Cuban MIGs scrambled Saturday and an F-16 responded from Homestead Air Reserve Base as a man often called Vietnam's James Bond flew a rented plane from Key West to Cuba, circled over Havana and dropped leaflets advocating rebellion and calling Fidel Castro ''an old dinosaur.''

Unknown to Ly Tong, 51, virtually every move he made was monitored by Cuban and U.S. authorities, who cooperated to avoid an international incident, according to Michael Sheehan, a U.S. Customs spokesman.

''Make no mistake about it,'' Sheehan said. ''This is a very, very, very lucky man. He is very lucky to be alive right now.''

In the end he walked away, punished only by forfeiting his 2-week-old pilot's license.

Tong, who said he had been planning the ''mission'' for months, seemed undaunted. He said he carefully chose Jan. 1, 2000, as the day of his flight.

ANTI-COMMUNIST

''Very important people are paying attention to what happens the first day of the third millennium,'' Tong said. ''How can I sacrifice my life for Cuban freedom? I believe in God, justice and my mission against communism.

In 1996, Cuban MiGs shot down two planes flown to the island by Brothers to the Rescue, a Miami-based exile group. Four pilots were killed.

Jose Basulto, founder and leader of that group and pilot of the only plane not shot down in 1996, expressed unabashed joy when he heard about the flyover.

''Very good. I congratulate him,'' Basulto said. ''I support any action that goes against Fidel Castro and strives to support Cuban opposition from within the island.''

This time, Cuba demonstrated restraint, U.S. officials said. Still, authorities of both nations were annoyed.

UNDER INVESTIGATION

''This incident is still under investigation,'' said Kathleen Bergen, a spokeswoman for the Federal Aviation Administration. ''We're still determining whether any federal laws were broken or violated.''

She and Sheehan said Tong ''voluntarily'' surrendered his pilot's license after he returned to Kendall-Tamiami Executive Airport and was confronted by authorities.

As his single-engine Cessna 172 rolled to a stop, a U.S. Customs Blackhawk helicopter descended seemingly out of nowhere, settling on the runway directly in front of him.

''He didn't know a lot of things, including the fact that we followed his every move,'' Sheehan said. ''These are sensitive times.''

HEIGHTENED TENSIONS

The incident came amid heightened tensions over the fate of Elian Gonzalez, the 6-year-old Cuban boy now enmeshed in an international custody battle, and it came on the 41st anniversary of the revolution that brought Castro to power.

Late Saturday, Tong also seemed oblivious to heightened tensions.

''I violated the airspace,'' he said. ''That's not important. The most important thing I try to do is energize the Cuban people to rise up and overthrow the Havana tyrant.

A former South Vietnamese fighter pilot shot down over North Vietnam in 1975 and imprisoned for five years, he now is an American citizen who lives in New Orleans but has been staying at the Kendall home of a friend.

He told his story at Tamiami Airport as he stood outside ADF Airways, which owns the plane. He wore a blue flight cap, brown leather dress shoes and a size-too-small orange flight suit with four patches.

He said he finally earned his U.S. pilot's license two weeks ago and rented the plane Friday, paying $240 for just four hours of flying. But he made a weekend of it.

Tong took it to Key West, where he refueled and spent New Year's Eve. Then, at about 7:15 a.m. Saturday, he set out for Cuba.

EASY MISSION

He called it the ''easiest mission in my life.''

He said he flew the plane only 10 or 15 feet above the ocean to avoid detection.

It didn't work.

A Customs radar center in Long Beach, Calif., tracked the plane as it violated Cuban airspace, Sheehan said.

The Cubans also saw the plane. They scrambled two MiGs, which flew out of Tong's sight but close enough to intervene, and they contacted the FAA, seeking information about the plane.

Meanwhile, the Air Force launched an F-16 to keep an eye on Tong and the MiGs, authorities said. It patrolled over the southern Florida Keys.

Tong later said he was blissfully unaware of all of that as he circled over Havana. Speaking as a sightseer, he was not impressed by the sights he saw.

''I stayed over congested areas,'' he said. ''It's a little dirty. After communism, all beauty becomes worse.

50,000 LEAFLETS

He said he rained nearly 50,000 pink, orange and yellow leaflets on the streets below. They were written in Spanish and English.

One leaflet lists seven action points. Among them:

''Demand your right to be the master of your own freedom and liberty. Insist on redressing every Cuban social and cultural issue associated with your inalienable human rights!''

''Coordinate Cuba's internal resistance forces with her global partners in quest for liberty, including all freedom fighters of Vietnam, China, Korea and everywhere else in the Universe, to overthrow Havana's tyrannical legacy of the Twentieth Century.''

''Get rid of Fidel Castro and the cruelty of his Twentieth Century regime.''

Authorities were considering what, if any, charges to file. The most likely appeared to be the aviation equivalent of littering, based on leaflets he dropped from the plane over Marathon en route to Miami.

So, by the end of the adventurous day, Tong was still a free man, which seemed to surprise him.

Believing he could be shot down or captured by Cuba, he had placed two leaflets and several pictures inside an envelope addressed to The Herald.

''Only my friends knew,'' he said. ''They expected me to be shot down or die or be put in prison. I was born to be a freedom fighter.

Herald staff writers Frank Davies and Elaine de Valle contributed to this report.