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On 31 January 2000, Alaska Airlines Flight 261's trimmable horizontal stabilizer jams and breaks from its control system during a flight to San Francisco. The aircraft enters a dive and crashes inverted into the Pacific Ocean. All 88 passengers and crew members on board are killed.
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00:00The pilots of Alaska Airlines Flight 261 wrestle with an MD-83 nose-diving towards the Pacific Ocean.
00:16We got it under control here.
00:20No, we don't.
00:23The airplane pitched down and rolled.
00:27Mayday!
00:28It actually gets inverted upside down.
00:32Amazingly, the pilots manage to keep the aircraft flying.
00:36This is like an air show maneuver.
00:39Speed brakes.
00:41Just seconds from impact, the pilots right their aircraft.
00:46If they had one shot to save the plane, or all would be lost.
00:49Here we go!
00:54D, D, D, D!
00:56D, D.
00:58D, D, D, D, D, D, D, I, M, D, D, E.
01:03D, D, D, D, D, D, D, D, D.
01:05Alaska Airlines Flight 261 takes flight,
01:19climbing into sunny skies over Puerto Vallarta, Mexico.
01:23Gear up.
01:27Gear's up.
01:29Captain Ted Thompson is an Air Force veteran.
01:33He's flown with Alaska Airlines for 17 years,
01:36Thank you, sir.
01:40First officer Bill Tansky has been flying for almost four decades.
01:45He's the one flying today.
01:47The pilots on 261 were highly regarded by their fellow pilots.
01:53These were really top-notch aviators.
01:56Flaps up.
02:01Flaps.
02:01The MD-83 is flying north to San Francisco for a stopover.
02:09From there, it's a short hop to its final destination, Seattle, Washington.
02:15Three flight attendants tend to the 83 passengers on board.
02:19Fifteen minutes after takeoff.
02:28That's strange.
02:30The pilots become aware of a problem.
02:33Planes out of trim.
02:40Trim refers to small adjustments to the horizontal stabilizer
02:44that 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,
02:54which is, of course, crucial for flight.
02:56The warning light indicates the horizontal stabilizer is jammed,
03:03pushing the nose down slightly.
03:06Let's check this out.
03:08Autopilot off?
03:09Good idea.
03:10Whoa.
03:16What's it doing?
03:17It's pushing down.
03:20First officer Tansky uses all his physical strength to keep the plane's nose up.
03:25The first officer is hand-flying the airplane,
03:28so he's manually got his hands on the control yoke,
03:32and increasingly there's more and more pressure that he's having to hold.
03:35He's using a lot of arm muscle,
03:39so this is something that they want to fix.
03:44Well, we're still climbing.
03:46That's good.
03:47All right, let's get to 310 and figure this out.
03:52By pulling back on the control column,
03:55the pilots can deflect the plane's elevators enough
03:58to enable the aircraft to continue climbing.
04:0021 minutes after takeoff,
04:06flight 261 levels off at 31,000 feet.
04:14Manual says try the pickle switch.
04:21Pickle switches are literally just a little toggle switch
04:25on the control column,
04:27and it moves the horizontal stabilizer
04:30such that it will push the nose up or down.
04:35Controls in the cockpit activate a two-foot jack screw in the tail.
04:40As the jack screw turns,
04:42it moves the stabilizer up or down.
04:45They were having to go through the manuals,
04:48and they were asking each other,
04:49what do you know?
04:50What can we do?
04:51What can we try?
04:51Nothing.
04:56Why don't you try?
05:00Captain Thompson tries to activate
05:02the horizontal stabilizer
05:04using what pilots call the suitcase handles.
05:09No dice.
05:12It's like trying to start your car.
05:14They were trying everything they could think of
05:16to get their plane to respond.
05:19Let's try it on autopilot.
05:21They hope the autopilot can keep the plane level.
05:28The plane is steady.
05:31All right.
05:32I'm thinking we get this plane on the ground sooner
05:34rather than later.
05:35Yep.
05:36Maybe LAX?
05:38Call dispatch.
05:40If you have a control problem,
05:43you have to get that plane on the ground.
05:45Dispatch 261 requesting a diversion to LAX.
05:52Our longitudinal trim system is inoperative.
05:56Captain Thompson contacts Alaska Airlines flight dispatcher
05:59in Seattle.
06:01Dispatch 261, copy that.
