- 5 weeks ago
Air Crash Investigation Series S22E05 Pacific Plunge
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TVTranscript
00:00The pilots of Alaska Airlines Flight 261 wrestle with an MD-83 nosediving towards the Pacific Ocean.
00:14We got it under control here. No, we don't.
00:19The airplane pitched down and rolled.
00:24Mayday!
00:26It actually gets inverted upside down.
00:30Amazingly, the pilots manage to keep the aircraft flying.
00:34This is like an air show maneuver.
00:37Speed brakes.
00:39Just seconds from impact, the pilots right their aircraft.
00:43If they had one shot to save the plane, or all would be lost.
00:47Here we go!
00:56Oh, it's up.
00:58I mean 109.
01:00You're up.
01:02I'm not sure I'm not sure.
01:03I'm not sure I'm not sure.
01:05Alaska Airlines Flight 261 takes flight, climbing into sunny skies over Puerto Vallarta, Mexico.
01:20You're up.
01:25Gear's up.
01:27Captain Ted Thompson is an Air Force veteran.
01:30He's flown with Alaska Airlines for 17 years.
01:35Thank you, sir.
01:38First Officer Bill Tansky has been flying for almost four decades.
01:42He's the one flying today.
01:44The pilots on 261 were highly regarded by their fellow pilots.
01:51These were really top-notch aviators.
01:54Flaps up.
01:58Flaps.
02:01The MD-83 is flying north to San Francisco for a stopover.
02:06From there, it's a short hop to its final destination, Seattle, Washington.
02:10Three flight attendants tend to the 83 passengers on board.
02:22Fifteen minutes after takeoff.
02:26That's strange.
02:28The pilots become aware of a problem.
02:32Planes out of trim.
02:33Trim refers to small adjustments to the horizontal stabilizer that maintains the pitch of the aircraft.
02:46When that light goes on, it tells the crew you're going to have a problem adjusting the nose up or down, which is, of course, crucial for flight.
02:54The warning light indicates the horizontal stabilizer is jammed, pushing the nose down slightly.
03:04Let's check this out.
03:06Autopilot off?
03:07Good idea.
03:11Whoa.
03:13What's it doing?
03:15It's pushing down.
03:16First officer Tansky uses all his physical strength to keep the plane's nose up.
03:23The first officer is hand-flying the airplane, so he's manually got his hands on the control yoke, and increasingly there's more and more pressure that he's having to hold.
03:34He's using a lot of arm muscle, so this is something that they want to fix.
03:40Well, we're still climbing.
03:44That's good.
03:45Let's get to 310 and figure this out.
03:50By pulling back on the control column, the pilots can deflect the plane's elevators enough to enable the aircraft to continue climbing.
04:0221 minutes after takeoff, flight 261 levels off at 31,000 feet.
04:10The manual says try the pickle switch.
04:19Pickle switches are literally just a little toggle switch on the control column, and it moves the horizontal stabilizer such that it will push the nose up or down.
04:33Controls in the cockpit activate a two-foot jack screw in the tail.
04:37As the jack screw turns, it moves the stabilizer up or down.
04:43They were having to go through the manuals, and they were asking each other, what do you know?
04:48What can we do?
04:49What can we try?
04:53Nothing.
04:54Why don't you try?
04:55Captain Thompson tries to activate the horizontal stabilizer using what pilots call the suitcase handles.
05:07No dice.
05:10It's like trying to start your car.
05:11They were trying everything they could think of to get their plane to respond.
05:17Let's try it on autopilot.
05:18They hope the autopilot can keep the plane level.
05:27Plane is steady.
05:29All right.
05:30I'm thinking we get this plane on the ground sooner rather than later.
05:33Yeah.
05:34Maybe LAX?
05:36Call dispatch.
05:37If you have a control problem, you have to get that plane on the ground.
05:46Dispatch 261, requesting a diversion to LAX.
05:50Our longitudinal trim system is inoperative.
05:54Captain Thompson contacts Alaska Airlines flight dispatcher in Seattle.
05:58Dispatch 261, copy that.
06:01If you want to land in LA, for safety reasons, we'll be looking at over an hour delay because of a flow problem right now.
06:09I didn't really want to hear about the flow.
06:12I'm concerned about suitable airports.
06:15Do you have a wind at LAX?
06:17It's 260 at 9.
06:21The pilots compare the wind conditions at Los Angeles and San Francisco airports.
06:28The pilots on this flight took such care, considering all their options on runways.
06:36There's a headwind at LAX, but at San Francisco, there's a crosswind.
