September 28, 2025 • 23 mins
On a foggy March day in 1977, the tiny Los Rodeos Airport on Tenerife in the Canary Islands became an unintended host to multiple diverted jumbo jets after a terrorist bombing closed their intended destination. Among them were two Boeing 747s: KLM Flight 4805 and Pan Am Flight 1736. What happened next would claim 583 lives and revolutionize aviation safety forever.
The KLM aircraft was piloted by Captain Jacob Veldhuyzen van Zanten, the airline's chief flight instructor and the face of their advertising—a man whose authority went virtually unquestioned. Under pressure from looming duty-time restrictions and deteriorating weather, van Zanten made a fateful decision to take off without proper clearance, despite his flight engineer's hesitant questions. Meanwhile, the Pan Am jet was still taxiing on the same runway, invisible in the thick fog that had enveloped the airport. Without ground radar, the control tower was blind to the impending disaster, and a cruel radio interference blocked the final warnings that might have saved hundreds of lives.
The collision was catastrophic—all 248 aboard KLM perished instantly, while only 61 of the 396 people on Pan Am survived. From this tragedy emerged fundamental changes that have shaped modern aviation: Crew Resource Management training that encourages all cockpit personnel to speak up regardless of rank, standardized communication protocols that eliminate ambiguity, and technological improvements like mandatory ground radar at major airports.
Listen as we dissect this tragic chain of events that reminds us how fragile our systems can be when communication breaks down and assumptions go unchallenged. Follow History's A Disaster on social media and share your thoughts at historysdisaster@gmail.com. Because understanding yesterday's disasters helps prevent tomorrow's tragedies.
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Special thank you to Lunarfall Audio for producing and doing all the heavy lifting on audio editing since April 13, 2025, the Murder of Christopher Meyer episode https://lunarfallaudio.com/
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
SPEAKER_00 (00:01):
March 27th, 1977 was a shitty day to take a vacation.
First, a terrorist bombingcloses the airport you're flying
into, causing your flight to getdiverted to a much smaller
regional airport with a singlerunway over a half hour away.
Foggy conditions on the groundwould end up causing delays, and
(00:22):
add to that, limited technologymeans no one can see a damn
thing.
And that sounds like a recipefor disaster.
And such a disaster it would be,it would go down as the worst
air disaster in history.
So what happened?
I'm Andrew, and this isHistory's A Disaster.
(00:49):
Tonight we are going to theCanary Islands, which is a
collection of seven largeislands and several smaller
ones, considered an autonomousregion of Spain, even though
it's way fucking south of Spain,just off the coast of Morocco.
And despite being volcanic inorigin, it is a tourist
(01:09):
destination for mostly Europeanson holiday.
Being somewhat tropical, it hasa ton of beaches and coastlines
that draw the crowds in.
And in 1977, the largest of theCanary Islands would be the site
of the worst aviation accidentin history.
And tonight's episode is broughtto you by the Flying Ace Can
(01:31):
Opener Company.
For those hard to open cans,nothing slices through the top
of a can like a hot knifethrough butter, quite like a
flying ace.
The morning of March 27th, 1977,began with the routine hum of
two Boeing 747s on theirrespective long haul journeys.
(01:55):
On the tarmac at Amsterdam'sSchiphol Airport, and I know I
did not pronounce that right.
KLM Royal Dutch Airlines Flight4805, a Boeing 747, prepared for
a charter flight to the CanaryIslands.
At the helm was Captain JacobVeldehousen van Zatten, an
(02:16):
experienced and well-respectedpilot, known informally as KLM.
He was not only a captain, butthe company's chief flight
instructor for their entire 747fleet.
This guy was so trusted that hisface was all over KLM's
advertising campaigns.
Aboard this flight were 248passengers and crew, and most of
(02:39):
them were Dutch tourists and 52of them were children.
Meanwhile, flying over theAtlantic, PM Flight 1736, which
was another Boeing 747, was onits final leg from New York's
JFK Airport to the samedestination.
Ran Canaria Airport on theisland of Las Palmas.
(03:02):
Flying the jet was CaptainVictor Grupps, a veteran pilot
with over 21,000 hours of flighttime.
The Pan Am Jumbojet carried 396people.
380 of them were passengers and16 crew members.
It was a long and boring flight,and most of them were looking
forward to being off the planeafter being stuck on it for over
(03:25):
13 hours.
(03:51):
These fucking shitheads werereally showing the Spanish how
serious they were about standingup to them in open conflict to
gain independence for theislands from Spain.
Cause you know, there's nothingthat says ready to fight to the
last man in open conflict thantrying to kill innocent
civilians with a bomb, thefucking cowards.
