(Adds reaction, background)
By David Shepardson
WASHINGTON, July 24 (Reuters) - The U.S. Senate voted 52-to-40 along party lines on Wednesday to confirm former Delta Air Lines executive Stephen Dickson to head the Federal Aviation Administration, an agency that has faced scrutiny relating to safety over the past year.
The approval of President Donald Trump's nominee for the post comes as the FAA grapples with an ongoing review of Boeing Co’s grounded 737 MAX planes following two crashes that killed a total of 346 people in October and March, as well as broader questions about how it certifies aircraft and whether it delegates too much authority to manufacturers.
The FAA had been without a Senate-confirmed chief for more than 18 months.
Transportation Secretary Elaine Chao praised the confirmation Wednesday, while Democrats have criticized Dickson's handling of a case involving a whistleblower who raised concerns over safety at Delta.
"With decades of experience in the airline industry overseeing flight operations, and service to our country as a United States Air Force officer, Captain Dickson is highly qualified to lead the FAA," Chao said.
Republicans have said there was no evidence Dickson had retaliated against the company pilot who had raised concerns. Senator Richard Blumenthal, a Democrat, said Dickson "is very simply not the right person for this job."
The 45,000-employee FAA has faced questions about why it lagged other countries in grounding the 737 MAX, and has since repeatedly said it will not allow the plane to fly again until it is safe to do so.
Blumenthal said "new leadership from the FAA is critically important in light of its failure to ground those 737 MAX airplanes ahead of the rest of the world."
Airlines for America, an industry group representing United Airlines, American Airlines Group Inc, Southwest Airlines Co and others, said Dickson "has the vision, knowledge and experience to lead the FAA at this crucial time for the agency and for commercial aviation."
Dickson left Delta in October after 27 years.
The FAA, which has been run by an acting chief Dan Elwell since January 2018, faces mounting questions from federal prosecutors, lawmakers and the Transportation Department's inspector general over its certification of the 737 MAX.
The agency is not expected to allow the planes to fly until October at the earliest after it directed Boeing on June 26 to address a separate software issue with the 737 MAX.
Elwell will need a waiver from Congress to continue as deputy FAA administrator because both he and Dickson are former U.S. military officers. (Reporting by David Shepardson; Editing by Bernadette Baum)