06:03If you want to land in LA for safety reasons,
06:06we'll be looking at over an hour delay
06:07because of a flow problem right now.
06:11I didn't really want to hear about the flow.
06:14I'm concerned about suitable airports.
06:16Do you have a wind at LAX?
06:19It's 260 at 9.
06:23The pilots compare the wind conditions
06:26at Los Angeles and San Francisco airports.
06:28The pilots on this flight took such care
06:33considering all their options on runways.
06:38There's a headwind at LAX,
06:40but at San Francisco, there's a crosswind.
06:4226 at 9 versus a direct crosswind.
06:46For safety reasons,
06:47I think something that lowers the ground speed makes sense.
06:52The headwind at LAX will help make it a safer landing.
06:56Once you're lined up for the LAX runway,
07:00you've got perfect winds coming right at your nose.
07:04It blows off the Pacific Ocean.
07:06It's predictable, it's constant,
07:08and it slows down your plane.
07:14Do the guys with the horizontal situation.
07:18Ten minutes after rerouting,
07:20a mechanic at Alaska Airlines maintenance facility
07:23in Los Angeles contacts the crew.
07:26Affirmative.
07:29The maintenance facility can talk directly to the pilots
07:32to provide them the expertise
07:34on the problem that they're dealing with.
07:38Did you try the suitcase and pickle switches?
07:40Yeah, we've tried just about everything.
07:42If you've got any hidden circuit breakers,
07:44we'd love to know about them.
07:46Yeah, I'll look into the circuit breaker guide
07:47as a double-check.
07:49And the alternate's in operative, too.
07:51Yep, our horizontal stabilizer appears to be jammed,
07:55the whole thing.
07:56Okay, thank you, sir.
07:58See you when you get to LAX.
08:02The response from Alaska Airlines maintenance
08:05was basically no response at all.
08:07They provided them no help.
08:09Really, the most they ever said to them,
08:11did you try the pickle switches and the suitcase handles,
08:14which is one of the first things that they did.
08:16All right, let's try the pickle switches again.
08:23You got it?
08:27The captain is warning the first officer
08:30as a reminder,
08:31when we click the autopilot off,
08:33be ready,
08:34because it's going to require
08:35a lot of effort from you right then.
08:39This will click the autopilot off.
08:41Stabilizer motion.
08:53Stabilizer motion.
08:55The nose of the plane drops,
08:58far more than the pilots anticipated.
09:02Holy crap!
09:06The airplane is pitched down significantly,
09:09and the airframe is shaking violently.
09:12They know something is very desperately wrong
09:15with the airplane.
09:16The problem is suddenly much worse.
09:19Flight 261 begins to nosedive.
09:23What are you doing?
09:25It got worse.
09:28They have to get the nose back up,
09:30or they'll have an unarrested descent
09:33all the way to the ocean.
09:35The crew of Alaska Airlines Flight 261
09:51struggles to regain control of their MD-83.
09:55They pulled back on the control yoke,
09:57holding a lot of force.
09:58They are now three minutes from impact.
10:18Speed brakes!
10:21The pilots deploy the speed brakes,
10:23control surfaces on the wings of their plane
10:26that increase drag.
10:28And he wanted to slow the plane down,
10:30and it would also give them more of a chance
10:32physically to pull the plane out of the dive.
10:42The speed brakes arrest the dive.
10:47Using all their strength,
10:49the pilots bring the aircraft back under control
10:51at 24,000 feet.
10:57Once we get the speed slowed,
10:59we will be okay.
11:01In 80 seconds,
11:03the plane has dropped 8,000 feet.
11:07The pilots pulled out of the dive
11:09with pure brute force.
11:11We've got it back.
11:14Under control here.
11:17No, we don't.
11:19Even though they've managed to pull out of the dive,
11:21it requires extreme effort
11:23to keep the nose of the plane level.
11:25Okay.
11:26It really wants to pitch down.
11:28They're really having to work physically
11:30at holding the nose up on this jet.
11:34They're in a fight for control of the airplane.
11:37It's a lot worse than it was.
11:39Yeah.
11:40We are in much worse shape now.
11:42This is a very experienced crew.
11:44These aviators have had problems in flights before,
11:47but nothing like this.
11:52Maintenance 261.
11:54Are you on?
