President Trump’s helicopter had trouble communicating with air traffic controllers on Thursday, for the second time this month.

As Marine One was about to take off in Washington, D.C., on Thursday afternoon, its calls to controllers went unheard, and another pilot had to intervene. 

The incident happened about an hour after the National Transportation Safety Board (NTSB) released new details about a similar incident in early August. In that case, Marine One, with Mr. Trump on board, flew within a mile of a commercial jet that had taken off from Ronald Reagan Washington National Airport outside of D.C. on Aug. 4. 

The NTSB found Marine One’s first attempt to contact air traffic controllers that day “was not received at all,” and a second attempt “was broken and completely unreadable.”

FAA technicians said “there was not adequate line-of-sight to ensure communications” from the Ellipse, a large lawn near the White House that Marine One has been using to take off amid construction at the White House.

Transportation Secretary Sean Duffy told CBS News on Aug. 11 the problem had been resolved. When asked how Marine One and the control tower are not able to hear each other, Duffy had said, “There’s been a lot of infrastructure that’s been built in Virginia and in the D.C. area. And so we have some interference with our antenna. And so we’re working right now on fixing that communication.”

“And so we already have a fix in place and that should not take place again,” Duffy said.

But on Thursday, it did happen again. The FAA, in a statement, did not address the apparent return of radio issues but confirmed air traffic controllers ultimately established contact with Marine One prior to takeoff.