Two Republicans leading congressional committees that oversee the Federal Aviation Administration want answers from the agency about its spending plans under the automatic spending cuts set to kick in Friday.

Sen. John Thune (R-S.D.) and Rep. Bill Shuster (R-Pa.) are questioning the FAA’s claim that it has to furlough thousands of air-traffic controllers, jeopardizing aviation safety, under the across-the-board cuts known as a sequester. On Monday, the lawmakers wrote to Transportation Secretary Ray LaHood demanding details of how the FAA plans to carry out a 5.1 percent budget cut. They say they’ve tried to get the information for more than a year.

“Given the administration and the department’s recent statements on a possible sequestration’s effects on the traveling public, it is imperative that the information we have continuously sought be provided as soon as possible,” wrote Thune and Shuster, ranking member of the Senate Committee on Commerce, Science and Transportation and chairman of the House Committee on Transportation and Infrastructure, respectively.

The two want to see the FAA’s spending plan for normal operations, which they say “should have been produced” by October 2012, and separate account-by-account plans for a full year of normal funding and a year under the budget cuts.

LaHood has warned in recent days that staff furloughs at the FAA could force the closure of 100 air traffic control centers and eliminate shifts at 60 others in small and midsize markets. The warnings have prompted skepticism from many Republicans, who say they are too dire and believe the agency has more room to maneuver than it is acknowledging.