11:5622 miles from Los Angeles,
11:59Captain Thompson updates Alaska Airlines' maintenance,
12:02hoping for advice on how to land safely.
12:05Yeah, 261.
12:06This is maintenance.
12:07Yeah, we've tried both the pickle switch
12:09and the suitcase handles,
12:10and it ran away full nose trim down.
12:13Oh.
12:14It ran away full trim.
12:16Yeah, now we're worse than we were.
12:18He's explaining that when he commanded nose up trim,
12:23the trim system moved nose down,
12:26moved in opposite direction of the way he commanded it,
12:29and it did so very quickly,
12:31and it did so with a lot of force.
12:33And you're getting full nose trim down
12:35and no nose trim up, correct?
12:37That's affirmative.
12:39We went full nose down,
12:40and now I'm afraid to try it again
12:42to see if we can get it to go back in the other direction.
12:44He is reluctant to try to move it again for the concern
12:50that if it gets worse yet,
12:52that they could lose control of the airplane entirely.
12:55If you want to try it, that's okay with me.
12:58If not, that's fine.
13:00See you at the gate.
13:00After the maintenance base at LAX said,
13:06oh, we'll see you at the gate,
13:08the pilots knew they were on their own.
13:10All they had left was they had themselves,
13:13their physical strength, and their wits.
13:15To land the plane,
13:18the pilots need to figure out
13:20how to control their descent
13:21without 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.
13:32They're literally test pilots,
13:34and they're having to utilize decades of experience
13:38to try to work their way through to a solution.
13:40We'd better talk to the people back there.
13:44Yeah.
13:45I know.
13:47Captain Thompson tries to reassure the passengers.
13:52Folks, we've had a flight control problem.
13:56We're, uh, intending to go to Los Angeles.
13:59Uh, we're working on it,
14:00and I don't anticipate any problems
14:02once we get a couple systems, uh, back on the line.
14:10With Los Angeles in sight,
14:13the pilots prepare for an emergency landing.
14:16Try flaps.
14:1715, 11.
14:19Let's go to 11.
14:22The pilots test the plane in a landing configuration.
14:27Okay, we're pretty stable here.
14:30But we've got to get down to 180 knots.
14:35The jet is very badly damaged,
14:37and they need to understand and find a way
14:41to control the pitch of the jet
14:43all the way through the landing.
14:45If it's controllable, we ought to just try and land it.
14:49First Officer Tansky suggests a risky high-speed landing.
14:53Okay.
14:55Let's head for L.A.
15:00Their predicament was dire.
15:02They would not be able to pull the plane up
15:06and do a go-round.
15:08The only chance they had was one shot
15:10to get it on the ground,
15:12or all would be lost.
15:13But as soon as they come up with a plan...
15:16You feel that?
15:21Yeah.
15:22The pilots hear thumps at the back of the plane.
15:26Then disaster strikes.
15:28The airplane pitched down and rolled.
15:31They know that they are in a life-threatening situation.
15:35This is pilots' nightmare.
15:37You're running out of time.
15:39If they do not control the jet,
15:40very quickly they'll lose the airplane.
15:45Mayday!
15:50Push and roll!
15:52Push and roll!
15:5318,000 feet above the Pacific Ocean,
15:57Flight 261 rolls left and goes into a dive.
16:02This is like an air show maneuver.
16:04The Blue Angels do this.
16:06The Thunderbirds do this.
16:10Dropping at 160 feet per second,
16:13time is running out.
16:17Okay.
16:18We are inverted.
16:20Now we've got to get it up.
16:23When the airplane was inverted,
16:25this is a very difficult situation
16:27because they've got to try to determine
16:30if they can maintain control of it
16:32and get the airplane back right side up.
16:37The plane starts responding.
16:40They're pushed on the control column
16:42to prevent the possibility of the stall,
16:44and then they roll the airplane
16:46toward wing's level
16:48in an attempt to maintain control of it.
16:51Push, push, push, push the blue side up.
16:54The top side of an attitude indicator
16:56is blue, like the sky,
16:58and so they need to get the blue side
17:00of the attitude indicator back on the top.
17:04On the ground,
17:06LAX controllers have lost contact
17:08with Flight 261.
17:10Sky West 5154,
17:12traffic at your 1 o'clock
17:13is an Alaska MD-80.
17:14Do you see him up there?
17:15They look for help from other pilots.
