In the wake of the botched Christmas Day airliner attack, industry groups, airport workers and others have renewed calls on Congress to confirm President Obama’s nominee to head the Transportation Security Administration.

The confirmation of Erroll Southers, a former FBI agent and the top law enforcement official at Los Angeles World Airports, has been pending since September. Trade groups and pilots union leaders say the latest incident heightens concerns that the agency still does not have a permanent leader.

Aviation and security experts made clear that Southers’ confirmation as administrator would not have prevented a Nigerian national from allegedly smuggling explosive material onto a Northwest Airlines flight from Amsterdam to Detroit and trying to detonate it.

“The TSA has been rudderless, but it’s hard to blame them, personally,” said Bruce Schneier, a security expert and author.

The suspect, Umar Farouk Abdulmutallab, was on a general counter-terrorism watch list that contains about 550,000 names that are shared with airlines and foreign security agencies. But his name was not on a no-fly list.

Sen. Jim DeMint (R-S.C.), the ranking member on the aviation subcommittee of the Senate Commerce, Science and Transportation Committee, has led the opposition to Southers’ confirmation by raising questions about whether he would allow TSA security screeners to unionize.

Southers, who also is associate director at USC’s Center for Risk and Economic Analysis of Terrorism Events, has the support of several airline trade groups and pilots associations.

“During a time when security is so important, we need to push politics aside,” said Steve Lott, spokesman for the International Air Transport Assn., a trade group that represents most of the world’s largest airlines. “It benefits the agency to have Southers in that role. They need a leader in that position.”

Bruce Hoffman, a professor at Georgetown University and expert on security matters, said he wouldn’t lay the blame for the Detroit incident entirely on the TSA. But he said the agency can better respond with a confirmed leader in charge.

“We will suffer by not having a leader,” he said.

The American Federation of Government Employees, the largest union representing government workers, made the same plea three weeks ago when the TSA inadvertently posted classified airport screening information on the Internet.

“This incident further illuminates the urgency of appointing a permanent leader at the agency,” the group said.

An interim chief has been running the TSA since January. Obama nominated Southers in September to fill the position. A Senate committee forwarded the nomination to the full Senate in November, and DeMint then put a hold on the nomination, a procedural move that can block a vote.

DeMint said he was troubled by Southers’ refusal to answer questions about whether he would recommend that TSA workers unionize.

In a letter to DeMint, Southers said he would consult with employee and industry groups before taking a position and would not pursue any action “that would potentially compromise the safety and security of the flying public.”

But DeMint said Monday: “The attempted terror attack in Detroit is a perfect example of why the Obama administration should not unionize the TSA and allow our airline security decisions to be dictated by union bosses.”

Jim Manley, spokesman for Senate Majority Leader Harry Reid (D-Nev.), noted that the Senate wanted to confirm Southers and nominees for other posts by unanimous consent before the Senate recessed on Christmas Eve, but DeMint’s hold on Southers blocked the plan.

“Hopefully, in light of this recent incident, he’ll relent and allow the Senate to confirm Mr. Southers,” Manley said. “The American people have every right to have a nominee in place at the TSA. The only thing Sen. DeMint is trying to do here is try to score cheap political points.”

Meanwhile, Friday’s incident has renewed calls for upgraded security.

Mike Karn, an American Airlines pilot and security chairman for the Coalition of Airline Pilots Assn., criticized the decision for air traffic controllers to immediately issue alerts only to airline crews that were crossing the Atlantic, rather than to all airborne U.S. crews.

“The rest of the flights over the rest of the world had no clue,” he said.

At the time, no one was certain if the attempted terrorist attack was part of a larger, coordinated effort to bring down other planes, he said. Had other airline crews been notified, they could have taken steps to limit access to cockpits in their aircraft, restrict passenger movement and been more vigilant about suspicious activity in the cabin, Karn said.

“This is an example of not doing what common sense tells you to do,” he said.

The incident also raised questions about the limited use of whole-body scanning devices, which some security officials believe could have helped detect the incendiary material allegedly strapped to Abdulmutallab’s body. The security screening device, which creates a type of detailed nude 3-D image of a passenger, was not used on Abdulmutallab when he boarded the plane at Amsterdam’s Schiphol Airport.

The U.S. Travel Assn., a nonprofit group that promotes the U.S. travel industry, said more testing of full-body scanners is needed to ensure that the devices strengthen security.

Before more invasive methods of airport screening are used, the Obama administration should establish oversight mechanisms to ensure that the measures aren’t abused, said Frances Townsend, a former domestic security advisor to President George W. Bush.

“There are privacy concerns, and, frankly, the case has to be made that it’s necessary and effective and that there are oversight measures in place that will assure people that their privacy and civil liberties will be appropriately protected,” Townsend said. “I don’t think people have that sense.”

hugo.martin@latimes.com

khennessey@tribune.com

Times staff writer Peter Nicholas contributed to this report.