Mr. Bourne, a native of Barbados who prosecutors say had criminal connections there, bought cocaine in bulk and arranged for baggage handlers in Barbados to hide it on planes bound for New York, several American Airlines employees testified.

On Boeing 757s, the Barbadian handlers hid the bricks of cocaine among loose bags and freight. On larger 767s, they stowed the drugs in giant containers that were filled with luggage at the terminal and then loaded onto the planes. On Airbus A300s, they found hidden spaces behind the wall and ceiling panels in the cargo hold.

Only the airline workers at Kennedy who were a part of the scheme knew where to look.

“I would take the drugs out of the ceiling, put it in the bag, mix it up with other bags coming down the plane and send it down the belt,” said Edwin Asencio, a former baggage handler for American Airlines.

If the hiding spots were secret, the practice was not. “I was bragging around the job that I was doing it, and I was trying to get my other friends involved so they could make extra money,” Mr. Asencio said.

Trafficking was heaviest during the winter months, when customs agents assigned to the tarmac were less likely to leave their cars, and when baggage workers could hide some of the bricks of cocaine inside their coats. When the customs agents were looming, the baggage handlers sometimes left the cocaine on the plane and tracked it as it hopped around the country. When it returned to Kennedy from a domestic trip, the workers — taking care that customs agents were nowhere in sight — removed the drugs.

Mr. Bourne sold the cocaine he smuggled for about $18,000 a kilogram and took home the biggest share of the profits, prosecutors said. They calculated that he made several million dollars, which was passed through businesses he ran in Brooklyn and in Barbados.