17:18Yes, sir.
17:18Definitely in a nose-down position,
17:20descending quite rapidly.
17:22He's inverted.
17:24Okay, keep your eye on him.
17:26Alaska 261,
17:27are you with us yet, sir?
17:3313,000 feet over the ocean,
17:35the pilot's efforts seem to pay off.
17:38The plane's nose starts to rise,
17:40but it's still inverted.
17:41Okay, let's kick rudder.
17:44Left rudder.
17:45Left rudder.
17:47The pilots are kind of
17:48hanging upside down like bats,
17:50and it was very difficult
17:51to reach the rudder pedal.
17:53Left rudder.
17:54I can't reach it.
17:55Okay, right rudder.
17:57Right rudder.
17:58Their one hope is
18:00if they could kick that rudder,
18:02they could flip the plane back over.
18:05Okay.
18:06We've got to get it over again.
18:09At least upside down we're flying.
18:18As the pilots fight
18:20to get the plane the right way up,
18:22the engines on flight 261 fail.
18:28There was a disruption in the airflow
18:31into the engines,
18:32and it caused a lost thrust.
18:36Speed brakes.
18:39Got it.
18:40Their demeanor was determined,
18:43collected.
18:44They were giving everything they had.
18:47The windscreen's full of the ocean.
18:49They're not going to solve this.
18:51Ah, here we go!
18:53He's hit the water.
19:05He's down.
19:21Search and rescue helicopters
19:22are immediately dispatched
19:24from Coast Guard stations.
19:26Search teams find debris
19:28floating 2.7 miles north
19:31of Anacapa Island
19:32off the coast of California.
19:35In addition to pieces of the plane,
19:37searchers are finding personal effects.
19:39A shoe, a passport, a postcard.
19:45Aviation safety advocate Mary Schiavo
19:47represents the families
19:49of six passengers from Flight 261.
19:52I remember this person's possessions.
19:58All the pictures were still in the wallet
20:00in the pants pocket.
20:06Except for the picture of his wife.
20:08And so we knew by that
20:11and by how they found things
20:13that he had been clutching.
20:15That was really important to her.
20:17rescuers search for survivors
20:22throughout the night.
20:23None are found.
20:30All 88 passengers and crew
20:32on board Flight 261 are dead.
20:35It's a terrible, tragic thing, of course.
20:39But, you know, we have a real
20:43well-established procedure here
20:44for how these tragedies are handled.
20:48Investigators from the NTSB,
20:51the National Transportation Safety Board,
20:53are assigned to find an explanation
20:55for the crash.
20:55LAX Maintenance is saying
20:58the pilots reported a jammed stabilizer.
21:01NTSB Systems Investigator
21:03Jeff Guzzetti joins the investigation.
21:06We knew quite a lot
21:07just from the transmissions
21:09between the flight crew
21:11and Los Angeles.
21:13Maybe they had a mechanical problem.
21:17Looks like they tried both switches.
21:19No luck.
21:20The plane pitched.
21:21Full nose trimmed down.
21:24We immediately began to research
21:26the horizontal stabilizer trim system
21:29to see how it was designed,
21:31how it functioned,
21:32and how the crew operated it normally.
21:35The leading edge of the horizontal stabilizer
21:38is raised or lowered by a jack screw.
21:41When activated,
21:43it moves up or down
21:45through an acme nut,
21:46changing the angle
21:47of the horizontal stabilizer.
21:52We need to see the jack screw assembly.
21:55Let's hope it's all in one piece.
21:59Investigators wonder
22:00how the horizontal trim system
22:02could have failed.
22:03I'll get this to the Navy.
22:06Recovering parts of the stabilizer system
22:09could give investigators
22:10important clues.
22:13But the wreckage field
22:15lies on the bottom of the ocean
22:16at a depth of 700 feet,
22:19well beyond the reach of scuba divers.
22:21We were able to tell the Navy
22:23what to look for,
22:24what the high-priority targets were.
22:27U.S. Navy crews
22:28use side-scan sonar
22:30to pinpoint the location
22:31of the wreckage.
22:34Remotely operated vehicles
22:35equipped with robotic arms
22:37are used to recover pieces
22:39of Flight 261.
22:43The black boxes
22:44are retrieved
22:45two days after the crash.
22:50Nine days into the investigation,
22:53essential parts
22:53of the horizontal stabilizer
22:55are also recovered.
