it's very clear we
have enough energy now that we're gonna be
able to get to land. FO HAYHOE: Track 073. CPT WATERS: Check. CPT WATERS: We
can do our landing, so infinitely
better than ditching. NARRATOR: But Captain
Waters still needs to safely land a plane with
engines he can't rely on. He's not sure how much longer engine one will
keep providing thrust. CPT WATERS: We did have an
engine that was now functioning, but I didn't trust it. At any point, I believed that we
possibly could just roll back to idle thrust again. NARRATOR: The safest
plan is to get the plane 5500 feet above ground and then reduce
power on the engine, to start losing speed
and altitude for landing. They could be on the ground
in less than five minutes. FO HAYHOE: We wanted to
stay as nice and as high as we could in a position
that we could manage a glide. CPT WATERS: Let's do this. NARRATOR: Engine one has brought
the plane as far as it needs to. Captain Waters pulls it
back to idle to reduce speed. CPT WATERS: I
closed the thrust lever and I began my approach
essentially for the arrival. FO HAYHOE: Two-thirty
knots. We're at three miles. CPT WATERS: Checked. NARRATOR: If all goes well,
they should be on the runway in less than four minutes. But they'll only have
one chance to get the plane on the ground. If something goes wrong, they don't have enough
thrust for a second attempt. CPT WATERS:
Ladies and gentlemen, this is the captain speaking. As you may be aware, we have a
small problem with our engines. Remain seated with
your seatbelts fastened and follow the directions
from your cabin crew. Cabin crew to landing stations. Okay, flaps one. Thanks. FO HAYHOE: Okay, flaps one. CPT WATERS: Gear down. FO HAYHOE: Gear down. NARRATOR: With the
plane's speed decreasing, the flaps and
landing gear are deployed. There are only two miles to go. ♪ ♪ AIR TRAFFIC CONTROLLER:
Cathay 780, do you have the
airfield in sight? FO HAYHOE: Cathay 780, affirm. NARRATOR: Hong Kong airport
has two parallel runways. It's built on an
island west of the city. AIR TRAFFIC CONTROLLER:
Cathay 780, we have both runways
available for your approach. NARRATOR: The crew is cleared
to land on either runway. The Airbus turns onto its final
approach to Hong Kong airport. Captain Waters is
confident he can get the plane on the ground safely. FO HAYHOE: Auto brake? CPT WATERS: Lower it. FO HAYHOE: Final items okay. NARRATOR: They're a
minute from touchdown. [alert sounds] Then, another alert: FO HAYHOE: It's overspeed. NARRATOR: It's an
overspeed warning, a signal the
aircraft is flying too fast. CPT WATERS: The speed was
not reducing to anything close to the speeds that were
indicated that we would be once we got into the
landing configuration. NARRATOR: Captain
Waters can't figure it out. They should be slowing down. He re-checks the controls. CPT WATERS: It just
looked completely wrong and I was very uneasy that things were once
again to get out of my control and that there was
something that I was missing. NARRATOR: Then he sees it. CPT WATERS: I looked up
at the gauges and, you know, my blood ran cold. NARRATOR: Engine number one, which he throttled
back minutes earlier, is still running
at 74 per cent power. High thrust -- too
high to land safely. CPT WATERS: I had that whole
feeling again of fear, anger. It was a scary moment. NARRATOR: Despite
confronting a new crisis one mile from the
runway at Hong Kong airport, Waters and
Hayhoe must carry on. FO HAYHOE: Speed
checked, two-forty. Eight hundred feet. NARRATOR: The
engine they put into idle for a safe, smooth landing
is still running at high speed. The outcome could be disastrous. FO HAYHOE: Five hundred. CPT WATERS: I could
not believe that we'd gone from a situation where
we were looking at ditching and now I had an
engine stuck at high thrust. NARRATOR: With no
other option available, they're going to have
to risk landing the plane at a dangerously high speed, and hope they can stop it, before overshooting the runway
and ending up in the water. FO HAYHOE: You've got
12,500 feet of runway, Mal. CPT WATERS: Check. CPT WATERS: You know,
we couldn't determine how much landing
distance was required. We were off the chart,
you know, for the speed and for the weight that we had. FO HAYHOE: Four hundred feet. CPT WATERS: The
longer we prolong this, the more unknown
things are happening. FO HAYHOE: It was our one chance
to get this on the ground, and we had to make
the best go at it. GPWS: Too low.
Terrain. Too low. Terrain. NARRATOR: Their speed is
over 100 miles per hour faster than normal -- so
fast the flight computer doesn't recognize that the
pilots are trying to land. GPWS: Pull up. CPT WATERS: It's
warning the pilot, like, you are putting the
aircraft in a dangerous spot and those warnings
are loud for a reason. And I just had to
put it all to the side, focus on what I
was trying to achieve. GPWS: Pull up.
