The New England Patriots are expected to announce at a news conference today that offensive coordinator Ron Erhardt will replace Chuck Fairbanks as coach.

Francis (Bucko) Kilroy, director of player personnel, is expected to be named general manager. Fairbanks held both jobs before being released to become coach at the University of Colorado.

The Patriots went to court to make Fairbanks honor his contract with them which had four years to go, and a settlement was arranged under which the Patriots received about $300,000.

Erhardt, 47, was brought to New England by Fairbanks in 1973, and was promoted to offensive coordinator when Robert (Red) Miller left the Patriot staff to become coach of the Denver Broncos.

Erhardt coached the Patriots for the final game of the regular season in 1978, when Fairbanks was temporarily suspended.

Fairbanks was suspended after he announced before a night game in Miami that he was resigning to accept the Colorado job. He was reinstated for a first-round game of the National Football League playoffs, which the Patriots lost to Houston.

Erhardt formerly coached at North Dakota State, where he had a 62-7-1 record. For New England, he called the plays for quarterback Steve Grogan.

Kilroy, 57, once played for the Philadelphia Eagles. He joined the Patriots as personnel director in 1971, after scouting for the Washington Redskins and Dallas Cowboys.

The Patriots had an 11-5 regular-season record in 1978 as they won the American Football Conference East Division. Fairbank's six-year record was 46-40. CAPTION: Picture, Ron Erhardt