06:4026 at 9 versus a direct crosswind.
06:44For safety reasons, I think something that lowers the ground speed makes sense.
06:50The headwind at LAX will help make it a safer landing.
06:54Once you're lined up for the LAX runway, you've got perfect winds coming right at your nose.
07:02It blows off the Pacific Ocean.
07:04It's predictable, it's constant, and it slows down your plane.
07:13Do the guys with the horizontal situation.
07:14Ten minutes after rerouting, a mechanic at Alaska Airlines' maintenance facility in Los Angeles contacts the crew.
07:26Affirmative?
07:27The maintenance facility can talk directly to the pilots to provide them the expertise on the problem that they're dealing with.
07:36Did you try the suitcase and pickle switches?
07:38Yeah, we've tried just about everything.
07:40If you've got any hidden circuit breakers, we'd love to know about them.
07:44Yeah, I'll look into the circuit breaker guide as a double check.
07:46And the alternate's inoperative, too.
07:49Yep, our horizontal stabilizer appears to be jammed, the whole thing.
07:55Okay, thank you, sir.
07:56I'll see you when you get to LAX.
08:01The response from Alaska Airlines' maintenance was basically no response at all.
08:06They provided them no help.
08:08Really, the most they ever said to them,
08:09did you try the pickle switches and the suitcase handles,
08:13which is one of the first things that they did.
08:16All right, let's, uh, let's try the pickle switches again.
08:22You got it?
08:26The captain is warning the first officer as a reminder,
08:29when we click the autopilot off, be ready,
08:32because it's going to require a lot of effort from you right then.
08:37This will click the autopilot off.
08:46The nose of the plane drops far more than the pilots anticipated.
09:00Holy crap!
09:01The airplane is pitched down significantly,
09:07and the airframe is shaking violently.
09:10They know something is very desperately wrong with the airplane.
09:14The problem is suddenly much worse.
09:17Flight 261 begins to nosedive.
09:20What are you doing?
09:23It got worse.
09:26They have to get the nose back up,
09:29or, uh, they'll have an unarrested descent all the way to the ocean.
09:33The crew of Alaska Airlines Flight 261 struggles to regain control of their MD-83.
09:54They pulled back on the control yoke, holding a lot of force.
09:57Center of Alaska 261, we are in a dive here.
10:05I've lost control of vertical pitch.
10:07Alaska 261, say again, sir.
10:09We are in a vertical dive at 26,000.
10:14They are now three minutes from impact.
10:17Ah, speed brakes!
10:20The pilots deploy the speed brakes,
10:22control surfaces on the wings of their plane that increase drag.
10:27And he wanted to slow the plane down,
10:29and it would also give them more of a chance physically
10:32to pull the plane out of the dive.
10:41The speed brakes arrest the dive.
10:46Using all their strength,
10:48the pilots bring the aircraft back under control at 24,000 feet.
10:52Once we get the speed slowed, we will be okay.
11:00In 80 seconds, the plane has dropped 8,000 feet.
11:06The pilots pulled out of the dive with pure brute force.
11:11We've got it back.
11:14Under control here.
11:16No, we don't.
11:17Even though they've managed to pull out of the dive,
11:21it requires extreme effort to keep the nose of the plane level.
11:24Okay.
11:25It really wants to pitch down.
11:27They're really having to work physically
11:29at holding the nose up on this jet.
11:33They're in a fight for control of the airplane.
11:36It's a lot worse than it was.
11:38Yeah.
11:39We are in much worse shape now.
11:40This is a very experienced crew.
11:43These aviators have had problems in flights before,
11:46but nothing like this.
11:51Maintenance 261.
11:53Are you on?
11:5622 miles from Los Angeles,
11:58Captain Thompson updates Alaska Airlines' maintenance,
12:01hoping for advice on how to land safely.
12:04Yeah, 261, this is maintenance.
12:06Yeah, we've tried both the tickle switch
12:08and the suitcase handles,
12:10and it ran away full nose trim down.
12:12Oh.
12:14It ran away full trim.
12:15And now we're worse than we were.
12:18He's explaining that when he commanded nose up trim,
12:22the trim system moved nose down,
12:25moved in opposite direction of the way he commanded it,
12:28and it did so very quickly,
12:30and it did so with a lot of force.
12:32And you're getting full nose trim down
12:34and no nose trim up, correct?
12:37That's affirmative.
12:38We went full nose down,
12:40and now I'm afraid to try it again
12:41to see if we can get it to go back in the other direction.