Terrain. Pull up. Terrain. CPT WATERS: Disregard that. NARRATOR: Captain
Waters pushes the nose down, forcing the
Airbus onto the runway. GPWS: Terrain. Pull up. Terrain. [collision] CPT WATERS: The
aircraft did not want to land. And I remember
thinking wow, this is it, 'cause it was very violent. [passengers screaming] MADELINE: I
thought, we're going to crash into bits and pieces. CPT WATERS: Brace! CPT WATERS: I managed to
keep that wing up high enough that I just grazed
the surface of the runway and I got it back under control. CPT WATERS: We're down. NARRATOR: Finally, the aircraft
is firmly on the ground. Now, they've got to
bring it to a stop. CPT WATERS: Full reverse! NARRATOR: They deploy reverse
thrust on the engines to slow the Airbus down while
applying full braking power. [passengers screaming] CPT WATERS: Immediately I just
step on the brakes, hold 'em, toe brakes to the floor. FO HAYHOE: No number
two reverse. No decel. NARRATOR: But with only one
partially functioning engine, they only have
one thrust reverser. They could still
overshoot the runway. CPT WATERS: I didn't
think we would stop by the end. NARRATOR: The Airbus is getting
close to the end of the runway. CPT WATERS: And I could judge
the deceleration rate was such that, you know, I started
to get a glimmer of like, man, I think we really,
uh, we could do this. NARRATOR: Finally, the
aircraft comes to a halt just a short distance
from the water's edge. They've used up
more than 8800 feet -- over a mile and a
half -- of runway. CPT WATERS: I can't believe it. FO HAYHOE: We made it. Nice one. FO HAYHOE: Once the aircraft
did stop, there's a look of, What the hell just happened? CPT WATERS: It was
just this humongous relief. You're so happy that, you know, we were gonna go home
and see our families. [sirens wailing] NARRATOR: Against all odds,
Flight 780 has landed safely. But it isn't out of danger yet. CPT WATERS:
Check the wheel temps. We may have to
order an evacuation. Get the checklist. NARRATOR: Captain Waters worries
that the extreme braking may have caused
their wheels to overheat. FO HAYHOE: Both
approaching 1,000 degrees. ♪ ♪ NARRATOR: His hunch is correct. CPT WATERS: Oh my goodness.
We, we've gotta be on fire. CPT WATERS: We need to
get everybody off the plane. CPT WATERS: This is the captain. Evacuate! Evacuate! Evacuate! MADELINE: Come this way
and leave everything behind. NARRATOR: Fire could
break out at any moment. With the inflatable
slides deployed, the passengers and crew evacuate safely
with only a few minor injuries. CPT WATERS: Once I was standing
on the ground I turned around and looked at the airplane
and it was like a scene from a Hollywood movie. The steam and smoke coming off. The fire services
were dousing the wheels and paramedics are turning up. People are being helped
away from the bottom of slides. ♪ ♪ NARRATOR: Within hours, Hong
Kong's Civil Aviation Department launches an investigation. Anne Evans is a flight
test engineer who works for the British Air
Accidents Investigation Branch. She's been asked to
join the investigation, in part because the Airbus's
Trent 700 engines were made by the British
company Rolls-Royce. ANNE: This Trent 700
is a very common engine fitted to a lot of
airplanes all over the world. So if there's an engineering
problem with a particular design then we want to
find that quickly. HONG KONG INVESTIGATOR:
Here's what we know. The engines on Flight
780 failed to respond to throttle commands. NARRATOR: Investigators meet to
discuss the few clues they have. ANNE: It's odd that
both engines stalled. NARRATOR: They're struck by the
fact that the same malfunction affected both
engines, one after the other. MARC: It's very rare to have two
systems fail at the same time given the level of
redundancy and reliability that's built into the engines. NARRATOR: This
suggests the cause may not be the
engines themselves. MARC: Critical systems like
that don't fail simultaneously. NARRATOR: It may be that
something far more mysterious is the cause of the problem. NARRATOR: In Hong Kong a team
of investigators begins trying to unravel the mystery of Cathay Pacific Flight 780's
two malfunctioning engines. ♪ ♪ They retrieve the black
box flight data recorder from the rear of the aircraft. It contains information
about the plane's functions throughout the flight. ANNE: The data
onboard the aircraft is key in this
type of investigation. NARRATOR: Investigators upload
the data from the recorder. ANNE: We need to see throttle
position and fuel flow. NARRATOR: The device
records 359 data parameters. They focus in on the
A330's engine functions. ANNE: Stop.
