Speaker 1: Imagine, just for a moment, that you are sitting in
Speaker 1: the cockpit of a one hundred ton commercial airliner.
Speaker 2: Right, You're just cruising comfortably at twenty six thousand.
Speaker 1: Feet exactly the air up there's thin, the temperature outside
Speaker 1: is well below freezing. But inside inside, everything is humming
Speaker 1: along perfectly routine Yeah, until, without warning, the vibrant, glowing
Speaker 1: color instrument panels right in front of you just go
Speaker 1: completely black, and.
Speaker 2: That deafening, reassuring roar of your massive jet engines abruptly
Speaker 2: goes silent.
Speaker 1: You are suspended in this eerie, absolute quiet, and then
Speaker 1: gravity takes hold.
Speaker 2: You're falling. It is absolute nightmare fuel.
Speaker 1: It really is. Welcome to the deep dive. I'm your host,
Speaker 1: and today our mission is to forensically examine the hidden
Speaker 1: catalysts behind five of aviation history's most harrowing flights.
Speaker 2: And as an aviation exit investigator, I can tell you
Speaker 2: the most terrifying part of this scenario is that the
Speaker 2: black box data reveals it almost never takes a massive
Speaker 2: explosion or like a torn off wing to bring down
Speaker 2: a commercial aircraft.
Speaker 1: Right, we expect massive machines to be brought down by
Speaker 1: massive failures but by analyzing real flight transcripts, radar records,
Speaker 1: and metallurgical autopsies, we're going to show you how the
Speaker 1: safety of hundreds of lives often hinges on microscopic details.
Speaker 2: It is deeply unsettling. We see over and over that
Speaker 2: a perfectly functional machine could be brought to its knees
Speaker 2: by an outside intruder so small it completely defies belief.
Speaker 1: Which brings us to our first investigation. The coast of
Speaker 1: the Dominican Republic, February nineteen ninety six.
Speaker 2: It's night, A light rain is falling on the tarmac.
Speaker 2: A Boeing seven five seven operated by Burgonaire as Flight
Speaker 2: three zero one is accelerating down the runway and.
Speaker 1: As I pick up speed, the first officer checks his
Speaker 1: instruments and calls out eighty knots.
Speaker 2: But the captain's airspeed gage is completely dead.
Speaker 1: I mean it is frozen, which is a glaring red flag.
Speaker 1: But the captain makes a fatal, irreversible decision here, right,
Speaker 1: He chooses to continue the time take off.
Speaker 2: Yeah, he does, And the moment that plane lifts off,
Speaker 2: the flight data recorder shows a cockpit plunging into absolute
Speaker 2: sensory overload.
Speaker 1: The autopilot engages, and suddenly the plane starts throwing these
Speaker 1: violently contradictory warnings.
Speaker 2: Right. First, there's a blaring, high pitched clacker. It's an
Speaker 2: overspeed alarm, screaming that they're flying too fast, pushing three
Speaker 2: hundred and fifty knots.
Speaker 1: But immediately following that, the cockpit is filled with an
Speaker 1: even more ominous sound, the violent mechanical rattle of.
Speaker 2: The stick shaker, which is exactly what it sounds like.
Speaker 2: It physically shakes the pilot's control column to warn them
Speaker 2: they're flying much too slow.
Speaker 1: Right, it means the air is separating from the wings
Speaker 1: and they are about to stall and fall out of
Speaker 1: the sky.
Speaker 2: So to understand this mechanical death trap, you have to
Speaker 2: look at how a plane actually knows its speed. It
Speaker 2: uses pitto tubes.
Speaker 1: Those little hollow metal probes on the outside of the
Speaker 1: nose right exactly.
Speaker 2: They measure ram air pressure against static air pressure. As
Speaker 2: you go faster, more air rams into the tube.
Speaker 1: But if that tube gets plug lugged, the air inside
Speaker 1: gets trapped.
Speaker 2: Right, and as the plane climbs into thinner air, that
Speaker 2: trapped pressurized air essentially tricks the sensors. The computer thinks
Speaker 2: the plane is accelerating to dangerous speeds even though it's
Speaker 2: actually slowing down.
Speaker 1: So the autopilot was receiving the captain's faulty two fast reading,
Speaker 1: and to slow the plane down, it pitched the nose
Speaker 1: up to fifteen degrees, acting like a giant.