(04:13):
Anyways, civilian aviationauthorities, in an act of
caution, immediately closed theairport, forcing all incoming
traffic to divert.
A number of large aircraft,including the two Boeing 747s,
were rerouted to the smallerregional airfield of Los Rodos
on the neighboring island ofTenerife.
(04:34):
The PNAM crew asked forpermission to fly a holding
pattern.
They had plenty of fuel tospare, and after having flown
from LA with only a singlestopover in New York, they were
really not looking forward tospending any more time on the
plane than possible.
Their request unfortunately gotdenied and they were forced to
divert to Tenerife.
(04:55):
Los Rodeos was ill-equipped tohandle this sudden surge of
heavy international traffic.
The airport featured a singlerunway, designated runway 1230,
and one main taxiway runningparallel to it.
When the diverted aircraft,which included five large
airliners, arrived, they took upso much space on the main apron
(05:19):
and taxiway that ran parallel tothe runway that they effectively
blocked it for its intendedpurpose.
This forced a highly unusual andinherently dangerous procedure
known as back taxiing orbacktracking, which means
instead of using the dedicatedtaxiway, departing planes were
forced to use the active runwayitself as a taxiway, moving in
(05:42):
the opposite direction of thedesignated takeoff traffic
before having to turn the planearound to take off.
The delay on the ground at LosVerdeos really fucked with the
KLM crew, particularly onCaptain Jacob Van Zanten.
As KLM's chief flight instructorfor the 747, Van Zanten held a
(06:03):
position of near unquestionableauthority, a culture of
seniority that meant the captainwas basically a god within the
cockpit.
And in the documentary Iwatched, he was kind of a dick
too.
With this culture of the captainis always right, no one in the
cockpit felt they could questionhis choices, which really put
(06:24):
First Officer Klaus Moors in abad position.
Captain Van Zanten could make orbreak his career at any time.
So doing anything to piss himoff was probably not a good
idea.
Beyond his professionalstanding, Van Zanten was also
under a more immediate personalburden.
New Dutch government regulationslimiting crew duty time had
(06:48):
recently been enacted.
These restrictions were verystrict and carried the threat of
criminal prosecution ifexceeded, creating a looming
deadline for the crew.
He knew that with the day'scomplications and worsening
weather, his window ofopportunity to get out of
Tenerife before an overnightstay was closing, and he
(07:08):
desperately wanted to get thefuck out of there.
This sense of urgency culminatedin a shitty decision to refuel
the aircraft at Los Rodeos.
This despite the fact thatnormal procedure is to only take
enough fuel to make thescheduled flight plus a little
extra in case of emergencies.
(07:28):
The KLM flight, a short25-minute hop to Los Palmas, did
not require the 55 tons of fuelthat was being loaded.
Van Zanten chose to do this toavoid the inevitable delays of
refueling in a newly reopenedand congested Las Palmas
airport.
(07:51):
The refueling process tookapproximately 35 minutes.
Passengers on the KLM flightwere allowed to de-plane and
reboard.
So instead of sitting in acramped plane, the passengers
got to enjoy sitting in acramped terminal with all the
other people that were stuckthere.
Delaying the plane even longer,they managed to lose a few
(08:13):
passengers, which is a switch.
Normally airlines lose yourluggage.
KLM apparently loses wholepeople.
A family of four had yet to makeit to the plane when reboarding
started.
The two kids had run off toexplore, so they had to run
around searching for them toround them up.
There was also a fifth personthat would not make it to the
(08:35):
plane.
Rabina Van Lanshot was one ofthree tour guides returning to
Teneriff, and she chose not toreturn to the plane.
The three of them were going toTeneriff anyways, so getting
back on the plane meant theywould be flying back to Gran
Canaria just to turn around andcome back to Tenerife.
(08:56):
And she was ready to be donewith the flight and see her
boyfriend.
After discussing it with herfriends who were getting back on
the plane, she snuck off, goingagainst KLM's request that
everyone get back on the plane.
Back on the tarmac, while thePan Am jet was ready to go, it
was now trapped.
Its path to the runwaycompletely blocked by the
(09:17):
stationary KLM plane and itsrefueling vehicle.
The 747 being over 200 feet inwidth didn't have the clearance
to make it around.
They were short by just 12 feet,so they had to wait on KLM to
get their act together and findthe people they misplaced and
take on fuel they didn't need.
(09:39):
As the KLM crew finally finishedits preparations and requested
permission to taxi, the weatherwent to shit rapidly.
A thick low-lying fog, which isa hallmark of the Tenerife
Airport's unique microclimate,rolled in and enveloped the
airfield.
