It was foggy. Not just a little misty, but that thick, pea-soup kind of fog that swallows everything in sight. On March 27, 1977, two Boeing 747s sat on the tarmac of a tiny regional airport in the Canary Islands, never intending to be there in the first place. This is the reality of el accidente de los rodeos. It wasn't just a "crash." It was a catastrophic collision of errors, bad luck, and a radio system that failed when it was needed most.
Most people call it the Tenerife airport disaster.
In Spain, it’s remembered as el accidente de los rodeos, named after Los Rodeos Airport (now Tenerife North). Even decades later, it remains the deadliest accident in aviation history. 583 people died. Think about that for a second. Two massive planes, full of families and vacationers, turned into a fireball on a runway because of a few seconds of confusion. It changed how we fly today, but the story of how it happened is far more complicated than a pilot just being in a hurry.
Why were they even at Los Rodeos?
Fate is a weird thing. Neither the KLM flight nor the Pan Am flight was supposed to be at Tenerife. They were both headed for Gran Canaria. But a bomb planted by a separatist group exploded in the flower shop at the Las Palmas terminal, and a second threat forced all incoming international flights to divert.
So, Los Rodeos got swamped.
It was a small airport. It had one runway and one narrow taxiway. Suddenly, it was packed with "jumbo jets" it wasn't designed to handle. The apron was so full that planes had to park on the taxiway itself. To take off, planes had to taxi down the actual runway, do a 180-degree turn (a "backtrack"), and then roar off into the sky. It was a logistical nightmare.
Jacob Veldhuyzen van Zanten was the captain of the KLM 4805. He was a celebrity pilot. His face was in the KLM magazine ads. He was the guy who trained other pilots. He was also under intense pressure. New Dutch regulations were very strict about "duty time" limits. If he didn't get that plane off the ground soon, he and his crew could face criminal prosecution for exceeding their legal hours. They would be stuck in Tenerife overnight, costing the airline thousands. He was in a rush.
The fog and the "Squelch"
By late afternoon, the weather turned. A thick cloud bank rolled over the airfield, dropping visibility to almost nothing. You couldn't see the other end of the runway. You couldn't even see the other plane.
The air traffic controllers (ATC) couldn't see the planes either. They didn't have ground radar. They were flying blind, relying entirely on what the pilots told them over the radio.
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The Pan Am flight, commanded by Victor Grubbs, was told to taxi down the runway and exit at "the third intersection." But the intersections weren't clearly marked. In the fog, the Pan Am crew struggled to figure out which turn was which. They passed the third one, thinking it was too sharp for a 747, and headed for the fourth.
Meanwhile, at the end of the runway, Van Zanten was ready to go.
He pushed the throttles forward. His co-pilot, Klaas Meurs, told him they didn't have ATC clearance yet. Van Zanten pulled back and told him to ask. Meurs did. The controller gave them their flight path after takeoff—their route—but not the actual "clearance to take off."
Meurs said, "We are now at takeoff." It was ambiguous. Did he mean they were at the takeoff position, or they were currently taking off?
The controller was confused. He told them, "OK... wait for takeoff, I will call you."
But right at that exact millisecond, the Pan Am pilot spoke up too. He said, "We're still taxiing down the runway!"
Because both people spoke at the same time, their signals interfered. It's called a "heterodyne" or a "squelch." On the KLM flight, all the pilots heard was a long, high-pitched whistle. They never heard the instruction to wait. They never heard that Pan Am was still on the runway.
The moment of impact
Imagine the cockpit of that KLM jet. Van Zanten is focused. He’s a pro. He hears the "OK" from the tower and ignores the rest because of the radio interference. He releases the brakes. The four massive engines of the 747 scream to life.
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The flight engineer, Willem Schreuder, felt something was wrong. "Is he not clear then, that Pan American?" he asked.
Van Zanten snapped back, "Yes, he is." He was certain.
In the Pan Am cockpit, they saw the lights of the KLM jet emerging from the fog. It was coming right at them. Fast. Grubbs yelled, "There he is! Look at him! Goddamn, that son-of-a-bitch is coming!" He slammed the engines into full power, trying to veer onto the grass to get out of the way.
Van Zanten saw them too. He tried to pull up. He pulled back so hard the tail of the KLM plane scraped 20 meters of the runway. He almost made it. The nose cleared the Pan Am jet, but the landing gear and the engines ripped through the top of the Pan Am fuselage.
The KLM plane stayed in the air for a few more seconds, then stalled and crashed, exploding instantly. There were no survivors on the KLM flight. On the Pan Am side, 61 people managed to scramble out of the wreckage before it was consumed by fire.
The investigation and the blame game
The aftermath of el accidente de los rodeos was a mess of international finger-pointing. The Dutch tried to blame the controllers or the Pan Am crew for not exiting where they were told. The Spanish and Americans pointed at Van Zanten’s haste.
Ultimately, the Dutch authorities accepted responsibility, and KLM paid out massive settlements. But the real "blame" was a system that allowed one person’s authority to go unchallenged.
This led to the birth of Crew Resource Management (CRM).
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Before Tenerife, the Captain was God. You didn't question him. If he said "we're going," you went. After this disaster, the industry realized that even the most experienced pilots make mistakes. CRM changed the culture of the cockpit. It taught co-pilots and engineers to speak up, and it taught captains to listen.
Why we still talk about Los Rodeos
It’s about more than just a crash. It’s a case study in "human factors." It shows how small, seemingly irrelevant things—a bomb in a different city, a foggy afternoon, a radio "squelch," a pilot worried about his shift ending—can align to create a tragedy.
Standardized language was also a huge takeaway. Controllers and pilots no longer say "OK." They use very specific, rigid phrases. You never say "takeoff" until the moment you are actually cleared to do it. You say "departure" instead.
If you fly today, you are safer because of what happened at Los Rodeos.
Actionable insights for the curious
If you’re interested in aviation history or safety, there are a few things you should do to understand the gravity of this event.
First, look up the "Swiss Cheese Model" of accident causation. It was popularized largely because of Tenerife. It explains how "holes" in different layers of safety—the weather, the technology, the human ego—all have to line up perfectly for a disaster to happen. It's a fascinating way to look at risk management in your own life or business.
Second, if you ever visit Tenerife, the memorial at Mesa Mota is worth seeing. It’s a "Spiral Staircase" to nowhere, representing the lives cut short. It’s a somber place, but it offers a perspective that a Wikipedia page can't.
Finally, pay attention to communication in high-stakes environments. The Tenerife disaster is the ultimate proof that "hearing" isn't the same as "understanding." In your own professional life, if something sounds ambiguous, clarify it. Don't assume the person on the other end of the "radio" knows what you’re doing.
The legacy of el accidente de los rodeos is written in the safety manuals of every airline on earth. We've learned that technology is only as good as the humans operating it, and that silence in a cockpit can be just as dangerous as an engine failure.
To truly honor those lost, we have to keep talking about why it happened. Aviation is a "blood-written" industry; every rule exists because someone didn't have it before. Tenerife was the most expensive lesson of all.