The Federal Aviation Administration is seeking a $512,000 fine against Braniff Inc. for operational and maintenance deficiencies uncovered during an inspection of the airline earlier this year, and Trans World Airlines has been fined $225,000 for maintenance and engineering violations found during a similar routine FAA inspection.

The Braniff inspection was conducted between Feb. 24 and March 24, and violations involved "operational and maintenance deficiencies which required corrections," according to Mitch Barker, an FAA spokesman.

The TWA inspection, conducted from Nov. 3, 1986 through Jan. 9, revealed logbook discrepancies involving maintenance and failures to follow proper procedures when doing maintenance.

"Considering the industry as a whole, this particular fine puts us in a position of {having} the smallest fine assessed so far of any major carrier," Don Morrison, a TWA spokesman, said. "Every one of those paperwork procedures has been corrected."

Penalties assessed against other carriers have ranged from $400,000 to a record high $9.5 million, paid by Eastern Air Lines last February. A year ago, Pan American World Airways paid $1.95 million. Other penalties include $666,000 against U.S. Air, $402,000 against Continental Airlines and $300,000 against Alaska Airlines.

In announcing the fines, the FAA indicated that "the basic safety" of Braniff and TWA "was not compromised." TWA was cited by the FAA as "very cooperative and aggressive in taking prompt action to correct all deficiencies."

J. Patrick Foley, Braniff's chief executive officer, said the airline will not pay the fine until it consults with the FAA in an effort to "mitigate" elements of the inspection.

Meanwhile, the FAA has moved up the date of its inspection of Northwest Airlines to January. The FAA had planned to inspect Northwest late next summer to give the airline time to complete its merger with Republic Airlines. But the date was changed "because the merger seemed to be taking longer than we expected," Bob Buckhorn, an FAA spokesman, said.

A Northwest jetliner crashed Aug. 16 on takeoff from Detroit, killing 156. Buckhorn said the agency was in the midst of reorganizing its inspection schedule of Northwest when the crash occurred.