12:45He is reluctant to try to move it again
12:48for the concern that if it gets worse yet,
12:51that they could lose control of the airplane entirely.
12:54If you want to try it, that's okay with me.
12:57If not, that's fine.
12:59See you on the gate.
13:00Okay.
13:02After the maintenance base at LAX said,
13:05oh, we'll see you at the gate,
13:07the pilots knew they were on their own.
13:10All they had left was they had themselves,
13:13their physical strength, and their wits.
13:16To land the plane,
13:17the pilots need to figure out how to control their descent
13:20without using the plane's trim system.
13:23You want to try the trim switch again or not?
13:26Uh, no.
13:28I don't know.
13:30It's up to you, man.
13:31They're literally test pilots,
13:33and they're having to utilize decades of experience
13:37to try to work their way through to a solution.
13:41We better talk to the people back there.
13:43Yeah.
13:45I know.
13:47Captain Thompson tries to reassure the passengers.
13:50Folks, we've had a flight control problem.
13:55We're, uh, intending to go to Los Angeles.
13:58Uh, we're working on it,
13:59and I don't anticipate any problems
14:01once we get a couple systems, uh, back on the line.
14:10With Los Angeles in sight,
14:12the pilots prepare for an emergency landing.
14:14We try flops.
14:1715.
14:1811.
14:18Let's go to 11.
14:21The pilots test the plane in a landing configuration.
14:27Okay, we're pretty stable here.
14:29But we've got to get down to 180 knots.
14:34The jet is very badly damaged,
14:37and they need to understand and find a way
14:40to control the pitch of the jet
14:43all the way through the landing.
14:45If it's controllable,
14:46we ought to just try and land it.
14:48First officer Tansky suggests a risky high-speed landing.
14:53Okay.
14:55Let's head for LA.
14:59Their predicament was dire.
15:02They would not be able to pull the plane up
15:05and do a go-around.
15:07The only chance they had
15:09was one shot to get it on the ground
15:11or all would be lost.
15:13But as soon as they come up with a plan...
15:17You feel that?
15:21Yeah.
15:22The pilots hear thumps at the back of the plane.
15:25Then disaster strikes.
15:28The airplane pitch down and roll.
15:31They know that they are in a life-threatening situation.
15:35This is pilots' nightmare.
15:37You're running out of time.
15:38If they do not control the jet,
15:40very quickly they'll lose the airplane.
15:44Mayday!
15:49Push and roll!
15:50Push and roll!
15:5318,000 feet above the Pacific Ocean,
15:56Flight 261 rolls left
15:58and goes into a dive.
16:01This is like an air show maneuver.
16:03The Blue Angels do this.
16:05The Thunderbirds do this.
16:09Dropping at 160 feet per second,
16:12time is running out.
16:13When the airplane was inverted,
16:24this is a very difficult situation
16:26because they've got to try to determine
16:29if they can maintain control of it
16:31and get the airplane back right side up.
16:34The plane starts responding.
16:39They're pushed on the control column
16:41to prevent the possibility of the stall
16:43and then they roll the airplane toward wings level
16:47in an attempt to maintain control of it.
16:50Push, push, push.
16:51Push the blue side up.
16:52The top side of an attitude indicator
16:55is blue like the sky
16:57and so they need to get
16:58the blue side of the attitude indicator
17:01back on the top.
17:04On the ground,
17:05LAX controllers have lost contact
17:07with Flight 261.
17:09Skywest 5154,
17:11traffic at your 1 o'clock
17:12is an Alaska MD-80.
17:13Do you see him up there?
17:14They look for help from other pilots.
17:17Yes, sir.
17:18Definitely in a nose down position.
17:19Descending quite rapidly.
17:21He's inverted.
17:23Okay, keep your eye on him.
17:25Alaska 261,
17:26are you with us yet, sir?
17:3213,000 feet over the ocean,
17:34the pilot's efforts seem to pay off.
17:37The plane's nose starts to rise,
17:39but it's still inverted.
17:41Okay, let's kick runner.
17:43Left runner.
17:44Left runner.
17:46The pilots are kind of
17:47hanging upside down like bats,
17:49and it was very difficult
17:50to reach the rudder pedal.
17:53Left runner.
17:54I can't reach it.
17:55Okay, right rudder.
17:56Right rudder.
17:58Their one hope
17:59is if they could kick that rudder,
18:01they could flip the plane back over.
18:04Okay.
18:06We gotta get it over again.
18:08Released upside down, we're flying.