Speaker 2: Air brake, and the captain, who is just completely bewildered
Speaker 2: by the contradictory alarms, reacted only to the overspeed warning.
Speaker 1: He pulled the throttles back.
Speaker 2: Yes, instead of pointing the nose down to gain lift,
Speaker 2: he slowed them down even more. The heavy seven to
Speaker 2: five seven stalled, rolled hard to the right, and plunged
Speaker 2: directly into the pitch black ocean.
Speaker 1: One hundred and eighty nine people died. Okay, let's unpack
Speaker 1: this because it's maddening to read that cockpit transcript.
Speaker 2: It really is.
Speaker 1: It's like having your car speedometer brake while you're on
Speaker 1: the highway, and instead of trusting your passengers working GPS,
Speaker 1: you just slam on the brakes in the fast lane.
Speaker 1: That is a perfect analogy, because the first officer's gauge
Speaker 1: was working perfectly the entire time it showed they were
Speaker 1: flying dangerously slow. Why didn't he just take the controls.
Speaker 2: It comes down to a lethal combination of cockpit culture
Speaker 2: and hierarchy. You have a junior first officer sitting next
Speaker 2: to a highly revered veteran captain.
Speaker 1: The transcript shows him offering pentitive suggestions right softly saying
Speaker 1: nose downs or yeah, but.
Speaker 2: He never physically takes the yolk. Deference to authority overrode
Speaker 2: his own instruments.
Speaker 1: But the true catalyst here is why the captain's gauge
Speaker 1: failed in the first place.
Speaker 2: Right, The forensic autopsy of those external POTO tubes revealed
Speaker 2: the culprit. The plane had sat on the tarmac for
Speaker 2: three weeks without the bright red protective covers over the.
Speaker 1: Sensors, and in that time, a tiny mud dauber wasp
Speaker 1: built a hard mud nest inside the tube. A single
Speaker 1: insect defeated a multi million dollar piece of aviation technology.
Speaker 2: It's a terrifying example of biology completely overriding machine. But
Speaker 2: in our next the machine was defeated by a simple
Speaker 2: human math.
Speaker 1: Error, forcing the pilots into the ultimate test of airmanship.
Speaker 2: Exactly, which takes us back to the exact scene we
Speaker 2: painted at the start of our deep dive. July nineteen
Speaker 2: eighty three, Air Canada Flight one four.
Speaker 1: To three, a brand new Boeing seven six seven flying
Speaker 1: at forty one thousand feet. Suddenly warning lights flash, the
Speaker 1: left engine fails.
Speaker 2: Then the right engine spools down to total silence.
Speaker 1: The cockpit goes totally dark. First Officer Maurice Quintel says,
Speaker 1: holy cow, I'm talking to a dead man.
Speaker 2: And the root cause here was a perfect storm of
Speaker 2: technical glitches and human miscalculation. The plane's fuel gauge processor
Speaker 2: had a microscopic faulty solder.
Speaker 1: Joint, so the ground crew had to calculate the fuel
Speaker 1: load manually. But Canada was transitioning to the metric system
Speaker 1: at the.
Speaker 2: Time, right so ground crews mistakenly calculated the fuel in
Speaker 2: pounds instead of kilograms.
Speaker 1: A pound is roughly half a kilogram. The plane needed
Speaker 1: twenty two thy three hundred kilograms of fuel to reach Edmonton,
Speaker 1: but it.
Speaker 2: Was loaded with twenty two three hundred pounds, exactly half
Speaker 2: of what it needed.
Speaker 1: So they literally ran the tank's bone dry at forty
Speaker 1: one thousand feet, and a plane that size doesn't just
Speaker 1: loose thrust, it loses its primary electrical and hydraulic power.
Speaker 2: You cannot steer a ninety five ton jetliner without hydraulics.
Speaker 2: The controls are far too heavy, but Boeing installed a
Speaker 2: tiny emergency propeller called a ram air turbine or a RAT.
Speaker 1: Here's where it gets really interesting. Think of the RAT
Speaker 1: like a hidden blade and a Swiss army knife. It
Speaker 1: drops into the slip stream to provide basic hydraulic power.
Speaker 2: Right The sheer force of the air rushing past the
Speaker 2: falling plane physically cranks a pump to power the steering cables.
