U.S. Transportation Secretary Sean Duffy said Friday that it is “unacceptable” that two commercial aircraft had to abort landings at a Washington airport this week because of an Army Black Hawk helicopter that was flying to the Pentagon.

In addition to the National Transportation Safety Board and Federal Aviation Administration investigating what happened Thursday afternoon at Ronald Reagan Washington National Airport, Duffy said he plans to talk to the Department of Defense to determine why rules were “disregarded.”

The aborted landings follow a deadly midair collision in January between a passenger jet and Army helicopter in Washington that killed 67 people. In March, the FAA announced that helicopters would be permanently restricted from flying near Reagan National on the same route where the collision occurred.

“Safety must ALWAYS come first,” Duffy said on the social platform X. “We just lost 67 souls! No more helicopter rides for VIPs or unnecessary training in a congested DCA airspace full of civilians. Take a taxi or Uber — besides most VIPs have black car service.”

Thursday’s incident involved a Delta Air Lines Airbus A319 and a Republic Airways Embraer E170, according to the NTSB. They were instructed around 2:30 p.m. by air traffic control to “perform go-arounds” because of a “priority air transport” helicopter, according to an emailed statement from the FAA.

The aircraft were not within the restricted mixed traffic area of Reagan National, the FAA told members of Congress in a separate memo seen by The Associated Press. The agency also said it appeared the helicopter “took a scenic route around the Pentagon” and didn’t fly directly to the heliport.

Army spokesperson Capt. Victoria Goldfedib said in a statement that the UH-60 Blackhawk was following published FAA flight routes and air traffic control from Reagan National when it was “directed by Pentagon Air Traffic Control to conduct a ‘go-around,’ overflying the Pentagon helipad in accordance with approved flight procedures.”

As a result the other aircraft were given go-around instructions by air traffic control “to ensure the appropriate deconfliction of airspace,” Goldfedib said.

“The United States Army remains committed to aviation safety and conducting flight operations within all approved guidelines and procedures,” she added.

Emma Johnson, a spokesperson for Delta Air Lines, said that the safety of their customers and all people is most important and that they’ll “cooperate with authorities as they investigate.” Republic Airways said in a statement that it is also cooperating with the investigations.

The FAA, which manages the nation’s airspace and oversees aviation safety, has come under criticism after the NTSB said there had been an alarming number of near misses in recent years in the congested skies around Reagan National.

The closure of the helicopter route near the airport makes permanent the restrictions put in place after the Jan. 29 midair collision. The FAA order includes a few exceptions for helicopter use, including presidential flights along with law enforcement and lifesaving missions.

Republican Sen. Ted Cruz of Texas, the chairman of the Commerce, Science and Transportation Committee, said on X that Thursday’s incident showcased the danger that can come with Army helicopters flying close to the airport.

“Thank God there was a decisive response from air traffic controllers and pilots, or else these two close calls could have resulted in the loss of hundreds of lives,” he said.

Democratic Sen. Maria Cantwell of Washington, the ranking member of the committee, which oversees the FAA, said the helicopter came from the same Army brigade involved in the January crash and took place less than a week after the brigade resumed flights in the area around the capital.

“It is far past time” for Defense Secretary Pete Hegseth and the FAA to “give our airspace the security and safety attention it deserves,” she said.