18:12As the pilots fight to get the plane the right way up,
18:22the engines on flight 261 fail.
18:26There was a disruption in the airflow
18:30into the engines,
18:31and it caused a loss of thrust.
18:35Speed brakes.
18:39Got it.
18:40Their demeanor was determined,
18:43collected.
18:44They were giving everything they had.
18:46The windscreen's full of the ocean.
18:48They're not gonna solve this.
18:50He's hit the water.
19:05He's down.
19:05He's down.
19:05He's down.
19:07He's down.
19:20Search and rescue helicopters
19:22are immediately dispatched
19:23from Coast Guard stations.
19:26Search teams find debris
19:28floating 2.7 miles north
19:30of Anacapa Island
19:31off the coast of California.
19:33In addition to pieces of the plane,
19:36searchers are finding personal effects.
19:39A shoe,
19:40a passport,
19:41a postcard.
19:44Aviation safety advocate Mary Schiavo
19:47represents the families
19:48of six passengers from Flight 261.
19:51I remember this person's possessions.
19:57All the pictures were still
19:58in the wallet
19:59in the pants pocket.
20:05Except for the picture of his wife.
20:09And so we knew by that
20:10and by how they found things
20:12that he had been clutching.
20:14That was really important to her.
20:20Rescuers search for survivors
20:21throughout the night.
20:23None are found.
20:29All 88 passengers and crew
20:32on board Flight 261 are dead.
20:34It's a terrible, tragic thing,
20:37of course.
20:38But, you know,
20:41we have a real,
20:42well-established procedure here
20:44for how these tragedies
20:45are handled.
20:48Investigators from the NTSB,
20:50the National Transportation Safety Board,
20:52are assigned to find
20:53an explanation for the crash.
20:56LAX maintenance is saying
20:58the pilot's reported
20:58a jammed stabilizer.
20:59NTSB Systems Investigator
21:03Jeff Guzzetti
21:03joins the investigation.
21:05We knew quite a lot
21:06just from the transmissions
21:09between the flight crew
21:11and Los Angeles.
21:13Maybe they had
21:13a mechanical problem.
21:16Looks like they tried
21:18both switches.
21:18No luck.
21:20The plane pitched.
21:21Full nose trim down.
21:24We immediately began
21:25to research
21:26the horizontal stabilizer
21:27trim system
21:28to see how it was designed,
21:30how it functioned,
21:31and how the crew
21:32operated it normally.
21:35The leading edge
21:36of the horizontal stabilizer
21:38is raised or lowered
21:39by a jack screw.
21:41When activated,
21:43it moves up or down
21:44through an acme nut,
21:46changing the angle
21:47of the horizontal stabilizer.
21:52We need to see
21:53the jack screw assembly.
21:55Let's hope it's
21:56all in one piece.
21:58Investigators wonder
21:59how the horizontal trim
22:01system could have failed.
22:03I'll get this
22:04to the Navy.
22:06Recovering parts
22:07of the stabilizer system
22:08could give investigators
22:09important clues.
22:13But the wreckage field
22:14lies on the bottom
22:15of the ocean
22:16at a depth of 700 feet,
22:18well beyond the reach
22:19of scuba divers.
22:20We were able
22:21to tell the Navy
22:22what to look for,
22:24what the high-priority
22:25targets were.
22:25U.S. Navy crews
22:28use side-scan sonar
22:29to pinpoint the location
22:31of the wreckage.
22:33Remotely operated vehicles
22:35equipped with robotic arms
22:36are used to recover
22:38pieces of Flight 261.
22:42The black boxes
22:43are retrieved
22:44two days after the crash.
22:46Nine days
22:51into the investigation,
22:52essential parts
22:53of the horizontal stabilizer
22:55are also recovered.
22:57We got the jack screw.
22:59And with the brainpower
23:01we had,
23:01we had a fighting chance
23:02to find out exactly
23:03what went wrong
23:04during this flight.
23:05What's this stuff?
23:14Investigators wonder
23:15if recovered parts
23:16from the horizontal stabilizer
23:18of Flight 261
23:19can provide clues
23:20about why it failed.
23:22It's some kind of metal.
23:25What they see
23:26is puzzling.
23:28We saw this
23:29little thin piece
23:31of metal
23:32that we thought
23:33looked like a slinky.
23:34that really struck us
23:36as something very odd.
23:42Why isn't the nut
23:44attached to the jack screw?
23:50Normally,
23:51the lower end
23:52of the jack screw
23:53is threaded
23:53through an acme nut.