Speaker 1: But without engines, they still didn't have a working transponder.
Speaker 1: They vanished from air traffic control screens.
Speaker 2: Controllers actually had to use old fashioned primary radar, just
Speaker 2: bouncing radio waves off raw metal to find them.
Speaker 1: So imagine you're the pilot. You're coming in far too
Speaker 1: high and fast over a decommissioned airbase in Gimli. How
Speaker 1: do you lay and a metal glider of that size.
Speaker 2: You do something commercial pilots are never trained to do.
Speaker 2: Captain Bob Pearson happened to be a glider pilot. He
Speaker 2: realized they would overshoot the runway, so he executed a forward.
Speaker 1: Slip, which means he radically crossed the controls right rudder
Speaker 1: one way, ailerons the other exactly.
Speaker 2: He essentially threw a massive passenger jet into a sideways
Speaker 2: freefall to create drag without gaining forward speed.
Speaker 1: Passengers were looking out the windows and seeing the ground
Speaker 1: staring straight back at them.
Speaker 2: Yeah, they landed on a dragstrip, blew two tires, scraped
Speaker 2: the nose gear, and stopped just short of two boys
Speaker 2: on bicycles.
Speaker 1: The Gimli crew managed to overpower their disabled machine. But
Speaker 1: what happens when the machine takes on a mind of
Speaker 1: its own and actively fights the pilot.
Speaker 2: That brings us to the terrifying mystery of the Boeing
Speaker 2: seven three seven rudder.
Speaker 1: Let's talk about United five eight five in Colorado Springs
Speaker 1: in nineteen ninety one and US Air four two seven
Speaker 1: in Pittsburgh in ninety four.
Speaker 2: In both cases, these planes were on a perfectly normal
Speaker 2: final approach, engines fully functional. Then suddenly they violently rolled
Speaker 2: over and plunged straight into the ground.
Speaker 1: Ten seconds from normal flight to complete obliteration. One hundred
Speaker 1: and fifty seven dead across both crashes.
Speaker 2: Investigators honed in on the dual servo valve inside the
Speaker 2: power control unit or PCU.
Speaker 1: That's essentially the power steering for the rudder, right, yeah.
Speaker 2: Yes, they suspected debris might be jamming the delicate metal
Speaker 2: slides inside this valve, causing the rudder to lock fully
Speaker 2: to one side a hard over, but.
Speaker 1: The manufacturer claimed internal filters would stop any debris. And wait,
Speaker 1: I've read the forensic reports on USIR four to seven. Right,
Speaker 1: if the valve jammed from debris violently enough to crash
Speaker 1: a jet, wouldn't investigators find physical scratch marks on the
Speaker 1: metal slides?
Speaker 2: You would think so, Yeah, But for five years they
Speaker 2: found absolutely nothing under the microscopes, zero scratches.
Speaker 1: Which is baffling. Until nineteen ninety six when East Wind
Speaker 1: flight five one seven rolled over in Richmond but miraculously survived.
Speaker 2: A pilot reported he stood on the rudder pedal with
Speaker 2: all his weight, but it felt like it was set
Speaker 2: in concrete. It would move.
Speaker 1: So they finally had an intact airplane and a living pilot.
Speaker 2: What's fascinating here is what they did next. They took
Speaker 2: that exact valve and subjected it to a gruesome torture
Speaker 2: test in Valencia, a thermal shock.
Speaker 1: Test, because these valves operate in extreme temperatures exactly.
Speaker 2: They froze the valve with liquid nitrogen to mimic high
Speaker 2: altitude cold, then blasted it with superheated hydraulley fluid.
Speaker 1: And because the inner slide and outer casing were different metals,
Speaker 1: they swelled at different rates. The valve jammed perfectly metal.
Speaker 2: On metal, but since it was thermal expansion, it left
Speaker 2: no scratch marks behind.
Speaker 1: Which explains the lack of physical evidence.
Speaker 2: But the truly horrific discovery was that the pressure spiked
Speaker 2: so hard it bypassed the normal channels. The valve actually
Speaker 2: reversed itself.
Speaker 1: Wow, So when the us OR pilot pushed the pedal
Speaker 1: to correct the plane from a gust of.
Speaker 2: Wind, the reversed valve took that command in st teared
Speaker 2: him directly into the ground. The hydraulic brain turned his
Speaker 2: survival instincts into a death sentence.
