Speaker 1: So I want you to close your eyes for a
Speaker 1: second and put yourself in a very specific place. Picture this.
Speaker 1: You are sitting in the cabin of a massive Boeing
Speaker 1: seven forty seven, four hundred.
Speaker 2: Oh yeah, the Queen of the Skies.
Speaker 1: Exactly, the Queen of the skies. You are cruising at
Speaker 1: thirty five thousand feet and you know, looking out your
Speaker 1: window there is nothing but the pitch black, freezing expanse
Speaker 1: of the Bearing Sea below you.
Speaker 2: That's a lonely place.
Speaker 1: To be, it really is. It's past five pm. The
Speaker 1: dinner trays have just been cleared away by the flight attendants,
Speaker 1: and all around you, three hundred and eighty six passengers
Speaker 1: are settling in, pills are being fluffed, reading lights are
Speaker 1: clicking off.
Speaker 2: Right. It's just that quiet, comfortable monotony of a long
Speaker 2: haul flight Detroit to Japan.
Speaker 1: Right, noyep, Detroit to Japan. And it's total serenity. Until
Speaker 1: suddenly that serenity is completely shattered out of nowhere. The
Speaker 1: plane takes a violent, aggressive lurch.
Speaker 2: Wow.
Speaker 1: Yeah, the floor just drops out from under you, and
Speaker 1: the aircraft snaps into a forty degree bank to the left.
Speaker 2: I mean to put that kind of angle into perspective.
Speaker 2: Commercial airliners, in normal comfortable flight, they rarely bank more
Speaker 2: than twenty five degrees during a standard turn right.
Speaker 1: And that's a smooth, controlled motion.
Speaker 2: Exactly a sudden forty degree bank in an aircraft that
Speaker 2: weighs nearly four hundred tons that is incredibly violent. It's
Speaker 2: this terrifying sideways skid that passengers usually only ever feel
Speaker 2: in their worst nightmare.
Speaker 1: And pilots really only experience when they're running like worst
Speaker 1: case disaster simulations. It is the absolute dread of every traveler.
Speaker 2: Oh absolutely so.
Speaker 1: Today on this deep dive, we are stepping out of
Speaker 1: the flight deck and onto the tarmac as aviation accident investigators.
Speaker 1: We're exploring the harrowing true story of Northwest Airlines Flight
Speaker 1: eighty five.
Speaker 2: It's such a wild story.
Speaker 1: It really is. Yeah, will uncover how a microscopic and
Speaker 1: visible failure nearly doomed over four hundred people and how
Speaker 1: sheer raw human ingenuity fought back. Okay, let's unpack this
Speaker 1: because to understand the terror of that moment, we have
Speaker 1: to look at what was happening up in the cockpit
Speaker 1: when the sky suddenly tilted sideways.
Speaker 2: Right, Let's set that scene so up on the flight deck,
Speaker 2: it's actually a time of transition. On these incredibly long
Speaker 2: international flights, airlines use an augmented.
Speaker 1: Crew, meaning they have extra pilots to.
Speaker 2: Rotate exactly two captains, two first officers flying in shifts
Speaker 2: to prevent fatigue. So at this exact moment, the senior crew,
Speaker 2: Captain John Hanson and first Officer David Smith are off duty.
Speaker 2: They're resting in the private crew cabin.
Speaker 1: So who's at the controls?
Speaker 2: At the controls are the fresh relief crew, Junior Captain
Speaker 2: Frank Gibe and first Officer Mike Fagan.
Speaker 1: And I mean these are highly seasoned aviators. Fagan is
Speaker 1: a Vietnam VET with twenty five years of flying experience.
Speaker 1: Guibe has over eleven thousand hours under his belt.
Speaker 2: That's a massive amount of experience.
Speaker 1: Yeah, but when that plane violently rolls, experience only gets
Speaker 1: you so far. The aircraft is shuddering, Guide's an immediate
Speaker 1: reaction is pure muscle memory. He disconnects the autopilot, grabs
Speaker 1: the control yoke, and physically wrestles the wings.
Speaker 2: Level, which is exactly what he's trained to do.
Speaker 1: Right, And my first assumption in that scenario, given the
Speaker 1: violent pull to the left would be a catastrop engine failure.
Speaker 2: Yeah, that is the most logical deduction for a pilot
Speaker 2: to make in that split second asymmetrical thrust from a
Speaker 2: blown engine or worse, an engine separating from the wing
Speaker 2: that will violently pull a plane to one side.