22:56We got the jack screw.
22:58And with the brain power we had,
23:02we had a fighting chance
23:03to find out exactly
23:04what went wrong
23:04during this flight.
23:10What's this stuff?
23:14Investigators wonder
23:15if recovered parts
23:16from the horizontal stabilizer
23:17of Flight 261
23:19can provide clues
23:20about why it failed.
23:21It's some kind of metal.
23:24What they see
23:26is puzzling.
23:28We saw this,
23:29this little
23:30thin piece of metal
23:31that we
23:32thought
23:33looked like a slinky.
23:34That really struck us
23:35as something
23:36very odd.
23:42Why isn't the nut
23:43attached to the jack screw?
23:44Normally,
23:51the lower end
23:51of the jack screw
23:52is threaded
23:53through an acme nut.
23:55When we looked at that
23:56and saw that
23:57the jack screw
23:58wasn't part of the acme nut,
24:00we asked ourselves,
24:00how can that happen?
24:02That really just
24:02blew our mind.
24:04The jack screw
24:05and the acme nut
24:06were found a few feet apart.
24:08They must have
24:09separated mid-flight.
24:13Threads
24:13an eighth of an inch
24:14thick
24:14inside the nut
24:15should hold it
24:16securely to the jack screw.
24:28Look at this.
24:30There's something
24:31unusual about the nut.
24:33Incredible.
24:35It's completely stripped.
24:37When we finally
24:38looked inside
24:39the acme nut,
24:40it revealed
24:41that there were
24:42no threads
24:43inside of it.
24:43Let's talk to
24:45metallurgy.
24:49It was shocking
24:50and stunning
24:51to us
24:51to see something
24:52like this.
24:52No one thought
24:53that you could get
24:54those thick threads
24:56to rip out.
24:59Interesting.
25:01Metallurgist
25:01Joe Epperson
25:02examines the stripped
25:03nut
25:04and the jack screw.
25:05It became
25:06immediately apparent
25:08apparent that
25:08that what we were
25:09looking at
25:10was actually
25:12the remainder
25:13of the threads
25:15that were
25:15inside the nut.
25:18Looks like
25:19the jack screw
25:20stripped the threads
25:20of the acme nut.
25:22The next step
25:23in the process
25:24was to figure out
25:26how the threads
25:28were reduced
25:29to such an extreme degree
25:31and then stripped
25:32out of the nut.
25:37There's some grease
25:38here on the bottom.
25:41The team
25:42studies residue
25:43observable
25:44on the jack screw.
25:45The way to prevent
25:47wear is by
25:48lubrication
25:49with grease.
25:51And in the case
25:52of an extreme
25:54wear event
25:55you want to look
25:56at
25:57is there grease
25:58where it's
25:59supposed to be?
26:01And there's some
26:02here at the top.
26:05In flight
26:06the jack screw
26:07rotates inside
26:08the nut.
26:10To prevent
26:10wear
26:11it needs to be
26:12lubricated
26:13regularly.
26:13There should be
26:15more grease
26:16here in the middle.
26:17That's the working
26:18area where it
26:19rotates the most.
26:21When we first
26:21looked at the
26:22jack screw
26:23there was
26:24very minimal
26:26signs that there
26:27was any
26:28grease
26:28on it
26:29at all.
26:32It was in the
26:32ocean for a week.
26:33Did the water
26:34wash the grease
26:34away?
26:35Nah,
26:36I don't think so.
26:38Grease doesn't
26:38wash off that
26:39easily.
26:41There's still
26:42some remnants
26:43here
26:43but none
26:45in the middle.
26:47We did find
26:48a little bit
26:49of a remnant
26:50of a grease
26:51at the very
26:51upper end
26:52and at the
26:53very lower
26:54end.
26:55It was
26:56very easy
26:57to conclude
26:57that being
26:59in the ocean
26:59had not
27:00washed away
27:01the grease
27:02from the
27:02working area
27:03of the
27:04jack screw.
27:06How could
27:06it be that
27:07there's so
27:07little grease
27:08on this
27:09jack screw?
27:10grease goes
27:19through here
27:20during the
27:20lubrication
27:21process.
27:24During
27:24maintenance,
27:25grease is
27:26applied to
27:26the interior
27:27of the nut
27:28through a
27:28small valve
27:29called a
27:30zerk fitting.
