The Vienna Jaycees yesterday offered $5,000 for information leading to the arrest and conviction of any person "criminally involved in the disappearance or detention of William E (Billy) Viscidi," the 12-year-old Vienna boy who has been missing for nine days.

"We're just hoping this reward will be enough incentive that anyone knowing something will come forward," Marine Kisner, public information officer, said.

Vienna police yesterday borrowed a U.S. Park Police helicopter to make an air search of the wooded areas that had been search last week by volunteers and dogs. Meanwhile, nine officers - one third of the Vienna police force - were following up more than 500 leads phoned in by area residents who report they have seen a boy fitting Billy's description.

Although it has not been officially called into the investigation, the FBI has been helping the Vienna police by following up leads from outside Virginia, Kisner said.

The Jaycees were telephoning Vienna residents yesterday asking for pledges to contribute to the reward fund.

Billy, son of Burton and I. Grace Viscidi of 503 Princeton Dr., was last seen by one of his three brothers after breakfast July 25. He walked away from his home down Nutley Street and appeared to be headed toward Interstate Rt. 66.

Billy is 4-feet-6, wieghs 70 pound and has dark brown eyes and medium-length dark brown hair.