Speaker 1: But a rapid scan of the engine instruments tells them
Speaker 1: a totally different story. The engines are perfectly fine. They
Speaker 1: are delivering full symmetrical power, which is wild right. Yet
Speaker 1: Guib and Fagan are still fighting with every ounce of
Speaker 1: upper body strength they have just to keep the wings
Speaker 1: from rolling over again. And then the central warning system
Speaker 1: shines in with a diagnosis. The screen just reads yaw,
Speaker 1: damp or lower oof.
Speaker 2: That specific warning is shilling. It tells the crew that
Speaker 2: the lower rudder of this massive seven forty seven has
Speaker 2: suffered a heart over, meaning it's jammed exactly for a
Speaker 2: reason they cannot yet fathom. The massive vertical control surface
Speaker 2: on the tail has violently deflected seventeen degrees to the
Speaker 2: left and it has locked completely in place.
Speaker 1: For anyone familiar with aerodynamics, you know, the rudder controls yaw,
Speaker 1: the nose pointing left or right. But a seventeen degree
Speaker 1: hard over at thirty five thousand feet isn't just a turn.
Speaker 1: It induces a massive aerodynamic slip.
Speaker 2: It's brutal on the airframe.
Speaker 1: Yeah, the aircraft is literally flying slightly sideways through the
Speaker 1: jet stream. To put it's simply, it's basically like a
Speaker 1: race car driver skidding sideways through a turn.
Speaker 2: That's a really good analogy, right.
Speaker 1: The nose is pointing one way, but the sheer momentum
Speaker 1: of four hundred tons of metal is pushing it in.
Speaker 2: Another, and the drag profile is just immense. The plane
Speaker 2: is no longer cutting efficiently through the air. It is
Speaker 2: acting like a massive air brake on one side, which
Speaker 2: creates severe structural stress on the vertical stabilizer.
Speaker 1: And the crew knows exactly how lethal this is, right
Speaker 1: because less than a year prior, an American Airlines airbus
Speaker 1: crashed in New York after catastrophic stress on its rudder
Speaker 1: system ripped the vertical stabilizer completely off the plane.
Speaker 2: Yeah, that was heavily on the minds of every pilot
Speaker 2: flying at that time.
Speaker 1: So they are wrestling a skidding, massive aircraft that is
Speaker 1: actively trying to flip itself over. Now knowing modern aviation,
Speaker 1: there is a checklist for every conceivable disaster. Boeing builds
Speaker 1: binders thicker than phone books.
Speaker 2: Oh for sure.
Speaker 1: So they just open the manual to the stuck rudder page. Right, Yeah,
Speaker 1: I imagine Fagan immediately flits to the rudder hard overtab
Speaker 1: and starts pulling circuit breakers to reset the system.
Speaker 2: Well, what's fascinating here is there is no page for this.
Speaker 1: Wait, really, there is no procedure none.
Speaker 2: You'd assume Boeing has a checklist for everything, but when
Speaker 2: Fagan cracks open that manual hoping for a lifeline, he
Speaker 2: finds almost nothing. There is no procedure for a rudder
Speaker 2: hard over at cruising altitude because mathematically it isn't supposed
Speaker 2: to happen.
Speaker 1: That is terrifying.
Speaker 2: It gets worse. The manual simply offers a single terrifying
Speaker 2: piece of advice, do not remove any pressure from the
Speaker 2: hydraulic system.
Speaker 1: Wait. Wait, it just says keep the hydraulics on and
Speaker 1: leaves them to figure out the rest.
Speaker 2: That is the extent of the guidance. They are entirely offscript.
Speaker 2: The engineering logic is that shutting off the hydraulics might
Speaker 2: cause the rudder to flutter wildly in the slipstream, which
Speaker 2: would tear the tail apart. Oh I see, yeah, So
Speaker 2: they have to leave the system fully pressurized, which means
Speaker 2: they are physically fighting the three thousand pounds per square
Speaker 2: inch of hydraulic pressure that is keeping that rudder locked
Speaker 2: in place.
Speaker 1: Which accelerates their next massive problem. Because they are plowing
Speaker 1: sideways through the sky, generating incredible drag, they have to
Speaker 1: maintain much higher engine thrust just to stay airborne.
