Two weeks ago, the FBI arrested Rezwan Ferdaus and accused the 26-year-old Massachusetts man of planning to fly an explosives-laden model airplane into the U.S. Capitol. The plot’s revelation sparked debate over the FBI’s tactics in investigating Muslims and drew attention to the possibility that someone could use remote-controlled aircraft to carry out a terrorist attack.

What the story did not do is prompt any renewed soul-searching over whether the legislative branch is prepared to cope with a catastrophic strike, even though it’s been several years since Congress looked seriously at the issue.

Ferdaus’s plan, even if it had been successful, seems unlikely to have inflicted large-scale damage on Congress. The same could not be said of the Sept. 11, 2001, terrorist attacks, when United Flight 93 may well have been headed for the Capitol before passengers brought it down in a Pennsylvania field. The next month, much of Congress ground to a halt after anthrax-laden envelopes were mailed to two senators’ offices.

Those incidents spurred an intense discussion on Capitol Hill: What if hundreds of lawmakers were killed or incapacitated? How quickly could the House and Senate gather to authorize special powers for the president, or appropriate money to fight a war?

“It is dismaying that 10 years later, the only plans we have in place to deal with a devastating terrorist attack on Congress are unrealistic, unconstitutional and/or counterproductive,” American Enterprise Institute scholar Norman Ornstein, the leading advocate for more sweeping changes, complained in a September op-ed in Roll Call.

In order to function, both the House and Senate require the presence of a “quorum,” meaning a majority of lawmakers “sworn and living.” In a nightmare scenario, more than half of members could be incapacitated by a bomb blast or an anthrax attack, and the chambers would be unable to pass laws. Or if 90-plus percent of the House were killed, Americans would see the odd spectacle of a tiny fraction of lawmakers setting important national policy.

In 2003, the Continuity of Government Commission — a private group led by former White House counsel Lloyd Cutler and former senator Alan Simpson (R-Wyo.) — issued a report recommending adoption of a constitutional amendment allowing temporary appointment of House members in the case of such an emergency.

While the constitution allows senators to be appointed, all House members must be elected by the people. Republicans, who controlled the House at the time, thought it would be wrong to change that principle.

Instead, a law was passed in 2005 calling for expedited special elections if 100 or more House seats become vacant due to “extraordinary circumstances.” The House also changed its own rules to allow the speaker to define down the size of a quorum in an emergency.

Echoing other critics, Ornstein wrote in September that the expedited elections would be “virtually impossible to carry out and would still leave the chamber inoperable for a critical 45 days after a devastating attack,” while the change in quorum rules could be unconstitutional.

Rep. Zoe Lofgren (D-Calif.), who backs a constitutional amendment, said last week she still thinks Congress has not done enough on this front.

“If you wanted to destroy the American government, you would destroy the House of Representatives and it would be crippled,” Lofgren said. “There ought to be a remedy for that so that our enemies couldn’t destroy us.”

But, Lofgren added, “Republicans have made clear they’re not willing to do anything further, so I’m working on things where there might be a chance something could happen.”

Rep. David Dreier (R-Calif.), who helped pass the measure calling for faster special elections, defends his party’s record.

“The House conducted a vigorous debate on this issue over six years ago . . . .” Dreier said last week. “Fortunately, we have not been faced with such a dire circumstance, but there are procedures in place if we ever do. And most important, [the special-elections law] maintains the integrity of the House of Representatives as the only federal office to which a person must be elected.”

Even those members who think the preparedness question remains worth asking don’t see it as a high priority. The possibility of a constitutional amendment is remote, and no other legislative solutions are on the table.

“I think there’s always room for improvement, and it never hurts to reconsider something, but I haven’t heard a groundswell of folks” talking about this recently, said Rep. Steve Chabot (R-Ohio), who chaired a subcommittee hearing on the subject in 2002.

Rep. Daniel E. Lungren (R-Calif.), who runs point on security issues as chairman of the House Administration Committee, said, “We have to constantly be looking at and reevaluating what the threats are and how do we respond in an effective way. I don’t think it’s ever a totally settled question.”