Time runs out for Cuban detainees. A year ago they rioted when told they would be deported; now some again face a plane ride to Havana.

One year ago, Cuban detainees rioted behind bars rather than face deportation to Cuba. Now, barring a court injunction or other twists in a fitful story, US officials plan to put a first 15 of them on a plane to Havana.

Since the riots ended with promises of individual deportation hearings and appeal reviews, hundreds of the Cubans have been released in the United States, deemed no danger to society.

But yesterday, the first of those still in custody finally ran through all their appeals and were ordered back to Cuba.

One year ago Saturday, the US signed an accord to normalize immigration relations with Castro's Cuba.

The news fell on thousands of Cubans trapped in a diplomatic netherworld - detained indefinitely in the US, bound for a Cuba that had refused to take them back - like a sudden squall in tropical skies.

The Cuban detainees sent up a panicked and violent message: They would rather stay behind bars in the US than be returned to Cuba. Within days, detainees in the Atlanta Penitentiary and Oakdale, La., detention center had rioted, taken over the institutions, and held guards as hostages.

Now the compromise that peacefully resolved those confrontations has come full circle. More than 1,500 detainees have been denied release in at least their initial hearing since the uprising last year, putting them in the pipeline for what the immigration service prefers to call repatriation.

But well over 2,000 of the detainees under guard during the uprising are now out on the streets. Gary Leshaw, a Legal Aid lawyer in Atlanta who has represented the Cubans, says he believes that the riot helped some of them win their freedom sooner.

The Cubans ordered back to Cuba will not depart without a stir. Mr. Leshaw intends to file immediately for a court injunction to keep the Cubans in the US while he sues for court hearings for each of their cases.

Even if the court decides each Cuban tapped for deportation should indeed be deported, then at least they will have had a fair hearing under due process.

The roots of the controversy go back to 1980. When President Carter welcomed Cuban refugees then ``with open arms,'' he got a massive boatlift of 125,000 from Mariel, Cuba, to Key West, Fla.

These Marielitos included a small but noteworthy proportion of criminals and mental patients.

With no normal immigration rules to cover this stunning influx, or to sort them out, the US government simply dubbed them ``entrants - status pending.'' Legally, this was like parole.

Those who committed crimes became ``excludable'' from the US based on the legal fiction that they have never officially entered the country, even though many have started American families.

As they finished serving out their sentences in prison, they simply entered indefinite detention by the Immigration and Naturalization Service - which was waiting for Cuba to take them back.

In 1984, Cuba agreed to take back the 2,746 then in detention, and 201 actually made the trip before President Fidel Castro broke off the agreement in anger over Radio Mart'i broadcasts by the US.

In 1986, the US Supreme Court ruled that the detainees had no constitutional rights or protection against indefinite detention because, technically, they never entered the country.

In Nov. 19, 1987, the US took up the immigration with Cuba again. By now, 3,800 Cubans were in detention. The confusion that broke out among detainees, believing that they would be deported, was reflected in Washington. While the INS said it planned to work through the remaining names on the list of 2,756, the State Department bureau that had negotiated the agreement insisted that it applied to whichever Cubans were currently deportable under the same status.

The 11-day sieges that erupted in Atlanta and Oakdale, La., were resolved by a Justice Department commitment to individually hear each case before deportation by INS panels, then re-review the cases by Justice Department panelists.

The decision to deport the first 15 provoked immediate outrage in the Cuban exile community in Miami, where it is believed that it is inhumane to return anyone to a country that violates the human rights of prisoners, as the Reagan administration charges.

``It's not that they're sending some criminals back to Cuba,'' says Siro del Castillo, a Miami community activist. ``It's that it opens the door to deportations.''

Staff writer Barbara Bradley in Washington contributed to this report.