Visibility dropped to less thana thousand feet, far below the
(10:00):
normal required minimums fortakeoff.
And it was so dense that thecontrol tower, which had no
ground radar, could no longersee the runway.
So now both crews were nowoperating completely blind,
forced to rely entirely on asystem of verbal communications
that was already undersignificant stress.
(10:26):
As the KLM 747 back taxi downthe runway, the Pan Am jet
followed at a distance behindit.
At 1702, the Tenerife ControlTower instructed the Pan Am crew
to taxi into the runway and takethe third taxiway.
This instruction, however, waspretty unclear and pretty
(10:49):
problematic.
The third taxiway, designatedCharlie 3, required a difficult
150-degree turn for 747.
And since shit really wasn'tmarked that great, it was
difficult to see in the fog.
The Pan Am crew was confused andconcerned, discussed the matter
(11:09):
in the cockpit, debating whetherthe tower had meant the first or
third exit, and ultimatelydecided to continue taxiing to
the fourth exit, Charlie 4,which offered a more standard 45
degree turn and made more senseto the crew.
The critical breakdown incommunication occurred between
the KLM cockpit and the controltower.
(11:32):
After completing the back taxiand turning 180 degrees to face
the end of the runway, KLM FirstOfficer Moores received and read
back their ATC clearance fortheir flight path.
Now this clearance is onlytelling them their flight path
after takeoff.
Permission for takeoff is acompletely separate event.
(11:54):
However, in a fatal edition, theco-pilot ended his transmission
with the non-standard phrase, weare now at takeoff.
The controller, who had not yetissued a takeoff clearance,
responded with okay, immediatelyfollowed by the crucial
instruction, stand by fortakeoff, I will call you.
(12:16):
But in shithead Van Zanten'smind, the mind of a jackass that
was in a hurry and thought hecould do no wrong, the okay was
a confirmation of his co-pilot'sstatement and the clearance he
was waiting for.
He immediately pushed thethrottles forward and began the
takeoff roll.
A split second later, in amoment of tragic irony, the
(12:39):
system's final defense wasrendered useless.
As the tower said standby fortakeoff, the Pan Am crew
transmitted, and we are stilltaxiing down the runway.
The two messages sent at thesame time overlapped, creating a
high-pitched whistling soundthat blocked both transmissions
(13:00):
in the KLM cockpit.
The final warning, a clearstatement that could have saved
583 lives, was completelyinaudible due to a simple
technical limitation.
In the KLM cockpit, the flightengineer William Schroeder felt
something was wrong and actuallytwice questioned the captain,
asking, is he not clear then?
(13:21):
Van Zanden, with the blindconviction of a man under
pressure, replied, Oh yeah.
His unchallenged authority andthe culture of deference in the
cockpit silenced any furtherquestioning, and the fatal
takeoff run continued.
From within the dense blindingfog, the crews of both aircraft
(13:42):
were suddenly confronted with ahorrific reality.
In approximately 1706, the PanAm crew, whose frantic cockpit
chatter revealed their growingunease, saw the landing lights
of the KLM 747 emerging from themist just 2,000 feet away and
closing fast.
(14:03):
Captain Grubbs yelled into thecockpit voice recorder, pushed
his throttles to full power, anddesperately tried to veer the
massive jet off the runway.
In the KLM cockpit, Van Zanton,having committed to the takeoff,
saw the lights of the Pan Am jetahead too late.
They were going way too fast tostop and not quite fast enough
(14:24):
for takeoff.
He pulled back on the yoke withfull force, trying to get his
aircraft airborne and clear theobstacle, but the attempt was
too late and too violent.
The aircraft tail dragged forover 60 feet along the runway
due to its high angle of attack.
The KLM 747 barely got off theground.
(14:52):
When it did leave the ground,its nose landing gear cleared
the Pan Am, but its left sideengines, lower fuselage, and
main landing gear struck theupper right side of the Pan Am's
fuselage, ripping apart themiddle of the Pan Am jet almost
directly above the wing.
The right side engines crashedthrough the Pan Am's upper deck
(15:15):
immediately behind the cockpit,instantly killing all of the
passengers seated there.
The KLM plane remained brieflyairborne, but the impact had
sheared off the number oneengine, caused significant
amounts of shredded material tobe ingested by the number two
engine and damaged the wings.
The plane immediately went intoa stall, rolled sharply, and hit
(15:38):
the ground approximately 500feet past the collision, sliding
down the runway for anotherthousand feet.
Upon impact with the runway, thefull load of fuel, which Van
Zanten just had to have, went upimmediately into a fireball that
could not be contained forseveral hours.
The destruction was total.
(15:58):
All 248 people on board the KLMflight were killed.
