The amendment in question repeals a rule approved by the NMB last May that allows employees of companies that fall under the Railway Labor Act to form unions if a majority votes in favor.
Under the old rules, workers who did not cast ballots in union elections would be counted as "no" votes. Under the revised version, they would not be counted.
Votes on the amendment and the larger FAA bill, which would fund the administration for the next four years, are expected to begin Tuesday afternoon.
Mica has criticized Congress for passing multiple short-term extensions of the FAA bill while it haggled over a long-term deal.
"Seventeen extensions is absolutely unbelievable," he said during a speech this week to the Washington Aero Club. "That's no way to run aviation in this country. I want a four-year bill. I don't want anything less."
In his Aero Club speech, Mica tweaked liberal supporters of the amendment to remove the union rule change, sponsored by Reps. Steve LaTourette (R-Ohio) and Jerry Costello (D-Ill.).
"I know that doesn't make Rachel Maddow very happy," Mica said of his support for the rules currently in the FAA bill.
GOP Rep. Mica unmoved by Obama FAA veto threat
By Keith Laing - 03/31/11 04:54 PM EDT