WASHINGTON, Jan 9 (Reuters) - The new head of the Federal Aviation Administration is set to appear next month before Congress as the agency faces questions on its oversight of planemaker Boeing following the emergency landing on Friday of a 737 MAX 9.

Mike Whitaker, who took over as the agency's head in late October, will testify before the U.S. House Transportation and Infrastructure Committee on Feb. 6, sources said. The hearing was in the works before the Alaska Airlines flight and is expected to cover a broad range of issues.

Senator J.D. Vance on Tuesday urged the Senate Commerce Committee to hold a hearing on the MAX and FAA oversight. "Every American deserves a full explanation from Boeing and the FAA on what’s gone wrong and on the steps that are being taken to ensure another incident does not occur in the future," he said. The FAA has scrutinized Boeing's quality and other issues in recent years as it faced harsh criticism for its actions in the run-up to the MAX certification. Following two fatal crashes in 2018 and 2019, the FAA grounded the plane for 20 months and mandated significant software and training improvements.

Boeing declined to comment on Tuesday.

The FAA continues to inspect each 737 MAX before an "airworthiness certificate is issued and cleared for delivery," the agency has noted. Typically the FAA delegates the final signoff on individual airplanes to the manufacturer once the model has been certified.

Alaska Airlines and the other U.S. 737 MAX 9 operator, United Airlines, said on Monday they found loose parts on multiple grounded aircraft.

The FAA did not directly answer questions about how it typically inspects those bolts before approving a plane for service. "The FAA inspects every airplane prior to issuing an airworthiness certificate," a spokesperson said.

The agency is still deciding whether to certify the smaller MAX 7. Whitaker told Reuters in an interview last month that he has no "specific timetable" to certify the plane, adding the agency will certify the plane when "we have all the data that we need and it is safe."

A 2020 congressional report concluded the MAX crashes "were the horrific culmination of a series of faulty technical assumptions by Boeing’s engineers, a lack of transparency on the part of Boeing’s management, and grossly insufficient oversight by the FAA."

The FAA has boosted Boeing oversight staffing and in 2022, the agency gave Boeing a shorter regulatory compliance program extension than the planemaker sought in order to "verify that Boeing completes required improvements."

(Reporting by David Shepardson in Washington Editing by Matthew Lewis)