Their fresh fuel load turningthe wreckage into an
incinerating pyre.
Robina would be the lonesurvivor from the KLM flight who
had chosen to stay behind inTenerife.
On the Pan Am jet, 61 peoplesurvived, all from the front
section of the aircraft, whichremained relatively intact after
(16:22):
the impact.
The remaining 335 people onboard died.
In total, 583 souls were lost.
The tower, blinded by the fog,heard the explosions but could
not see what had happened.
Sending rescue crews initiallyto the KLM wreckage without
knowing a second aircraft hadbeen involved.
(16:45):
It would be another 20 minutesafter crews got to the KLM plane
before they knew there was asecond plane burning.
20 minutes survivors had towait, praying for rescue.
The scene was utter chaos.
The left wing was destroyed andthe entire top half of the
airplane was ripped off.
Doors were crumpled or smashedclosed, survivors struggled to
(17:08):
escape, one door wouldeventually be forced open.
The passengers used any meansnecessary to escape, whether by
the single open door or any holein the plane they could find.
Without a ladder or any othermeans of getting down,
passengers were faced withjumping down nearly 20 feet to
the debris-filled ground below.
(17:30):
The survivors gathered near theleft wing of the plane, which
had remained intact, sitting byhelplessly, unable to do
anything for anyone that wasstill trapped in the wreckage,
as they had to wait for thefirst responders.
The fire was just burning toointensely for them to get
anywhere near it.
(17:54):
In the post-crash investigationthat followed, the Spanish
investigative authority,Subsecretaria de Aviation Civil,
concluded that the fundamentalcause was the KLM captain's
actions, his decision to takeoff without clearance, his
failure to obey the standby fortakeoff instructions, and his
(18:16):
emphatic denial that the Pan Amaircraft was on the runway.
The Dutch investigation, whileacknowledging the captain's
role, placed a greater emphasison the mutual miscommunications
between the KLM crew and airtraffic control.
The KLM co-pilot's non-standardphrase, we are now at takeoff,
and the tower's bag okay wereconsidered examples of
(18:39):
inadequate language thatcontributed to the
misunderstanding.
Even though initially theydesperately tried to push the
blame onto anyone else, blamingthe air traffic controllers
listening to the radio and notpaying enough attention.
Then they blamed it on their badEnglish, confusing the pilots.
When that didn't quite pan out,they blamed the Pan Am pilots
(19:01):
for not following orders andturning off.
Which, none of which reallymatters, since they never got
permission to take off, anyways.
Ultimately, KLM admitted itscrew was responsible and
financially compensated thevictims' families.
The crash at Tenerife became thecatalyst for complete overhaul
(19:22):
of modern aviation safety.
The sheer scale and complexityof the accident provided an
undeniable lesson.
Safety could not be guaranteedby the brilliance of individual
pilots alone.
The paradigm shifted from aculture that sought to pinpoint
a single culprit to one thatlooked at the entire system for
(19:43):
points of failure.
The 583 people who perished thatday became the unfortunate
founders of a new era of safety.
And their deaths led to somesignificant changes that are
felt today and making air travelsafer.
The first and most significantchange was the establishment of
(20:04):
crew resource management as amandatory component of pilot
training.
The investigation into the KLMcockpit revealed a profound
psychological failure, a steepauthority gradient where the
flight engineers' correct andcrucial question was easily
dismissed by his captain, thesupposedly legendary Mr.
(20:24):
KLM.
The aviation industry recognizedthat a cockpit environment where
subordinates fear challenging asuperior's decision is a
critical vulnerability.
The CRM was designed todismantle this rigid hierarchy.
It promotes a flanner commandstructure fostering open
communication, mutual support,and shared decision making among
(20:49):
all crew members.
Pilots are now explicitlytrained to be assertive, to
speak up if they have a concern,and to ensure that safety
decisions are a product oftwo-way communication, not a
single individual's assumption.
Second, the accident highlightedthe deadly ambiguity of
language.
(21:09):
The KLM co-pilot's non-standardphrase we are now at takeoff and
the controller's vague okaydemonstrated that a lack of
standardized terminology couldhave serious consequences.
As a result, the airlineindustry adopted a universal set
of concise, aeronauticalphrases.
(21:29):
Most critically, the wordtakeoff is now used exclusively
to issue a clearance fortakeoff.
All other instructions use theword departure to avoid any
confusion.
This single global standard haseliminated the possibility of a
pilot mistaking a routeclearance for a takeoff
clearance.
(21:50):
Finally, the crash led tofundamental changes in airport
infrastructure and procedures.
The fact that the Tenerifecontrol tower was blind to the
aircraft on its own runway was aserious technological
vulnerability.