What's going on here? NARRATOR: Right away,
they notice something unusual. ANNE: Thrust levers are moving
but fuel flow's flat-lining. NARRATOR: After
the pilots had tried to restore power to the engines by pushing the throttle up, the
fuel flow remained the same. MARC: They gave
some thrust commands but no corresponding response
from either engines at the time. CPT WATERS: Damn it! MARC: So we really needed to
understand what caused that. NARRATOR: Investigators
wonder if a fuel flow problem caused Flight
780's engine trouble. ANNE: Thank you. NARRATOR: The
flight data recorder helps them spot the problem. But to try to
pinpoint the cause, they turn to another
source of onboard data. It's called the
post flight report. ANNE: Engine two
control system fault. It says that the VSV was jammed. NARRATOR: It contains in-depth
data about the error messages that appeared on the monitoring
system throughout the flight. CPT WATERS: Okay. ANNE: It's a piece of
information for troubleshooting to tell the maintainers that
the aircraft's had a problem and what they
need to do to fix it. ANNE: Something was
retarding the valve. NARRATOR: Anne Evans discovers
that -- early in the flight -- the computers detected
a problem in a key part of the fuel system
called the main metering valve. ANNE: So the warnings that
were coming up were warnings to do with the main
metering valve supplying fuel to the engine. NARRATOR: The main metering
valve is made up of a piston that slides within a cylinder. When pilots move
the thrust levers, it increases or
decreases the flow of fuel to the A330's turbo fan engines. ANNE: That valve wasn't moving.
It wasn't able to respond to the commands. NARRATOR: To figure out why the
metering valve malfunctioned, the investigators send it
to Rolls-Royce for analysis. PAUL: We have the best expertise about to strip those
components here in the UK. And we cut the outer
sleeve of the metering valve in half to see what was
inside the metering valve. NARRATOR: After cutting
open the valve to study it... ANNE: That's not normal, is it? NARRATOR: ... they
find something they've never seen before: a strange white substance
coating the walls of the valve. ANNE: What we saw seemed
like very, very fine powder, very, very small particles. ♪ ♪ NARRATOR: Technicians
examine the white powder under an electron microscope. They discover it's
made up of tiny spheres stuck to the metal
walls of the valve. ♪ ♪ The investigators dig
deeper to see if the powder can be found in other
parts of the fuel system. ANNE: We immediately
started finding small particles even within the
fuel tank itself. So the fuel system
and the engine had some sort of contaminant that
we didn't really understand what it was. NARRATOR: Could the mysterious
particles in the fuel system explain why the
pilots had such difficulty controlling engine power? PAUL: The metering
valve was kind of deluged with this material which had
silted the metering valve up and caused it to become
stuck in its current position. NARRATOR: The investigators
need to learn all they can about the strange substance. ANNE: Having
identified this particulate within the various areas of
the fuel system and the engine, our first
thought: Well what is it? NARRATOR: X-ray
analysis reveals the chemical
makeup of the material. It shows that the powder is a type of super
absorbent polymer or SAP. When it comes into
contact with water, it creates a gel-like substance. ANNE: These are
organic compounds designed to absorb water. That gave us a clue as
to where they'd come from. NARRATOR: The investigators
know that the powder is used in refueling trucks to
prevent water from getting into aircraft fuel tanks. The refueling trucks pump
fuel from underground tanks and pipes, through a
filter on the truck, and into the aircraft. If the fuel is
contaminated with water, the powder in the filter
absorbs it by forming a gel inside the filter. ANNE: So the super absorbent
powder is there really to just absorb the
water and make sure that we're protecting the
aircraft from the presence of water in the tanks. NARRATOR: But
the waterlogged gel is supposed to
stay in the filter. It should never
end up in the fuel. ANNE: It is so commonly
used within the industry for this purpose of
filtering out water. What we didn't
understand was how did it get onboard the aircraft? [alert sounding] ♪ ♪ NARRATOR: The investigators
suspect that filters in a fuel truck at
Surabaya Airport -- Flight 780's
departure point -- may have contributed to the
plane's dual engine failure. To find out, they take the
filters to a lab for testing. ANNE: This one
looks somehow collapsed. NARRATOR: They discover that one
of the filters on the truck used to refuel Flight 780 is damaged. ANNE: The condition of
the filters was very unusual. MARC: We were all very surprised
to see the crushed filter because that
don't normally happens, and it was probably an
indication of something abnormal having occurred during the
refueling of the aircraft. NARRATOR: The
investigators wonder, Did the damaged filter somehow