27:30so the
27:33zerk fitting
27:34is this
27:35fitting right
27:36here and
27:37what mechanics
27:38have to do
27:38is put a
27:39grease gun
27:39hose in
27:40here and
27:40then squirt
27:41grease into
27:42this little
27:42grease fitting
27:43that goes
27:43inside this
27:44passage.
27:46That zerk fitting
27:46should have
27:47preserved and
27:47kept the
27:48remnants of
27:49whatever grease
27:49it saw last.
27:50What's that?
27:58It's packed
27:59with dried
28:00grease.
28:01I've been
28:02around grease
28:03long enough
28:03to know that
28:04if you don't
28:05replenish it
28:06and if you
28:07just leave it
28:07eventually it
28:09dries up
28:10and gets
28:10hard and
28:12it basically
28:12says that
28:14it had not
28:15been replenished.
28:18How long
28:19has it been
28:19clogged like
28:19this?
28:20At least
28:23a year
28:23maybe more.
28:26Finding
28:26this block
28:27suggests
28:28long-term
28:29abuse
28:30to the
28:30grease.
28:34I'd say
28:35we have
28:35a maintenance
28:35issue here.
28:37Time to
28:38talk to
28:38the airline.
28:40We were
28:41very suspicious
28:42about
28:43how well
28:44this component
28:46was lubricated
28:46or whether
28:47it was
28:47lubricated
28:48at all
28:48and so
28:49we had
28:49our doubts
28:50as to
28:51whether or
28:51not this
28:52component
28:52was being
28:53properly
28:53maintained
28:54by the
28:54airline.
28:58NTSB
28:59investigators
29:00travel to
29:00Alaska Airlines
29:01operations facility
29:02in San Francisco.
29:04You worked on
29:05the plane
29:06in September
29:07in September 1999.
29:07Is that true?
29:08Yes, I did.
29:09They tracked
29:10down the
29:11mechanic who
29:11was responsible
29:12for the last
29:13lubrication of the
29:14jack screw
29:14assembly four
29:15months before
29:16the accident.
29:18Could you walk
29:19us through how you
29:20lubricate the
29:20jack screw
29:21assembly?
29:21I'll tell you
29:23this, it's not
29:24my favorite
29:25job.
29:28The team
29:29learns that
29:29jack screw
29:30lubrications are
29:31done most
29:31often on the
29:32night shift,
29:33outside the
29:34hangar,
29:35sometimes in
29:35the rain.
29:38You'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
29:45gust of wind.
29:47You're up and
29:4730 feet off the
29:48ground.
29:49Some mechanics
29:50don't like that
29:51job.
29:52They're not
29:52stable up there.
29:55To reach the
29:55jack screw
29:56assembly, remove
29:56a panel first.
29:59How do you
29:59apply the grease?
30:01I use the
30:01paintbrush.
30:02Sometimes I put
30:03a big glob in my
30:04hand to make
30:04sure it's on
30:04there.
30:06Aircraft,
30:06especially large
30:07aircraft, need
30:09grease.
30:10They need to
30:10have lubricants,
30:12and it's messy.
30:15The most
30:15effective way is
30:16to fill your
30:17hand with grease
30:17and actually
30:19move it up and
30:20down on the
30:21jack screw,
30:21filling all the
30:22screw grooves,
30:23filling them
30:24with grease.
30:26What about
30:27greasing the
30:27acme nut?
30:31Investigators
30:31focus on how
30:32the mechanic
30:33greased the
30:34acme nut on
30:34the jack screw.
30:36We use a
30:36grease gun to
30:37the zerk fitting.
30:39You pump
30:40grease in until
30:41you see fresh
30:41grease coming
30:42out.
30:43Well, how do
30:44you know whether
30:44the lubrication
30:45is being done
30:45properly and when
30:46to stop pumping
30:47the grease gun?
30:50I don't.
30:52Would you be
30:52able to see the
30:53grease coming out
30:54from the top of
30:54the acme nut
30:55during lubrication?
30:57No, I can't
30:58remember looking
30:59to see if there
30:59was.
31:02One of the first
31:03things that that
31:03tells me is that
31:05he couldn't have
31:05known that that
31:06zerk fitting has
31:06taken grease.
31:07You have no idea
31:08that it's clogged.