In the wake of the crash, thewidespread installation of
ground radar at major airportsbecame standard.
(22:12):
This technology provides airtraffic controllers with a
visual representation of allaircraft on the ground, which
greatly improved situationalawareness, especially in shitty
weather conditions.
Additionally, the non-standardpractice of using an active
runway for taxiing wasre-evaluated, with strict
(22:33):
guidelines now in place to lowerthe risk of such operations.
And that was the Tenerife AirDisaster.
Thanks for listening, and if youlike the show, please consider
leaving a rating or review onyour app of choice.
And you can reach out to theshow at historiesandisaster at
(22:56):
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And share the episodes with yourfriends.
They'll love it.
Take care of yourself out there.
Chase that dream.
Live for today.
Because tomorrow is neverguaranteed.
(23:17):
Thanks and goodbye.
March 27th, 1977 was a shitty day to take a vacation.
First, a terrorist bombingcloses the airport you're flying
into, causing your flight to getdiverted to a much smaller
regional airport with a singlerunway over a half hour away.
Foggy conditions on the groundwould end up causing delays, and
(00:22):
add to that, limited technologymeans no one can see a damn
thing.
And that sounds like a recipefor disaster.
And such a disaster it would be,it would go down as the worst
air disaster in history.
So what happened?
I'm Andrew, and this isHistory's A Disaster.
(00:49):
Tonight we are going to theCanary Islands, which is a
collection of seven largeislands and several smaller
ones, considered an autonomousregion of Spain, even though
it's way fucking south of Spain,just off the coast of Morocco.
And despite being volcanic inorigin, it is a tourist
(01:09):
destination for mostly Europeanson holiday.
Being somewhat tropical, it hasa ton of beaches and coastlines
that draw the crowds in.
And in 1977, the largest of theCanary Islands would be the site
of the worst aviation accidentin history.
And tonight's episode is broughtto you by the Flying Ace Can
(01:31):
Opener Company.
For those hard to open cans,nothing slices through the top
of a can like a hot knifethrough butter, quite like a
flying ace.
The morning of March 27th, 1977,began with the routine hum of
two Boeing 747s on theirrespective long haul journeys.
(01:55):
On the tarmac at Amsterdam'sSchiphol Airport, and I know I
did not pronounce that right.
KLM Royal Dutch Airlines Flight4805, a Boeing 747, prepared for
a charter flight to the CanaryIslands.
At the helm was Captain JacobVeldehousen van Zatten, an
(02:16):
experienced and well-respectedpilot, known informally as KLM.
He was not only a captain, butthe company's chief flight
instructor for their entire 747fleet.
This guy was so trusted that hisface was all over KLM's
advertising campaigns.
Aboard this flight were 248passengers and crew, and most of
(02:39):
them were Dutch tourists and 52of them were children.
Meanwhile, flying over theAtlantic, PM Flight 1736, which
was another Boeing 747, was onits final leg from New York's
JFK Airport to the samedestination.
Ran Canaria Airport on theisland of Las Palmas.
(03:02):
Flying the jet was CaptainVictor Grupps, a veteran pilot
with over 21,000 hours of flighttime.
The Pan Am Jumbojet carried 396people.
380 of them were passengers and16 crew members.
It was a long and boring flight,and most of them were looking
forward to being off the planeafter being stuck on it for over
(03:25):
13 hours.
(03:51):
These fucking shitheads werereally showing the Spanish how
serious they were about standingup to them in open conflict to
gain independence for theislands from Spain.
Cause you know, there's nothingthat says ready to fight to the
last man in open conflict thantrying to kill innocent
civilians with a bomb, thefucking cowards.
(04:13):
Anyways, civilian aviationauthorities, in an act of
caution, immediately closed theairport, forcing all incoming
traffic to divert.
A number of large aircraft,including the two Boeing 747s,
were rerouted to the smallerregional airfield of Los Rodos
on the neighboring island ofTenerife.
(04:34):
The PNAM crew asked forpermission to fly a holding
pattern.
They had plenty of fuel tospare, and after having flown
from LA with only a singlestopover in New York, they were
really not looking forward tospending any more time on the
plane than possible.
Their request unfortunately gotdenied and they were forced to
divert to Tenerife.
(04:55):
Los Rodeos was ill-equipped tohandle this sudden surge of
heavy international traffic.
The airport featured a singlerunway, designated runway 1230,
and one main taxiway runningparallel to it.
When the diverted aircraft,which included five large
airliners, arrived, they took upso much space on the main apron
(05:19):
and taxiway that ran parallel tothe runway that they effectively
blocked it for its intendedpurpose.
