WASHINGTON, April 18— A member of the Federal Bureau of Investigation's hostage-rescue team died today after falling from a helicopter in a routine training mission, the bureau announced.
The agent, James K. McAllister, 34 years old, slipped from a rope attached to the helicopter and fell 40 feet to 60 feet to the ground, officials said.
The fall, described as accidental, occurred at the bureau's training academy in Quantico, Va. Mr. McAllister, a 16-year veteran of the bureau, was declared dead at a nearby hospital.
A Federal law-enforcement official, who asked not to be named, said Mr. McAllister was participating in an operation in which members of the rescue team quickly slide down a rope hung from the craft.
According to the law-enforcement official, the death may have resulted from windy conditions this morning. ''It's possible that the winds caused the helicopter to veer,'' the official said. The bureau said it would conduct an internal inquiry into the death.
Mr. McAllister was one of the original members of the 50-member Hostage Rescue Team, which was set up in 1983 to deal with terrorist acts. The squad had been mobilized several times and was on constant alert in the 1984 Olympic Games in Los Angeles.
He was the third F.B.I. agent killed in the last two weeks. On April 11, two agents, Benjamin P. Grogan and Jerry Dove, were killed in a suburb of Miami in a shootout with two men accused of a series of armed car and bank robberies. The two suspects were also shot to death in the battle, which left five other F.B.I. agents wounded.
Mr. McAllister's widow, Kimberly, has been an F.B.I. agent since 1983. He is also survived by two children from a previous marriage.