31:09So we found a
31:11variety of ways in
31:12which mechanics
31:13lubricated this
31:14component and that
31:16gave us some
31:17pause because it's
31:18a very critical
31:18component and if
31:19you don't lubricate
31:20it properly you
31:21could end up with
31:21an accident like
31:22the one that just
31:23happened.
31:24The team discovers
31:26that the methods
31:27Air Alaska
31:27mechanics use to
31:28lubricate the
31:29jackscrew assembly
31:30don't follow
31:31maintenance standards.
31:34The last time the
31:34jackscrew was
31:35lubricated was about
31:36four months before
31:38the accident.
31:38But it's not just
31:42the way the jackscrew
31:43assembly is being
31:44lubricated that
31:45bothers investigators.
31:46It's also the
31:47frequency.
31:48And before that?
31:50January 1999.
31:52They're doing it
31:53every...
31:562,500 hours.
31:59They can see there's
32:01a long period between
32:02lubrications.
32:05Is that even within
32:06regulations?
32:06I'll find out.
32:12We knew we had kind
32:13of a research project
32:14on our hands.
32:15Some of the documents
32:15that we requested from
32:17the manufacturer, from
32:18the FAA, from the
32:19airline came in the
32:20form of internal
32:21memorandums from
32:23engineering departments
32:25or requests from
32:26maintenance to extend
32:28an interval.
32:28It really began to
32:30paint a picture of how
32:32the lubrication
32:34intervals were
32:34extended.
32:36Check it out.
32:44The airline made
32:45multiple requests to
32:47extend the intervals on
32:48the lubrications.
32:51In 1987, the interval
32:55between lubrications
32:56was 500 hours.
32:58The intervals between
33:01lubrications are measured
33:03by the number of hours
33:04the plane is in the air.
33:05In 1991, it goes up
33:09to 1,200 hours.
33:12By 1996, it increases
33:17all the way up to 2,500
33:20hours.
33:21They just continued to
33:26extend, extend, extend,
33:27extend.
33:29Approved by the FAA?
33:30Yeah.
33:31Every one of them was
33:32approved.
33:37Investigators conclude that
33:38the lubrication of jack
33:39screws was not only
33:40conducted poorly, it was
33:42also performed less and
33:44less frequently.
33:44If you're going to extend
33:47these lubrication functions,
33:48then you better be doing
33:50something to make sure
33:50that what you're doing
33:51is correct.
33:52But even if the lubrication
33:55wasn't being done properly,
33:56regular inspections should
33:58have caught the wear on
34:00that Acme nut.
34:01True.
34:02They should have inspected
34:03it regularly.
34:05Was the jack screw
34:06assembly on Flight 261
34:08inspected when and how
34:09it should have been?
34:10We looked at the
34:11maintenance records for
34:12information about the
34:13last check.
34:16I've got something.
34:17Investigators dig deeper
34:22into the records of
34:23Flight 261 to find out
34:25how the jack screw
34:26assembly was inspected.
34:28Yeah, this doesn't look
34:29right to me.
34:31The team finds paperwork
34:33which reveals that during
34:35a routine inspection, a
34:37mechanic at the airline's
34:38Oakland facility observed
34:40that the Acme nut was
34:41badly worn.
34:43You sure the reading is
34:44.040?
34:45A mechanic who did that
34:48wear check reported that
34:50he found it to be at the
34:51limit.
34:54This nut was wearing fast
34:56and something needed to
34:58be done.
35:01The lead mechanic ordered
35:02the nut to be replaced.
35:05This was evidence that
35:06someone had caught the fact
35:07that this Acme nut was
35:09worn out.
35:10Most of the Alliance,
35:11the decision would be we
35:13will get the piece to the
35:14airplane as soon as possible
35:16and replace it.
35:18But the entry is crossed
35:20out.
35:21I don't get it.
35:23Well, when we saw that
35:23they had crossed out the
35:25first entry, it was very
35:26suspicious.
35:27Something was up.
35:28It was fishy to us.
35:30We have to find out what
35:31went on here.
35:31Do you remember inspecting an
35:40MD-83 on September 27th,
35:411997?
35:42I remember it well.
35:45Investigators contact
35:47John Leotin, the lead
35:48mechanic who reported the
35:50worn Acme nut on flight 261.
35:54I wrote up the evaluation.
