Did History Actually Teach Us Anything? - Episode 13 Tenerife Airport Disaster 

Laura: Welcome to did history actually teach us anything. 
The podcast where we unravel the most well-known tales of calamity, mishap, and unforeseen consequences that have shaped the course of history. And consider whether we've actually learned anything from them all these years later.. 
In this podcast, we examine the historical events that you may think you know about already and the causes that led to them, be they icebergs or bakers ovens. 
We will consider whether these tragedies could have been avoided, and some of the surprising things we do differently now as a result. 
But this podcast, isn't just about dates and events. It's about learning from the past, drawing insights from hindsight, and gaining a deeper appreciation for the complexities of what really happened in these events we think we know so well. 
So get ready to encounter remarkable individuals, pivotal moments and fascinating insights that will make you appreciate health and safety and environmental management as far more than just red tape.
On this episode, we'll be discussing one of aviation's darkest moments - the Tenerife Airport Disaster.
Back in 1977, a tragic collision between two Boeing 747 jumbo jets occurred on the Spanish island of Tenerife, resulting in hundreds of lost lives.
Joining us is Lucy, one of our health and safety experts, who will begin by giving us a brief explanation of the circumstances that led to the Tenerife Airport disaster. 


Lucy: When you look at what happened in Tenerife, it wasn't just one thing that went wrong - it was a perfect storm of problems that collided on March the 27th, 1977.
The disaster primarily involved two Boeing 747s: KLM Flight 4805 from Amsterdam to Las Palmas and Pan Am Flight 1736 from Los Angeles to Las Palmas via New York. What many people don't realize is that these planes weren't even supposed to be at Los Rodeos Airport, (now Tenerife North Airport) in the first place. A bomb threat at Grand Canaria Airport, their intended destination, forced them to divert along with several other aircraft.
This created absolute chaos at an airport that wasn't designed to handle so many large aircraft. Los Rodeos was a relatively small regional airport with just one main runway and a parallel taxiway. The fog that day was incredibly thick - we're talking visibility down to about 300 meters at times - meaning only one tenth of the runway was actually visible.


Laura: Beyond the challenging conditions at Los Rodeos that day, what specific factors ultimately led to these two aircraft colliding on the runway? 


Lucy: Ultimately what really caused the disaster was a catastrophic breakdown in communication. The Dutch KLM captain, Jacob  Veldhuyzen van Zanten, who was actually the airline's chief flight instructor and even featured in their safety advertisements, mistakenly believed he had clearance for takeoff and began accelerating down the runway. At the same time, the Pan Am aircraft was still on that same runway, trying to find their assigned exit in the heavy fog.
The air traffic controllers were speaking Spanish-accented English, while communicating with Dutch and American pilots. There was radio interference that cut out crucial warnings. The KLM crew used non-standard phraseology, saying they were "at takeoff" rather than "ready for takeoff", creating ambiguity, and critically, the KLM co-pilot expressed uncertainty but deferred to his senior captain rather than being more assertive about his concerns.
Another complicating factor was the immense pressure on the KLM crew. They were approaching their duty time limits, which would've meant mandatory rest periods and significant delays for their passengers. This created a subtle but real pressure to depart quickly, which may have influenced the captain's eagerness to take off.


Laura: So what actually happened during the crash? Can you talk us through a rough timeline of what would've been happening?


