BY JENNIFER BABSON

  KEY WEST -- The hijacking of a Cuban airliner to Key West in March became a ''15-hour night of terror'' for passengers who at one point were gasping for air and a woman who had a phone cord wrapped around her neck by the hijacker, federal prosecutors said Tuesday.

  Adermis Wilson Gonzalez held the aircraft and its passengers hostage as the plane left Nueva Gerona, on Cuba's Isle of Youth, bound for Havana, then left the Cuban capital for Key West hours later, prosecutors and witnesses told the jury.

  Wilson, 34, is charged with air piracy and faces 20 years in prison if convicted. The hijacking of a Cuban plane was the second in four months.

  The trial before U.S. District Judge Shelby Highsmith is expected to last through the week.

  Prosecutors say Wilson, a former Cuban military recruit, used bogus ceramic grenades he had crafted himself in the March 31-April 1 incident, which drew the personal negotiation efforts of Cuban President Fidel Castro and James Cason, the top U.S. diplomat in Cuba.

  ''There probably could not be a more clear-cut, well-defined, perfect case of air piracy,'' said Lilly Ann Sanchez, who is prosecuting the case along with Assistant U.S. Attorney Seth Eric Miles.

  Stewart G. Abrams, Wilson's court-appointed attorney, offered another view, saying his client was ''a family man'' who wanted a better life for his 3-year-old stepson, who was on the flight, and may not have initially understood exactly what trouble he had gotten himself into.

  ''There are two sides to every story,'' Abrams said.

  The judge prohibited Abrams from bringing up Castro's and Cason's involvement in negotiations as the government presented its case, though the defense is expected to broach the subject in detail later.

  CREW TESTIFIES

  Among those testifying Tuesday were a Cuban pilot and a flight attendant who communicated with Wilson during the extended standoff at Havana's José Martí International Airport, where the Cubana AN-24 twin-engine plane sat for hours after Wilson allegedly commandeered it and before it took off for Florida.

  What began as a routine, 34-minute flight to Havana from Nueva Gerona turned into an ordeal, witnesses said Tuesday, when Wilson brandished what looked to be two grenades and said he was taking over the plane as it made its final descent into Havana.

  ''I immediately took it to be a joke. I just couldn't believe it,'' said Margarita Noriega Tong, a Cuban exile from New York who was seated behind Wilson and his family.

  Flight attendant Salvador Requeny Robles said Wilson made it clear he didn't want the aircraft, which had about 15 minutes' worth of fuel left, to reach Havana.

  ''If the wheels touch ground, I am going to blow up the plane,'' Robles said Wilson threatened. Rojas and Wilson then began communicating through the plane's intercom system with pilot Jorge Armando Rojas, who remained locked behind a cockpit door with a peephole for most of the runway standoff.

  Rojas testified that he landed the plane anyway after instructing his copilot to send a special distress code to air-traffic controllers in Havana.

  With fuel running out, an attempt to reach the United States ''might lead to the aircraft simply falling into the sea and everybody [being] killed,'' the pilot told the jury.

  After landing, Rojas said he immediately switched off the plane's engines and fuel systems, fearing that if the grenades detonated, a massive fire would erupt.

  ASSAULTS WOMAN

  Back in the plane's cabin, an edgy Wilson grabbed a female passenger and looped the black cord of the intercom phone around her neck, Robles said.

  'She's crying. She tells him, `Please, I have children.' She cries quite a bit. He tells her he's going to put the grenade in her mouth,'' Robles said.

  Wilson held the woman for nearly an hour, using the phone attached to the cord around her neck to communicate with the pilot, Robles said.

  A portable generator later restored some power -- but not air conditioning -- to passengers who were getting hotter by the minute, witnesses said. In the passenger cabin, water ran out, a young girl was choking for air and was administered oxygen from canisters. Several other people with medical conditions were getting ill.

  Between 4 and 4:30 a.m. April 1, Robles said, Wilson ordered about 18 male passengers into a narrow luggage compartment next to the cockpit. The rest of the people were moved to the middle of the plane, where they were told to bang on windows to demand fuel from the Cuban authorities so the plane could depart Havana.

  ''The situation was becoming more critical by the moment,'' Rojas said, adding that Wilson refused requests to bring a doctor on board.

  Agreeing to a request by the pilot to release some passengers because of concern over the weight of the plane, Wilson allowed 22 people to jump out of the plane onto the runway. Wilson also allowed a new crew and pilot to come into the plane to fly it to Florida.

  Meantime, Wilson's brother was helicoptered to the Havana runway, prosecutors said. He handed Wilson $250, which Wilson had requested from Cuban authorities.

  Robles testified that the brother told Wilson: ``Why have you done this? . . . You know, you have broken Mami and Papi's heart.''