Speaker 2: Right, they're burning fuel like crazy, exactly.
Speaker 1: They're burning through their fuel at an unsustainable rate. They
Speaker 1: need a run away, and they need it immediately. But
Speaker 1: a quick look at the navigation charts shows they are
Speaker 1: in a geographical nightmare.
Speaker 2: Yeah, they are deep over the Northern Pacific. They make
Speaker 2: the critical decision to turn back toward Anchorage, Alaska, but
Speaker 2: that safe harbor is thirteen hundred kilometers.
Speaker 1: Away, and they're in a dead zone. Right.
Speaker 2: Adding to the nightmare, they are in a communications dead zone.
Speaker 2: Standard very high frequency or VHF radios rely on line
Speaker 2: of sight. They are far too distant from any land
Speaker 2: based antenna to reach air traffic control.
Speaker 1: I mean, you are fighting for your life gripping the
Speaker 1: yolk with white knuckles, and when you key the microphone
Speaker 1: to declare an emergency, you get dead air.
Speaker 2: Talk about feeling isolated, right.
Speaker 1: So they ultimately had to rely on a relay system.
Speaker 1: They found another Northwest flight Flight nineteen that was closer
Speaker 1: to the Alaskan coast and started bouncing their distress calls
Speaker 1: off that aircraft, just to get word to anchorage that
Speaker 1: they are declaring a red emergency.
Speaker 2: And while that radio drama unfolds, the physical reality inside
Speaker 2: the cockpit is crossing the threshold of human endurance. Senior
Speaker 2: Captain John Hanson returns to the flight deck and takes command.
Speaker 1: Thank goodness.
Speaker 2: Yeah, but because of the plane desperately wants to spiral
Speaker 2: out of the sky to the left, the pilots have
Speaker 2: to input maximum opposite controls.
Speaker 1: This is where the biomechanics of this situation become horrifying.
Speaker 1: We aren't talking about holding a steering wheel slightly off center, No,
Speaker 1: not at all. They are locking their right leg out
Speaker 1: completely straight, driving their full body weight into the right
Speaker 1: rudder pedal, and using their backs and shoulders to wrench
Speaker 1: the control yoke to the right.
Speaker 2: The muscular strain is so severe that lactic acid builds
Speaker 2: up almost instantly, muscles begin to violently cramp and shake.
Speaker 2: A single pilot can only maintain that immense physical pressure
Speaker 2: for about ten to fifteen minutes before their body simply
Speaker 2: gives out.
Speaker 1: Wow, only ten minutes.
Speaker 2: Yeah, So Hanson and Fagan are forced to choreograph this
Speaker 2: highly dangerous dance where they swap control. One physically exhausted
Speaker 2: pilot carefully hands the immense structural tension over to the other,
Speaker 2: shakes out his cramped limbs, and prepares to take the
Speaker 2: burning back a few minutes later.
Speaker 1: That is just grueling, and meanwhile the atmosphere in the
Speaker 1: main cabin is deadly serious. Captain Guive steps out to
Speaker 1: brief the lead flight attendants. He looks them in the
Speaker 1: eye and tells them it's a red emergency, which.
Speaker 2: Means they have to prepare for the worst.
Speaker 1: Exactly that means preparing the cabin for a high speed crash, landing,
Speaker 1: structural failure, or evacuation. Those flight attendants then have to
Speaker 1: walk out into the aisles, look three hundred and eighty
Speaker 1: six terrified passengers in the face, and calmly demonstrate how
Speaker 1: to brace for impact.
Speaker 2: It requires an unbelievable level of compartmentalization. But back in
Speaker 2: the cockfit, the flight crew realizes that brute strength isn't
Speaker 2: going to get them on the ground safely.
Speaker 1: Right. They can't just muscle it all the way down.
Speaker 2: No, they're flying blind. Procedurally, they need engineering help to
Speaker 2: invent a solution that doesn't exist in any manual.
Speaker 1: And here's where it gets really interesting. This is when
Speaker 1: they resort to the high frequency or HF radio to
Speaker 1: reach the Northwest system's operation center back in Minnesota.
Speaker 2: Now, HF radio is an archaic, frustrating technology. It works
Speaker 2: by bouncing signals off the Earth's ion a sphere. It
Speaker 2: is notoriously weak, drifting, and staticky.
Speaker 1: It sounds basically like two Campbell's soup cans connected by
Speaker 1: a string.