35:55The 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, at the
36:10very least, must be replaced.
36:14There's no doubt in my mind.
36:16It was the end of my shift.
36:18When I came back the next
36:21work day, the plane was
36:22closed up.
36:25The plane returned to service
36:26with the worn nut.
36:30If the nut had been replaced,
36:32the plane would still be
36:34flying, and 88 people would
36:37still be alive.
36:40How could a maintenance
36:42facility allow the airplane
36:44to be put back into revenue
36:46service with the
36:48the wear that it found
36:49on the Acme nut?
36:52When investigators probe
36:54further, they learn that
36:55the amount of wear on the
36:57Acme nut was rechecked
36:58by other mechanics.
37:00They determined that it was
37:01just within minimum limits.
37:05Alaska Airlines maintenance
37:07misses a warning sign.
37:09The wear on the nut
37:10should at least have been
37:11monitored.
37:12But it wasn't.
37:14The next time that jack
37:15screw was looked at was in
37:17the NTSB laboratory.
37:20The plane flew with the worn
37:22nut for two more years before
37:24it took off from Puerto Vallarta
37:25on the day of the accident.
37:27Gear up.
37:30First officer Tansky and
37:32Captain Thompson had no idea
37:34that their stabilizer was on the
37:36verge of failure.
37:37The team turns to the voice recorder
37:47to find out how the devastating
37:49chain of events unfolded
37:51on board flight 261.
37:59Let's check this out.
38:01Autopilot off?
38:02Good idea.
38:04Good idea.
38:07Whoa!
38:1013 minutes after takeoff from
38:11Puerto Vallarta,
38:13the worn threads in the Acme nut
38:15cause the jack screw to jam,
38:16preventing movement of the
38:18horizontal stabilizer.
38:19Try it again.
38:23The captain's trying to rectify
38:25the jam stabilizer.
38:26While cruising at 31,000 feet,
38:33the CVR picks up the sound of a
38:35click followed by a thumb.
38:38We think that the pilot was moving
38:40his thumb switch on his yoke in an
38:43attempt to move the jack screw
38:45through the nut.
38:45The threads finally give way,
38:51and the jammed jack screw
38:52pulls up through the nut,
38:54causing the stabilizer to move
38:56upwards.
38:57A stopper is all that prevents it
38:59from separating completely.
39:05It got worse.
39:07With the horizontal stabilizer
39:09pushing the nose further down,
39:11the plane goes into a dive.
39:12Through sheer brute force,
39:16the pilots hold the jack screw
39:17in place and recover the plane.
39:22Okay.
39:23It really wants to pitch down.
39:30You feel that?
39:32Stop.
39:33Let's hear that again.
39:36But eight minutes later,
39:37there's another series of thumps.
39:42You feel that?
39:46The stopper holding the jack screw
39:48in place finally gives out.
39:56Push and roll!
39:57The damage to the stabilizer
39:59makes flight 261 uncontrollable.
40:03The plane rolls over
40:04and dives towards the ocean.
40:07Push, push, push, push the blue side up.
40:10Flying upside down,
40:12the crew makes a last-ditch attempt
40:14to right their plane.
40:15Three, two, one.
40:18Speed brakes.
40:22Got it.
40:23The pilots of flight 261
40:25give everything they have
40:26to save the plane.
40:28It was just total professional
40:31fighting for that plane
40:32till the very end,
40:34and they expressed the realization
40:35that the fight was over.
40:38I was sickened
40:54by what I listened on the CBR.
40:59This accident
41:00could have been prevented.
41:01They greased that jack screw.
41:09This doesn't happen.
41:18The amount of money
41:19that would have saved these lives,
41:23it's a cup of coffee.
41:24It's literally a few dollars of grease.
41:31I still get angry about it.
41:35In the wake of the accident,
41:37the intervals between
41:38jack screw lubrications
41:40at Alaska Airlines
41:41is reduced from 2,500 hours
41:43to 650 hours.
41:45We lost 88 people
41:47because of lack of lubrication.
41:51This is a maintenance accident,
41:54pure and simple.
41:56It is truly a tragedy.
42:01It was just one of those cases
42:03that you work on
42:04that's never going to leave you.
42:07Not ever.
42:10It was tough.
42:11Superfood
42:14Panic
42:28Panic
42:33Panic
42:35Panic
42:36Panic
42:38Panic