23:56When we looked at that
23:57and saw that
23:57the jack screw
23:58wasn't part of the acme nut,
24:00we asked ourselves,
24:01how can that happen?
24:02That really just blew our mind.
24:04the jack screw
24:05and the acme nut
24:06were found a few feet apart.
24:08They must have separated
24:09mid-flight.
24:13Threads an eighth
24:14of an inch thick
24:15inside the nut
24:16should hold it securely
24:17to the jack screw.
24:18Look at this.
24:29There's something unusual
24:32about the nut.
24:33Incredible.
24:35It's completely stripped.
24:38When we finally
24:39looked inside
24:39the acme nut,
24:41it revealed
24:42that there were
24:42no threads
24:43inside of it.
24:44Let's talk to
24:45Metallurgy.
24:46It was shocking
24:50and stunning
24:51to us
24:52to see something
24:52like this.
24:53No one thought
24:54that you could get
24:55those thick threads
24:56to rip out.
24:59Interesting.
25:01Metallurgist
25:02Joe Epperson
25:03examines the stripped
25:04nut
25:04and the jack screw.
25:06It became
25:07immediately apparent
25:08that what we
25:09were looking at
25:10was actually
25:12the remainder
25:13of the threads
25:15that were
25:16inside the nut.
25:18Looks like
25:19the jack screw
25:20stripped the threads
25:21of the acme nut.
25:23The next step
25:24in the process
25:25was to figure out
25:26how the threads
25:28were reduced
25:29to such an extreme
25:31degree
25:31and then stripped
25:33out of the nut.
25:34There's some
25:38grease here
25:39on the bottom.
25:42The team
25:43studies residue
25:44observable
25:45on the jack screw.
25:46The way
25:47to prevent
25:47wear
25:48is by
25:49lubrication
25:50with grease
25:51and in
25:52the case
25:53of an
25:54extreme wear
25:55event
25:55you want
25:56to look
25:57at
25:57is there
25:58grease
25:59where
25:59it's
26:00supposed
26:00to be.
26:01and there's
26:03some here
26:03at the top.
26:06In flight
26:07the jack screw
26:08rotates inside
26:09the nut.
26:10To prevent
26:11wear
26:11it needs
26:12to be
26:12lubricated
26:13regularly.
26:15There should
26:15be more
26:16grease
26:16here in
26:16the middle.
26:18That's the
26:18working area
26:19where it
26:19rotates the
26:20most.
26:21When we
26:22first looked
26:22at the
26:23jack screw
26:23there was
26:25very minimal
26:26signs that
26:27there was
26:28any grease
26:29on it
26:30at all.
26:31It was
26:32in the
26:33ocean
26:33for a
26:33week.
26:34Did
26:34the water
26:34wash
26:34the
26:35grease
26:35away?
26:36I don't
26:37think so.
26:38Grease
26:38doesn't wash
26:39off that
26:39easily.
26:42There's still
26:43some remnants
26:43here but
26:45none in
26:45the middle.
26:47We did
26:48find a
26:49little bit
26:50of a
26:50remnant
26:50of a
26:51grease
26:51at the
26:52very
26:52upper
26:52end
26:53and at
26:54the
26:54very
26:54lower
26:54end.
26:56It was
26:56very easy
26:57to conclude
26:58that being
26:59in the
26:59ocean
27:00had not
27:01washed
27:01away
27:02the
27:02grease
27:02from
27:03the
27:03working
27:03area
27:03of the
27:04jack
27:05screw.
27:06How could
27:07it be
27:07that there's
27:08so little
27:08grease
27:09on this
27:10jack
27:10screw?
27:19Grease goes
27:20through here
27:20during the
27:21lubrication
27:21process.
27:22during
27:25maintenance
27:26grease
27:26is applied
27:27to the
27:27interior
27:28of the
27:28nut
27:28through
27:29a
27:29small
27:29valve
27:30called
27:30a
27:30zerk
27:30fitting.
27:32So
27:33the
27:34zerk
27:34fitting
27:34is this
27:35fitting
27:36right here
27:37and what
27:38mechanics have
27:38to do
27:39is put a
27:39grease gun
27:40hose in
27:40here and
27:41then squirt
27:41grease
27:42into this
27:43little grease
27:43fitting that
27:44goes inside
27:44this passage.
27:46That zerk
27:47fitting should
27:47have preserved
27:48and kept
27:48the remnants
27:49of whatever
27:49grease it
27:50saw last.
27:54What's that?
27:59It's packed
28:00with dried
28:00grease.
