BALTIMORE, SEPT. 13 -- The Maryland Air National Guard flew 12 convicted drug traffickers to Miami today for deportation to their native Jamaica, the first such military flight used in the U.S. war on drugs.

The Jamaicans, eight from Maryland jails and four from New York, were led in handcuffs and waist chains under heavy guard at dawn from an Immigration and Naturalization Service van to a waiting C-130 Hercules transport plane at Glenn L. Martin Airport just east of Baltimore.

"Everything went off like clockwork," said Capt. Mike Milord, an Air National Guard spokesman. Three hours and 25 minutes later, the National Guard plane landed at Miami International Airport, where the 12 prisoners were whisked to an American Airlines plane and flown to Kingston, Jamaica.

The second flight was also completed without incident, according to National Guard and immigration officials.

Milord and the INS local deputy director, Don Crocetti, said today's National Guard flight was the first time a military aircraft has been used to help deport convicted aliens under a new cooperative agreement in the nation's fight against illegal drug use. Deportees usually are flown by commercial airlines.

Crocetti said Maryland is the only state so far to sign such an agreement.

"It will streamline the process of deporting offenders," Milord said.

It will also cost less, Crocetti said. Because the Maryland Air National Guard provides the transportation without charge, he said, the INS will avoid paying commercial air fares for the convicts and their guards.

Crocetti estimated that today's flight saved INS $5,000 to $7,000, including one-way air fares for the 12 Jamaicans and round trips for eight INS officers who accompanied them.

Ultimately, he said, INS hopes to arrange direct flights from Maryland to Jamaica by the Air National Guard, "but that is just at the discussion stage now."

Milord said such flights generally do not entail additional costs for the Air National Guard. Flight crews must fly a certain number of training hours every month, he said, and deportation flights can serve as a "normal training mission."

"They have to fly, whether they're empty or full," Crocetti said.

In preparation for today's flight, Crocetti said eight of the 12 Jamaicans were brought to Baltimore by van from Salisbury, Md., where INS leases space from the Wicomico County Department of Corrections for aliens awaiting deportation. The other four were flown by commercial airliner from New York to Baltimore-Washington International Airport.

All 12 had completed their prison sentences, and as convicted felons, automatically faced deportation, he said. In Kingston, he said, they will be questioned by Jamaican customs officials and held if wanted by police there.

He said most "have rather long criminal histories . . . . These guys are dangerous." At the airport here, Crocetti displayed a seven-foot-long "rap sheet" of one of the Jamaicans, showing arrests and convictions for drug trafficking and other offenses since 1982.

Several deportees shouted angrily at photographers and attempted to shield their faces as they were herded from the van to the plane.

"A lot of them belong to posses {gangs}," said Crocetti, "and they don't want to be seen or identified as being deported."