Textron, Inc. pleaded guilty in federal court here yesterday to a currency violation in connection with a payoff who helped arrange the sale of Bell helicopters to that country.

U.S. District Judge Thomas A. Flannery accepted the guilty plea and fined the firm $131,670 as the Justice Department requested. The fine represents a $100,000 criminal fine for the currency violation and $31,670 as the amount that a Bell helicopter division employe smuggled out of the country to use for the payoff.

According to information filed by the Justice Department, an employe of the Bell division based in Fort Worth Tex., first went to the Dominican Republic in 1976 in response to that country's interest in buying helicopters.

He allegedly agreed to funnel a $31,670 commission check on the sale to the country's secretary of state for defense, Gen. Rene Beauchamp. The money actually was delivered to Beauchamp's secretary, identified as a col. Munoz, with the understanding that it was failing to report that it had sent said.

The specific charge to which the Providence, R.I., firm pleaded guilty was failing to report that it had sent more than $5,000 out of the country.

The justice Department had been investigating alleged foreign payoffs by Textron for more than a year. The probe drew public attention when the corporation's former top executive officer, G. William Miller, was nominated to be chairman of the Federal Reserve Board.

Miller denied to Senate Banking Committee Chairman William Proxmire (D-Wis.) any knowledge of the payoffs, and was later confirmed by the Senate.

There was nothing in the plea agreement or the charges filed yesterday to indicate that Miller or any other high Textron officials were aware of payoffs.

Yesterday's plea apparently ends any active Justice Department investigation of the bribery allegations, although the probe reportedly also focused on payments to additional countries.

However, the plea agreement did leave open the possibility of perjury charges against any Textron officials found to have lied before the banking committee or before the Securities and Exchange Commission, which also investigated the payoff allegations.

The person for whom the Dominican Republic payoff was made, Beauchamp, is now the Dominican Republic's ambassador to Argentina.

Textron officials declined to comment on the criminal plea entered for the firm yesterday before Judge Flannery, Dow Jones News Service reported.