WASHINGTON — Almost nine months before Wednesday night’s midair collision at Ronald Reagan National Airport, Maryland’s two U.S. senators warned about the safety implications of overcrowding the air space around the airport.

U.S. Sen. Chris Van Hollen and then-U.S. Sen. Ben Cardin joined their counterparts from Virginia to be the only four holdouts in the 100-member Senate to vote against a Federal Aviation Administration reauthorization bill.

Their concerns stemmed from a provision that added 10 new flights to DCA, one of the busiest airports in the country.

Van Hollen said at the time that he was “outraged” about the change and that an amendment for additional safety measures was not brought up for a vote.

“The runway at DCA is already the busiest in our nation and the addition of these 10 flights jeopardizes both its safety and operations,” Van Hollen, a Democrat, said in a statement after voting against the bill. “I am deeply concerned about the long-lasting implications this will have for my constituents who travel to and from DCA.”

Those concerns were still very real Thursday, he said, after the crash between an American Airlines flight and a Black Hawk helicopter in which all 67 people aboard both aircraft were believed to be dead.

The Democratic senator said in an interview that it will be important for the National Transportation Safety Board to conduct a thorough investigation. Addressing how the crowded runways at DCA are impacting safety should be part of that process or a broader review of the situation at the airport, he said.

“It did not make sense to add more slots, more airplanes, coming into an already congested airport. I believed that then and I believe that now,” Van Hollen said. “That is obviously a separate question as to what caused this particular collision.”

Cardin, a three-term Democrat who did not run for reelection last year, also said during the vote last May that he was “greatly disappointed” that the amendments were blocked. The FAA itself indicated the added flights “would add to already overburdened flight operations” while the Senate instead “prioritized convenience of a few senators over the safe operations of the busiest runway in the United States,” he said in a statement.

The reauthorization passed in the Democratic-controlled Senate by a vote of 88 to 4. It passed 351 to 69 in the Republican-controlled House, with all eight Maryland representatives voting in favor.

Van Hollen said the overcrowding issue then and now is mostly focused on DCA and not other regional airports like BWI Marshall Airport.

Another important factor worth looking into further, he said, will be the understaffing of air traffic controllers. As President Donald Trump takes actions to trim the size of the federal workforce, he and others say it is essential for safe flying to have well-staffed air traffic staff.

It’s unclear whether air traffic controllers are part of the hiring freeze Trump implemented last week or if they’re exempt under a “public safety” exception, he said.

“But what we do know, and it’s been very established, is how they’re understaffed and underresourced,” he said. “The administration wants to come in and sort of push a lot of people out. It’s going to make a bad situation even worse.”

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