28:02I've been
28:03around grease
28:03long enough
28:04to know
28:04that if you
28:05don't replenish
28:06it and if
28:07you just
28:07leave it,
28:08eventually
28:09it dries
28:10up and
28:11gets hard
28:11and it
28:12basically says
28:14that it
28:15had not
28:15been
28:16replenished.
28:18How long
28:19has it been
28:20clogged
28:20like this?
28:23At least
28:24a year,
28:25maybe more.
28:27Finding
28:27this block
28:28he suggests
28:29long-term
28:30abuse
28:30of the
28:31grease.
28:35I'd say
28:35we have
28:36a maintenance
28:36issue here.
28:38Time to
28:39talk to
28:39the airline.
28:41We were
28:42very suspicious
28:43about how
28:45well this
28:46component was
28:47lubricated
28:47or whether
28:48it was
28:48lubricated
28:48at all.
28:49And so
28:50we had
28:50our doubts
28:51as to
28:52whether or
28:52not this
28:52component
28:53was being
28:53properly
28:54maintained
28:54by the
28:55airline.
28:59NTSB
28:59investigators
29:00travel to
29:01Alaska Airlines
29:01operations
29:02facility in
29:03San Francisco.
29:05You worked
29:05on the plane
29:06in September
29:071999,
29:08that true?
29:08Yes,
29:09I did.
29:10They tracked
29:10down the
29:11mechanic who
29:11was responsible
29:12for the last
29:13lubrication of
29:14the jack screw
29:14assembly four
29:16months before
29:16the accident.
29:19Could you walk
29:19us through how
29:20you lubricate
29:20the jack screw
29:21assembly?
29:23I'll tell you
29:23this, it's not
29:25my favorite job.
29:28The team
29:29learns that
29:30jack screw
29:30lubrications are
29:31done most often
29:32on the night
29:33shift, outside
29:34the hangar,
29:35sometimes in
29:36the rain.
29:36You're working
29:39off high-lift
29:40trucks, which
29:41will sometimes
29:42move with a
29:43gust of wind.
29:44The airplane
29:45moves with a
29:46gust of wind.
29:47You're up and
29:4830 feet off the
29:49ground.
29:50Some mechanics
29:50don't like that
29:51job.
29:52They're not
29:53stable up there.
29:55To reach the
29:56jack screw
29:56assembly, remove
29:57a panel first.
29:59How do you
30:00apply the grease?
30:01I use a
30:02paint brush.
30:03Sometimes I put
30:03a big glob in
30:04my hand to make
30:04sure it's on
30:05there.
30:05Aircraft,
30:07especially large
30:08aircraft, need
30:09grease.
30:10They need to
30:11have lubricants,
30:12and it's
30:12messy.
30:15The most
30:16effective way is
30:17to fill your
30:17hand with grease
30:18and actually move
30:20it up and down
30:21on the jack
30:21screw, filling
30:22all the screw
30:23grooves, filling
30:24them with grease.
30:27What about
30:27greasing the
30:28acme nut?
30:31Investigators
30:32focus on how
30:33the mechanic
30:33greased the
30:34acme nut on
30:35the jack screw?
30:36We use a
30:37grease gun to
30:37the zerk
30:38fitting.
30:40You pump
30:40grease in until
30:41you see fresh
30:42grease coming
30:42out.
30:44Well, how do
30:44you know whether
30:44the lubrication
30:45has been done
30:45properly and
30:46when to stop
30:47pumping the
30:48grease gun?
30:50I don't.
30:52Would you be
30:53able to see the
30:53grease coming
30:54out from the
30:54top of the
30:55acme nut during
30:55lubrication?
30:58No, I can't
30:58remember looking
30:59to see if there
30:59was.
31:00one of the
31:03first things
31:03that that
31:04tells me is
31:05that he
31:05couldn't have
31:06known that
31:06that zerk
31:06fitting has
31:07taken grease.
31:08You have no
31:08idea that it's
31:09clogged.
31:11So we found a
31:12variety of ways
31:12in which
31:13mechanics lubricated
31:14this component
31:15and that gave us
31:17some pause because
31:18it's a very
31:19critical component
31:19and if you don't
31:20lubricate it
31:21properly, you
31:21could end up
31:22with an accident
31:22like the one
31:23that just
31:23happened.
31:24The team
31:26discovers that
31:27the methods
31:27Air Alaska
31:28mechanics use
31:29to lubricate
31:29the jackscrew
31:30assembly don't
31:31follow maintenance
31:32standards.