Speaker 2: Right, Yeah, pretty much. But through this crackling wall of
Speaker 2: noise they manage to get a hold of John Doherty,
Speaker 2: a lead seven four seven one four hundred expert at Northwest.
Speaker 2: Doherty was actually at home relaxing when his pager went off,
Speaker 2: thrusting him into this high altitude puzzle.
Speaker 1: So Doherty is on this awful radio connection trying to
Speaker 1: troubleshoot a plane he can't even see, and because the
Speaker 1: aircraft is violently shaking from the aerodynamic stress of the slip,
Speaker 1: Captain Hansen decides to descend to fourteen.
Speaker 2: Thousand feet, which makes sense on paper.
Speaker 1: The logic seems perfectly sound. Right drop to a lower
Speaker 1: altitude where the air is denser, providing more lift and
Speaker 1: theoretically better control surface authority. But instead they walk right
Speaker 1: into a bizarre physics trap.
Speaker 2: A trap built entirely by the plane's automated systems. As
Speaker 2: they descend, they naturally begin to slow down their air speed,
Speaker 2: but the rudder's hydraulic system on A seven forty seven
Speaker 2: features a mechanism designed to protect the tail at high speeds.
Speaker 1: Okay, I think I see the mechanism here. It's an
Speaker 1: aerodynamic blowdown limit exactly.
Speaker 2: It limits how far the rudder can physically move when
Speaker 2: the plane is flying fast like mock point eighty five,
Speaker 2: because a full deflection at that speed would rip the
Speaker 2: tail off right.
Speaker 1: So, when they are flying fast, the sheer physical force
Speaker 1: of the air hitting the rudder is stronger than the
Speaker 1: hydraulic pump. The air pushes back against the jam, but
Speaker 1: as they slow down.
Speaker 2: The aerodynamic pressure decreases, the force of the air pushing
Speaker 2: back against the rudder weakens, but the hydraulic pump is
Speaker 2: still pushing at an unrelenting three thousand psi.
Speaker 1: Oh no, so as the plane slows, the hydraulics win
Speaker 1: the tug of war.
Speaker 2: They do, the jammed piston extends even further to its
Speaker 2: new limit. The slower they fly, the further left the
Speaker 2: rudder forces itself. It actively makes the aircraft harder to control.
Speaker 2: The closer they get to the ground.
Speaker 1: That is a terrifying feedback loop, which means they can't
Speaker 1: just deer with the wings anymore. The drag is two
Speaker 1: immense So what do they do. They have to rely
Speaker 1: on asymmetrical thrust. They push the throttles up on the
Speaker 1: left wings engines and pull the throttles back on the
Speaker 1: right wings engines. It's essentially using the massive power of
Speaker 1: those Pratt and Whitney engines to overpower the aerodynamic drag
Speaker 1: of the tail.
Speaker 2: Steering the plane through raw thrust vectors.
Speaker 1: Yeah, it's like paddling a canoe on only one side
Speaker 1: to force it to go straight.
Speaker 2: That's spot on, But it requires incredible anticipation. Because jet
Speaker 2: engines have spool up and spool down lag. You can't
Speaker 2: just snap them into power like a car engine.
Speaker 1: No, it takes a few seconds for the engines to react. Right.
Speaker 2: It is brilliant improvised airmanship, but it leads them to
Speaker 2: the most dangerous phase of the entire ordeal. They are
Speaker 2: finally approaching anchorage, surrounded by the towering, snow capped Alaskan
Speaker 2: mountains and the freezing waters of cook Inlet.
Speaker 1: Right, So they're threading a needle with a four hundred
Speaker 1: ton aircraft that wants to fly sideways, and the margin
Speaker 1: for error is absolute zero.
Speaker 2: It's literally zero. In a normal aviation scenario, if a
Speaker 2: landing looks unstable, if a gust of wind catches them,
Speaker 2: or they aren't lined up perfectly, a pilot will simply
Speaker 2: push the throttles forward, execute a go around, and circle
Speaker 2: back to try again.
Speaker 1: But with locked rudder applying maximum takeoff thrust to execute
Speaker 1: a go around would be a death end sentence, wouldn't it.
Speaker 1: Absolutely The asymmetrical power needed, combined with the extreme drag
Speaker 1: would likely roll the aircraft completely over.