Lucy: The sequence of events during those final moments was tragically fast. At approximately 5:06 PM local time, the KLM Boeing 747 began its takeoff role, accelerating down the runway through the thick fog. The Captain, van Zanten, was likely confident they were cleared for takeoff based on the miscommunications we've discussed.
At the same time, the Pan Am aircraft was still on that same runway, having missed their assigned exit taxiway due to the poor visibility. They were moving slowly, trying to locate their turnoff point, when the flight crew heard the KLM's engines powering up in the distance.
The Pan Am pilots immediately recognized the danger and made a desperate attempt to manoeuvre their aircraft off the runway, while also radioing "we're still on the runway!". Unfortunately, due to the radio interference, this critical warning was likely obscured.
By the time either plane saw the other through the fog, it was too late. The KLM jet struck the Pan Am plane at high speed.
The KLM's undercarriage and engine struck the upper right side of the Pan Am aircraft, tearing through its fuselage. The impact was catastrophic - both aircraft erupted into flames immediately. The fully-fueled KLM plane crashed back onto the runway and slid for several hundred feet before exploding in a fireball that witnesses reported was visible even through the dense fog.
The Pan Am aircraft was severed into several sections. Remarkably, some passengers in the forward section of the Pan Am plane survived because that portion remained somewhat intact. These survivors, along with some crew members, managed to escape through breaks in the fuselage before fire engulfed the entire wreckage. This would've been a terrifying experience for the surviving passengers and crew members.
Emergency response was hampered by the fog and the airport's limited resources, but rescue teams worked heroically to reach survivors as quickly as possible. In total, 61 people from the Pan Am flight survived, which means 335 of their 396 passengers and crew perished, while tragically all 248 people aboard the KLM flight, including the captain Van Zanten, perished instantly. Altogether, 583 people lost their lives that day, making this the deadliest accident in aviation history not involving terrorism.


Laura: Is there any way that the crash could have been avoided? 


Lucy: Absolutely, Laura. Looking back at all the factors, there were several critical points where different decisions could have prevented this tragedy.
For starters, better contingency planning for airport diversions could have prevented such overcrowding. Had there been clearer protocols for handling multiple diverted jumbo jets, they might have been sent to different airports altogether.
The communication issues could have been addressed through standardized phraseology that left no room for misinterpretation. If the KLM pilot had said, "ready for takeoff", instead of " we are at takeoff", or if the controllers and Pan Am crew had been able to communicate without radio interference, the confusion might never have happened.
The heavy fog was obviously a major factor, but ground radar systems could have helped controllers track the exact positions of aircraft when visibility was poor Los Rodeos didn't have this technology at the time.
Perhaps most importantly, there needed to be a stronger cockpit culture where co-pilots felt empowered to challenge captains more forcefully. The KLM co-pilot did express uncertainty about the takeoff clearance, but he didn't push hard enough when faced with his captain's determination to depart.
What's particularly heartbreaking is that the Pan Am crew was actively trying to exit the runway. They were following instructions correctly, but simply couldn't find their assigned taxiway in the fog. Had they been given clearer guidance or had just a few more minutes to clear the runway, the disaster would've been avoided.


Laura: What about the original bomb threat at Grand Canaria? Could that have had an impact at all? 


Lucy: Sadly, yes. The way that the original emergency - the bomb threat at Grand Canaria - was handled played a significant part in the whole tragedy. The airport was closed for hours, even though the actual explosion caused only minor damage to the terminal floor. A more proportionate response might have allowed flights to resume sooner, preventing the dangerous congestion at Los Rodeos.
It is also important to note that Los Rodeos Airport itself presented challenges. It sits at a higher elevation and is known for rapid weather changes, with fog frequently rolling in from the nearby mountains. A different choice of diversion airport with better facilities and weather conditions might have prevented the accident entirely. 


Laura: Was anyone held responsible for the crash? And what were the repercussions on the airlines? 


Lucy: The official investigation primarily blamed KLM Captain Van Zanten for taking off without proper clearance, though the Dutch authorities argued for more distributed responsibility considering the airport facilities, weather, and ambiguous communications. No criminal charges were filed.
KLM accepted liability and settled most claims out of court, with payments reportedly exceeding $110 million in 1970s dollars - a substantial financial blow to the airline. Pan Am, while not found at fault, also faced numerous lawsuits that contributed to their financial challenges in subsequent years.
The investigation itself was extensive with the formal report not released until November, 1978 - more than 19 months after the accident. This lengthy process reflected both the complexity of the disaster and the sensitive international aspects of the investigation.
The psychological impact on surviving crew members and air traffic controllers was severe, with many unable to return to their previous roles. Both airlines suffered reputational damage, though KLM ultimately recovered while Pan Am's struggles continued.