31:34The last time
31:35the jackscrew
31:35was lubricated
31:36was about
31:37four months
31:38before the
31:38accident.
31:41But it's not
31:42just the way
31:43the jackscrew
31:44assembly is being
31:45lubricated that
31:45bothers investigators.
31:47It's also the
31:48frequency.
31:49And before that?
31:50January 1999.
31:51They're doing it
31:54every 2,500 hours.
32:00They can see
32:01there's a long
32:02period between
32:03lubrications.
32:05Is that even
32:06within regulations?
32:08I'll find out.
32:12We knew we had
32:13kind of a research
32:14project on our
32:15hands.
32:15Some of the
32:15documents that we
32:16requested from
32:17the manufacturer,
32:18from the FAA,
32:19from the airline
32:20came in the form of
32:21internal memorandums
32:23from engineering
32:24departments or
32:26requests from
32:27maintenance to
32:28extend an interval.
32:29It really began to
32:30paint a picture of
32:33how the lubrication
32:34intervals were
32:35extended.
32:43Check it out.
32:45The airline made
32:46multiple requests
32:47multiple requests
32:47to extend the
32:48intervals on
32:48lubrications.
32:51In 1987, the
32:55interval between
32:56lubrications was
32:58500 hours.
33:00The intervals
33:01between lubrications
33:03are measured by the
33:04number of hours the
33:05plane is in the air.
33:06In 1991, it goes up
33:10to 1,200 hours.
33:13By 1996, it increases
33:17all the way up to
33:202,500 hours.
33:25They just continued to
33:27extend, extend, extend.
33:29Approved by the FAA?
33:31Yeah.
33:31Every one of them was
33:32approved.
33:33Investigators conclude
33:38that the lubrication of
33:39jack screws was not
33:40only conducted poorly,
33:42it was also performed
33:44less and less frequently.
33:45If you're going to extend
33:48these lubrication functions,
33:49then you better be doing
33:50something to make sure
33:51that what you're doing
33:52is correct.
33:54But even if the
33:55lubrication wasn't being
33:56done properly, regular
33:57inspections should have
33:59caught the wear on that
34:00Acme nut.
34:02True.
34:03They should have
34:03inspected it regularly.
34:05Was the jack screw
34:07assembly on Flight 261
34:08inspected when and how
34:10it should have been?
34:11We looked at the
34:12maintenance records for
34:13information about the
34:14last check.
34:15I've got something.
34:21Investigators dig deeper
34:23into the records of
34:24Flight 261 to find out
34:26how the jack screw
34:27assembly was inspected.
34:29Yeah, this doesn't look
34:30right to me.
34:32The team finds paperwork
34:34which reveals that during
34:35a routine inspection,
34:37a mechanic at the
34:38airline's Oakland facility
34:40observed that the Acme
34:41nut was badly worn.
34:44You sure the reading is
34:456.040?
34:47A mechanic who did that
34:49wear check reported that
34:50he found it to be at the
34:52limit.
34:55This nut was wearing fast
34:57and something needed to be
34:59done.
35:01The lead mechanic ordered
35:03the nut to be replaced.
35:04This was evidence that someone
35:07had caught the fact that this
35:09Acme nut was worn out.
35:11Most of the alliance,
35:12the decision would be
35:13we will get the piece to the
35:15airplane as soon as possible
35:17and replace it.
35:18But the entry is crossed out.
35:22I don't get it.
35:23Well, when we saw that they had
35:25crossed out the first entry,
35:26it was very suspicious.
35:28Something was up.
35:29It was fishy to us.
35:30We have to find out
35:32what went on here.
35:38Do you remember inspecting
35:39an MD-83 on September 27th,
35:411997?
35:42I remember it well.
35:45Investigators contact
35:46John Leotin,
35:48the lead mechanic who reported
35:50the worn Acme nut on
35:51flight 261.
35:52I wrote up the evaluation.
35:57The nut is worn down.
35:59Replace it.
36:03It was an alarming discovery.
36:05In order for that aircraft
36:06to be safe to fly,
36:09that nut assembly,
36:10at the very least,
36:12must be replaced.
36:14There's no doubt in my mind.
36:16It was the end of my shift.
36:19When I came back the next workday,
36:21the plane was closed up.
36:25The plane returned to service
36:26with the worn nut.
36:30If the nut had been replaced,
36:33the plane would still be flying.
36:35And 88 people
36:36would still be alive.
36:40How could a maintenance facility
36:42allow the airplane
36:44to be put back
36:46into revenue service
36:47with the wear
36:48that it found
36:49on the Acme nut?