This forced a highly unusual andinherently dangerous procedure
known as back taxiing orbacktracking, which means
instead of using the dedicatedtaxiway, departing planes were
forced to use the active runwayitself as a taxiway, moving in
(05:42):
the opposite direction of thedesignated takeoff traffic
before having to turn the planearound to take off.
The delay on the ground at LosVerdeos really fucked with the
KLM crew, particularly onCaptain Jacob Van Zanten.
As KLM's chief flight instructorfor the 747, Van Zanten held a
(06:03):
position of near unquestionableauthority, a culture of
seniority that meant the captainwas basically a god within the
cockpit.
And in the documentary Iwatched, he was kind of a dick
too.
With this culture of the captainis always right, no one in the
cockpit felt they could questionhis choices, which really put
(06:24):
First Officer Klaus Moors in abad position.
Captain Van Zanten could make orbreak his career at any time.
So doing anything to piss himoff was probably not a good
idea.
Beyond his professionalstanding, Van Zanten was also
under a more immediate personalburden.
New Dutch government regulationslimiting crew duty time had
(06:48):
recently been enacted.
These restrictions were verystrict and carried the threat of
criminal prosecution ifexceeded, creating a looming
deadline for the crew.
He knew that with the day'scomplications and worsening
weather, his window ofopportunity to get out of
Tenerife before an overnightstay was closing, and he
(07:08):
desperately wanted to get thefuck out of there.
This sense of urgency culminatedin a shitty decision to refuel
the aircraft at Los Rodeos.
This despite the fact thatnormal procedure is to only take
enough fuel to make thescheduled flight plus a little
extra in case of emergencies.
(07:28):
The KLM flight, a short25-minute hop to Los Palmas, did
not require the 55 tons of fuelthat was being loaded.
Van Zanten chose to do this toavoid the inevitable delays of
refueling in a newly reopenedand congested Las Palmas
airport.
(07:51):
The refueling process tookapproximately 35 minutes.
Passengers on the KLM flightwere allowed to de-plane and
reboard.
So instead of sitting in acramped plane, the passengers
got to enjoy sitting in acramped terminal with all the
other people that were stuckthere.
Delaying the plane even longer,they managed to lose a few
(08:13):
passengers, which is a switch.
Normally airlines lose yourluggage.
KLM apparently loses wholepeople.
A family of four had yet to makeit to the plane when reboarding
started.
The two kids had run off toexplore, so they had to run
around searching for them toround them up.
There was also a fifth personthat would not make it to the
(08:35):
plane.
Rabina Van Lanshot was one ofthree tour guides returning to
Teneriff, and she chose not toreturn to the plane.
The three of them were going toTeneriff anyways, so getting
back on the plane meant theywould be flying back to Gran
Canaria just to turn around andcome back to Tenerife.
(08:56):
And she was ready to be donewith the flight and see her
boyfriend.
After discussing it with herfriends who were getting back on
the plane, she snuck off, goingagainst KLM's request that
everyone get back on the plane.
Back on the tarmac, while thePan Am jet was ready to go, it
was now trapped.
Its path to the runwaycompletely blocked by the
(09:17):
stationary KLM plane and itsrefueling vehicle.
The 747 being over 200 feet inwidth didn't have the clearance
to make it around.
They were short by just 12 feet,so they had to wait on KLM to
get their act together and findthe people they misplaced and
take on fuel they didn't need.
(09:39):
As the KLM crew finally finishedits preparations and requested
permission to taxi, the weatherwent to shit rapidly.
A thick low-lying fog, which isa hallmark of the Tenerife
Airport's unique microclimate,rolled in and enveloped the
airfield.
Visibility dropped to less thana thousand feet, far below the
(10:00):
normal required minimums fortakeoff.
And it was so dense that thecontrol tower, which had no
ground radar, could no longersee the runway.
So now both crews were nowoperating completely blind,
forced to rely entirely on asystem of verbal communications
that was already undersignificant stress.
(10:26):
As the KLM 747 back taxi downthe runway, the Pan Am jet
followed at a distance behindit.
At 1702, the Tenerife ControlTower instructed the Pan Am crew
to taxi into the runway and takethe third taxiway.
This instruction, however, waspretty unclear and pretty
(10:49):
problematic.
The third taxiway, designatedCharlie 3, required a difficult
150-degree turn for 747.
And since shit really wasn'tmarked that great, it was
difficult to see in the fog.
The Pan Am crew was confused andconcerned, discussed the matter
(11:09):
in the cockpit, debating whetherthe tower had meant the first or
third exit, and ultimatelydecided to continue taxiing to
the fourth exit, Charlie 4,which offered a more standard 45
degree turn and made more senseto the crew.