Laura: Lucy, can you tell us what life was like for those who lived in the local area after the event and for the families of those who lost their lives?


Lucy: The impact on Tenerife was profound. Local residents, many of whom served as first responders or volunteers, experienced lasting psychological effects. The small tourism- dependent island suddenly became associated with aviation's worst disaster.
For victims' families - mostly Dutch tourists and American passengers - grief was compounded by challenges of identifying remains, repatriation and navigating foreign legal systems. Support systems for disaster victims weren't as developed then, leaving many feeling abandoned once media attention faded.
Memorial initiatives include the "Stairway to Heaven" monument in the Netherlands with 583 stairs - one for each victim - and a memorial near the airport in Tenerife. Annual pilgrimages to these sites continue decades later.
Perhaps most meaningfully, many survivors and victims' families became aviation safety advocates, ensuring that lessons from Tenerife led to lasting changes. Their advocacy created a living memorial that continues to save lives today.


Laura: To end, what lessons were learned as a result of the crash, and do we do anything differently now because of it? 


Lucy: The Tenerife air disaster fundamentally changed aviation safety, Laura. It's one of those watershed moments where we can clearly see a before and after in how things are done.
First and foremost, it revolutionized how pilots and controllers communicate. The industry developed what we now call "standardized phraseology"- specific words and phrases that have exact meanings and can't be misinterpreted. For example, pilots now must read back clearances word for word, and specific terms like "lineup and wait" replaced ambiguous phrases.
Perhaps the biggest change was the development of Crew Resource Management. This completely transformed cockpit culture from the 'captain is God' mentality to one where every crew member is expected to speak up about safety concerns. Modern training focuses heavily on teamwork, communication, and decision making under pressure. Junior crew members are now specifically trained to assertively raise concerns, and captains are trained to listen. 
Technologically, there have been massive improvements. Ground radar is now standard at major airports to track aircraft movements even in zero visibility. Runway incursion warning systems alert controllers if an aircraft enters an active runway without clearance.
The disaster also led to changes in how we handle language barriers in aviation. English was standardized as the international aviation language, with proficiency requirements for pilots and controllers worldwide. 
The concept of sterile cockpit procedures was reinforced, where pilots focus solely on flight-related duties during critical phases of flight, with no extraneous conversation. New protocols for handling diverted aircraft were developed, ensuring that airports don't become dangerously congested.
There's now much more focus on human factors in aviation safety - recognizing how stress, fatigue and psychological pressure can impact decision-making. . Flight time limitations became more strictly enforced, and duty hours carefully monitored to prevent the kind of time pressure that may have influenced the KLM captain's decision-making.
The International Civil Aviation Organization also tightened regulations around low-visibility operations. Nowadays, many airports simply close when visibility drops below certain minimums, rather than trying to operate in dangerous conditions like we saw at Tenerife .
I think what strikes me the most about the Tenerife Airport disaster is how it demonstrates that disasters rarely have a single cause. It's almost always a chain of events where multiple safeguards fail simultaneously. That's why modern safety systems are designed with multiple redundancies, and why we focus on creating a culture where people feel empowered to stop operations when something doesn't seem right. 
When I visit airports now and see the meticulous way ground movements are managed, with clear communications and multiple safety checks, I can see the legacy of those 583 people who lost their lives that foggy day in Tenerife. Their tragedy has made flying dramatically safer for all of us. 


Laura: Thanks for joining us on this episode of "Did History Actually Teach Us Anything?". If you enjoyed this episode, please follow our social media channels, leave us a rating and review, and share our podcast with anyone who wants to learn more about the risky side of history. 
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