Speaker 1: It took a decade to find that hidden flaw, but
Speaker 1: our next investigation uncovers a flaw the manufacturer knew about
Speaker 1: before the plane even crashed.
Speaker 2: You nineteen seventy two American Airlines Flight ninety six a DC.
Speaker 1: Ten, the explosive blowout of the rear cargo door over
Speaker 1: windsor the cabin floor collapsed into the cargo hold, severing
Speaker 1: the flight cables.
Speaker 2: Captain Bryce McCormick miraculously landed using only engine thrust to.
Speaker 1: Steer, but the institutional failure here is staggering. The NTSB
Speaker 1: demanded an airwordiness directive to redesign the outward opening door, which.
Speaker 2: Would have grounded the fleet, so instead the FAA made
Speaker 2: a gentleman's agreement with McDonald Douglas to fix it voluntarily, and.
Speaker 1: It wasn't done properly, which leads to nineteen seventy four
Speaker 1: Turkish Airlines Flight nine to eighty one in Paris.
Speaker 2: An illiterate baggage handler forced the cargo lever closed. The
Speaker 2: pins didn't engage, but the warning light turned off anyway.
Speaker 1: At twelve thousand feet, the door blue the floor collapsed,
Speaker 1: destroying all hydraulics. Three hundred and forty six people died.
Speaker 2: It was completely preventable.
Speaker 1: So what does this all mean? During the lawsuits, journalists
Speaker 1: discovered the applegate memo.
Speaker 2: Oh, that memo is chilling.
Speaker 1: The manufacturer knew about the explosive decompression risk two years
Speaker 1: before the first incident. It's a tragic example of tombstone technology.
Speaker 2: Waiting for fatalities to justify safety expenses.
Speaker 1: Right, regulatory bodies are supposed to protect us from corporate negligence,
Speaker 1: But what happens when the regulators themselves intentionally disable a
Speaker 1: safety net.
Speaker 2: Look at August nineteen ninety seven Korean air flight eight
Speaker 2: zero one, approaching Guam at one thirty in the morning
Speaker 2: in heavy rain.
Speaker 1: The airport's glide slope is under repair.
Speaker 2: And the tired captain flying on the backside of the
Speaker 2: clock saw his unusable glide slope indicator flicker to life
Speaker 2: due to spurious radio signals.
Speaker 1: Relying on this false data, he descended three miles too
Speaker 1: early and crashed into Nimitz Hill.
Speaker 2: But the airport had a minimum Safe Altitude Warning radar
Speaker 2: system and MSIW designed to alert controllers if a plane
Speaker 2: was too low.
Speaker 1: So why didn't it go off?
Speaker 2: If we connect this to the bigger picture, the FAA
Speaker 2: had intentionally altered the software.
Speaker 1: Wait, they altered the safety software.
Speaker 2: Yes, because the alarm gave too many nuisance warnings near
Speaker 2: the hilly airport. They pushed its perimeter eighty kilometers out
Speaker 2: to see.
Speaker 1: They muffled the very system meant to save them, just
Speaker 1: to avoid annoyed.
Speaker 2: Controllers exactly, and the crash was horrific.
Speaker 1: Survivor Barry Small only lived because his broken legs stopped
Speaker 1: him from moving forward while others were trapped by seat crossbars.
Speaker 2: And he's still fighting today to change those seat designs
Speaker 2: and remove overhead duty free.
Speaker 1: Alcohol which fueled the intense cabin fire that night. It's
Speaker 1: just staggering. When we look at all these cases, we
Speaker 1: see the fragile chain of aviation safety.
Speaker 2: It's an ongoing war against the tiniest vulnerabilities, from.
Speaker 1: The biological anomaly of a wasp to human math error's
Speaker 1: microscope bic thermal jams, and the hubris of corporate and
Speaker 1: regulatory bodies.
Speaker 2: As our planes become increasingly automated, designed to calculate everything
Speaker 2: for us, we really have to wonder if we are
Speaker 2: engineering the pilot out of the equation.
Speaker 1: Entirely, which is a terrifying thought to leave you with.
Speaker 1: If a computer trusts blocked sensor over human intuition, we
Speaker 1: have to ask ourselves in the flight decks of the future,
Speaker 1: who is actually flying the plane