House Majority Whip Tony Coelho (D-Calif.) and the Democratic Congressional Campaign Committee said yesterday they violated campaign finance laws by accepting use of a private yacht and aircraft for political events.

Coelho and the committee said the violation was an oversight.

The yacht and airplane were owned or controlled by Vernon Savings and Loan of Dallas at a time when the institution and a top officer, Don Dixon, were under scrutiny by federal regulators for alleged mismanagement and abuse of assets.

The savings and loan, which had assets of $1.4 billion, failed last March, although House Speaker Jim Wright (D-Tex.) had pressured the Federal Home Loan Bank Board to go easy on the institution.

Unreimbursed use of the yacht and aircraft are forbidden by federal campaign laws banning political contributions by corporations or banks in federal campaigns.

In a statement released here, Coelho said he should have reimbursed the savings and loan for seven events held aboard the yacht in 1985 and last year during his reelection campaign. He said he was reimbursing the institution $25,168.

Coelho at the time headed the campaign committee, which tries to help Democrats win election to the House.

The committee's records show $23,282 of fund-raising events on the boat and campaign travel for which the committee now has remimbursed Vernon, according to committee chairman Rep. Beryl Anthony Jr. of Arkansas.

{The Dallas Morning News reported this week that Wright flew on a Vernon plane but was not obligated to report it because the flight was arranged by the campaign committee. An aide said Wright did not know the plane belonged to Vernon, the newspaper reported.}

The Federal Savings and Loan Insurance Corp. took over the Vernon thrift on March 20, charging in court that Dixon had enriched himself by mismanaging and abusing the thrift's assets and driven the institution $350 million into debt.

The FSLIC sued Dixon and six other Vernon officers in U.S. District Court in Dallas in April, alleging fraud and racketeering. Dixon then filed for bankruptcy in Santa Ana, Calif., and has sued to have the fraud allegations tried by the U.S. bankruptcy court there.

Dixon's attorney has denied the charges.