A highly decorated retired Navy captain arrested in Fairfax County on drunk driving charges was found hanged in his jail cell yesterday less than two hours after a magistrate had refused to release him into the custody of his two sons.

Cecil Elwood Harris, 65, of the 8800 block of Beauchamp Drive in Fairfax, had been jailed at the Groveton police station for four hours and was about to be released at 12:15 a.m. when he was discovered hanging from a jail bar by a sweater tied around his neck. It was his birthday.

Harris' cell, like all eight on the first floor of the jail, is supposed to be monitored by police through a closed circuit television system. But police Capt. Thomas L. Shaw said poor lighting in the jail makes it difficult for officers to monitor the cells.

Harris, who had been arrested three previous times for drunk driving, was arrested Tuesday after police spotted the former World War II fighter pilot weaving his car back and forth across Rte. 1 near its intersection with Mount Vernon Memorial Highway around 6:30 p.m.

Harris was given a test at the scene to determine his alcohol level, and police said it showed Harris was legally drunk. Police said Harris was arrested and taken to the Groveton police station about 8 p.m. after being checked by a rescue squad. He was placed in jail after a magistrate ruled he should be held.

About 10 p.m. Harris' sons, Michael and Thomas, drove to the station and attempted to have their father released. The county magistrate on duty, Richard Dix, refused to release Harris and told his sons their father must stay in jail four hours, said police spokesman Cpl. William Brown. It is Fairfax's "normal procedure" to hold those arrested on drunk driving charges for that time as a safety precaution, Brown said.

Chief Fairfax Magistrate Milton Alexander said, however, that the release of a person jailed on drunk driving charges is purely within the discretion of the magistrate on duty. In the past, people arrested on drunk driving charges have been released in less than four hours, he said.

"Normally, we look at a person and determine if he is mobile in order to release him to the custody of a third party," Alexander said. Dix could not be reached for comment.

The sons returned to the police station "two or three" more times, Shaw said, although police kept no records of when they arrived. He said police continued to refuse to release Harris and that the sons were not allowed to see him during any of their visits. Shaw said that, too, was normal police procedure.

Bruce Stokes of the 5400 block of Franconia Road in Fairfax County said he was in the cell next to Harris' when Harris hanged himself. "It was about 11:30 . . . ," said Stokes. "I heard a loud thump when he jumped off his bed." Stokes, who was being held on a malicious wounding charge, said he was uncertain if he yelled for help. "Nobody came in until about 45 minutes later. Two officers came in and looked at the guy and saw that he was dead. They said 'Oh no, We got trouble on our hands now.' "

Stokes said the officers attempted to revive Harris and then called for an ambulance.

Yesterday's hanging was the second at the Groveton jail since 1969, said police spokesman Warren Carmichael. He said yesterday's incident is under investigation. An autopsy is being performed, he said. Members of Harris' family declined comment on his death.

Harris, who leaves a wife and four children, was born in Faulkton, S.D. He was awarded the Navy Cross, two Silver Stars, the Distinguished Flying Cross and three Air Medals in World War II.

Harris, who had headed the Navy's aviation periodicals and history staff, won his highest medals for his exploits as a fighter pilot in the Pacific during World War II. His Navy Cross cited his action intercepting two flights of Japanese fighters which had attacked Clark Field in the Philippines. " . . . He dauntlessly engaged in the fierce dogfight . . . successively knocking down two enemy planes," the citation read.