By David Shepardson

WASHINGTON U.S. Transportation Deputy Secretary Polly Trottenberg is taking over as acting head of the Federal Aviation Administration, the department said on Thursday.

President Joe Biden also plans to name Katie Thomson, the FAA's chief of staff, as deputy administrator, replacing Bradley Mims.

Trottenberg's appointment is effective immediately. She replaces Billy Nolen, who has been acting head of the FAA since April 2022. Nolen announced in April that he would resign after a new administrator was nominated.

In March, Denver International Airport CEO Phil Washington withdrew his nomination to serve as FAA administrator after Republican criticism. The White House has not yet named a new nominee.

Transportation Secretary Pete Buttigieg said he has "full confidence in Polly’s steady hand during the search for a permanent administrator."

Mims is leaving the FAA to head up the Transportation Department's Office of Small and Disadvantaged Business Utilization.

The United States has faced serious questions about aviation safety after a series of close-call runway incidents this year and a computer outage in January that led to the first nationwide grounding of departing passenger airliners since September 2001.

The National Transportation Safety Board is investigating six runway incursion events since January including some that could have been catastrophic.

Trottenberg previously served as New York City’s transportation commissioner, as senior USDOT policy official under President Barack Obama, and as an aide in the U.S. Senate to Senator Charles Schumer.

Thomson has served various roles at the FAA during two presidential administrations and has also served in senior USDOT roles, most recently as director of implementation of the Bipartisan Infrastructure Law.

Reuters earlier reported that Nolen is expected to take a position with electric air taxi firm Archer Aviation.

(Reporting by David Shepardson; Editing by Chris Reese and Leslie Adler)