Both 747 captains were eager to get going and off Tenerife, including Capt. Victor Grubbs at the helm of the Pan Am jumbo, who had already flown for eight hours (the flight had originated in LA and he took over at a New York stopover) but more importantly van Zanten; he and his crew were running out of time in terms of their permitted period of duty and he was in a hurry to get to his destination. Also, as separately reported, “Van Zanten knew that every moment the fog got worse made it that much likelier that the Tenerife tower would shut down the airport. He saw that his window of opportunity to get out of Tenerife before an overnight stay was closing. It was now or never–time to go.”
He had taxied to the start of the runway and turned the plane 180 degrees to prepare for takeoff as Grubbs’ Pan Am 747 was also on the runway looking in the dense fog for a taxiway turnoff (as instructed by the control tower).
Unfamiliar with the airport, Grubbs missed the first turnoff and was headed for a second when the fateful exchange of messages came between the tower and KLM. Here’s the full story, and forgive the comprehensiveness but it’s essential, I believe, to understanding who did what when and why.:
KLM taxis ahead and onto the runway, with the Pan Am Clipper ambling several hundred yards behind. Captain Van Zanten will steer to the end, turn around, then hold in position until authorized for takeoff. Pan Am’s instructions are to turn clear along a left-side taxiway to allow the other plane’s departure. Once safely off the runway, they will report so to the tower.
Unable to differentiate the taxiways in the low visibility, the Pan Am pilots miss their assigned turnoff. Continuing to the next one is no big problem, but now they’re on the runway for several additional seconds.
At the same time, having wheeled into position at the end, Van Zanten comes to a stop. His first officer, Klaas Meurs, takes the radio and receives the ATC route clearance. This is not a takeoff clearance, but rather a procedure outlining turns, altitudes, and frequencies for use once airborne. Normally it is received well prior to an aircraft taking the runway, but the pilots have been too busy with checklists and taxi instructions until now. They are tired, annoyed, and anxious to get going. The irritability in the pilots’ voices, Van Zanten’s in particular, has been duly noted by the control tower and other pilots. First officer Meurs, sitting to Van Zanten’s right, reads back the altitudes, headings and fixes, then finishes off with an unusual, somewhat hesitant phrase, backdropped by the sound of accelerating engines. “We are now, uh, at takeoff.”
Van Zanten releases the brakes. “We gaan,” he is heard saying on the cockpit voice recorder. “Let’s go.”
“At takeoff” is not standard phraseology among pilots. But it’s explicit enough to grab the attention of the Pan Am crew and the control tower. It’s hard for either party to believe KLM is actually moving, but both reach for their microphones to make sure.
“And we’re still taxiing down the runway,” relays Bob Bragg, the Pan Am first officer.
At the same instant, the tower radios a message to KLM. “Okay,” says the controller. “Standby for takeoff. I will call you.”
Ten seconds later there is one final exchange, clearly and maddeningly audible on the post-crash tapes. “Report when runway clear,” the tower says to Pan Am.
“We’ll report when we’re clear,” acknowledges Bob Bragg.
Focused on the takeoff, Van Zanten and his first officer apparently miss this. But the second officer, sitting behind them, does not. Alarmed, with their plane now racing forward at a hundred knots, he leans forward. “Is he not clear?” he asks. “That Pan American?”
“Oh, yes,” Van Zanten answers emphatically.
In the Pan Am cockpit, nose-to-nose with the still unseen, rapidly approaching interloper, there’s a growing sense that something isn’t right. “Let’s get the fuck out of here,” Captain Victor Grubbs says nervously.
A few moments later, the lights of the KLM 747 emerge out of the grayness, dead ahead, 2,000 feet away and closing fast.
“There he is!” cries Grubbs, shoving the thrust levers to full power. “Look at him! Goddam, that son of a bitch is coming!” He yanks the plane’s steering tiller, turning left as hard as he can, toward the grass at the edge of the runway.
“Get off! Get off! Get off!” shouts Bob Bragg. [Bob Bragg died of natural causes in February of this year.–Bruce]
When van Zanten saw the Pan Am Clipper, he used the only option he had at that point–too late to stop–and tried to take off at suboptimal speed. It didn’t work. Although the nose of his 747 cleared the Pan Am, the tail had been dragging along the runway for a few hundred yards and the rear of the KLM took the top off all but the front of the Pan Am plane; indeed, the 61 survivors at Tenerife, including the cockpit crew, were all in the front of the Pan Am. The KLM plane cartwheeled and exploded, freshly refueled, with no survivors at all.
Van Zanten was as fine and as experienced a pilot as KLM, or any of the world’s airlines, had at the time. His skill, training, credentials, and expertise were impeccable, and he had the years and years of flying time that are required to achieve the highest level of excellence. But he still was the proximate cause of the greatest aviation disaster of all time. Process was ignored, subordinates were ignored, checklists were ignored, contrary information was ignored. He knew, implacably, best.
So endeth today’s parable.
The Tenerife story is my distilled compendium of several sources, including:
NTSB Investigation into United Flight 173, https://web.archive.org/web/20090304190529/http://www.airdisaster.com/investigations/ua173.shtml
Wikipedia (inevitably) on Flight 173:
Crew resource management:
The Tenerife disaster:
The Telegraph, “The true story behind the deadliest air disaster of all time” (by Patrick Smith, author and pilot: March 27, 2017):
Wired, “March 27, 1977: The worst air disaster ever” (March 26, 2009):