After six weeks of voting, Delta Air Lines flight attendants failed to gather enough votes to join the Association of Flight Attendants, or AFA, a national labor union.

AFA said in a statement that not enough of the eligible flight attendants voted, and therefore the results, despite showing strong support from those people who did vote, failed to meet the requirements of the National Mediation Board.

Federal rules require a majority turnout by those eligible to vote. Although around 40 percent of eligible attendants voted, federal policy reads failure to vote as a vote against the measure. There were only 5,375 total votes cast. National Mediation Board rules required 6,691 ballots to be cast for the election to count. There were 13,380 Delta flight attendants eligible to vote.

Under federal law, Delta employees could vote on union membership if the company merges with a heavily unionized work force, such as Northwest's.

Those supporters, combined with strong union support at Northwest, will clearly be enough for the flight attendants to win union representation after the merger with Northwest is finalized, Patricia Friend, president of the Association of Flight Attendants (AFA), said in a prepared statement.

Pilots are currently the only unionized work group at Delta.