release powder into the fuel? They separate the
layers of filter material. ANNE: We undertook a
very laborious process of dissecting the filters, all
the different layers designed to not only take away water but also catch any
particulate as well. NARRATOR: They then examine
a sample under a microscope. And they make a puzzling find. Within the filter fibers, the powder made up of spheres
contains an unusual feature. ANNE: It looks
like sodium crystals? The spheres are
encrusted with salt. MARC: When we found out
that there was salt involved, that was really
mysterious to us because salt is not normally
found in the fuel. ANNE: Had salt water
got into the fuel system? ANNE: This one's
straight from the manufacturer. NARRATOR: Finding
answers requires more tests, this time with a
brand new filter. ANNE: What we wanted to do
was test these filter monitors to see could we
produce these spheres, and what conditions
did you need to have for these spheres to be created? NARRATOR: They expose the
filters to salt water under pressure, the same pressure
used inside the fuel truck. ANNE: We tried to
mimic those conditions, the fueling process
that would have occurred in the dispenser. ♪ ♪ NARRATOR: They
soon have an answer. ANNE: Wow. Would
you look at that? NARRATOR: It's a
major discovery. When fuel and salt water
pass through the filter, it collapses just like the
one from the airport fuel truck in Surabaya. ANNE: We were able on
the fuel rig to be able to collapse a filter, so
we knew we'd got pretty close to reproducing the conditions
that we'd seen on that day. NARRATOR: Even more significant
to their investigation, they find the test filter
releases spheres identical to those found in
Flight 780's fuel system. ANNE: What was important
was that we demonstrated we could generate spheres. NARRATOR: It appears that
salt water was responsible for the
collapse of fuel filter, leading to powder contamination
in Flight 780's fuel system. But one critical
question remains. HONG KONG INVESTIGATOR:
So how did salt water get into the fuel system? NARRATOR: The investigators
learn that -- prior to departure at Surabaya airport
-- Flight 780 was loaded with 54,000 pounds of fuel. MARC: It was very difficult
for the investigation team to determine exactly how
salt water could have got into the fuel system. NARRATOR: When they
dig through the records of Surabaya
Airport's fuel hydrant system, they find that the
system is located near the sea. HONG KONG INVESTIGATOR:
March 2010. This was taken just
days before the incident. I think we may have our answer. NARRATOR: The team discovers that the
underground hydrant system that stores and
supplies fuel to the pump truck was recently upgraded. During construction, the
fuel pipes had been opened up and possibly
exposed to groundwater. MARC: There had
been construction work on the hydrants and
the investigation team highly suspected that
would have been an opportunity for salt water to come
into the hydrant system. ANNE: If then the pipes
are not flushed sufficiently, then that salt water
could still be present when you start
refueling aircraft. NARRATOR: The team now believes
they know what happened to Cathay Pacific Flight 780. The underground fuel supply --
contaminated with salt water -- broke down a filter, releasing
a powder into the fuel. The powder jammed
the metering valves, preventing enough fuel
from reaching the engines. FO HAYHOE: Engine one stall. ANNE: We had fuel contamination and that contamination
throughout the fuel system led to the seizure of
both main metering valves such that the pilot
no longer had control over the power of the engines. NARRATOR: Investigators
believe Captain Waters was able to restore some
thrust in engine number one only because its
fuel metering valve wasn't yet completely jammed. Some fuel was
still getting through. CPT WATERS:
Slowly. Slowly. Come on. FO HAYHOE: Rotation
increasing in engine one. CPT WATERS: It's working. NARRATOR: Once the
spheres jammed the valve, it was stuck open, making it difficult to slow
down the plane during landing. ♪ ♪ [collision] CPT WATERS: Brace! Ugh! NARRATOR: Expert
piloting brought Flight 780 safely to a stop. CPT WATERS: I can't believe it. ♪ ♪ FO HAYHOE: Nice one. ANNE: I think the
crew did a great job. It's not an
emergency that's trained for. MARC: We can be very
thankful to the crew. They behaved in a
very professional manner, and they have our admiration. ♪ ♪ NARRATOR: Since the accident,
there have been efforts to improve the regulation
of aviation fuel handling and storage. The company that
manufactures the filters has redesigned them
to prevent collapse and powder contamination. For their
outstanding courage and skill, Malcolm Waters and David Hayhoe
were given the highest honor in civil aviation,
The Polaris Award. FO HAYHOE: It was very
special to be given the award. It was an incredible honor. CPT WATERS: It was the
Federation of Air Pilots that awarded that award. So when, you know, your fellow
pilots say, job well done. We really think that,
you know, you pulled it off, so yeah, very
humbled and honored. ♪ ♪
