This is an I-Heart podcast. Guaranteed Human.

It was late March, 1979, and an unseasonably warm day was settling in over Tulsa, Oklahoma.

Down at the main hangar of the American Airlines maintenance facility, just east of Tulsa Airport,

mechanics in coverals mingled with engineers in crisp shirts and

ties under bright fluorescent light, serenaded by an endless whiz of drills and the thrum

of heavy machinery.

The facility was then, and still is, the world's largest commercial airlines base.

Back in 1979, it employed around 6,000 people, servicing as many as 10 to 15 aircraft

at any one time.

One of them, on that day in late March, was a sparkling, aluminium-panelled Macdonald Douglas DC-10.

Registration number N110 AA.

The model was notable for its distinctive tri-jet design, with an engine on each wing and one

in the tail.

This particular aircraft was seven years old and had flown thousands of hours since its

first delivery in 1972.

It carried movie stars, people on business, families jetting off on vacation, but now it

was just another machine undergoing a routine

maintenance check, including an inspection of the engines.

MacDonald Douglas had an official procedure for this.

It involved first removing the engine and then the pylon, a curved strip of metal that

held the engine to the wing.

It was a complex, meticulous job and one that also involved having to disconnect 79 different

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