Sen. Wendell H. Ford (D-Ky.) yesterday proposed taking the Federal Aviation Administration out of the Transportation Department and making it a separate agency with a seven-year term for the FAA chief.

The FAA has been sharply criticized in recent months over safety issues. Aviation industry executives complain that its parent agency has too often interfered with FAA affairs -- ranging from personnel matters to decisions on contracts for equipment purchases.

"The FAA has to be a professional and technical agency. It needs to be depoliticized," said Ford, who chairs the Commerce, Science and Transportation aviation subcommittee. The FAA has been part of the Transportation Department since the department was formed in 1966.

The Senate Commerce Committee has spurned the nomination of a former Western Air Lines executive to be deputy director of the agency. The panel plans to return the nomination of Lawrence M. Hecker, vice president of Western's flight operations, to the White House before Congress departs today on August recess.

Hecker was named by President Reagan April 24, but the committee declined to schedule confirmation hearings because several members said they had doubts about Hecker's management qualifications for the agency's No. 2 job.

"We've got some terrific administrators of the regions. I can look at several I know who would be excellent deputy administrators," Ford said. "It would give some hope and new morale to the agency to let those from within move to the top."

Hecker, 64, was vice president for flight operations at Western from January 1986 until March when Western merged with Delta Air Lines. Since then, he has worked as a $268-a-day FAA consultant.

Ford said his plan to create an independent FAA is not intended as a reflection on the policies of Transportation Secretary Elizabeth Hanford Dole or any of her predecessors, but the rapid growth in air travel has made it necessary to provide some stability to the agency.

Allan McArtor, the newly appointed FAA administrator, is the third FAA chief to serve in the Reagan administration.

"The agency has been excessively politicized," said Sen. Frank R. Lautenberg (D-N.J.), a supporter. "It's pretty obvious when the word comes down from DOT, it's swallowed at the FAA level."

McArtor said he welcomes public debate about a separate FAA because it will focus attention on crucial aviation issues. But he emphasized that he thinks the FAA's work can be best accomplished "within the existing architecture."

Aviation industry sources said the Transportation Department's involvement in day-to-day FAA business has, at times, made the FAA inefficient. In some cases, the department has overruled hiring decisions made by the FAA administrator. In other cases, some contracts to buy equipment require department approval after they have been drawn up by the FAA.