Speaker 2: It would induce an uncontrollable spin. They have exactly one
Speaker 2: shot to put this crippled jet squarely on the runway
Speaker 2: numbers wow. So to maintain control authority over that aggressively
Speaker 2: deflected rudder, Dougherty on the ground suggests they carry extra speed.
Speaker 2: They add twenty knots to their approach speed. They're coming
Speaker 2: in extremely hot, burning up precious runway distance.
Speaker 1: I want to paint the picture of these final seconds.
Speaker 1: You are in the cabin. You've been in the brace
Speaker 1: position for twenty minutes. You were staring at your knees,
Speaker 1: listening to the deafening roar of the engines constantly spooling
Speaker 1: up and down as the pilots fight the yaw.
Speaker 2: It must have been horrifying back there.
Speaker 1: Right and upfront. The concrete of the runway is rushing
Speaker 1: at the cockpit at over three hundred kilometers per hour,
Speaker 1: and there is a deadly mechanical booby trap waiting for
Speaker 1: them the millisecond the wheels.
Speaker 2: Touched the tarmac, and that trap is the mechanical linkage
Speaker 2: between the rudder pedals and the nosewheel steering to help
Speaker 2: pilots steer on the ground. The systems are connected, oh.
Speaker 1: Man, So that seventeen degree rudder deflection locked into the
Speaker 1: pedals is going to instantly command the nose wheel to
Speaker 1: yank the plane violently off the runway the moment it
Speaker 1: makes contact.
Speaker 2: YEP at three hundred kilometers an hour, veering into the
Speaker 2: grass would shear the landing gear off, rupture the fuel tanks,
Speaker 2: and destroy the aircraft.
Speaker 1: To survive this, Fagan and Hans and orchestrate a terrifying
Speaker 1: split second handover right. At the moment of touchdown, Fagan
Speaker 1: takes sole control of a yoke, focusing entirely on fighting
Speaker 1: the crosswinds and keeping the massive wings level.
Speaker 2: It's all about timing here, exactly.
Speaker 1: Because the instant the main landing gear hits the concrete,
Speaker 1: Hanson aggressively grabs the nose tiller, which is the small
Speaker 1: steering wheel next to his left hip, and physically overpowers
Speaker 1: the hydraulic urge to veer left, slamming on the brakes.
Speaker 2: The coordination required is superhuman, and against all the physical
Speaker 2: variables fighting them, it works, thank goodness. The heavy anti
Speaker 2: skid breaking, the violent screech of the tires, the sheer
Speaker 2: physical willpower of those two men keeps the massive jet
Speaker 2: on the center line until it finally grinds to a halt.
Speaker 2: All four hundred and four people on board are entirely safe.
Speaker 1: The silence in that cockpit after the engine spun down
Speaker 1: must have been deafening. A guaranteed catastrophe completely averted. But
Speaker 1: while the passengers slide down the emergency choots and eventually
Speaker 1: get to go home, the NTSB investigators are just waking up.
Speaker 2: Yeah, their job is just starting right.
Speaker 1: They have a four hundred ton engineering mystery sitting on
Speaker 1: a runway in Alaska. What invisible flaw nearly brought the
Speaker 1: Queen of this Guy's down?
Speaker 2: While the NTSB dispatches a specialized team led by investigators
Speaker 2: Carolyn de Forge and Sylvie Dion. When they finally get
Speaker 2: a lift up to examine the towering tail section of
Speaker 2: the aircraft, the first clue is glaringly obvious.
Speaker 1: What did they find?
Speaker 2: A massive trail of red hydraulic fluid leaking down the
Speaker 2: internal bulkheads. They trace that leak directly to a component
Speaker 2: called the power control module or PCM.
Speaker 1: Which is the hydraulic cart that takes the pilot its
Speaker 1: input and physically moves the rudder exactly And the source
Speaker 1: of the failure is almost absurdly small. On this massive module,
Speaker 1: there is an end cap. It's just a circular piece
Speaker 1: of machined aluminum about two point five inches in diameter,
Speaker 1: and it had completely sheared off.
Speaker 2: It fractured right at the threads, and when that cat
Speaker 2: blew off under immense pressure, the hydraulic piston inside the
Speaker 2: module shot out completely past its design limits, firmly jamming
Speaker 2: the rudder at seventeen degrees, and.
Speaker 1: The metallurgical analysis revealed the culprit was pure unadulterated metal.
