WASHINGTON, Jan 11 (Reuters) - Three U.S. senators on Thursday said the recent Alaska Airlines’ Boeing 737 Max 9 fuselage blowout raises serious questions about the largest U.S. planemaker's manufacturing quality control.

"We need clear and accurate answers as soon as possible," wrote Senators Ed Markey, J.D. Vance and Peter Welch to Boeing CEO Dave Calhoun, citing reports of loose bolts found on United Airlines and Alaska 737 MAX 9 planes.

"Given the previous tragic crashes of Boeing 737 Max aircraft, we are deeply concerned that the loose bolts represent a systemic issue with Boeing’s capabilities to manufacture safe airplanes." (Reporting by David Shepardson Editing by Chris Reese)