The critical breakdown incommunication occurred between
the KLM cockpit and the controltower.
(11:32):
After completing the back taxiand turning 180 degrees to face
the end of the runway, KLM FirstOfficer Moores received and read
back their ATC clearance fortheir flight path.
Now this clearance is onlytelling them their flight path
after takeoff.
Permission for takeoff is acompletely separate event.
(11:54):
However, in a fatal edition, theco-pilot ended his transmission
with the non-standard phrase, weare now at takeoff.
The controller, who had not yetissued a takeoff clearance,
responded with okay, immediatelyfollowed by the crucial
instruction, stand by fortakeoff, I will call you.
(12:16):
But in shithead Van Zanten'smind, the mind of a jackass that
was in a hurry and thought hecould do no wrong, the okay was
a confirmation of his co-pilot'sstatement and the clearance he
was waiting for.
He immediately pushed thethrottles forward and began the
takeoff roll.
A split second later, in amoment of tragic irony, the
(12:39):
system's final defense wasrendered useless.
As the tower said standby fortakeoff, the Pan Am crew
transmitted, and we are stilltaxiing down the runway.
The two messages sent at thesame time overlapped, creating a
high-pitched whistling soundthat blocked both transmissions
(13:00):
in the KLM cockpit.
The final warning, a clearstatement that could have saved
583 lives, was completelyinaudible due to a simple
technical limitation.
In the KLM cockpit, the flightengineer William Schroeder felt
something was wrong and actuallytwice questioned the captain,
asking, is he not clear then?
(13:21):
Van Zanden, with the blindconviction of a man under
pressure, replied, Oh yeah.
His unchallenged authority andthe culture of deference in the
cockpit silenced any furtherquestioning, and the fatal
takeoff run continued.
From within the dense blindingfog, the crews of both aircraft
(13:42):
were suddenly confronted with ahorrific reality.
In approximately 1706, the PanAm crew, whose frantic cockpit
chatter revealed their growingunease, saw the landing lights
of the KLM 747 emerging from themist just 2,000 feet away and
closing fast.
(14:03):
Captain Grubbs yelled into thecockpit voice recorder, pushed
his throttles to full power, anddesperately tried to veer the
massive jet off the runway.
In the KLM cockpit, Van Zanton,having committed to the takeoff,
saw the lights of the Pan Am jetahead too late.
They were going way too fast tostop and not quite fast enough
(14:24):
for takeoff.
He pulled back on the yoke withfull force, trying to get his
aircraft airborne and clear theobstacle, but the attempt was
too late and too violent.
The aircraft tail dragged forover 60 feet along the runway
due to its high angle of attack.
The KLM 747 barely got off theground.
(14:52):
When it did leave the ground,its nose landing gear cleared
the Pan Am, but its left sideengines, lower fuselage, and
main landing gear struck theupper right side of the Pan Am's
fuselage, ripping apart themiddle of the Pan Am jet almost
directly above the wing.
The right side engines crashedthrough the Pan Am's upper deck
(15:15):
immediately behind the cockpit,instantly killing all of the
passengers seated there.
The KLM plane remained brieflyairborne, but the impact had
sheared off the number oneengine, caused significant
amounts of shredded material tobe ingested by the number two
engine and damaged the wings.
The plane immediately went intoa stall, rolled sharply, and hit
(15:38):
the ground approximately 500feet past the collision, sliding
down the runway for anotherthousand feet.
Upon impact with the runway, thefull load of fuel, which Van
Zanten just had to have, went upimmediately into a fireball that
could not be contained forseveral hours.
The destruction was total.
(15:58):
All 248 people on board the KLMflight were killed.
Their fresh fuel load turningthe wreckage into an
incinerating pyre.
Robina would be the lonesurvivor from the KLM flight who
had chosen to stay behind inTenerife.
On the Pan Am jet, 61 peoplesurvived, all from the front
section of the aircraft, whichremained relatively intact after
(16:22):
the impact.
The remaining 335 people onboard died.
In total, 583 souls were lost.
The tower, blinded by the fog,heard the explosions but could
not see what had happened.
Sending rescue crews initiallyto the KLM wreckage without
knowing a second aircraft hadbeen involved.
(16:45):
It would be another 20 minutesafter crews got to the KLM plane
before they knew there was asecond plane burning.
20 minutes survivors had towait, praying for rescue.
The scene was utter chaos.
The left wing was destroyed andthe entire top half of the
airplane was ripped off.
Doors were crumpled or smashedclosed, survivors struggled to
(17:08):
escape, one door wouldeventually be forced open.
The passengers used any meansnecessary to escape, whether by
the single open door or any holein the plane they could find.