Speaker 2: Fatigue, which is an explanation that sent absolute shockways through
Speaker 2: the engineering world.
Speaker 1: Because aviation parts aren't just built to look sturdy, they
Speaker 1: are governed by incredibly strict mathematical models. This specific aluminum
Speaker 1: alloy module was engineered with a meantime before failure and
Speaker 1: MTBF of thirty thousand years.
Speaker 2: Yeah, that number is wild.
Speaker 1: I mean, human civilization was painting caves thirty thousand years ago.
Speaker 1: How do you even calculate a lifespan that outlasts the
Speaker 1: next ice age for a plane that just wants to
Speaker 1: fly from Detroit to Japan.
Speaker 2: Well, it's based on mathematical fatigue cycles. They calculate the
Speaker 2: maximum structural load of part will experience on an average
Speaker 2: flight and build a safety margin so massive that the
Speaker 2: metal should technically never yield, right. It was designed to
Speaker 2: outlast the physical air bout hundreds of times over.
Speaker 1: So wait, if a part mathematically modeled to last thirty
Speaker 1: millennia suddenly shatters midflight in a fraction of that time,
Speaker 1: my mind immediately goes to external damage. Did a mechanic
Speaker 1: drop a wrench on it? Did it get scored during installation?
Speaker 2: The investigators hunted for exactly that kind of anomaly. They
Speaker 2: dug into the intricate maintenance logs of this specific tail
Speaker 2: number and discovered a massive revelation, which was this was
Speaker 2: not a standard seven four to seven four hundred. Northwest
Speaker 2: was the launch customer for this variant. This exact aircraft
Speaker 2: was line number one, the very first seven forty seven
Speaker 2: four hundred ever built.
Speaker 1: Wait, really the prototype.
Speaker 2: Exactly I mean to be precise, Before it ever carried
Speaker 2: a single pay passenger. It was utilized by Boeing as
Speaker 2: the primary flight test aircraft WOW. During certification, test pilots
Speaker 2: intentionally subject the airframe to extreme structural stress, high G maneuvers,
Speaker 2: extreme rudder inputs, maximum pressurization cycles, things the commercial jet
Speaker 2: will never experience in normal service.
Speaker 1: So this plane had seen some things definitely.
Speaker 2: By the time of the Anchorage incident, this specific plane
Speaker 2: had endured over fifty five thousand hours of flight and
Speaker 2: more than seven thousand grueling takeoffs and landings.
Speaker 1: It had essentially lived multiple lifetimes in dog years compared
Speaker 1: to the rest of the fleet. The metal was exhausted.
Speaker 1: It was.
Speaker 2: But here is the deeply frustrating part for the NTSB,
Speaker 2: even knowing its violent test history. Extensive metallurgical testing could
Speaker 2: not pinpoint the exact root cause of the fracture.
Speaker 1: Really, none of it.
Speaker 2: None fluorescent dyes, ultraviolet lights, electron microscopic analysis, none of
Speaker 2: it could definitively explain why the metal cracked in that
Speaker 2: exact thread at that exact moment. They ordered rigorous ultrasound
Speaker 2: and inspections for the entire global fleet, but the core
Speaker 2: mystery lingered in the.
Speaker 1: Archives until lightning struck twice in the exact same place.
Speaker 2: Four years later, an Air France cargo plane, which was
Speaker 2: also a seven forty seven four hundred, suffered the exact
Speaker 2: same terrifying lower rudder hard over.
Speaker 1: The NTSB investigators must have fill a cold sweat getting
Speaker 1: that phone call.
Speaker 2: They immediately mobilized to examine the fractured module from the
Speaker 2: Air France plane, and this time under the microscope they
Speaker 2: found a smoking gun.
Speaker 1: And it wasn't just general fatigue this time.
Speaker 2: Right, No, it wasn't general vague fatigue from being a
Speaker 2: test plane. They found a microscopic manufacturing defect. There was
Speaker 2: an incredibly sharp radius at the bottom of the threads
Speaker 2: inside the aluminum.
Speaker 1: Cap a stress concentrator.
Speaker 2: Precisely a tiny, nearly invisible flaw in how the metal
Speaker 2: was cut on a Lathe caused all the hydraulic stress
Speaker 2: to focus on one microscopic point. It allowed a crack
Speaker 2: to form and slowly propagate over thousands of flights until
Speaker 2: it finally gave way.