36:51When investigators
36:53probe further,
36:55they learned
36:55that the amount of wear
36:56on the Acme nut
36:57was rechecked
36:58by other mechanics.
37:00They determined
37:01that it was just
37:02within minimum limits.
37:05Alaska Airlines maintenance
37:07misses a warning sign.
37:09The wear on the nut
37:10should at least
37:11have been monitored.
37:12But it wasn't.
37:14The next time
37:15that jack screw
37:15was looked at
37:16was in the NTSB laboratory.
37:18The plane flew
37:21with the worn nut
37:22for two more years
37:23before it took off
37:24from Puerto Vallarta
37:25on the day
37:26of the accident.
37:28Gear up.
37:30First Officer Tansky
37:32and Captain Thompson
37:33had no idea
37:34that their stabilizer
37:36was on the verge
37:37of failure.
37:40That's strange.
37:42The plane's out of trim.
37:43The team turns
37:46to the voice recorder
37:47to find out
37:48how the devastating
37:49chain of events
37:50unfolded
37:51on board
37:51flight 261.
37:59Let's check this out.
38:01Autopilot off?
38:03Good idea.
38:04Whoa!
38:1013 minutes
38:10after takeoff
38:11from Puerto Vallarta
38:12the worn threads
38:14in the acme nut
38:15cause the jack screw
38:16to jam
38:16preventing movement
38:17of the horizontal stabilizer.
38:20Try it again.
38:23The captain's
38:24trying to rectify
38:25the jam stabilizer.
38:28While cruising
38:29at 31,000 feet
38:31the CVR
38:34picks up the sound
38:35of a click
38:36followed by a thump.
38:38We think that
38:39the pilot
38:40was moving
38:41his thumb switch
38:42on his yoke
38:42in an attempt
38:43to move
38:44the jack screw
38:45through the nut.
38:49The threads
38:50finally give way
38:51and the jammed
38:52jack screw
38:53pulls up
38:53through the nut
38:54causing the stabilizer
38:55to move upwards.
38:57A stopper
38:58is all that prevents
38:59it from separating
39:00completely.
39:01It got worse.
39:07With the horizontal stabilizer
39:09pushing the nose
39:10further down
39:11the plane
39:11goes into a dive.
39:14Through sheer
39:15brute force
39:16the pilots
39:17hold the jack screw
39:18in place
39:18and recover the plane.
39:22Okay.
39:24It really wants
39:24to pitch down.
39:25you feel that?
39:32Stop.
39:33Let's hear that again.
39:36But eight minutes
39:37later
39:37there's another
39:38series of thumps.
39:43You feel that?
39:44the stopper
39:47holding the jack screw
39:48in place
39:49finally gives out.
39:56Push and roll!
39:58The damage
39:59to the stabilizer
40:00makes flight 261
40:01uncontrollable.
40:03The plane rolls over
40:04and dives
40:05towards the ocean.
40:06push, push, push, push, push
40:09the blue side up.
40:10Flying upside down
40:12the crew makes
40:13a last ditch
40:13attempt to right
40:14their plane.
40:15speed brakes.
40:22Got it.
40:23The pilots
40:24of flight 261
40:25give everything
40:26they have
40:27to save the plane.
40:28It was just
40:30total professional
40:31fighting for that
40:32plane until the
40:33very end
40:34and they expressed
40:35the realization
40:36that
40:36the fight
40:38was over.
40:42Here we go!
40:45I was sickened
40:55by what I listened
40:55on the CBR.
41:00This accident
41:01could have been
41:01prevented.
41:07They greased
41:08that jack screw.
41:10This doesn't happen.
41:15The amount
41:19of money
41:20that would
41:21have saved
41:22these lives
41:23is a cup
41:24of coffee.
41:25It's
41:26literally
41:27a few dollars
41:28of grease.
41:31I still get
41:32angry
41:33about it.
41:36In the wake
41:37of the accident,
41:38the intervals
41:38between jack screw
41:39lubrications
41:40at Alaska Airlines
41:41is reduced
41:42from 2,500 hours
41:44to 650 hours.
41:46We lost
41:4788 people
41:48because of
41:49lack of lubrication.
41:51This is
41:52a maintenance
41:53accident,
41:54pure and simple.
41:57It is truly
41:57a tragedy.
42:01It was just
42:02one of those
42:03cases that you work
42:04on that's never
42:04going to leave you.
42:05not ever.
42:10It was tough.
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