Without a ladder or any othermeans of getting down,
passengers were faced withjumping down nearly 20 feet to
the debris-filled ground below.
(17:30):
The survivors gathered near theleft wing of the plane, which
had remained intact, sitting byhelplessly, unable to do
anything for anyone that wasstill trapped in the wreckage,
as they had to wait for thefirst responders.
The fire was just burning toointensely for them to get
anywhere near it.
(17:54):
In the post-crash investigationthat followed, the Spanish
investigative authority,Subsecretaria de Aviation Civil,
concluded that the fundamentalcause was the KLM captain's
actions, his decision to takeoff without clearance, his
failure to obey the standby fortakeoff instructions, and his
(18:16):
emphatic denial that the Pan Amaircraft was on the runway.
The Dutch investigation, whileacknowledging the captain's
role, placed a greater emphasison the mutual miscommunications
between the KLM crew and airtraffic control.
The KLM co-pilot's non-standardphrase, we are now at takeoff,
and the tower's bag okay wereconsidered examples of
(18:39):
inadequate language thatcontributed to the
misunderstanding.
Even though initially theydesperately tried to push the
blame onto anyone else, blamingthe air traffic controllers
listening to the radio and notpaying enough attention.
Then they blamed it on their badEnglish, confusing the pilots.
When that didn't quite pan out,they blamed the Pan Am pilots
(19:01):
for not following orders andturning off.
Which, none of which reallymatters, since they never got
permission to take off, anyways.
Ultimately, KLM admitted itscrew was responsible and
financially compensated thevictims' families.
The crash at Tenerife became thecatalyst for complete overhaul
(19:22):
of modern aviation safety.
The sheer scale and complexityof the accident provided an
undeniable lesson.
Safety could not be guaranteedby the brilliance of individual
pilots alone.
The paradigm shifted from aculture that sought to pinpoint
a single culprit to one thatlooked at the entire system for
(19:43):
points of failure.
The 583 people who perished thatday became the unfortunate
founders of a new era of safety.
And their deaths led to somesignificant changes that are
felt today and making air travelsafer.
The first and most significantchange was the establishment of
(20:04):
crew resource management as amandatory component of pilot
training.
The investigation into the KLMcockpit revealed a profound
psychological failure, a steepauthority gradient where the
flight engineers' correct andcrucial question was easily
dismissed by his captain, thesupposedly legendary Mr.
(20:24):
KLM.
The aviation industry recognizedthat a cockpit environment where
subordinates fear challenging asuperior's decision is a
critical vulnerability.
The CRM was designed todismantle this rigid hierarchy.
It promotes a flanner commandstructure fostering open
communication, mutual support,and shared decision making among
(20:49):
all crew members.
Pilots are now explicitlytrained to be assertive, to
speak up if they have a concern,and to ensure that safety
decisions are a product oftwo-way communication, not a
single individual's assumption.
Second, the accident highlightedthe deadly ambiguity of
language.
(21:09):
The KLM co-pilot's non-standardphrase we are now at takeoff and
the controller's vague okaydemonstrated that a lack of
standardized terminology couldhave serious consequences.
As a result, the airlineindustry adopted a universal set
of concise, aeronauticalphrases.
(21:29):
Most critically, the wordtakeoff is now used exclusively
to issue a clearance fortakeoff.
All other instructions use theword departure to avoid any
confusion.
This single global standard haseliminated the possibility of a
pilot mistaking a routeclearance for a takeoff
clearance.
(21:50):
Finally, the crash led tofundamental changes in airport
infrastructure and procedures.
The fact that the Tenerifecontrol tower was blind to the
aircraft on its own runway was aserious technological
vulnerability.
In the wake of the crash, thewidespread installation of
ground radar at major airportsbecame standard.
(22:12):
This technology provides airtraffic controllers with a
visual representation of allaircraft on the ground, which
greatly improved situationalawareness, especially in shitty
weather conditions.
Additionally, the non-standardpractice of using an active
runway for taxiing wasre-evaluated, with strict
(22:33):
guidelines now in place to lowerthe risk of such operations.
And that was the Tenerife AirDisaster.
Thanks for listening, and if youlike the show, please consider
leaving a rating or review onyour app of choice.
And you can reach out to theshow at historiesandisaster at
(22:56):
gmail.com with questions,comments, or suggestions.
As well as follow the show onsocial media, like Facebook,
Instagram, TikTok, YouTube,whatever.
And share the episodes with yourfriends.
They'll love it.
Take care of yourself out there.
Chase that dream.
Live for today.
Because tomorrow is neverguaranteed.
(23:17):
Thanks and goodbye.
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