Speaker 1: So the Air France failure was a clear manufactur uring defect. Now,
Speaker 1: that didn't technically explain the pure fatigue of the Northwest
Speaker 1: flight four years earlier, but at that point the Federal
Speaker 1: Aviation Administration had seen enough.
Speaker 2: Yeah, two near disasters were two too many to leave
Speaker 2: to chance. The FAA had to act. But grounding the
Speaker 2: entire global fleet of seven forty sevens to hunt for
Speaker 2: phantom microscopic cracks inside sealed hydraulic modules would cause apocalyptic
Speaker 2: economic fallout.
Speaker 1: Oh for sure the industry would grind to a halt,
Speaker 1: so aerospace engineers designed a brilliantly simple fail safe. Instead.
Speaker 1: They mandated that a physical metal plug be installed directly
Speaker 1: over the end cap on every control module.
Speaker 2: Which is such an elegant solution.
Speaker 1: Meaning if the threads fail and that cap ever blows
Speaker 1: off again, this new plug physically blocks the piston from
Speaker 1: sliding out of its housing. It completely stops the rudder
Speaker 1: from jamming into a heart over.
Speaker 2: It neutralizes the threat mechanically without relying on perfect metallurgy.
Speaker 2: But you know, if we connect this to the bigger picture,
Speaker 2: it raises a question investigators rarely have the luxury to ask,
Speaker 2: which is why did they serve previous flights with similar
Speaker 2: rudder failures like US air Flight four twenty seven ended
Speaker 2: in total catastrophic tragedy.
Speaker 1: What made Northwest eighty five different?
Speaker 2: Two critical factors. First, the sheer scale of the Boeing
Speaker 2: seven forty seven. It is so massive that it utilizes
Speaker 2: a split rudder design. There is an independent upper rudder
Speaker 2: and a lower rudder.
Speaker 1: And only the lower one failed.
Speaker 2: Right if the seven forty seven had a single massive rudder,
Speaker 2: one hundred percent of the yaw control would have deflected
Speaker 2: and the plane would have flipped inverted instantly.
Speaker 1: The engineering redundancy saved them, but the humans and the
Speaker 1: loop saved them too.
Speaker 2: Oh totally masterful Crew resource management or CRM. From the
Speaker 2: moment the plane lurched EGO vanished, they communicated flawlessly, They
Speaker 2: utilized their expert on the.
Speaker 1: Ground, and they divided the punishing physical lady exactly, and.
Speaker 2: They trusted each other with their lives during that high
Speaker 2: speed touchdown choreography.
Speaker 1: It is an incredible testament to aviation professionalism. The Airline
Speaker 1: Pilots Association actually awarded the crew of Flight eighty five
Speaker 1: with the Superior Airmanship Award. They looked a guaranteed catastrophe
Speaker 1: in the eye and simply refuse to blink. So what
Speaker 1: does this all mean for you, the listener, Well, it's.
Speaker 2: A sobering reminder of the complex environment we operate in today.
Speaker 2: We fly in an era of pristine mathematical engineering, where
Speaker 2: parts are modeled on supercomputers to last thirty thousand years
Speaker 2: and safety is calculated to the decimal point.
Speaker 1: But Northwest eighty five prove that mathematical perfection is an
Speaker 1: illusion when it meets the chaotic imperfect physical world, test
Speaker 1: plane stresses, microscopic manufacturing anomalies, invisible cracks propagating in the dark.
Speaker 2: It's a lot to think about, it really is.
Speaker 1: We trust these mathematical models implicitly every time we bore
Speaker 1: a flight. But when the math fails, when the metal snaps,
Speaker 1: and when the manual is completely blank, survival doesn't come
Speaker 1: down to a microchip or an algorithm. It comes down
Speaker 1: to raw, physical human flying skills.
Speaker 2: Are we in danger of losing the art of hand
Speaker 2: flying in our modern obsession with automation? What happens when
Speaker 2: our reliance on perfect, predictive models blinds us to the
Speaker 2: unpredictable realities of the physical world.
Speaker 1: It is a tension that accident investigators and aerospace engineers
Speaker 1: constantly battle to balance. Something to chew on the next
Speaker 1: time you're settling in at thirty five thousand feet, leaning
Speaker 1: your head against the window and drifting off into that serene,
Speaker 1: comfortable darkness.