The 80,000 creditors of bankrupt Braniff International overwhelmingly approved a plan by the Hyatt Corp. of Chicago to put Braniff back in the air, officials in Fort Worth, Tex., said yesterday.

Although the actual vote tally will not be announced until later, the approval was a major step in allowing Braniff to reorganize and fly again.

Trust officer Tracy Mai of the Merchantile National Bank of Dallas, which administered the voting, said during a hearing in the court of U.S. Bankruptcy Judge John Flowers that the vote was "overwhelmingly" in favor of the plan.

Flowers must still give the court's approval for the plan. Then a 10-day appeals period, to anyone with objections, must elapse before the association with Hyatt will be final.

It was not known how quickly Flowers would rule.

Braniff filed for bankruptcy in May 1982.

Braniff officials have estimated the earliest the new Braniff could fly would be late December or January.

The seven classes of Braniff's creditors--weighed generally by how much Braniff owed them--according to federal bankruptcy laws had to approve the plan with Hyatt before it could be implemented.

The plan calls for Hyatt to invest $70 million in Braniff in exchange for 80 percent of the stock in a new company.